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  Subjects -> CHEMISTRY (Total: 849 journals)
    - ANALYTICAL CHEMISTRY (50 journals)
    - CHEMISTRY (598 journals)
    - CRYSTALLOGRAPHY (22 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (42 journals)
    - ORGANIC CHEMISTRY (45 journals)
    - PHYSICAL CHEMISTRY (67 journals)

CHEMISTRY (598 journals)                  1 2 3 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 8)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 26)
ACS Catalysis     Full-text available via subscription   (Followers: 32)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 17)
ACS Combinatorial Science     Full-text available via subscription   (Followers: 23)
ACS Macro Letters     Full-text available via subscription   (Followers: 23)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 227)
ACS Photonics     Full-text available via subscription   (Followers: 11)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 21)
Acta Chemica Iasi     Open Access   (Followers: 2)
Acta Chimica Sinica     Full-text available via subscription   (Followers: 1)
Acta Chimica Slovaca     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 5)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 7)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 50)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 53)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 14)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 19)
Advances in Nanoparticles     Open Access   (Followers: 14)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Science and Technology     Full-text available via subscription   (Followers: 12)
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 2)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 67)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 14)
American Journal of Chemistry     Open Access   (Followers: 26)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 13)
Analyst     Full-text available via subscription   (Followers: 38)
Angewandte Chemie     Hybrid Journal   (Followers: 158)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 208)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 1)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 3)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 14)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antiviral Chemistry and Chemotherapy     Hybrid Journal  
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7)
Applied Spectroscopy     Full-text available via subscription   (Followers: 23)
Applied Surface Science     Hybrid Journal   (Followers: 28)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 3)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 2)
Avances en Quimica     Open Access   (Followers: 1)
Biochemical Pharmacology     Hybrid Journal   (Followers: 10)
Biochemistry     Full-text available via subscription   (Followers: 283)
Biochemistry Insights     Open Access   (Followers: 5)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 9)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 1)
Biomacromolecules     Full-text available via subscription   (Followers: 19)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 4)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 108)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 93)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 2)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 2)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 24)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 10)
Canadian Mineralogist     Full-text available via subscription   (Followers: 3)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 67)
Catalysis for Sustainable Energy     Open Access   (Followers: 6)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 7)
Cellulose     Hybrid Journal   (Followers: 7)
Cereal Chemistry     Full-text available via subscription   (Followers: 4)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 1)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 12)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 70)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 23)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 19)
Chemical Reviews     Full-text available via subscription   (Followers: 170)
Chemical Science     Open Access   (Followers: 21)
Chemical Technology     Open Access   (Followers: 16)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemical Week     Full-text available via subscription   (Followers: 8)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 55)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 25)
ChemInform     Hybrid Journal   (Followers: 8)
Chemistry & Biodiversity     Hybrid Journal   (Followers: 6)
Chemistry & Biology     Full-text available via subscription   (Followers: 30)
Chemistry & Industry     Hybrid Journal   (Followers: 5)
Chemistry - A European Journal     Hybrid Journal   (Followers: 144)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 18)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Hybrid Journal   (Followers: 2)
Chemistry Letters     Full-text available via subscription   (Followers: 45)
Chemistry of Materials     Full-text available via subscription   (Followers: 226)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access  
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 2)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 9)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 10)
Chromatographia     Hybrid Journal   (Followers: 24)
Chromatography Research International     Open Access   (Followers: 7)
Clay Minerals     Full-text available via subscription   (Followers: 9)
Cogent Chemistry     Open Access  
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 10)
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 3)
Combustion Science and Technology     Hybrid Journal   (Followers: 18)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 1)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 12)
Computational Chemistry     Open Access   (Followers: 2)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 9)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 2)
Copernican Letters     Open Access  
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 5)
Crystal Structure Theory and Applications     Open Access   (Followers: 3)
CrystEngComm     Full-text available via subscription   (Followers: 11)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 56)
Dalton Transactions     Full-text available via subscription   (Followers: 20)
Detection     Open Access   (Followers: 2)
Developments in Geochemistry     Full-text available via subscription   (Followers: 2)
Diamond and Related Materials     Hybrid Journal   (Followers: 12)
Dislocations in Solids     Full-text available via subscription  
Doklady Chemistry     Hybrid Journal  
Drying Technology: An International Journal     Hybrid Journal   (Followers: 4)
Eclética Química     Open Access   (Followers: 1)
Ecological Chemistry and Engineering S     Open Access   (Followers: 4)
Ecotoxicology and Environmental Contamination     Open Access  
Educación Química     Open Access   (Followers: 1)
Education for Chemical Engineers     Hybrid Journal   (Followers: 5)
EJNMMI Radiopharmacy and Chemistry     Open Access  
Elements     Full-text available via subscription   (Followers: 2)
Environmental Chemistry     Hybrid Journal   (Followers: 9)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)

        1 2 3 | Last

Journal Cover Chemistry - An Asian Journal
  [SJR: 1.833]   [H-I: 75]   [15 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1861-4728 - ISSN (Online) 1861-471X
   Published by John Wiley and Sons Homepage  [1576 journals]
  • Metal-free, Initiator-free Graphene Oxide Catalyzed Trifluoromethylation
           of Arenes
    • Authors: Jingyu Zhang; Yun Yang, Jingxian Fang, Guo-Jun Deng, Hang Gong
      Abstract: The direct C-H trifluoromethylation of arenes catalyzed by graphene oxide (GO) under safe conditions is described. This strategy is metal free, initiator free, safe, and scalable. It employs a readily available CF3 source and could easily control the reaction to obtain a mono-trifluorinated product. This method opened a new field for GO-catalyzed chemistry.
      PubDate: 2017-07-26T21:26:13.068769-05:
      DOI: 10.1002/asia.201700939
       
  • Perfluoroalkylated Calix[4]pyrrole: fluoride ion extraction from aqueous
           medium
    • Authors: Sinchan Maji; Debaprasad Mandal
      Abstract: Octaalkenyl calix[4]pyrrole (CH₂=CH(CH₂)₂)₈C4P) is highly useful for post functionalization towards design of different calix[4]pyrrole with desired functionality. Functionalization with perfluoroalkyl chains [CF₃(CF₂)n; Rfn] gives perfluoroalkyl calix[4]pyrroles (Rfn(CH₂)4)₈C4P; n=6, 8), having>60% fluorine content which creates hydrophobic environment inside the calix[4]pyrrole cavity and recognizes fluoride and chloride ion from solution as well as solid. Fluoride ion is extracted efficiently from aqueous CsF and TBAF solutions by (Rf₆(CH₂)₄)₈C4P as droplets. Fluorous chain generates hydrophobic environment which destroys the hydration shell associated with anion and separates out fluoride ion as droplets from aqueous medium. Further fluoride ion competitively replaces chloride ion from (Rf₆(CH₂)₄)₈C4P cavity.
      PubDate: 2017-07-25T21:25:36.51229-05:0
      DOI: 10.1002/asia.201700897
       
  • Fluorescence and Sensing Applications of Graphene Oxide and Graphene
           Quantum Dots: A Review
    • Authors: Peng Zheng; Nianqiang Wu
      Abstract: Graphene oxide and graphene quantum dots are attractive fluorophores, which are inexpensive, non-toxic, photo-stable, water-soluble, biocompatible and environmentally friendly. They find extensive applications in fluorescent biosensors and chemi-sensors, in which they either serve as fluorophores or quenchers. As fluorophores, they display the tunable photoluminescence emission and the "Giant Red-Edge Effect". As quenchers, they exhibit a remarkable quenching efficiency via either electron transfer or Förster resonance energy transfer (FRET) process. In this review article, the origin of fluorescence and the mechanism of excitation wavelength-dependent fluorescence of graphene oxide and graphene quantum dots are discussed. The sensor design strategies based on graphene oxide and graphene quantum dots are presented. The applications of such sensors in health care, environment, agriculture and food safety are highlighted.
      PubDate: 2017-07-25T14:20:22.942597-05:
      DOI: 10.1002/asia.201700814
       
  • Precisely designed isopeptide bridge-crosslinking endows artificial
           hydrolases with predominant stability and catalytic activity under extreme
           denaturing conditions
    • Authors: Yu Bai; Chao Wang, Guodong Liang, Wenqing Lai, Huifang Xue, Yanbo Ling, Maosheng Cheng, Keliang Liu
      Abstract: Enzymes normally lose their activities under extreme conditions due to the dissociation of their active tertiary structure. If an enzyme could maintain its catalytic activity under non physiological or denaturing conditions, it might be used in more applications in the pharmaceutical and chemical industries. Recently, we reported a coiled-coil six-helical bundle (6HB) structure as a scaffold for designing artificial hydrolytic enzymes. Here, intermolecular isopeptide bonds were incorporated to enhance the stability and activity of such biomolecules under denaturing conditions. These isopeptide bridge-tethered 6HB enzymes showed exceptional stability against unfolding and retained or even had increased catalytic activity for a model hydrolysis reaction under thermal and chemical denaturing conditions. Thus, isopeptide bond-tethering represents an efficient route to construct ultrastable artificial hydrolases, with promising potential to maintain biocatalysis under extreme conditions.
      PubDate: 2017-07-25T08:25:34.126095-05:
      DOI: 10.1002/asia.201701021
       
  • Low Band Gap Donor–Acceptor Conjugated Systems Based on 3-Alkoxy or
           3-Pyrrolidino-4-cyanothiophene and Benzothiadiazole Units
    • Authors: Gurunathan Savitha; Chady Moussallem, Magali Allain, Frédéric Gohier, Pierre Frère
      Abstract: Electrodeposited conjugated polymers with donor—acceptor structures combining 3-hexyloxy or 3-pyrrolidino-4-cyanothiophene, 3,4-ethylenedioxythiophene (EDOT), and benzothiadiazole building blocks present electrochromic properties upon oxidation. In the presence of the pyrrolidinocyano thiophene moieties, the oxidation leads to a blue to brown color change, while with EDOT and hexyloxycyano thiophene units a switch from green to pale blue is observed. The tree of glass “The blue cedar” is an original Geneviève Péan creation (www.revedeverre.net). More information can be found in the Full Paper by Pierre Frère et al. (
      DOI : 10.1002/asia.201700545).
      PubDate: 2017-07-24T03:55:24.014316-05:
       
  • Covalent functionalization of graphene by nucleophilic addition reaction:
           synthesis and optical limiting property
    • Authors: Xiujuan Xu; Peiying Li, Lei Zhang, Xuejian Liu, Hao-Li Zhang, Qingzhao Shi, Baojiang He, Wenjuan Zhang, Zhan Qu, Pu Liu
      Abstract: Covalent functionalization of reduced graphene oxide (rGO) was prepared by conjugated polymers with different monomers, using nucleophilic addition reaction between rGO and nitrogen anions. Three conjugated polymers containing tetraphenylethylene, carbazole and phenyl groups were used, due to the π-π interaction and "polymer wrapping" effect, the dispersion stability of rGO was improved. Even the reacting site in polymers were same to each other, there were great differences in the reactivity of the polymers, the dispersion stability of the resultant composites, and also the OL performances of the resultant composites. The differences maybe contributed to their π-conjugated structure and steric hindrance of the moiety in polymer skeleton, which was hardly mentioned before. Besides, the resultant materials rGO-P1 and rGO-P3 both showed excellent OL response even at 4 μJ, these behaviors enabled their potential application in photonic and optoelectronic devices to protect human eyes or optical sensors from damage by intense laser irradiation.
      PubDate: 2017-07-21T04:10:50.570738-05:
      DOI: 10.1002/asia.201700899
       
  • Synthesis, Structure and Properties of Near-Infrared
           [b]-Phenanthrene-Fused BF2 Aza-dipyrromethenes
    • Authors: Jiuen Cui; Wanle Sheng, Qinghua Wu, Changjiang Yu, Erhong Hao, Petia Bobadova-Parvanova, Marie Storer, Abdullah M. Asiri, Hadi M. Marwani, Lijuan Jiao
      Abstract: A new class of phenanthrene-fused BF2 aza-dipyrromethene (aza-BODIPY) dyes has been synthesized through tandem Suzuki reaction and oxidative ring-fusion reaction or the Palladium catalyzed intramolecular C-H activation reaction. These phenanthrene-fused aza-BODIPY dyes are highly photostable and display markedly red shifted absorption (up to 771 nm) and emission bands (around 800 nm) in the Near-Infrared (NIR) region. Density functional theory (DFT) calculation and cyclic voltammetry studies indicate that upon annulations, the more-pronounced stabilization of the LUMO is the origin of bathochromic shift of the absorption and high photostability.
      PubDate: 2017-07-20T21:16:01.013597-05:
      DOI: 10.1002/asia.201700876
       
  • Micelle Directing synthesis of the Ag-doped WO3 and MoO3 Composite for the
           Photocatalytic Water Oxidation and Organic Dyes Adsorption
    • Authors: Nasen Bate; Hongfei Shi, Li Chen, Jiabo Wang, Shasha Xu, Weilin Chen, Jianping Li, En-Bo Wang
      Abstract: In this paper, Ag-doped WO3 (MoO3) composite has been prepared by a simple micelle directed method and high temperature sintering route. The as-prepared samples were characterized by XRD, ICP, TEM, XPS, DRS, BET, PL and EIS techniques. The photocatalytic experiments reveal that their oxygen production rates are up to 95.43 μmol (75.45 μmol) for Ag-doped WO3 (MoO3), which is 9.5 (7.3) times higher than that of pure WO3: 9.012 μmol (MoO3: 9.00 μmol) under visible light illumination (λ ≥ 420 nm), respectively. The improvement of photocatalytic activities are attributed to the enhancement of their visible-light absorption and the separation efficiency of photogenerated carriers by Ag doping. Moreover, Ag-doped WO3 (MoO3) also shows excellent adsorption property for RhB and MB in aqueous solution, and the maximum Qt towards RhB and MB are 822 and 820 mg·g-1 for Ag-doped WO3, and 642 and 805 mg·g-1 for Ag-doped MoO3, respectively.
      PubDate: 2017-07-20T07:11:22.020513-05:
      DOI: 10.1002/asia.201700951
       
  • Phosphorylated Polyacrylonitrile Fiber as an Efficient and Greener
           Acetalization Catalyst
    • Authors: Gang Xu; Jian Cao, Yali Zhao, Lishuo Zheng, Minli Tao, Wenqin Zhang
      Abstract: A novel solid acid catalyst (PANEAPF) was developed by immobilization of phosphoric acid on polyacrylonitrile fiber via covalent bond. Various characterization techniques such as elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. were utilized to confirm the successful grafting and the stability of the fiber catalysts during application. The PANEAPF showed high catalytic activity in the acetalization of aldehydes due to the high utilization efficiency of its functionalized acid sites. Besides, the strong polarity micro-environment in the surface layer of the PANEAPF make it highly suitable for catalytic application no matter in water or alcohol. Furthermore, the fiber catalyst can be applied to acetalization of aldehydes in a continuous flow process at room temperature, and shows excellent reactivity and superior recyclability (over 20 times). In a word, many advantages of the PANEAPF such as simple preparation, convenient acid amount regulatability, high durability, and eco-friendly process make it very attractive for fixed-bed reactors in chemical industry.
      PubDate: 2017-07-20T04:18:03.736466-05:
      DOI: 10.1002/asia.201700846
       
  • Robust Acenaphthoimidazolylidene Palladacycles: Highly Efficient Catalysts
           for the Amination of N-heteroaryl Chlorides
    • Authors: Tao Tu; Qinyue Deng, Yang Zhang, Haibo Zhu
      Abstract: A series of robust N-heterocyclic carbene palladacycles have been successfully developed, which exhibited high catalytic activity and selectivity toward the challenging amination of N-heteroaryl chlorides. Diverse primary and secondary amines are fully compatible with our new developed catalytic system. Remarkably, no double amination products could be detected when primary amines were utilized in our catalytic transformation. Furthermore, the protocol has been successfully extended to synthesize Rosiglitazone, a clinical drug for diabetes mellitus, highlighting its potential pharmaceutical feasibility.
      PubDate: 2017-07-18T13:30:28.2589-05:00
      DOI: 10.1002/asia.201700877
       
  • Natural compounds in cancer prevention: effects of coffee extracts and
           their main polyphenolic component 5-CQA on oncogenic Ras proteins
    • Authors: Alessandro Palmioli; Carlotta Cairamelli, Renata Tisi, Michela Spinelli, Gaia De Sanctis, Elena Sacco, Cristina Airoldi
      Abstract: Recent epidemiological studies demonstrate that consumption of healthy foods, especially rich in polyphenols content, might reduce the incidence of cancer and degenerative diseases. In particular, chlorogenic acids (CGAs) occur ubiquitously in food, representing the most abundant polyphenols in the human diet. A number of CGA beneficial biological effects, including anti-inflammatory activity, anti-carcinogenic activity and protection against neurodegenerative diseases have been reported. However, the molecular mechanisms at the basis of these biological activities have not yet been investigated in depth. By combining NMR spectroscopy, molecular docking, surface plasmon resonance and ex vivo assay on Ras-dependent breast cancer MDA-MB-231 cell line, we contributed to the elucidation of the molecular bases of the activity of CGAs and natural extracts from green and roasted coffee beans as chemo-protective dietary supplements.
      PubDate: 2017-07-18T07:15:36.045804-05:
      DOI: 10.1002/asia.201700844
       
  • A pyridoindole based multifunctional bioprobe: pH-induced fluorescence
           switching and specific targeting of lipid droplets
    • Authors: Bahadur Sk; Pilendra Thakre, Raghuvir Singh Tomar, Abhijit Patra
      Abstract: A versatile fluorescent probe, PITE, based on alkyl substituted pyridoindole (PI) and tetraphenylethylene (TE) exhibiting facile pH-induced fluorescence switching in solution, nanoparticles and solid state is presented. Strong fluorescence in the solid state besides solution and aggregated state allow sensing of toxic acid vapor. Fluorescence "off-on" switching of PITE by exposing to trifluoracetic acid and triethylamine vapor is visualized through naked eyes. A unified picture of switchable fluorescence of PITE is obtained by comprehensive spectroscopic investigations coupled with quantum mechanical calculations. Strong fluorescence, large Stokes shift, high photostability and biocompatibility of PITE makes it a viable probe for sub-cellular imaging. Extensive fluorescence microscopic studies employing organisms including lower and higher eukaryotes reveal specific localization of PITE to lipid droplets (LDs). It has been known that LDs are dynamic sub-cellular organelles linked to various physiological processes and human diseases. Hence, the specific detection of LDs in diverse organisms is important to biomedical research and health care. Isolation of LDs and subsequent colocalization studies ascertain selective targeting of LDs by easily affordable, lipophilic bioprobe, PITE. Thus, PITE turns out to be a promising multifunctional probe for chemo-sensing as well as selective tracking of LDs.
      PubDate: 2017-07-18T07:15:29.678489-05:
      DOI: 10.1002/asia.201700898
       
  • PET-based halogen-free photosensitizers: covalent meso-aryl as electron
           donors to effectively induce the formation of excited triplet state and
           singlet oxygen for BODIPY compounds
    • Authors: Xian-Fu Zhang; Nan Feng
      Abstract: Pristine BODIPY compounds have negligible efficiency to generate excited triplet state and singlet oxygen. In this report we show that attaching a good electron donor to BODIPY core can lead to the singlet oxygen formation up to 58% quantum efficiency. For this purpose, BODIPYs with meso-aryl (phenyl, naphthyl, anthryl, and pyrenyl) were synthesized and characterized. The fluorescence, excited triplet state and singlet oxygen formation properties for these compounds were measured in various solvents by UV-vis absorption, steady-state and time-resolved fluorescence methods, as well as laser flash photolysis technique. In particular, the presence of anthryl and pyrenyl showed substantial enhancement on the singlet oxygen formation ability of BODIPY up to 58% and 34% quantum efficiency respectively, due to their stronger electron donating ability. Upon the increase in singlet oxygen formation, the fluorescence quantum yield and lifetime values of an aryl-BODIPY showed concomitant decrease. The increase in solvent polarity enhances singlet oxygen generation but decreases fluorescence quantum yield. The results are explained by the presence of intramolecular photoinduced electron transfer from the aryl moiety to BODIPY core. This method of promoting T1 formation is very different from the traditional heavy atom effect by I, Br or transition metal atoms. This type of novel photosensitizers may find important applications in organic oxygenation reactions and photodynamic therapy of tumors.
      PubDate: 2017-07-13T05:31:31.615953-05:
      DOI: 10.1002/asia.201700794
       
  • Complexation Between (O-methyl)6-2,6-Helic[6]arene and Tertiary Ammonium
           Salts: Acid-Base/Chloride Ion Responsive Host-Guest Systems and Synthesis
           of [2]Rotaxane
    • Authors: Chuan-Feng Chen; Qiang Shi, Ying Han
      Abstract: Complexation between (O-methyl)6-2,6-helic[6]arene and a series of tertiary ammonium salts was described. It was found that the macrocycle could form stable complexes with the tested aromatic and aliphatic tertiary ammonium salts, which were evidenced by 1H NMR spectra, ESI mass spectra and DFT calculations. Especially, the binding and release process of the guests in the complexes could be efficiently controlled by acid/base or chloride ion, which represents the first acid-base and chloride ion responsive host-guest systems based on the macrocyclic arenes and protonated tertiary ammonium salts. Moreover, the first 2,6-helic[6]arene-based [2]rotaxane was also synthesized by the condensation between the host-guest complex and isocyanate.
      PubDate: 2017-07-13T05:31:10.67366-05:0
      DOI: 10.1002/asia.201700857
       
  • Stereoselective synthesis of pillar[4]arene[1]cis-diepoxy-p-dione and its
           X-Ray crystal structure of host‒guest system
    • Authors: Chengyou Han; Dezhi Zhao, Tian Li, Daofeng Sun
      Abstract: Herein we successfully develop a novel route to give rise to polarity for the pillararenes by the introduction of oxygenated functionalities into pillar[5]arene to stereoselectively synthesize the pillar[4]arene[1]cis-diepoxy-p-dione. Its host‒guest properties with different dinitrile molecules were also investigated and characterized by NMR and X-ray crystallography.
      PubDate: 2017-07-13T03:25:20.420212-05:
      DOI: 10.1002/asia.201700791
       
  • Unique solid-state emission behaviors of aromatic difluoroboronated
           β-diketones as an emitter in organic light-emitting devices
    • Authors: Hisahiro Sasabe; Kanako Sasaki, Michitaka Mamiya, Yurie Suwa, Taiki Watanabe, Natsuki Onuma, Kohei Nakao, Minoru Yamaji, Junji Kido
      Abstract: Aromatic difluoroboronated β-diketones (BF2DKs) are a well-known class of luminescent organic materials that exhibit high photoluminescent quantum efficiency and unique aggregation-dependent fluorescence behavior. However, there have been only a few reports on their use in solid-state electronic devices such as organic light-emitting diodes (OLEDs). In this work, we investigated the solid-state properties and OLED performances of a series of π-extended BF2DKs that previously exhibited intense fluorescence in the solution state. The BF2DKs formed exciplexes with a carbazole derivative and exhibited thermally activated delayed fluorescence behavior, realizing orange electroluminescence with a peak external quantum efficiency of 10% that is apparently exceeded the theoretical efficiency limit of conventional fluorescent OLEDs (7.5%) assuming a light out-coupling factor of 30%.
      PubDate: 2017-07-13T00:45:20.307947-05:
      DOI: 10.1002/asia.201700800
       
  • SO2F2 Mediated One-Pot Synthesis of Arylcarboxylic Acids and Esters from
           Phenols via a Pd-Catalyzed Carbon Monoxide Insertion
    • Authors: Wan-Yin Fang; Jing Leng, Hua-Li Qin
      Abstract: A one-pot Pd-catalyzed carbonylation of phenols to their corresponding arylcarboxylic acids and esters through the insertion of carbon monoxide is developed. This protocol provides a mild condition for direct synthesis of arylcarboxylic acids and esters from inexpensive and abundant starting materials of phenols, SO2F2 and CO. This method was found to tolerate a broad of functional groups and was also applicable for modification of complicated natural products.
      PubDate: 2017-07-12T06:40:38.951245-05:
      DOI: 10.1002/asia.201700891
       
  • Organic Dye Adsorption by Amphiphilic Tris-Urea Supramolecular Hydrogel
    • Authors: Juri Takeshita; Yuki Hasegawa, Kazushige Yanai, Ayumu Yamamoto, Ayumi Ishii, Miki Hasegawa, Masamichi Yamanaka
      Abstract: The development of an effective adsorbent for cleansing polluted water is required for environmental purification. In this respect, a supramolecular hydrogel constructed by the self-assembly of small molecules could be a strong candidate. Adsorption experiments of organic dyes were performed using supramolecular hydrogels of amphiphilic tris-urea 1. Cationic organic dyes were adsorbed efficiently; indeed, the adsorption of methylene blue was as high as 4.19 mol equivalents relative to 1. Two luminescence peaks were observed in the rhodamine 6G-adsorbed supramolecular hydrogels, and their ratios varied with the amount of dye adsorbed. Fluorescence microscopy images of the supramolecular hydrogel at lower dye levels exhibited fibrous fluorescence consistent with the fibrous aggregates of 1. According to these results, adsorption may proceed gradually, that is, occurring initially on the fibers and later in the aqueous spaces of the supramolecular hydrogel.Color up! An amphiphilic tris-urea-based supramolecular hydrogel adsorbs organic dyes from aqueous solutions. Excellent adsorption ratios are achieved, and a step-wise adsorption mechanism is revealed through luminescence spectroscopic monitoring of the adsorption process.
      PubDate: 2017-07-12T06:05:35.789451-05:
      DOI: 10.1002/asia.201700708
       
  • Controllable synthesis of ultra-thin NiCo2O4 nanosheet incorporated
           composite nanotubes towards efficient oxygen reduction
    • Authors: Yunpeng Huang; Fen Cui, Yan Zhao, Jian Bao, Jiabiao Lian, Yuanguo Xu, Tianxi Liu, Hua-Ming Li
      Abstract: Exploring non-precious metal-based ORR electrocatalysts featuring high efficiency, low cost and environmental friendliness is of great importance for the broad applications of fuel cells and metal-air batteries. In this work, one-dimensional (1D) SnO2 nanotubes (SNT) deposited with ultra-thin NiCo2O4 nanosheets was successfully fabricated through a productive electrospinning technique followed by sintering and low-temperature co-precipitation strategy. This hierarchically engineered architecture has ultrathin NiCo2O4 nanosheets uniformly and fully erecting on both walls of tubular SNT, which manifests improved electrochemical activity as oxygen reduction reaction (ORR) catalyst in terms of positive onset potential and high current density, as well as superior tolerance to crossover effects and long-term durability with respect to the commercial Pt/C catalyst. The excellent performance of SNT@NiCo2O4 composites may originate from their rationally designed hierarchical tubular nanostructure with completely exposed active sites and interconnected 1D networks for efficient electron and electrolyte transfer, making this composite nanotubes promising candidate to replace Pt-based catalysts for practical fuel cell and metal-air battery applications.
      PubDate: 2017-07-12T02:40:20.546731-05:
      DOI: 10.1002/asia.201700750
       
  • A Computational Study of a Single-Walled Carbon-Nanotube-Based Ultrafast
           High-Capacity Aluminum Battery
    • Authors: Preeti Bhauriyal; Arup Mahata, Biswarup Pathak
      Abstract: Armchair single-walled carbon nanotubes (SWNT) have been explored as a cathode material for aluminum batteries using density functional calculations. The stable system, in which AlCl4 is adsorbed on SWNT, exhibits an ultrafast charge/discharge rate with a more favorable diffusion on the inner surface than on the outer surface. Storage capacities as high as 275 mAh g−1 can be obtained in (25,25) SWNT as compared to previously studied graphite cathode (70 mAh g−1). This study provides a mean to further explore carbon nanotube materials for aluminum batteries. More information can be found in the Full Paper by Biswarup Pathak et al. (
      DOI : 10.1002/asia.201700570).
      PubDate: 2017-07-12T01:07:42.505736-05:
       
  • Supported C-Scorpionate Vanadium(IV) Complexes as Reusable Catalysts for
           Xylene Oxidation
    • Authors: Jiawei Wang; Luísa M. D. R. S. Martins, Ana P. C. Ribeiro, Sónia A. C. Carabineiro, José L. Figueiredo, Armando J. L. Pombeiro
      Abstract: C-scorpionate vanadium(IV) complexes supported on functionalized carbon nanotubes act as reusable, efficient, and selective catalysts for the halogen-free oxidation of xylenes with peroxide. More information can be found in the Full Paper by Luísa M. D. R. S. Martins, Ana P. C. Ribeiro et al. (
      DOI : 10.1002/asia.201700499).
      PubDate: 2017-07-11T06:25:53.117959-05:
       
  • Modulation of Open-shell Characters of Amine-inserted Diphenoquinones via
           Structural Modification
    • Authors: Yuya Matsuta; Daisuke Sakamaki, Ryohei Kurata, Akihiro Ito, Shu Seki
      Abstract: Four novel amine-inserted diphenoquinones have been synthesized as rare examples of para-extended quinones having a heteroatom in the conjugation pathway. The X-ray crystal analysis revealed that all the molecules maintained extended quinoidal structures through the central three-coordinate nitrogen atom. These compounds showed open-shell diradical characters originating from thermally accessible triplet states, and it was demonstrated that the singlet–triplet gaps of this type of molecule could be finely tuned by changing the substituent on the nitrogen atom. More information can be found in the Communication by Daisuke Sakamaki, Akihiro Ito, Shu Seki et al. (
      DOI : 10.1002/asia.201700652).
      PubDate: 2017-07-11T06:25:46.392748-05:
       
  • Aggregation-Induced Emission Characteristics of o-Carborane-Functionalized
           Tetraphenylethylene Luminogens: the Influence of Carborane Cages on
           Photoluminescence
    • Authors: Hong Yan; Xiang Li, Yongheng Yin, Changsheng Lu
      Abstract: TPE-carborane hybrids are constructed, and the impact of carborane substituents on the AIE characteristics of TPE-cores has been investigated. When altering the 2-R-group on the carborane unit by -H, -CH3 or phenyl group, the luminescent quantum yield of the corresponding TPE derivatives can be manipulated from 0.18 to 0.63 in solid state. The emission color exhibits an obvious shift by 100 nm (from blue to yellow).
      PubDate: 2017-07-11T05:43:49.488303-05:
      DOI: 10.1002/asia.201700922
       
  • Water Oxidation by in-situ generated [RuII(OH2)(NCNHCO)(pic)2]+
    • Authors: Wei Su; Kui Zhou, Fanglin Cai, Cheng Chen, Bibimaryam Mousavi, Somboon Chaemchuen, Francis Verpoort
      Abstract: : A dinuclear ruthenium complex [RuII(NCNHCO)(pic)2]22+ (2) was firstly prepared and characterized spectroscopically and electrochemically. Instead of the conventional ligand exchange, complex 2 dissociates in-situ to afford two single-site Ru aqua complexes, [RuII(OH2)(NCNHCO)(pic)2]+, which mediates water oxidation through proton-coupled electron transfer events. In electrokinetic studies, complex 2 demonstrated a TOF of 150.3 s-1 comparable to those state-of-the-art catalysts at neutral conditions. TONs of 2173 and 217 were attained in chemical and photochemical water oxidation when 2 was used as a catalyst, exhibiting good stability. Notably, a TOF of 1.3 s-1 was achieved at CAN-driven water oxidation, which outper-formed most of the reported single-site Ru complexes, indicating that complex 2 is one of most active water oxidation catalysts (WOCs) to date. The unique coordination configuration and outstanding catalytic perfor-mance of complex 2 might shed light on the design of novel molecular WOCs.
      PubDate: 2017-07-11T03:40:32.882663-05:
      DOI: 10.1002/asia.201700837
       
  • Molecular design of thermally activated delayed fluorescent emitters using
           2,2'-bipyrimidine as an acceptor in donor-acceptor structure
    • Authors: Hee-Jun Park; Si Hyun Han, Jun Yeob Lee
      Abstract: D-A-D type thermally activated delayed fluorescence (TADF) emitters, 5,5'-bis(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)-2,2'-bipyrimidine (Ac-bpm) and 5,5'-bis(4-(10H-phenoxazin-10-yl)phenyl)-2,2'-bipyrimidine (Px-bpm), based on 2,2'-bipyrimidine accepting unit were developed and their TADF devices were fabricated. The orthogonal geometry between the donor unit and the 2,2'-bipyrimidine accepting core facilitated a HOMO/LUMO spatial separation, thus realizing thermally activated delayed fluorescence. They exhibited electroluminescence ranging from green to yellow, depending on the donor unit, with a maximum external quantum efficiencies of up to 17.1%.
      PubDate: 2017-07-11T00:40:27.335785-05:
      DOI: 10.1002/asia.201700889
       
  • Synthesis and Configuration of Neomaclafungin A
    • Authors: Shijun Zhu; Yikang Wu
      Abstract: The relative and absolute configuration of neomaclafungins were impossible to establish by spectroscopic analyses alone because of the lack of exploitable 1H-1H couplings and nOe's between the upper and the lower subunits. This very difficult task now is finally completed by an enantioselective total synthesis of neomaclafungin A (revised) and its diastereomer (reported). The results also provided a key reference for the complete structures for other neomaclafungins and the long-known closely related natural product maclafungin.
      PubDate: 2017-07-10T20:40:55.579537-05:
      DOI: 10.1002/asia.201700950
       
  • Self-Templated Stepwise Synthesis of Monodispersed Nanoscale Metalation
           
    • Authors: Yanshu Shi; Xiaoran Deng, Shouxin Bao, Bei Liu, Bin Liu, Ping’an Ma, Ziyong Cheng, Maolin Pang, Jun Lin
      Abstract: Size and shape controlled growth of nanoscale microporous organic polymers (MOPs) is a big challenge scientists confronted with, meanwhile, rendering these materials for in vivo biomedical applications is still scarce. In this study, monodispersed nano metalation covalent organic polymers (MCOP, M = Fe, Gd) with sizes around 120 nm were prepared by a self-templated two-step solution-phase synthesis method. The metal ions (Fe3+) played important roles in miniature the particle size and functionalization of the products during reaction with p-phenylenediamine (Pa), and then the resultant Fe-Pa complex was used as a template for the subsequent formation of MCOP following the Schiff base reaction with 1,3,5-triformylphloroglucinol (Tp). The high tumor suppression efficiency for this Pa-based COP was reported for the first time. This study demonstrates the potential use of MCOP as a photothermal agent for biomedical application, and also provides an alternative route to fabricate nano sized MCOPs.
      PubDate: 2017-07-10T10:41:24.288249-05:
      DOI: 10.1002/asia.201700796
       
  • Sequential Dy(OTf)3-Catalyzed Solvent-Free Per-O-Acetylation and
           Regioselective Anomeric De-O-Acetylation of Carbohydrates
    • Authors: Yi-Ling Yan; Jiun-Rung Guo, Chien-Fu Liang
      Abstract: Dysprosium(III) trifluoromethanesulfonate-catalyzed per-O-acetylation and regioselective anomeric de-O-acetylation of carbohydrates can be tuned by adjusting the reaction medium. In this study, per-O-acetylation of unprotected sugars by using a near stoichiometric amount of acetic anhydride under solvent-free conditions resulted in the exclusive formation of acetylated saccharides as anomeric mixtures, whereas anomeric de-O-acetylation in methanol resulted in a moderate to excellent yield. Reactions with various unprotected monosaccharide or disaccharide followed by a semi-one-pot sequential conversion into the corresponding acetylated glycosyl hemiacetal also resulted in high yields. Furthermore, the obtained hemiacetals could be successfully transformed into trichloroimidates following Dy(OTf)3-catalyzed glycosylation
      PubDate: 2017-07-08T06:20:21.69586-05:0
      DOI: 10.1002/asia.201700867
       
  • Thermosensitive Triterpenoid-Appended Polymers with Broad Temperature
           Tunability Regulated by Host–Guest Chemistry
    • Authors: Jie Hao; Yuxia Gao, Ying Li, Qiang Yan, Jun Hu, Yong Ju
      Abstract: Thermoresponsive water-soluble polymers are of great importance since they typically show a lower critical solution temperature (LCST) in aqueous media. In this research, the LCST change in broad temperature ranges of copolymers composed of natural glycyrrhetinic acid (GA)-based methacrylate and N,N′-dimethylacrylamides (DMAs) was investigated as a function of the concentration and the content of GA pendants. By complexation of GA pendants with β-cyclodextrin (β-CD), a side-chain polypseudorotaxane was obtained, which exhibited a significant increase in the LCST of copolymers. Moreover, the precisely reversible control of the LCST behavior was realized through adding a competing guest molecule, sodium 1-admantylcarboxylate. This work illustrates a simple and effective approach to endow water-soluble polymers with broad temperature tunability and helps us further understand the effect of a biocompatible host–guest complementary β-CD/GA pair on the thermoresponsive process.Be our guest: A simple and effective approach to endow water-soluble polymers with broad temperature tunability regulated by host–guest chemistry of natural products is described (see figure).
      PubDate: 2017-07-07T06:32:21.915993-05:
      DOI: 10.1002/asia.201700581
       
  • Synthesis and electrochromic properties of star-shaped oligomers with
           phenyl cores
    • Authors: Jinming Zeng; Xiaoyuan Zhang, Xiaoting Zhu, Ping Liu
      Abstract: A series of star-shaped conjugated oligomers, 1,3,5-tri(2'-thienyl) benzene (3TB), 1,3,5-tri(3',4'-ethylenedioxythienyl) benzene (3EB), 1,3,5-tri[5',2"-(3",4"-ethylenedioxythienyl)-2'-thienyl] benzene (3ETB), and 1,3,5-tri[5',2"-(3",4"-ethylenedi- oxythienyl)-2'-thienyl]-4-(3',4'-ethylenedioxythienyl)benzene (3TB-4EDOT), were synthesized. The star-shaped polymer, poly(1, 3,5-tri[5',2"-(3",4"-ethylenedioxythineyl)-2'-thienyl]benzene) (P3ETB), was also prepared. The electrochemical and electrochromic properties of these conjugated oligomers and polymer were investigated. These oligomer and polymer films showed reversible, clear color changes upon electrochemical doping and dedoping. The color of the P3ETB film reversibly changed from orange to blue under doping and dedoping. The switching times for doping and dedoping were 1.2 and 0.9 s, respectively.
      PubDate: 2017-07-05T02:30:49.159339-05:
      DOI: 10.1002/asia.201700890
       
  • Fabrication of mesoporous silica-coated upconverting nanoparticles with
           ultrafast photosensitizer loading and 808 nm NIR light triggering
           capability for photodynamic therapy
    • Authors: Renlu Han; Junhui Shi, Zongjun Liu, Hao Wang, You Wang
      Abstract: A novel photodynamic therapy nanoplatform based on mesoporous silica-coated upconverting nanoparticles (UCNP) with electrostatic-driven ultrafast photosensitizer (PS) loading and 808 nm near infrared (NIR) light triggering capabilities has been fabricated. By positively charging inner channels of the mesoporous silica shell with amino groups, a quantitative dosage of negatively charged PS, exemplified with Rose Bengal (RB) molecules, can be uploaded in 2 min. In addition, the electrostatic-driven technique simultaneously provides the platform with both excellent PS dispersity and leak-proof properties due to the repulsion between the same charged molecules and the electrostatic attraction between different charged PS and silica channel wall respectively. The as-coated silica shell with an ultrathin thickness of 12 ± 2 nm is delicately fabricated to facilitate ultrafast PS loading and efficient energy transfer from UCNP to PS. The outside surface of silica shell is capped with hydrophilic β-cyclodextrin which not only enhances the dispersion of resulting nanoparticles in water but also plays a role of "gatekeepers" blocking the pore opening and preventing PS leaking. The in vitro cells lethality experiment demonstrates that RB molecules can be activated to effectively generate singlet oxygen and kill cancer cells upon 808 nm NIR light irradiation.
      PubDate: 2017-07-03T22:16:07.256766-05:
      DOI: 10.1002/asia.201700836
       
  • Aqueous Phase Synthesis of Size-Tunable Copper Nanocubes for Efficient
           Aryl Alkyne Hydroboration
    • Authors: Subashchandrabose Thoka; Mahesh Madasu, Chi-Fu Hsia, Shu-Ya Liu, Michael Hsuan-Yi Huang
      Abstract: Copper nanocubes with average sizes of 82, 95, and 108 nm have been synthesized in an aqueous mixture of cetyltrimethylammonium chloride (CTAC) surfactant, copper acetate, and sodium ascorbate reductant heated at 100 ºC for 40 min. Copper nanowires with an average length of 25 m can also be prepared this way by simply increasing the volume of sodium ascorbate introduced. Small shifts in the plasmonic absorption band positions with tunable particle sizes have been observed. The copper nanocubes were employed to catalyze hydroboration of phenylacetylene and various substituted aryl alkynes with 100% (E)-product selectivity and 82‒95% product yields. The copper nanocubes are cheap to make and should catalyze a broad scope of organic coupling reactions.
      PubDate: 2017-07-03T09:20:35.508469-05:
      DOI: 10.1002/asia.201700856
       
  • Selective Separation of Aliphatic Nitriles by Employing a Two-Dimensional
           Interdigitated Coordination Polymer
    • Authors: Subhradeep Mistry; Raghunandan Hota, Srinivasan Natarajan
      Abstract: Coordination polymer for isomer separation: Two two-dimensional interdigitated coordination polymers, [M(C8H3N3O4)(C12H10N4)]⋅DMF [M = Zn(II) and Co(II)], were synthesized and characterized. The Zn-containing polymer selectively separated cis-crotononitrile from the cis/trans mixture as well as a mixture containing the structural isomer (allylnitrile). More information can be found in the Full Paper by Srinivasan Natarajan et al. (
      DOI : 10.1002/asia.201700485).
      PubDate: 2017-07-03T06:01:17.534138-05:
       
  • Facile Construction of Quinoline-2-carboxylate Esters through Aerobic
           Oxidation of Alkyl 4-Anilinocrotonates Induced by a Radical Cation Salt
    • Authors: Xiaodong Jia; Pengfei Li, Yu Shao, Yu Yuan, Wentao Hou, Xiaofei Liu, Xuewen Zhang, Honghe Ji
      Abstract: Making trees from the grass! A facile construction of quinoline-2-carboxylate esters is described. In the presence of dioxygen and a radical cation salt, sp3 C–H bonds in 4-anilinocrotonates can be easily oxidized, and after a domino process, the pharmaceutically relevant quinoline derivatives were afforded in high yields, avoiding harsh reaction conditions and tedious starting material synthesis. More information can be found in the Communication by Xiaodong Jia et al. (
      DOI : 10.1002/asia.201700560).
      PubDate: 2017-07-03T06:01:03.99229-05:0
       
  • Enhanced Fluorescence Imaging and Photodynamic Cancer Therapy Using Hollow
           Mesoporous Nanocontainers
    • Authors: Suk ho Hong; Hyunjin Kim, Yongdoo Choi
      Abstract: Smart silica nanobombs: An “off-on” type of photodynamic therapy agent was developed from hollow mesoporous silica nanoparticles (HMSNPs), to enable not only an enhanced delivery of photosensitizers to cancer cells, but also a selective turn-on of fluorescence signal and phototoxicity inside the cancer cells. Both the fluorescence and singlet-oxygen generation of the photosensitizer were quenched (i.e. OFF) when loaded inside the HMSNPs. After internalization of HMSNPs into cancer cells, the photosensitizer was released from the HMSNPs, thereby regaining fluorescence and phototoxicity (i.e. ON). More information can be found in the Communication by Yongdoo Choi et al. (
      DOI : 10.1002/asia.201700371).
      PubDate: 2017-07-03T06:00:54.077624-05:
       
  • Gly-Decorated Praseodymium-Stabilized Nanosized Selenotungstate Cluster:
           Synthesis, Structure, and Oxidation Catalysis
    • Authors: Jingyang Niu; Ling Yang, jipeng Guo, Li Li, Qisen Liu, Pengtao Ma, Jingping Wang
      Abstract: A flexible one-pot strategy exploiting pyramidal SeIV heteroatom is employed for the assembly of praseodymium-containing gly-decorated polyoxotungstate [{Pr3(H2O)10[Se2W22O76(gly)2]}2(Se2W7O30H2)]18- (1a), which is constructed from one {Se2W7O30H2} unit and two identical {Pr3(H2O)10[Se2W22O76(gly)2]} units. Furthermore, the catalytic performance of Cs2Na4H12[{Pr3(H2O)10[Se2W22O76(gly)2]}2 (Se2W7O30H2)]∙25H2O (1) for alkenes epoxidation with hydrogen peroxide was investigated under mild reaction conditions. and the experimental results suggest that compound 1 exhibit good catalytic performance for the epoxidation of cyclooctene.
      PubDate: 2017-07-01T00:05:57.920963-05:
      DOI: 10.1002/asia.201700801
       
  • Various Current Responses of Single Ag Nanoparticle Collisions on Au
           Ultramicroelectrode Depending on Collision Condition
    • Authors: Seon Kyu Mun; Sangmin Lee, Dong Young Kim, Seong Jung Kwon
      Abstract: Collisions of silver (Ag) nanoparticles (NPs) with a more electrocatalytic gold (Au) or platinum (Pt) ultramicroelectrode (UME) surface have been observed using an electrochemical method. Depending on the applied potential to the UME, the current response of Ag NPs collision onto the UME resulted in various shape changes. A staircase decrease, a blip decrease, and a blip increase of the hydrazine oxidation current were obtained at an applied potential of 0.33 V, 0.80 V, and 1.3 V, respectively. Different behaviors of Ag NP collision on the UME surface were suggested for each shape of current response. Ag NP attachment which hindered the diffusion flux to the UME caused a staircase decrease of electrocatalytic current. Instantaneous blocking of the hydrazine oxidation by Ag NP collision and, following recovery of the current via oxidation of Ag NP caused a blip decrease of electrocatalytic current. The formation of higher oxidation state of Ag on the Ag NP and its electrocatalytic hydrazine oxidation resulted in a blip increase of the electrocatalytic current. The analysis of the current response for the single NP collision experiment can be a useful tool to understand the various behaviors of NPs on the electrode surface.
      PubDate: 2017-06-29T12:05:34.711327-05:
      DOI: 10.1002/asia.201700770
       
  • MnO2-Promoted Oxidative Radical Sulfonylation of Haloalkynes with Sulfonyl
           Hydrazides: C(sp)–S Bond Formation towards Alkynyl Sulfones
    • Authors: Pengquan Chen; Chuanle Zhu, Rui Zhu, Wanqing Wu, Huanfeng Jiang
      Abstract: A catalyst-free oxidative radical sulfonylation of haloalkynes with sulfonyl hydrazides is reported. It represents an example of C(sp)−S bond formation using sulfonyl hydrazides as sulfonyl radical sources. Various alkynyl sulfones were synthesized in moderate to good yields. Having MnO2 as the oxidant is very critical for this transformation. Remarkably, the self-coupling reaction of haloalkynes through C(sp)−C(sp) bond formation is significantly inhibited under the standard reaction conditions.C(sp)−S Bond Formation: A catalyst-free oxidative radical sulfonylation of haloalkynes with sulfonyl hydrazides has been developed. Various alkynyl sulfones were synthesized in moderate to good yields, and MnO2 was used as the oxidant.
      PubDate: 2017-06-29T07:55:40.775581-05:
      DOI: 10.1002/asia.201700550
       
  • Surface engineering of ITO Substrate to improve memory performance of
           asymmetric conjugated molecule with a side chain
    • Authors: Xiang Hou; Xue-Feng Cheng, Xin Xiao, Jing-Hui He, Qing-Feng Xu, Hua Li, Na-Jun Li, Dong-Yun Chen, Jian-Mei Lu
      Abstract: Organic multilevel random resistive access memories (RRAMs) of electrode/organic layer/electrode sandwich-like structure suffer from poor reproducibility such as low effective ternary device yield and wide threshold voltage distribution, and the improvement by organic material renovation is rather limited. In contrast, surface engineering of the electrode surfaces rather than molecule design was demonstrated to effectively boost the performance of organic electronics. In this work, we introduce surface engineering into organic multilevel RRAMs to enhance their ternary memory performance. A new asymmetric conjugated molecule containing phenothiazine and malononitrile with a side chain (PTZ-PTZO-CN) was fabricated into indium tin oxide (ITO)/ PTZ-PTZO-CN/Al sandwich-like memory device. Modifying the ITO substrate by phosphonic acids (PA) prior to device fabrication increases the ternary device yield (the ratio of effective ternary device) and narrows the threshold voltage distribution. The crystallinity analysis reveals that PTZ-PTZO-CN growing on untreated ITO crystalize into two phases. This crystalline ambiguity was eliminated and the sole crystal phase was obtained as same as in the powder state after surface engineering of ITO. The unified crystal structure and improved grain mosaicity result in the lower threshold voltage and thus higher ternary device yield. Our result demonstrated that PA-modification has also improvement on the memory performance based on the asymmetric conjugated molecule with a side chain.
      PubDate: 2017-06-28T06:00:58.275871-05:
      DOI: 10.1002/asia.201700706
       
  • Tuning 2D Light Upconversion Emission by Modulating Phonon Relaxation
    • Authors: Hyung Min Kim; Bum Jin Kim, Soo Yeong Lim, Youngho Cho, Sang Hwan Nam, Yung Doug Suh, Chan Ryang Park
      Abstract: The photonic upconversion in rare earth atoms is widely used to convert "invisible" near infrared photons to "visible" photons with continuous wave light. Using a patterned substrate, the upconversion become a type of process for creating new information incorporating security codes. The amount of information in the cipher increases in proportion to the number of emission colors as well as the pattern structure. Subsequently, changing the chemical composition of upconversion phosphors on 2D substrates is required to manufacture information-rich upconversion cryptography. In this study, we exploited temperature-controlled thermal reaction on upconversion films deposited on a quartz substrate to prepare security information codes. Multiple color emission was generated from upconversion films as the result of inserting high-frequency molecular oscillators into the film structures. Fourier-transform infrared (FT-IR) and time-resolved study corroborated the mechanism of spectral variation of upconversion films.
      PubDate: 2017-06-28T01:00:23.327346-05:
      DOI: 10.1002/asia.201700782
       
  • Chiral Gold Nanoclusters: Atomic Level Origins of Chirality
    • Authors: Chenjie Zeng; Rongchao Jin
      Abstract: Chiral nanomaterials have received wide interest in many areas, but the exact origin of chirality at the atomic level remains elusive in many cases. With recent significant progress in atomically precise gold nanoclusters (e.g., thiolate-protected Aun(SR)m), several origins of chirality have been unveiled based upon atomic structures determined by using single-crystal X-ray crystallography. The reported chiral Aun(SR)m structures explicitly reveal a predominant origin of chirality that arises from the Au–S chiral patterns at the metal–ligand interface, as opposed to the chiral arrangement of metal atoms in the inner core (i.e. kernel). In addition, chirality can also be introduced by a chiral ligand, manifested in the circular dichroism response from metal-based electronic transitions other than the ligand's own transition(s). Lastly, the chiral arrangement of carbon tails of the ligands has also been discovered in a very recent work on chiral Au133(SR)52 and Au246(SR)80 nanoclusters. Overall, the origins of chirality discovered in Aun(SR)m nanoclusters may provide models for the understanding of chirality origins in other types of nanomaterials and also constitute the basis for the development of various applications of chiral nanoparticles.Handy cluster chirality! Chiral nanomaterials have received wide interest, but the exact origin of chirality at the atomic level has remained elusive for a long time. Recent significant progress in atomically precise gold nanoclusters (see figure) and total structure determination has unveiled several origins of chirality, that is, chirality in the core, chirality at the Au–S interface, chiral patterns of achiral ligand, and chiral ligand induction.
      PubDate: 2017-06-27T03:34:17.582868-05:
      DOI: 10.1002/asia.201700023
       
  • Interaction of VIVO(acac)2 with human serum transferrin and albumin
    • Authors: João Costa Pessoa; Isabel Correia, Ielyzaveta Chorna, Isabel Cavaco, Somnath Roy, Maxim L. Kuznetsov, Nádia Ribeiro, Gonçalo Justino, Fernanda Marques, Teresa Santos Silva, Marino Santos, Hugo M. Santos, José L. Capelo, James Doutch
      Abstract: [VO(acac)2] is a remarkable vanadium compound and has potential as a therapeutic drug. It is important to clarify how it is transported in blood, but the reports addressing its binding to serum proteins have been contradictory. We use several spectroscopic and mass spectrometric techniques (ESI and MALDI-TOF), small-angle X-ray scattering and size exclusion chromatography (SEC) to characterize solutions containing [VO(acac)2] and either human serum apotransferrin (apoHTF) or albumin (HSA). DFT and modeling protein calculations are carried out to disclose the type of binding to apoHTF. The measured circular dichroism spectra, SEC and MALDI-TOF data clearly prove that at least two VO-acac moieties may bind to apoHTF, most probably forming [VIVO(acac)(apoHTF)] complexes with residues of the HTF binding sites. No indication of binding of [VO(acac)2] to HSA is obtained. We conclude that VIVO-acac species may be transported in blood by transferrin. At very low complex concentrations speciation calculations suggest that [(VO)(apoHTF)] species form.
      PubDate: 2017-06-26T12:17:36.808364-05:
      DOI: 10.1002/asia.201700469
       
  • N-Bridged Annulated BODIPYs: Synthesis of Highly Fluorescent Blue-shifted
           Dyes
    • Authors: Hua Lu; Yanping Wu, John Mack, XuQiong Xiao, Zhifang Li, Zhen Shen
      Abstract: A series of novel BODIPY dyes has been prepared through the introduction of an N-bridged annulated meso-phenyl ring at one of the belta-positions of the BODIPY core. An unusual blue shift of the main spectral bands is observed,since the fusion of a meso-substituent results in a marked relative destabilization of the LUMO. The greater rigidity of the ring-fused structure leads to very high fluorescence quantum yields. The position of the main spectral bands can be fine-tuned by introducing electron withdrawing and donating groups onto the meso-phenyl ring.
      PubDate: 2017-06-26T06:20:09.861982-05:
      DOI: 10.1002/asia.201700584
       
  • Water and Carbon Dioxide: A Unique Solvent for the Catalytic
           Polymerization of Ethylene in Miniemulsion
    • Authors: Jean-Christophe Daigle; Frank P Lucien, Per B. Zetterlund, Jerome P. Claverie
      Abstract: The catalytic polymerization of ethylene is performed in water pressurized with CO2. The size of the initial monomer droplets and of the resulting polymer particles can be varied by simply changing the CO2 pressure. Furthermore, at identical ethylene partial pressure, the polymerizations performed in the presence of CO2 are significantly faster than in its absence. Thus, the combination of CO2 and water is a promising green solvent to perform catalytic emulsion polymerizations.
      PubDate: 2017-06-26T03:18:11.438711-05:
      DOI: 10.1002/asia.201700669
       
  • Luminescence Color Tuning of Stable Luminescent Solid Materials from Blue
           to NIR Based on Bis-o-Carborane-Substituted Oligoacenes
    • Authors: Hirofumi Naito; Kenta Nishino, Yasuhiro Morisaki, Kazuo Tanaka, Yoshiki Chujo
      Abstract: It was known that the aryl-substituted o-carboranes showed highly-efficient solid-state emission in the previous studies. To demonstrate color tuning of solid-state emission from aryl−o-carborane-based system, bis-o-carborane-substituted oligoacenes were synthesized and their properties were systematically investigated. Optical and electrochemical measurements revealed efficient decreases in energy band gaps and lowest unoccupied molecular orbital (LUMO) levels by adding the number of fused benzene rings for the extension of π-conjugation. As a consequence, bright solid-state emission was observed in the region from blue to near infrared (NIR). Furthermore, various useful features were obtained from the modified o-carboranes as an optical material. The naphthalene derivatives exhibited the AIE property and almost 100% quantum efficiency in the crystalline state. Furthermore, it was shown that the tetracene derivative having NIR-emissive property had high durability toward photo-bleach under UV irradiation.
      PubDate: 2017-06-26T01:18:38.35145-05:0
      DOI: 10.1002/asia.201700815
       
  • New Promising Method for the Challenging Synthesis of
           5-Acyl-2-Amino-3-Cyanothiophenes: Chemisry and Fluorescent Properties
    • Authors: Kseniya I. Lugovik; Alexander K. Eltyshev, Enrico Benassi, Nataliya P. Belskaya
      Abstract: Independent of the substrate structure and reaction conditions, 2-cyano-3-aminothioacrilonitriles, which contains two active electrophilic centers, were shown to interact with various active halo methylene compounds under mild conditions to afford 5-acyl-2-amino-3-cyanothiophenes as the only products. A series of new polyfunctional thiophene derivatives with a rare combination of functionalities were synthesized and their photophysical properties were experimentally and computationally investigated. The calculated electronic characteristics of the ground and excited states were compared to the experimental results, which provided a good understanding of the relationship between the optoelectronic properties and the molecular structures. After absorption of light quanta, the systems populate an intramolecular charge transfer (ICT) Franck-Condon state, and emission occurs from a twisted ICT (TICT) minimum.
      PubDate: 2017-06-24T04:47:32.424396-05:
      DOI: 10.1002/asia.201700721
       
  • A Carborane-Containing Fluorophore as a Stain of Cellular Lipid Droplets
    • Authors: Andrew Wu; Jacek L. Kolanowski, Badwi B. Boumelhem, Kylie Yang, Rebecca Lee, Amandeep Kaur, Stuart T. Fraser, Elizabeth J. New, Louis M. Rendina
      Abstract: The use of fluorescent markers and probes greatly enhances biological investigations but relies on the provision of an array of fluorophores with diverse properties. Herein we report a novel carborane-containing coumarin, 5, which is sufficiently lipophilic to localise in cellular lipid droplets. In non-polar solvents which show comparable polarities to those of a lipid environment, compound 5 exhibits a fluorescence quantum yield two orders of magnitude greater than found in aqueous solvents, adding a further degree of selectivity to lipid droplet imaging. Compound 5 can stain lipid droplets in ex vivo adipocytes as well as in cultured cells, and can be utilised in flow cytometry as well as confocal microscopy.High selectivity for lipids: The solvent-dependent photophysical properties and lipophilic nature of a novel carborane-coumarin fluorophore results in exquisite selectivity toward cellular lipid droplets.
      PubDate: 2017-06-22T08:20:45.054978-05:
      DOI: 10.1002/asia.201700423
       
  • Synthesis and Structure of N,N-Dinitroamidoborane Complexes
    • Authors: Sema Leybovich Ioffe; Alexey Yurievich Sukhorukov, Ivan Sergeevich Golovanov, Vladimir Alexandrovich Tartakovsky, Oleg Petrovich Shitov
      Abstract: A general approach to the synthesis of borohydride complexes containing one or two dinitroamide fragments has been suggested. Based on a smooth substitution of halide in haloborane or dibromoborane complexes with N,N-dinitroamide salts, this method provides various N,N-dinitroamidoboranes complexes in good yields and in analytically pure form. Using spectroscopic and computational methods, it was demonstrated that dinitroamidoborane complexes can be formed both as B,N- and B,O-isomers, which do not interconvert at ambient temperature.
      PubDate: 2017-06-21T11:47:05.68769-05:0
      DOI: 10.1002/asia.201700603
       
  • Selective and Tunable Near-Infrared and Visible Light Transmittance of
           MoO3−x Nanocomposites with Different Crystallinity
    • Authors: Ning Li; Yamei Li, Guangyao Sun, Yining Ma, Tianci Chang, Shidong Ji, Heliang Yao, Xun Cao, Shanhu Bao, Ping Jin
      Abstract: In this Communication, we report MoO3−x nanocomposites in which the near-infrared and visible light transmittance can be selectively modulated through the crystallinity. The MoO3−x nanocomposites were fabricated by a hydrothermal method, and their optical properties were characterized by UV-Vis spectrometer. The obtained results proved the possibility to tune the nanocomposite's optical properties in the UV/Visible spectral region: crystalline MoO3 mainly regulates the near-infrared range (800–2600 nm), and amorphous MoO3−x mainly changes the visible range from 350 nm to 800 nm and MoO3−x, with semi-crystalline structures mainly modulating around 800–1000 nm. These kinds of optical modulations could be attributed to small polar absorption, free electron absorption and plasmon absorption according to different crystallinity. Our work may create new possibilities for future applications such as photochromism, photocatalysis, and electrochromism.Crystal light: MoO3−x with different crystallinities is combined with TiO2, which improves the solar modulation efficiency due to the heterojuction between MoO3−x and TiO2. By controlling the crystallinity, we achieve selective tunable solar modulation in the visible and near-infrared range to widen the applications of MoO3−x.
      PubDate: 2017-06-21T04:21:13.044876-05:
      DOI: 10.1002/asia.201700437
       
  • Metal-ion induced in situ ligand oxidation for self-assembled clusters:
           from bis(5-(2-pyridine-2-yl)-1,2,4-triazole-3-yl)methane to alcohol or
           ketone
    • Authors: Wei-Quan Lin; Yuan-Yuan Peng, Lang Tong, Jian-Hua Jia, Jun-Liang Liu, Yan-Cong Chen, Wen-Bin Chen, Ming-Liang Tong
      Abstract: Hydrothermal reactions of metal nitrates and ligand bis(5-(pyridine-2-yl)-1,2,4-triazol-3-yl)methane (H2L1) on same condition gave three cluster compounds, {Cr2}, {Zn12} and {Fe8}. Notably, methylene group of H2L1 was in situ oxidized either to hydroxymethylated (L2-O)3- in the metallo-ring {Zn12} or to a rigid carbonylated (L3=O)2- in the screw-type {Fe8}. In light of comparative experiment results, NO3- was deduced to be of a catalytic role in ligand oxidation. Metal ions could be regarded as an "induced" tool for clusters generation in self-assembly process.
      PubDate: 2017-06-20T13:01:54.627719-05:
      DOI: 10.1002/asia.201700719
       
  • Synthesis, Optoelectronic and Self-assembly Properties of Diazadioxaacene
           Derivatives
    • Authors: Jinchong Xiao; Huhang Pan, Jingdan Duan, Guixia Zhai, Pengcheng Jin, Xiaohui Zhao, Li Jiang
      Abstract: Two novel diazadioxaacene derivatives (ADOP and ADOQ) have been successfully synthesized and characterized. Their single crystal analyses disclose that molecule ADOP forms a twisted topology configuration, while ADOQ adopts a reclining chair architecture. Both of them emit strong blue fluorescence in organic solvents. Moreover, they can self assemble to form regular nanobelts and nanowires respectively via a simple surfactant-assisted method.
      PubDate: 2017-06-20T09:36:24.247574-05:
      DOI: 10.1002/asia.201700700
       
  • Tuning surface polarity of microporous organic polymers for CO2 capture
    • Authors: Qihua Yang; Jian Chen, He Li, MingMei Zhong
      Abstract: CO2 capture is very important for reducing CO2 concentration in atmosphere. Herein, we report the preparation of microporous polymers with tunable surface polarity for CO2 capture. -NH2, -SO3H and -SO3Li functionalized porous polymers have been successfully prepared by post-synthesis modification of microporous polymers (P-PhPh3 prepared with 1,3,5-triphenylbenzene as monomer and AlCl3 as catalyst) via chemical transformations such as nitration-reduction, sulfonation and cationic exchange. The CO2 adsorption selectivity (CO2/N2 and CO2/H2) and isosteric heats of the microporous polymers increase markedly after modification, P-PhPh3-NH2 and P-PhPh3-SO3Li afford higher CO2 uptake capacity than P-PhPh3 at pressure less than 0.15 bar due to the enhanced interaction of CO2 with -NH2 and -SO3Li functional groups. Moreover, functionalized porous polymers could be stably used for CO2 capture. Surface modification is an efficient approach for tuning CO2 capture properties of porous polymers.
      PubDate: 2017-06-20T05:47:51.99229-05:0
      DOI: 10.1002/asia.201700779
       
  • Bifunctional Boron Phosphate as an Efficient Catalyst for Epoxides
           Activation to Synthesize Cyclic Carbonates with CO2
    • Authors: Zhimin Xue; Xinhui Zhao, Jingfang Wang, Tiancheng Mu
      Abstract: Development of inexpensive, easily-prepared, non-toxic and efficient catalysts for the cycloaddition of CO2 with epoxides to synthesize five-membered cyclic carbonates is a very attractive topic in the field of CO2 transformation. In this work, we conducted the first work on the cycloaddition of CO2 with epoxides to produce cyclic carbonates catalyzed by a binary catalyst system consisted of KI and boron phosphate (BPO4), which were both inexpensive and non-toxic, and various corresponding cyclic carbonates could be produced with high yields (93-99%) at 110 oC with a CO2 pressure of 4 MPa under solvent-free conditions. In the BPO4/KI catalyst system, BPO4, a Brønsted and Lewis acid hybrid, played the role on activating the epoxy ring through the formation of hydrogen bond with Brønsted acidic sites and the interaction with Lewis acidic sites simultaneously, and thus enhanced the activity of KI for the cycloaddition of CO2 with epoxides significantly. Additionally, the activity of BPO4/KI catalyst system showed no noticeable decrease after reused five times, indicating that the BPO4 was stable under the reaction conditions.
      PubDate: 2017-06-19T13:40:24.14549-05:0
      DOI: 10.1002/asia.201700688
       
  • Ruthenium-Catalyzed [2 + 2 + 2] Cycloaddition of 1,6-Enynes and
           Unactivated Alkynes: Access to Ring-fused Cyclohexadienes
    • Authors: Alphonse Tenaglia; Rui Liu, Laurent Giordano
      Abstract: The [2 + 2 + 2] intermolecular carbocyclization reactions between 1,6-enynes and alkynes catalyzed by Cp*Ru(cod)Cl are reported to provide bicyclohexa-1,3-dienes. The presented reaction conditions are compatible with internal and terminal alkynes and the chemo- and regioselectivity issues are controlled by the presence of substituents at the propargyl carbon center of the alkyne(s) partner(s).
      PubDate: 2017-06-19T09:45:40.103219-05:
      DOI: 10.1002/asia.201700642
       
  • NiCo2S4 Materials for Supercapacitor Applications
    • Authors: Yong-Ping Gao; Ke-Jing Huang
      Abstract: Cobalt–nickel sulfide (NiCo2S4) shows extensive potential for innovative photoelectronic and energetic materials owing to distinctive physical and chemical properties. In this review, representative strategies for the fabrication and application of NiCo2S4 and composite nanostructures are outlined for supercapacitors, with the aim of promoting the development of NiCo2S4 and their composites in the supercapacitor field through an analysis and comparison of diverse nanostructures. A brief introduction into the structures, properties, and morphologies are presented. Further prospects and promising developments of the materials in the supercapacitor field are also proposed.Two metals are better than one: Cobalt–nickel sulfide (see figure) shows extensive potential for innovative photoelectronic and energetic materials owing to distinctive physical and chemical properties. In this review, representative strategies for the fabrication of NiCo2S4 and composite nanostructures for applications as supercapacitors are outlined.
      PubDate: 2017-06-19T09:01:16.648059-05:
      DOI: 10.1002/asia.201700461
       
  • Catalytic oxidation of alcohol to carboxylic acid with hydrophobic cobalt
           catalyst in hydrocarbon solvent
    • Authors: Song Shi; Meng Liu, Li Zhao, Min Wang, Chen Chen, Jin Gao, Jie Xu
      Abstract: A hydrophobic cobalt catalyst was synthesized and proved to be effective in the alcohol oxidation under the assistance of hydrocarbon solvent with oxygen as the terminal oxidant. A series of catalyst with different water contact angles was applied to investigate the hydrophobic effect. Further insight in to the reaction process was researched by reaction kinetics, isotopic effect, etc. It showed that thehydrocarbon solvent participated in the alcohol oxidation, andwith the aid of the in-situ generated free radicals, the α-C-H bond was smoothly activated and the alcohol was converted to carbonyl compounds. The hydrophobic effect promoted the alcohol oxidation through affecting the solvent oxidation.
      PubDate: 2017-06-19T07:15:57.293489-05:
      DOI: 10.1002/asia.201700717
       
  • Impact of Fluorine Atoms on Perylene Diimide Derivative for Fullerene-free
           Organic Photovoltaics
    • Authors: Zhikuan Chen; Liang Zhao, Hua Sun, Xiaoyuan Liu, Changmei Liu, Haiquan Shan, Jiuxu Xia, Zongxiang Xu, Fei Chen, Wei Huang
      Abstract: The incorporation of fluorine atoms in organic semiconducting materials has attracted much attention recently due to its unique function to manipulate the molecular packing, film morphology and molecular energy levels. In this work, two perylenediimide (PDI) derivatives FPDI-CDTph and FPDI-CDTph2F were designed and synthesized to investigate the impact of fluorination on non-fullerene acceptors. Both FPDI-CDTph and FPDI-CDTph2F exhibited strong and broad absorption profiles, suitable lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels, and good electron transport ability. Compared with FPDI-CDTph, the fluorinated acceptor (FPDI-CDTph2F) afforded an optimal bulk heterojunction morphology with an interconnected and nanoscale phase separated structure that allowed more efficient exciton dissociation and balanced charge transport. Consequently, organic solar cells based on FPDI-CDTph2F showed a much higher power conversion efficiency (PCE) of 6.03% than that of FPDI-CDTph based devices (4.10%) without any post-fabrication treatment.
      PubDate: 2017-06-14T23:20:40.177815-05:
      DOI: 10.1002/asia.201700661
       
  • 'Two-Point' Self-Assembly and Photoinduced Electron Transfer in meso-Donor
           Carrying Bis(Styryl Crown Ether)BODIPY-Bis(Alkyl Ammonium)Fullerene
           Donor-Acceptor Conjugates
    • Authors: Francis D'Souza; Shuai Shao, Habtom Gobeze, Paul Karr
      Abstract: BF2-chelaed dipyrromethene, BODIPY, was functionalized to carry two stryryl crown ether tails and a secondary electron donor at the meso-position. Using a 'two-point' self-assembly strategy, a bis-alkyl ammonium functionalized fullerene, C60 was allowed to self-assemble the crown ether voids of BODIPY to obtain multi-modular donor-acceptor conjugates. As a consequence of the two-point binding, the 1:1 stoichiometric complexes formed yielded complexes of higher stability in which fluorescence of BODIPY was found to be quenched suggesting occurrence of excited state processes. The geometry and electronic structure of the self-assembled complexes were derived from B3LYP/3-21G(*) method where no steric constraints between the entities was observed. An energy level diagram was established using spectral, electrochemical and computational results to help understand the mechanistic details of excited state processes originating from 1bisstyrylBODIPY*. Femtosecond transient absorbance studies were indicative of the formation of an exciplex state prior to the charge separation process to yield bisstyrylBODIPY*+-C60*- radical ion-pair. The time constants for charge separation were generally lower compared to charge recombination process. The present studies bring out the importance of multi-mode binding strategy to obtain stable self-assembled donor-acceptor conjugates capable of undergoing photoinduced charge separation needed in artificial photosynthetic applications.
      PubDate: 2017-06-13T09:15:45.142201-05:
      DOI: 10.1002/asia.201700662
       
  • Polydiacetylene/Anti-HBs Nanobio-Complexes for Visible and Fluorescent
           Detection of Hepatitis B Surface Antigen on Nitrocellulose Membrane
    • Authors: Jinkyu Roh; Su Yeon Lee, Sangho Park, Dong June Ahn
      Abstract: Immunochromatographic assay (ICA) using nitrocellulose (NC) membrane offers several advantages. This technique is a rapid and straightforward method in contrast to other immunoassays. Polydiacetylene (PDA) vesicles have unique optical properties to show red color and red fluorescence at the same time. In this system, red-phase PDA vesicles are used as a fluorescent dye as well as a surface for immobilized hepatitis B surface antibody (HBsAb). PDA has remarkable stability than other fluorescent dyes. In this study, the most suitable PDA/HBsAb complexes is introduced for detecting hepatitis B surface antigen (HBsAg). Then, the PDA/HBsAb complexes affixed antibody is attached to NC membrane, which has two lines to confirm detection of HBsAg. The main advantage of this system is that the detection of HBsAg can be observed in both visible and fluorescent images due to optical properties of polydiacetylene. Detection of HBsAg is observed up to 0.1 ng/ml by fluorescent analysis and confirmed red line on NC membrane up to 1 ng/ml (HBsAg) by the naked eye. Consequently, these results show that PDA/HBsAb complexes were successfully applied to ICA for the diagnosis of hepatitis B.
      PubDate: 2017-06-11T22:15:29.919204-05:
      DOI: 10.1002/asia.201700769
       
  • Azo-based Fluorogenic Probes for Biosensing and Bioimaging: Recent
           Advances and Upcoming Challenges
    • Authors: Anthony Romieu; Arnaud Chevalier, Pierre-Yves Renard
      Abstract: The use of non-fluorescent azo dyes as dark quenchers in activatable optical bioprobes based on Förster resonance energy transfer (FRET) mechanism and designed to target a wide range of enzymes, has been well established for over two decades. The key value of the azo moiety (-N=N-) to also act as an efficient "ON-OFF" switch of fluorescence once introduced within the core structure of conventional organic-based fluorophores (mainly fluorescent aniline derivatives) has been recently exploited in the developement of alternative reaction-based small-molecule probes based on the "pro-fluorescence" concept. These unprecedented "azobenzene-caged" fluorophores are valuable tools for the detection of a wide range of reactive (bio)analytes. This review highlights the most recent and relevant advances that have been made in the design and biosensing/bioimaging applications of azo-based fluorogenic probes. Emphasis is also placed on relevant achievements in synthesis of bioconjugatable/biocompatible azo dyes used as starting building blocks in the rational and rapid construction of these fluorescent chemodosimeters. Finally, a brief glimpse of the possible future biomedical applications (theranostics) of these "smart" azobenzene-based molecular systems is presented.
      PubDate: 2017-06-08T09:20:26.335075-05:
      DOI: 10.1002/asia.201700682
       
  • -Co(OH)2 nanosheets: A superior pseudocapacitive electrode for
           high energy supercapacitors
    • Authors: Vanchiappan Aravindan; Mr. Makhan Maharjan, Qingyu Yan, Vanchiappan Aravindan, Srinivasan Madhavi
      Abstract: In this work, -Co(OH)2 nanosheets are explored as efficient pseudocapacitive material for the fabrication of 1.6 V class high energy supercapacitors in asymmetric fashion. As-synthesized -Co(OH)2 nanosheets displayed an excellent electrochemical performance owing to the unique structure, morphology and reversible reaction kinetics (fast Faradic reaction) in both three electrode and asymmetric configuration (with activated carbon, AC). For example, in three electrode set-up, -Co(OH)2 exhibits a high specific capacitance of ~675 F g-1 at scan rate of 1 mV s-1. In asymmetric supercapacitor, -Co(OH)2 AC cell delivers a maximum energy density of 37.3 Wh kg-1 at a power density of 800 W kg-1. Even at harsh conditions (8 kW kg-1), the energy density of 15.64 Wh kg-1 is registered for -Co(OH)2 AC assembly. Such an impressive performance of -Co(OH)2 nanosheets in asymmetric configuration reveals the emergence of pseudo-capacitive electrode towards the fabrication of high energy electrochemical charge storage systems.
      PubDate: 2017-06-08T05:20:30.300476-05:
      DOI: 10.1002/asia.201700707
       
  • Combination of Mass Signal Amplification and Isotope-Labeled Alkanethiols
           for the Multiplexed Detection of miRNAs
    • Authors: Hyunook Kang; Seol-Hye Hong, Jiha Sung, Woon-Seok Yeo
      Abstract: We report a fast and sensitive method for the multiplexed detection of miRNAs by combining mass signal amplification and isotope-labeled signal reporter molecules. In our strategy, target miRNAs are captured specifically by immobilized DNAs on gold nanoparticles (AuNPs), which carry a large number of small molecules, called amplification tags (Am-tags), as the reporter for the detection of target miRNAs. For multiplexed detection, we designed and synthesized four Am-tags containing 0, 4, 8, 12 isotopes so that they had same molecular properties but different molecular weights. By observing the mass signals of the Am-tags on AuNPs decorated along with different probe DNAs, four types of miRNAs in a sample could be easily discriminated, and the relative amounts of these miRNAs could be quantified. The practicability of our strategy was further verified by measuring the expression levels of two miRNAs in HUVECs in response to different CuSO4 concentrations.
      PubDate: 2017-06-07T21:20:41.159573-05:
      DOI: 10.1002/asia.201700696
       
  • π-Extended Dihydrophenazines with Three-State NIR Electrochromism
           Involving Large Conformational Changes
    • Authors: Juri Nagasaki; Satoru Hiroto, Hiroshi Shinokubo
      Abstract: π-Extended dihydrophenazines were successfully prepared by oxidation of 2-(N-arylamino)anthracenes. Their roof-type conformations were revealed by X-ray diffraction analysis, and the analysis of the optical properties indicated the presence of intramolecular charge-transfer processes. Upon chemical oxidation, the electronic absorption dramatically changed in a two-step fashion. The ESR analysis revealed that, depending on the amount of oxidant added, either a paramagnetic radical cation or a diamagnetic dication was generated. The NMR analysis revealed a conformational change upon oxidation, which was supported by theoretical calculations. A three-state electrochromic behavior was observed during the electrochemical oxidation and reduction cycles, showing sequential switching between visible and near-infrared (NIR) absorption properties upon application of electrochemical stimuli.
      PubDate: 2017-06-07T07:00:13.530906-05:
      DOI: 10.1002/asia.201700840
       
  • Strongly Luminescent Cyclometalated Gold(III) Complexes Supported by
           Bidentate Ligands Displaying Intermolecular Interactions and Tunable
           Emission Energy
    • Authors: Chi-Ming Che; Kaai Tung Chan, Glenna So Ming Tong, Qingyun Wan, Gang Cheng, Chen Yang
      Abstract: A series of charge-neutral Au(III) complexes, which comprise of dicarbanionic C-deprotonated biphenyl ligand and bidentate ancillary ligands ([Au(C^C)(L^X)]; L = O (1-9) or P (10-11); X = O, N or P), were prepared. All the complexes are emissive in degassed CH2Cl2 solutions and in thin-film samples with Φem up to 18% and 35% respectively, except 5 and 6, which bears (N^O)-type ancillary ligands. Variation of the electronic characteristics of the β-diketonate ancillary ligand was demonstrated to be a viable route for tuning the emission colour from blue-green (peak λem at ca. 466 nm for 1 and 2; 501 nm for 4a and 4b) to orange (peak λem at 585 nm for 3), in contrast to the common observations that the ancillary ligand has a negligible effect on the excited state energy of the Au(III) complexes reported in the literature. DFT/TDDFT calculations revealed that the energies of the 3ππ*(C^C) and the 3ILCT(O^O) excited states (ILCT = intraligand charge transfer) switch in order on going from O^O = acac (acac = acetylacetonate) to aryl-substituted β-diketonate ligand. Solution-processed and vacuum-deposited OLED devices of selected complexes were prepared. The vacuum deposited OLED fabricated with 2 displays a sky blue emission with a maximum EQE of 6.71% and CIE coordinates of (0.22, 0.40). The crystal structures of 7 and 9 reveal short intermolecular Au(III)···Au(III) contacts, with intermetal distances of 3.408 and 3.453 Å, respectively. DFT/TDDFT calculations were performed on 7 and 9 to account for the non-covalent interactions. Solid samples of 1, 3 and 9 exhibit excimeric emission at room temperature, which is rarely reported in Au(III) complexes.
      PubDate: 2017-06-06T07:15:22.683318-05:
      DOI: 10.1002/asia.201700686
       
  • Coupling Reactions of Alkynyl Indoles and CO2 by Bicyclic Guanidine:
           Origin of Catalytic Activity'
    • Authors: Choon Wee Kee; Kai Qi Elizabeth Peh, Ming Wah Wong
      Abstract: Density functional theory calculations were used to investigate the three possible modes of activation for the coupling of CO2 with alkynyl indoles in the presence of a guanidine base. The first of these mechanisms, involving electrophilic activation, was originally proposed by Skrydstrup et al. (Angew. Chem. Int. Ed. 2015, 54, 6682). The second mechanism involves the nucleophilic activation of CO2. Both of these electrophilic and nucleophilic activation processes involve the formation of a guanidine-CO2 zwitterion adduct. We have proposed a third mechanism involving the bifunctional activation of the bicyclic guanidine catalyst, allowing for the simultaneous activation of the indole and CO2 by the catalyst. We demonstrated that a second molecule of catalyst is required to facilitate the final cyclization step. Based on the calculated turnover frequencies, our newly proposed bifunctional activation mechanism is the most plausible pathway for this reaction under these experimental conditions. Furthermore, we have shown that this bifunctional mode of activation is consistent with the experimental results. Thus, this guanidine-catalyzed reaction favors a specific-base catalyzed mechanism rather than the CO2 activation mechanism. We therefore believe that this bifunctional mechanism for the activation of bicyclic guanidine is typical of most CO2 coupling reactions.The computer never lies! DFT calculations revealed that the bicyclic guanidine-catalyzed coupling reaction of alkynyl indoles with CO2 proceeds via a specific base-catalyzed mechanism (via bifunctional activation) rather than an electrophilic or nucleophilic CO2 activation mechanism.
      PubDate: 2017-06-05T13:26:01.380612-05:
      DOI: 10.1002/asia.201700338
       
  • Block Copolymers Templated Approach to Nanopatterned Metal-organic
           Framework films
    • Authors: Meimei Zhou; Yi-nan Wu, Baozhen Wu, Xianpeng Yin, Ning Gao, Fengting Li, Guangtao Li
      Abstract: The fabrication of patterned metal-organic framework (MOF) films with precisely controlled nanoscale resolution has been a fundamental challenge in nanoscience and nanotechnology. In this study, nanopatterned MOF films were fabricated using a layer-by-layer (LBL) growth method on functional templates (such as a bicontinuous nanoporous membrane or a structure with highly long-range-ordered nanoscopic channels parallel to the underlying substrate) generated by the microphase separation of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) block copolymers. HKUST-1 can be directly deposited on the templates without any chemical modification because the pyridine groups in P2VP interact with metal ions via metal-BCP complexes. As a result, nanopatterned MOF films with feature sizes below 50 nm and controllable MOF layer thicknesses can be fabricated by controlling the number of LBL growth cycles. The proposed fabrication method further extends the applications of MOFs in various fields.
      PubDate: 2017-06-02T10:45:28.116873-05:
      DOI: 10.1002/asia.201700307
       
  • Potential of the high photovoltaic performance non-fullerene small
           molecules
    • Authors: Wanning Li; Huifeng Yao, Hao Zhang, Sunsun Li, Jianhui Hou
      Abstract: Over the past decades, fullerene derivatives have become the most successful electron acceptors in the organic solar cells (OSCs) and have achieved great progress, showing power conversion efficiencies (PCEs) of over 11%. However, fullerenes have some drawbacks such as weak absorption, limited energy-level tunability, and morphological instability. In addition, fullerene-based OSCs usually suffer from large energy losses of over 0.7 eV, which limits further improvement of the PCE. Recently, non-fullerene small molecules have emerged as promising electron acceptors in OSCs. Their highly tunable absorption spectra and molecular energy levels have enabled the fine optimization of the resulting devices, and the highest PCE has surpassed 12%. Furthermore, several studies have shown that OSCs based on small molecule acceptors (SMA) have very efficient charge generation and transport efficiency at relatively low energy losses below 0.6 eV, suggesting great potential for the further improvement of OSCs. In this focus review, we analyze the challenges and potential of SMA-based OSCs and discuss the molecular design strategy for highly efficient SMAs.
      PubDate: 2017-06-02T04:29:19.473278-05:
      DOI: 10.1002/asia.201700692
       
  • [n]Cyclo-3,6-phenanthrenylenes: Synthesis, structure and fluorescence
    • Authors: Yi Tian; Koki Ikemoto, Sota Sato, Hiroyuki Isobe
      Abstract: Five congeners of [n]cyclo-3,6-phenanthrenylene with 3, 4, 5, 7 and 8 panels were obtained from one-pot macrocyclization of dibromophenanthrene, and their crystal structures with diverse molecular shapes were revealed by X-ray crystallography. The compounds, except the four-panel congener, were highly fluorescent in solution, with quantum yields up to 85%. The least fluorescent four-panel congener showed the smallest change in its absorption spectrum from that of monomeric phenanthrene, which provided an interesting structure-activity relationship for fluorescent macrocycles to guide future studies.
      PubDate: 2017-06-01T21:26:15.011366-05:
      DOI: 10.1002/asia.201700563
       
  • Vanadium chloroperoxidases, the missing link in the formation of
           chlorinated compounds and chloroform in the terrestrial environment'
    • Authors: Ron Wever; Phil Barnett
      Abstract: It is well established that the majority of chlorinated organic substances found in the terrestrial environment are produced naturally. The presence of these compounds in soils is not limited to a single ecosystem. Natural chlorination is also wide spread phenomenon in grasslands and agricultural soils typical for non-forested areas. These chlorinated compounds are formed from chlorination of natural organic matter consisting of very complex chemical structures such as lignin. Chlorination of several lignin model compounds results in the intermediate formation of trichloroacetyl-containing compounds which are also found in soils. These decay in general via a haloform type reaction mechanism to CHCl3. Released into the atmosphere CHCl3 will produce chlorine radicals by photolysis which will in turn lead to natural depletion of ozone. There is clear evidence that fungal chloroperoxidases able to produce HOCl are involved in the chlorination of natural organic matter. The objective of this review is to clarify the role and source of the various chloroperoxidases involved in the natural formation of CHCl3
      PubDate: 2017-06-01T04:20:46.93609-05:0
      DOI: 10.1002/asia.201700420
       
  • Programmed Site-selective direct Palladium Catalyzed Arylations of
           Thieno[3,2-b]thiophene
    • Authors: Tung Thanh Dang; Thi Minh Ha Vuong, Hien Nguyen, Didier Villemin, Thanh Tin Le, Hung Huy Nguyen
      Abstract: Mono-, di-, tri- and tetra-arylated thieno[3,2-b]thiophenes were synthesized by direct site-selective Pd-catalyzed C-H activation reactions with various aryl bromides in the presence of a phosphine-free Pd(OAc)2/KOAc catalyst system in DMAc. The arylation of 2-arylthieno[3,2-b]thiophen¬e took place at the C-3 position when the 2-aryl substituents bear electron-withdrawing groups, and at the C-5 position when they are bulky and possess electron-donating groups
      PubDate: 2017-06-01T04:20:26.568113-05:
      DOI: 10.1002/asia.201700562
       
  • Modulation of Open-Shell Characters of Amine-inserted Diphenoquinones via
           Structural Modification
    • Authors: Yuya Matsuta; Daisuke Sakamaki, Ryohei Kurata, Akihiro Ito, Shu Seki
      Abstract: In this study, a series of triphenylamine derivatives with two 2,6-diphenylphenoxy radicals (2a-d), which could be regarded as amine-inserted diphenoquinones have been synthesized and investigated their structures and electronic properties. The structures of 2a-d were confirmed by the single crystal X-ray analysis, showing the characteristic bond length alternation patterns for closed-shell quinoids. The solutions of 2a-d exhibited clear ESR signals even at room temperature, indicating their thermally accessible diradical states. The NMR and ESR measurements showed that the diradical character of 2a-d were increased in the order of 2a < 2b < 2c < 2d, well-reproduced by theoretical calculations. The results of this work strongly suggest that the diradical character of this class of compounds could be tuned by changing the substituent on the central nitrogen atom.
      PubDate: 2017-05-31T01:20:40.761167-05:
      DOI: 10.1002/asia.201700652
       
  • Toward Benzobis(thiadiazole)-based Diradicaloids
    • Authors: Jishan Wu; Yi Liu, Hoa Phan, Tun Seng Herng, Tullimilli Y. Gopalakrishna, Jun Ding
      Abstract: We theoretically predicted that acetylene-bridged benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole (BBT) oligomers would show a quick increase of diradical character with extension of chain length. To validate the hypothesis, six stable BBT-based diradicaloids were synthesized and fully characterized by X-ray crystallographic analysis and various spectroscopic measurements. Three of them showed prominent paramagnetic activity at elevated temperatures due to thermal population from the open-shell singlet ground state to triplet excited state. It was also found that substitution by electron-donating triphenylamine groups at the termini promoted the diradical character and reduced the singlet-triplet energy gap, and at the same time, resulted in intense near-infrared absorption.
      PubDate: 2017-05-30T22:20:24.516078-05:
      DOI: 10.1002/asia.201700732
       
  • Diketopyrrolopyrrole-Porphyrin based Conjugated Polymers for Ambipolar
           Field-Effect Transistors
    • Authors: Shichao Zhou; Cheng Li, Jianqi Zhang, Yaping Yu, Andong Zhang, Yonggang Wu, Weiwei Li
      Abstract: Porphyrin-based molecules have been widely used in dye-sensitized solar cells and bulk-heterojunction solar cells, but their application in field-effect transistors (FETs) is limited. In this work, two conjugated polymers based on diketopyrrolopyrrole and porphyrin were developed for FETs. The polymers exhibit extra-low band gap with aligned energy levels close to -4.0 eV and -5.0 eV because of the strong electron-donating and withdrawing ability of aromatic units. With additionally high crystalline properties, ambipolar charge carrier transport with a hole mobility of 0.1 cm2 V-1 s-1 in FETs were achieved based on these polymers, which also represents the highest performance based on porphyrin-polymer FETs.
      PubDate: 2017-05-30T04:15:24.914993-05:
      DOI: 10.1002/asia.201700472
       
  • Dual emission channels for simultaneous sensing Cys and Hcy in living
           cells
    • Authors: Ying Li; Weimin Liu, Hongyan Zhang, Mengqi Wang, Jiasheng Wu, Jiechao Ge, Pengfei Wang
      Abstract: The development of a fluorescent probe to distinguish between cysteine (Cys) and homocysteine (Hcy) is always a challenge due to their structural similarity, especially simultaneously detection of Cys and Hcy utilizing different emission channels. In this work, we designed and synthesized a new fluorescent probe to differentiate Cys and Hcy based on coumarin derivative with chlorine atom and α,β-unsaturated aldehyde. The Cys or Hcy-induced different cascade reaction with the probe lead to the corresponding products with distinct photophysical properties. The nonfluorescent probe responded to Cys and emitted strong blue fluorescence, whereas it reacted to Hcy and generated yellow fluorescence without interference with GSH. In additon, the probe was successfully applied to distinguish Cys and Hcy in living cells.
      PubDate: 2017-05-29T04:27:53.376419-05:
      DOI: 10.1002/asia.201700583
       
  • Photo-Induced Cyclization of (o-Alkylbenzoyl)phosphonates to
           Benzocyclobutenols
    • Authors: Naoki Ishida; Takaaki Yano, Tatsuya Yuhki, Masahiro Murakami
      Abstract: (o-Alkylbenzoyl)phosphonates readily cyclize to highly strained benzocyclobutenols simply upon irradiation with UV light. The remarkable efficiency is ascribed to the electron-accepting character of the phosphonate substituent, which facilitates thermal ring closing of the o-quinodimethane intermediate and suppresses reversion to the starting carbonyl compound.
      PubDate: 2017-05-23T21:20:35.337571-05:
      DOI: 10.1002/asia.201700766
       
  • Aqueous Oxidations Started by TiO₂ Photo-induced Holes Can Be a
           Rate-determining Step
    • Authors: Yuanzheng Gong; Chun Yang, Hongwei Ji, Chuncheng chen, Wanhong Ma, Jincai Zhao
      Abstract: In aqueous TiO2 photocatalytic hydroxylation of weakly polar aromatics, unlike usual polar aromatic cases of normal H/D KIEs, a series of inverse H/D KIEs of 0.7~0.8 were observed, which indicated that the oxidtion started by photo-induced hvb+ can be the rate-determining step.
      PubDate: 2017-05-23T03:20:24.855003-05:
      DOI: 10.1002/asia.201700658
       
  • Aziridine-Mediated Ligation at Phenylalanine and Tryptophan Sites
    • Authors: Kiran Bajaj; Rajeev Sakhuja
      Abstract: An efficient approach towards peptide synthesis has been described that allows an easy access to variety of small peptides via one-pot aziridine-mediated ligation-desulfurization strategy. The present protocol afforded a library of phenylalanine and tryptophan containing α-peptides in good yields by regioselective ring-opening of aziridine-3-aryl-2-carboxylates with peptide thioacids followed by desulfurization.
      PubDate: 2017-05-23T02:20:26.504238-05:
      DOI: 10.1002/asia.201700538
       
  • Effective, Low Cost Recovery of Toxic Arsenate Anions from Water Using
           Hollow Sphere Trapper Geodes
    • Authors: Sherif A. El-Safty; Mohamed A. Shenashen, Naeem Akhtar, Mahmoud M. Selim, Wafaa M. Morsy, Hitoshi Yamaguchi, Satoshi Kawada, Abdulaziz A. Alhamid, Naoki Ohashi, Izumi Ichinose, Ahmed Alamoudi
      Abstract: Because of the devastating impacts of arsenic to terrestrial and aquatic organisms, recovery, removal, disposal and management of arsenic-contaminated water has a considerable challenge and become an urgent necessity in the field of water treatment. This study reports control fabrication of low-cost adsorbents based on microscopic NiO hollow sphere geode-shelled a 100 nm of poly-CN nano-sphere particles-like nodules of poly-carbon nitride that intrinsically stacked and wrapped around the hollow nest spheres to form 500-700 nm shell. This C-, N-doped NiO hollow sphere adsorbent (named CNN) with multi-diffusive open-pore holes, and caves with connective open macro/meso-windows along the entire and well-dispersed hollow sphere particles lead to create trap vesicles for capture/extraction/separation of arsenate (AsO43 −) species from an aqueous solution. The CNN considered as potentially attractive adsorbent for AsO43 − species due to (i) superior removal/trapping capacity from water samples, and (ii) selectively AsO43 − trapping from real sample water that mainly includes chloride and nitrate anions and Fe2+, and Mn2+, Ca2+, and Mg2+ cations. The structural stability of hierarchal geodes in trap vehicle-shaped nests after 20 reuse/cycles without significant decrease in recovery efficiency of AsO43 - species was evident. For affording control of low-capital adsorbent and toxin waste-management, such superior CNN dead-end AsO43 - trapping/recovery system may lead to the following; (i) evidently enabled continuous control on the AsO43 - disposal management to re-diffuse or spread in water scarcity environment, and (ii) economically presented low-cost and eco-friendly CNN adsorbent for AsO43 - species, and (iii) selectively produced water-free-arsenate species. These CNN trapper geodes show potential to be excellent adsorbent candidates for environment remediation tools and humanhealthcare from toxicants.
      PubDate: 2017-05-22T21:21:17.068086-05:
      DOI: 10.1002/asia.201700666
       
  • Activation of CO2 by Vanadium Nitrogenase
    • Authors: Nathaniel Sickerman; Yilin Hu, Markus Walter Ribbe
      Abstract: The reduction of CO2 into useful products, including hydrocarbon fuels, is an ongoing area of particular interest due to efforts to mitigate buildup of this greenhouse gas. While the industrial Fischer-Tropsch process can facilitate the hydrogenation of CO2 with H2 to form short-chain hydrocarbon products under high temperatures and pressures, a desire to perform these reactions under ambient conditions has inspired the use of biological approaches. Particularly, enzymes offer insight into how to activate and reduce CO2, but only one enzyme, nitrogenase, can perform the multielectron, multiproton reduction of CO¬2 into hydrocarbons. The vanadium-containing variant, V-nitrogenase, displays especial reactivity towards the hydrogenation of CO and CO2. This Focus Review discusses recent progress towards the activation and reduction of CO2 with three primary V-nitrogenase systems. These systems span both ATP-dependent and ATP-independent processes and utilize approaches with whole cells, isolated proteins, and extracted cofactors.
      PubDate: 2017-05-22T13:20:27.221542-05:
      DOI: 10.1002/asia.201700624
       
  • Pd Nanoparticles immobilized on individual calcium carbonate plate derived
           from mussel shell waste: An eco-friendly catalyst for copper-free
           Sonogashira coupling reaction
    • Authors: Trin Saetan; Chutiparn Lertvachirapaiboon, Ekgasit Sanong, Mongkol Sukwattanasinitt, Sumrit Wacharasindhu
      Abstract: Conversion of waste into high value materials has been considered an important sustainability strategy in modern chemical industries. Large volume of shell waste is generated globally from mussel cultivation. In this work, mussel shell wastes (Perna viridis) are transformed into individual calcium carbonate plate (ICCP) and apply as a support for heterogeneous catalyst. Palladium nanoparticles (3-6 nm) are deposited with even dispersion on ICCP surface as demonstrated by X-ray diffraction and scanning electron microscopy. Using the system, Sonogashira cross coupling reactions between aryl iodides and terminal acetylenes are accomplished in high yields with the use of 1% Pd/ICCP in the presence of potassium carbonate without any use of copper metal or external ligand. The Pd/ICCP can also be reused up to three times with remaining activity over 90% and negligible Pd metal leaching. This work demonstrates that mussel shell waste can be used as an inexpensive and effective support for metal catalysts in coupling reactions as demonstrated by our successful performance of Pd catalyzed, copper-free Sonogashira cross coupling process
      PubDate: 2017-05-22T10:21:49.272613-05:
      DOI: 10.1002/asia.201700537
       
  • Hetero Face-to-Face Porphyrin Array with the Cooperative Effects of
           Coordination and Host-Guest Complexation
    • Authors: Yusuke Chiba; Maning Liu, Yasuhiro Tachibana, Tetsuaki Fujihara, Yasushi Tsuji, Jun Terao
      Abstract: We successfully synthesized a hetero face-to-face porphyrin array composed of ZnTPP and RuTPP(DABCO)₂ (TPP: 5,10,15,20-tetraphenylporphyrin, DABCO: 1,4-diazabi-cyclo[2.2.2]octane) in 2:1 molar ratio. A cyclic Zn porphyrin dimer (ZnCP) was also used as the host molecule for the Ru porphyrin. In the latter, the Ru-DABCO bonding in RuTPP(DABCO)₂ was stabilized by the host-guest complexation. Reaction progress kinetic analysis of the ligand substitution reaction of RuTPP(DABCO)₂ and that in ZnCP revealed the stabilization mechanism of the Ru-DABCO bonding. Photoinduced electron transfer (PET) from the Zn porphyrin to the Ru porphyrin was observed in the porphyrin array. The host-guest stabilization of unstable complex for construction of a donor-accepter-donor structure is expected to be a new method for an artificial photosynthesis.
      PubDate: 2017-05-22T08:20:29.819223-05:
      DOI: 10.1002/asia.201700738
       
  • Lewis Base-Mediated Silylations of Alcohols: Asymmetric Synthesis of
           Chiral Organosilicon Compounds Controlled by Chiral Ar-BINMOLs
    • Authors: Li-Wen Xu; Jin-Feng Zou, Mu-Yi Chen, Zheng Xu, Li Li, Yu-Ming Cui, Zhan-Jiang Zheng, Li-Wen Xu
      Abstract: In the past years, successful stereoselective functionalizations of hydroxyl groups of alcohol substrates with chlorosilanes have evolved silyl ether formation from a functional group protection to an enantioselective synthetic strategy. In this work, a family of structurally specific chiral diols, chiral 1,1'-binaphthalene-2--arylmethanol-2'-ol (Ar-BINMOL), -controlled desymmetrization of dichlorosilanes is presented, which led to the facile construction of desired silicon-stereogenic organosilicon compounds with high yields and good diastereoselectivities. IN addition, the enantioselective silylation of Ar-BINMOLs or Ar-BINMOL-derived phosphines might not only be of interest for the development of highly stereoselective nucleophilic silylation, but also bring light into the construction of novel chiral phosphine ligands bearing an atropisomeric silicon-stereogenic siloxane as silicon-based bulky group.
      PubDate: 2017-05-18T20:45:49.429655-05:
      DOI: 10.1002/asia.201700640
       
  • Graphene Oxide Conjugated Magnetic Beads for RNA Extraction
    • Authors: Xuan-Hung Pham; Ahruem Baek, Tae Han Kim, Sang Hun Lee, Won-Yeop Rho, Woo-Jae Chung, Dong-Eun Kim, Bong-Hyun Jun
      Abstract: A magnetic material that consists of silica-coated magnetic beads conjugated with graphene oxide (GO) was successfully prepared for facile ribonucleic acid (RNA) extraction. When the GO-modified magnetic beads were applied to separate the RNA from the lysed cell, the cellular RNAs were readily adsorbed to and readily desorbed from the surface of the GO-modified magnetic beads by urea. The amount of RNA extracted by the GO-modified magnetic beads was ~170% as much as those of the control extracted by a conventional phenol-based chaotropic solution. These results demonstrate that the facile method of RNA separation by using GO-modified magnetic beads as an adsorbent is an efficient and simple way to purify intact cellular RNAs and/or microRNA from cell lysates.
      PubDate: 2017-05-16T01:50:33.194459-05:
      DOI: 10.1002/asia.201700554
       
  • Dual-fluorophore raspberry-like nanohybrids for ratiometric pH sensing
    • Authors: Isaac Acquah; Jinkyu Roh, Dong June Ahn
      Abstract: We report on the development of raspberry-like silica structures formed by the adsorption of 8-hydroxypyrene-1,3,6-trisulfonate (HPTS)@silica nanoparticles (NPs) on rhodamine B isothiocyanate (RBTIC)@silica NPs for ratiometric fluorescence-based pH sensing. To overcome the well-known problem of dye leaching which occurs during encapsulation of anionic HPTS dye in silica NPs, we utilized a polyelectrolyte-assisted incorporation of the anionic HPTS. The morphological and optical characterization of the as-synthesized dye-doped NPs and the resulting nanohybrids were carried out. The pH-sensitive dye, HPTS, incorporated in the HPTS-doped silica NPs provided a pH-dependent fluorescence response while the RBITC-doped silica provided the reference signal for ratiometric sensing. We evaluated the effectiveness of the nanohybrids for pH sensing; the ratio of the fluorescence emission intensity at 510 nm and 583 nm at excitation wavelengths of 454 nm and 555 nm respectively. The results showed a dynamic response in the acidic pH range. With this approach, nanohybrids containing different dyes or receptors could be developed for multifunctioning and multiplexing applications.
      PubDate: 2017-05-14T23:21:10.024294-05:
      DOI: 10.1002/asia.201700616
       
  • Selective Separation of Aliphatic Nitriles Employing a Two-Dimensional
           Interdigitated Coordination Polymer
    • Authors: Srinivasan Natarajan; R Hota, S Mistry
      Abstract: A room temperature slow diffusion reaction of the metal nitrates [M = Zn(II) and Co(II)] with 5-azido isopthalic acid (AIPA) and 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (BPDB) resulted a new two dimensional interdigitated coordination polymer, [M(C8H3N3O4)(C12H10N4)].DMF [DMF = dimethyl formamide (C3H7NO)]. The non bonded DMF molecules, was found to exchange through a single-crystal to single-crystal (SCSC) fashion with many aliphatic nitrile compounds. More importantly, the present compound, I.DMF(Zn) appears to absorb cis-crotononitrile selectively from the cis-trans mixture as well as a mixture containing the structural isomer (allylnitrile). It also preferentially absorbs propionitrile from an equimolar mixture of acetonitrile, propionitrile and butyronitrile (1:2:1). The cobalt compound exhibits anti-ferromagnetic behavior.
      PubDate: 2017-05-12T06:10:53.458284-05:
      DOI: 10.1002/asia.201700485
       
  • Inverse Electron-Demand Diels-Alder Reactions: Principles and Applications
    • Authors: Jianwei Xu; Zhuang Mao Png Png, Huining Zeng Zeng, Qun Ye
      Abstract: Inverse electron-demand Diels-Alder reaction (iEDDA) represents an intriguing class of cycloaddition reaction that has attracted increasing attention for its applications in bioorthogonal chemistry, total synthesis of natural products, and materials science. In many cases, the application of iEDDA has been demonstrated as an innovative approach to achieve the target structures. The theoretical aspects of this class of reactions are of particular interest for scientists to understand various factors, such as steric strain and electron density of the attached groups, to govern the reaction and thus to elucidate the reaction mechanism. This review aims to summarize both the theoretical investigations and the application-driven research work of iEDDA. First of all, the historical aspects and the theoretical basis of the reaction, especially the recent advances on time-dependent density functional theory (TD-DFT) calculations as well as catalysis strategies will be highlighted and discussed. Secondly, the applications of this novel reaction in the context of materials science, bioorthogonal chemistry and total synthesis of natural products will be elaborated with selected recent examples. The challenges and opportunities of iEDDA will be highlighted to render more insights for its potential applications in many other research areas.
      PubDate: 2017-05-12T02:16:36.673353-05:
      DOI: 10.1002/asia.201700442
       
  • Single-walled Carbon Nanotube Based Ultrafast High Capacity Al-ion Battery
    • Authors: Preeti Bhauriyal; Arup Mahata, Biswarup Pathak
      Abstract: Exploring a suitable electrode material is a fundamental step in the direction of the development of Al-ion battery for enhanced performance. In this work, we have explored the feasibility of single-walled carbon nanotubes (SWNTs) as a cathode material for Al-ion batteries using the density functional theory calculations. Carbon nanotubes with the hollow structures and large surface area overcome the difficulty of activating the opening of interlayer spaces as observed in graphite electrode during the first intercalation cycle. Our results show that AlCl4 binds strongly with the SWNT resulting into energetically and thermally stable AlCl4 adsorbed SWNT system. The diffusion calculation shows that the SWNT system allows ultrafast diffusion of AlCl4 with a more favourable inner surface diffusion over outer surface diffusion. Our charge density difference and Bader atomic charge analysis confirm the oxidation of SWNT on AlCl4 adsorption, showing a similar behaviour like previously studied graphite cathode. The average open-circuit voltage and AlCl4 storage capacity increases with increasing SWNT diameter and can be as high as 1.96 V and 275 mAh/g, respectively in (25,25) SWNT compared to graphite (70 mAh/g). All of these properties show that SWNTs are potential cathode material for high-performance Al-ion batteries and should be explored further.
      PubDate: 2017-05-11T06:55:43.566348-05:
      DOI: 10.1002/asia.201700570
       
  • Thiomaleimide functionalization for selective biological fluorescence
           detection of peroxynitrite as tested in HeLa and RAW 264.7 cells
    • Authors: Tesla Yudhistira; Sandip V. Mulay, Kyungjin Lee, Youngsam Kim, Hee-Sung Park, David G. Churchill
      Abstract: : The role of fluorescent molecules in diagnosis, treatments as well as in biomedical research has great current medicinal significance; related research continues to reveal new practical systems with enhanced features for interfacing of substituted molecules with biological systems. As part of an effort to better understand chalcogenide systems, a new dithiomaleimide BODIPY (BDP-NGM) probe has been designed, synthesized and characterized. The fluorescence of BDP-NGM was quenched by the incorporation of [3,4-bis(phenylthio)] on the maleimide-4-phenyl moiety which is in turn placed at the meso-position of the BODIPY system. The probe shows a "turn-ON" fluorescence response upon reaction with ONOO−; mass spec evidence reveals evidence for oxidation of the sulfur groups to sulfone groups. A ~18.0-fold emission intensity enhancement was found, compared with emission signal from other ROS/RNS; superoxide however gave a modest turn on signal (~5.0-fold). The reaction was completed within 10 min judging from the monitoring of the turn-ON fluorescence process; the detection limit was found to be 100 nM. BDP-NGM can be used for the detection of ONOO− under both acidic and basic conditions. Live cell imaging showed that the current probe can be used for the selective detection of ONOO− in living systems.
      PubDate: 2017-05-11T03:56:36.1191-05:00
      DOI: 10.1002/asia.201700527
       
  • Nitrogen-Doped Graphitic Porous Carbons Derived from in Situ Formed g-C3N4
           Templates for Oxygen Reduction Reaction
    • Authors: Feng Yan; Qi Li, Dan Xu, Xu Ou
      Abstract: Heteroatom-doped carbon materials have been considered as substitutes of Pt-based electrocatalysts for oxygen reduction reaction (ORR) in alkaline fuel cells. Here, we reported the synthesis of oxygen-containing nitrogen-doped carbon (ONC) nanosheets via the carbonization of a mixture containing glucose and dicyandiamide (DCDA). In situ formed graphitic carbon nitride (g-C3N4) derived from DCDA provides a nitrogen-rich template, facilitating the formation of ONC nanosheets. The resultant ONC materials with high nitrogen contents, high specific surface areas, and mesoporous total volume displayed the excellent electrochemical performances, including a similar ORR onset potential, half-potential, a higher diffusion-limited current and excellent tolerance to methanol than that of the commercial Pt/C catalyst, respectively. Moreover, the ONC-850 remained high long-term durability even after 1000 cycles, as well as the high electron transfer number of 3.92 (4.0 for Pt/C). Additionally, this work provides a deep insights and versatile strategy for the synthesis of cost-effective 2D N-doped carbon electrocatalysts.
      PubDate: 2017-05-11T02:55:36.086608-05:
      DOI: 10.1002/asia.201700586
       
  • Current Advances in Highly-multiplexed Antibody-based Single-cell
           Proteomic Measurements
    • Authors: Lu Huang; Sean Alan Michael, Yangfan Chen, Hongkai Wu
      Abstract: Single cell measurements have played a critical role in revealing the complex signaling dynamics and heterogeneity present in cells but there is still much to learn. Measuring samples from bulk populations of cells often masks information and dynamics present in subsets of cells. Common single cell protein studies rely on fluorescent microscopy and flow cytometry but are limited in multiplexing ability due to spectral overlap. Recently, technology advancements in single cell proteomics have allowed highly multiplexed measurement of multiple parameters simultaneously using barcoded microfluidic enzyme-linked immunosorbent assays (ELISA) and mass cytometry techniques. In this review, we will describe recent work around multi-parameter single cell protein measurements and critically analyze the techniques.
      PubDate: 2017-05-11T01:55:52.213714-05:
      DOI: 10.1002/asia.201700404
       
  • Janus Copper Mesh Film with Water Unidirectional Transportation Ability
           toward High Efficiency Oil/Water Separation
    • Authors: Zhongjun Cheng; Bohan Wang, Hua Lai, Pengchang Liu, Dongjie Zhang, Da Tian, Hongwei Liu, Xiaoyan Yu, Bo Sun, Kening Sun
      Abstract: Inspired by the special asymmetric wettability and controllable permeating function of cell membrane, we reported a Janus nanostructured copper mesh film with unidirectional water transportation ability, on which, water can permeate from the hydrophobic side to the hydrophilic side, while it be retained from the opposite direction. Noticeably, based on the special unidirectional water permeation property, both heavy oil/water mixtures (ρoil> ρwater) and light oil/water mixtures (ρoil < ρwater) can be separated. Meanwhile, the film demonstrates high separating efficiency and good recyclability. This paper reports a new Janus film to realize the high efficient oil/water separation, given the smart controllability in wettability of the film, it is believed to potentially be used in many practical applications, such as wastewater treatment and oil spill clean-up.
      PubDate: 2017-05-10T09:00:35.961673-05:
      DOI: 10.1002/asia.201700488
       
  • Low band gap donor - acceptor conjugated systems based on 3-alkoxy or
           3-pyrrolidino - 4-cyanothiophene and benzothiadiazole units
    • Authors: Gurunathan Savitha; Chady Moussallem, Magali Allain, Frédéric Gohier, Pierre Frère
      Abstract: 3-hexyloxy-4-cyanothiophene, 3-pyrrolidino-4-cyanothiophene and 3,4-ethylenedioxythiophene (EDOT) units are used with benzothiadiazole as building blocks for developing three new conjugated Donor-Acceptor-Donor derivatives. The DAD molecules have in common the central acceptor part formed by combining the electron-withdrawing cyano groups and benzothiadiazole moiety. Theoretical calculations and the UV-vis and electrochemical data reveal the key role of the end capped donor to tune the electronic properties of the derivatives. The study of the electropolymerization process of the three derivatives show the strong influence of the donor parts both on the reactivity of the precursors and on the electronic properties of the resulting polymers. Derivatives end capped with pyyrolidinocyano thiophene or EDOT units lead to film of polymers presenting low band gap around 0.9 - 1.4 eV. Upon oxidation, the two polymers present well different behaviors. In presence of the pyrrolidino-cyanothiophene moieties, the oxidation leads to a blue shift of the absorption bands while with EDOT units, classical red shift giving high absorption in the NIR region was observed for the oxidized states.
      PubDate: 2017-05-09T20:55:28.327547-05:
      DOI: 10.1002/asia.201700545
       
  • A Tunable Cyclic Container: Guest-Induced Conformational Switching,
           Efficient Guest Exchange and Selective Isolation of C70 from Fullerene
           Mixture
    • Authors: Sankar Prasad Rath; Pritam Mondal
      Abstract: An adaptable cyclic porphyrin dimer with highly flexible linkers has been utilized as an artificial molecular container, which can efficiently encapsulate various aromatic guests (TCNQ/C60/C70) through strong π-π interaction by adjusting its cavity size and conformation. Also, the planar aromatic guest (TCNQ) can be easily exchanged by the larger aromatic guests (C60/C70) selectively. During the guest exchange process, the two porphyrin rings switch their relative orientation according to the size and shape of the guests. Such behaviors of the cyclic container have been thoroughly investigated using UV-visible, NMR, and X-ray crystal structure determination of the host-guest assemblies. The electrochemical and photophysical studies demonstrate an occurrence of photoinduced electron transfer from bisporphyrin to TCNQ/C60/C70 in the respective host-guest assemblies. The cyclic host can form complexes with C60 and C70 with association constants of 2.8±0.2×105 and 1.9±0.3×108 M-1, respectively, which represents the highest binding affinities for C70 reported so far for the zinc(II) bisporphyrinic receptors. Such a high selectivity in binding C70 over C60 further allows easy extraction and efficient isolation of C70 from a C60/C70 fullerene mixture. Experimental evidences are substantiated by DFT calculations.
      PubDate: 2017-05-09T14:50:27.04512-05:0
      DOI: 10.1002/asia.201700600
       
  • Synthesis of substituted 2-amino-1,3-oxazoles via copper-catalyzed
           oxidative cyclization of enamines and N, N-dialkyl formamides
    • Authors: Peng Gao; Juan Wang, Zijing Bai, Desuo Yang, Ming-Jin Fan, Zheng-Hui Guan
      Abstract: A facile synthesis of 2-amino-1,3-oxazoles via CuI-catalyzed oxidative cyclization of enamines and N,N-dialkyl formamides has been developed. The reaction proceeds through an oxidative C-N bond formation, followed by an intramolecular C(sp2)-H bond functionalization/C-O cyclization in one-pot. This protocol provides a direct access to useful 2-amino-1,3-oxazoles and features protecting group free nitrogen sources, readily available starting materials, broad substrate scope and mild reaction conditions.
      PubDate: 2017-05-09T01:20:42.12867-05:0
      DOI: 10.1002/asia.201700503
       
  • A Facile Construction of Quinoline-2-carboxylate Esters through An Aerobic
           Oxidation of Alkyl 4-Anilinocrotonates Induced by Radical Cation Salt
    • Authors: Xiao Dong Jia; Pengfei Li, Yu Shao, Yu Yuan, Wentao Hou, Xiaofei Liu, Xuewen Zhang, Honghe Ji
      Abstract: A facile construction of quinoline-2-carboxylate esters through an aerobic oxidation of alkyl 4-anilinocrotonates was described. In the presence of dioxygen, sp3 C-H bonds in 4-anilinocrotonates can easily be oxidized by catalytic radical cation salt, providing a radical intermediate. After further oxidation and domino cyclization, the desired quinoline derivatives were afforded in high yields. This reaction provided a new way to construct the pharmaceutically relevant quinoline skeleton, avoiding harsh reaction conditions and tedious starting material synthesis.
      PubDate: 2017-05-08T21:26:05.487284-05:
      DOI: 10.1002/asia.201700560
       
  • Mechanism of Nickel-catalysed Suzuki-Miyaura coupling of amides
    • Authors: Xu Zhengyang; Haizhu Yu, Fu Yao
      Abstract: Ni-catalyzed Suzuki-Miyaura coupling of N-tert-butoxycarbonyl (N-Boc) protected amides provides a versatile strategy for the construction of C-C bonds. Herein, density functional theory (DFT) methods have been used to elucidate the mechanistic details, and especially the necessity of N-Boc, K3PO4 and H2O in this reaction. Our study corroborates the previous proposal that the overall catalytic cycle includes three steps: oxidative addition, transmetalation, and reductive elimination. Three possible transmetalation mechanisms are examined to interpret the effect of K3PO4 and H2O. In the most feasible transmetalation mechanism, K3PO4 (acting as a Lewis base) first ligates with the Lewis acid PhBpin. The formed K3PO4-PhBpin complex readily undergoes the H transfer step with H2O. Throughout the catalytic cycle, the H transfer in the transmetalation step is the rate-determining step. The theoretical results show good agreement with the experimental data.
      PubDate: 2017-05-08T10:25:42.975578-05:
      DOI: 10.1002/asia.201700313
       
  • Supported C-scorpionate vanadium (IV) complexes as reusable catalysts for
           xylene oxidation
    • Authors: Jiawei Wang; Luisa Martins, Ana P. C. Ribeiro, Sónia A. C. Carabineiro, José L. Figueiredo, Armando J. L. Pombeiro
      Abstract: C-scorpionate vanadium(IV) [VOxCl3-x{κ3-RC(pz)3}] [pz = pyrazol-1-yl; x = 0, R = SO3 (1); x = 1, R = CH2OH (2) or CH2OSO2Me (3)] complexes supported on functionalized carbon nanotubes (CNT) are the first V-scorpionate catalysts used so far for the neat oxidation of o-, m- or p-xylene, with TBHP (70% aqueous solution), to the corresponding toluic acids (main products), tolualdehydes and methylbenzyl alcohols. Remarkably, a p-toluic acid yield of 43% (73% selectivity, TON = 1.34 × 103) was obtained with 2@CNT in a simple microwave-assisted mild oxidation procedure, using a very low catalyst charge (3.2 × 10-2 mol% vs. substrate). Further, this occurred in the absence of any bromine source, what is significant towards the development of a greener and more sustainable process for xylenes oxidation. Moreover, catalysts reuse with preservation of their activity was found for up to six consecutive cycles. The effects of reaction parameters, such as reaction time, temperature, amount of catalyst or type of heating source, on the performance of the above catalytic systems are reported and discussed.
      PubDate: 2017-05-06T06:23:26.076716-05:
      DOI: 10.1002/asia.201700499
       
  • CO2 Assisted Activating Cellulose for Preparation of Superhydrophobic
           Nanocoating
    • Authors: Jinfang Wang; Zhimin Xue, Tingting Yu, Zhimin Liu, Tiancheng Mu
      Abstract: There is increasing demand for superhydrophobic materials which could be used for separating oil and water efficiently. In order to avoid secondary pollution, it is desirable to prepare such materials with green technology. Here we present an environment benign method for fabricating superhydrophobic materials by using organic base based solvents in which cellulose can be dissolved and activated. Then dissolved cellulose could be chemical modified with green silanization reagent, and the solvent can be recycled after CO2 is removed. The obtained cellulose nanocoating exhibited excellent hydrophobic effect. Spray it on the filter paper (water contact angle (WCA) is 165°) for oil and water separation, the separation efficiency is more than 95%; spray it on ordinary sponge (WCA is 163°), it can be used as oil absorber. It can also absorb a certain amount of bisphenol A (BPA) (the concentration decreased by 66% from the origin concentration 0.1 mM). Besides the high efficiency for the separation of oil and water, it is resistant to a wide range of pH solutions, which means that it could be used in harsh environments. More importantly, the process is cost-effective, the solvent can be recycled and the whole process is green. Thus the activation method provides a green route for the preparation of other cellulose-based materials.
      PubDate: 2017-05-04T08:15:48.02596-05:0
      DOI: 10.1002/asia.201700335
       
  • The development of G-quadruplex-based assays for the detection of small
           molecules and toxic substances
    • Authors: Dik-Lung Ma; Chung-Hang Leung
      Abstract: G-quadruplexes can be induced to form from guanine-rich (G-rich) DNA sequences by certain small molecules or metal ions. In concert with an appropriate signal transducer, such as a fluorescent dye or a phosphorescent metal complex, the ligand recognition event can be transduced into a luminescent response. This Focus Review is aimed to highlight the recent examples of aptamer-based or metal-mediated G-quadruplex assays for the detection of small molecules and toxic substances in the latest three years. We discuss the mechanisms and features of the different assays and present an outlook and perspective for the future of this field.
      PubDate: 2017-05-03T22:15:31.818301-05:
      DOI: 10.1002/asia.201700533
       
  • Metal oxide nanostructures generated from in-situ sacrifice of zinc in
           bimetallic textures as flexible Ni/Fe fast battery electrodes
    • Authors: Tianyi Huang; Zhifang Liu, Zitong Zhang, Bangqing Xiao, Yong Jin
      Abstract: An "in-situ sacrifice" process was devised in this work as a room-temperature, all-solution processed electrochemical method to synthesize nanostructured NiOx and FeOx directly on current collectors. After electrodepositing NiZn/FeZn bimetallic textures on copper net, zinc component is etched and the remnant nickel/iron are evolved into NiOx and FeOx by the "in-situ sacrifice" activation we proposed. As prepared electrodes exhibit high areal capacities of 0.47 mAh cm-2 and 0.32 mAh cm-2, respectively. By integrating NiOx as cathode, FeOx as anode and PVA/KOH gel as separator/solid-state electrolyte, the assembled quasi-solid-state flexible battery delivers a volumetric capacity of 6.91 mAh cm-3 at 5 mA cm-2, along with a maximum energy density of 7.40 mWh cm-3 under a power density of 0.27 W cm-3 and a maximum tested power density of 3.13 W cm-3 with a 2.17 mWh cm-3 energy density retention. Our room-temperature synthesis, which only consumes minute electricity, makes it a promising approach for large-scale production. We also emphasize the etching zinc in-situ sacrifice process used in this work as a general strategy for the growth of metal-based nanostructures for high performance battery materials.
      PubDate: 2017-05-03T01:20:39.98308-05:0
      DOI: 10.1002/asia.201700518
       
  • Resistance Controllability in Alkynylgold(III) Complex- based Resistive
           Memory for Flash-type Storage Applications
    • Authors: Peng Wang; Yu Fang, Jun Jiang, Yujin Ji, Youyong Li, Junwei Zheng, Qingfeng Xu, Jian-Mei Lu
      Abstract: Due to the demands of state-of-the-art information technologies that are suitable for big data storage, the necessity for organic memory devices (OMDs) materials is highlighted. However, OMDs based on metal complexes are limited to only several types of transition metal complex systems bearing nitrogen-donor ligands. In this paper, we attempt to introduce novel alkynylgold(III) materials into memory devices with superior performance. In this respect, an alkynyl-containing coumarin gold (III) complex, (C19N5H11)Au-C≡C-C9H5O, has been synthesized and integrated into a sandwiched Al/[(C19N5H11)Au-C≡C-C9H5O]/ITO device. By precisely controlling the compliance current (Icc), the devices show different switching characteristics from Flash-type binary resistance switching (Icc ≤ 10-3 A) to WORM-type ternary resistance switching (Icc = 10-2 A). This work explores electrical gold(III) complex-based memories for potential use in organic electronics.
      PubDate: 2017-05-02T10:16:17.776603-05:
      DOI: 10.1002/asia.201700369
       
  • Lateral Extension of Benzodithiophene System: Construction of Heteroacenes
           Containing Various Chalcogens
    • Authors: Lei Zhang; Jichang Wei, Dong Meng, Zhaohui Wang
      Abstract: A series of novel linear acenes with five fused rings, which contain thiophene, selenophene, and tellurophene as the outmost rings, have been successfully synthesized from well-known benzodithiophene (BDT). It was found that the optical, electrochemical properties and crystal packing motifs could be modulated by changing heteroatoms in the outmost rings.
      PubDate: 2017-05-02T09:54:48.973814-05:
      DOI: 10.1002/asia.201700552
       
  • Enhanced fluorescence imaging and photodynamic cancer therapy using hollow
           mesoporous nanocontainer
    • Authors: Suk ho Hong; Hyunjin Kim, Yongdoo Choi
      Abstract: Here we show that "off-on" type of photodynamic therapy agents could be developed using hollow mesoporous silica nanoparticles (HMSNP), which can be used not only for enhancing delivery of photosensitizers to cancer cells but also for enabling switchable optical properties of the photosensitizers. Fluorescence and singlet oxygen generation of the photosensitizer-loaded HMSNP is turned off in its native state. In vitro cell studies showed that this HMSNP-based "off-on" agent may have potential utility in selective fluorescence detection and photodynamic therapy of cancers.
      PubDate: 2017-04-30T10:53:39.220393-05:
      DOI: 10.1002/asia.201700371
       
  • Aggregation behaviour of non-ionic twinned amphiphiles and their
           application as biomedical nanocarriers
    • Authors: Abhishek K. Singh; Bala N. S. Thota, Boris Schade, Katharina Achazi, Abdullah Khan, Christoph Böttcher, Sunil K. Sharma, Rainer Haag
      Abstract: A new class of twinned amphiphiles was developed by conjugating a pair of hydrophilic head groups from mPEG chains (Mn: 350 or 1000) and a pair of hydrophobic segments from linear alkyl chains (C11 or C18) through a novel spacer synthesized from glycerol and p-hydroxybenzoic acid. The aggregation phenomena of the amphiphiles were proven by DLS and fluorescence experiments, whereas size and morphology of the aggregates were evaluated by cryo-TEM, the measurements proved the formation of globular, thread-like or rod-like micelles as well as planar double-layer assemblies, depending on the amphiphile's molecular structure. The applicability of these non-ionic amphiphilic systems as nanocarriers for hydrophobic guest molecules was demonstrated by encapsulating a hydrophobic dye, Nile red, and a hydrophobic drug, Nimodipine. The transport capacity results for both Nimodipine and Nile Red prove them as a promising candidate for drug delivery.
      PubDate: 2017-04-28T10:30:38.355246-05:
      DOI: 10.1002/asia.201700450
       
  • Mechanistic Insights of Palladium-Catalyzed Silylation of Aryl Iodides
           with Hydrosilanes by DFT Study
    • Authors: Zheng Xu; Jin-Zhou Xu, Jin Zhang, Zhan-Jiang Zheng, Jian Cao, Yu-Ming Cui, Li-Wen Xu
      Abstract: The catalytic cycles of palladium-catalyzed silylation of aryl iodides initiated by oxidative addition of hydrosilane or aryl iodide via three different mechanisms, which are characterized by intermediates R3Si-PdII-H (Cycle A), Ar-PdII-I (Cycle B) and PdIV (Cycle C), have been explored by hybrid density functional theory (DFT) in details. Our calculations suggested that the chemical selectivity and reactivity of the reaction depend on the ligation state of catalyst and specific reaction conditions including feeding order of substrates, and the presence of base. For less bulky biligated catalyst, Cycle C is energetically favored over Cycle A, through which the silylation process is slightly favored over the reduction process. Interestingly, for bulky monoligated catalyst, Cycle B is energetically more favored over the general accepted Cycle A, in which the silylation channel is slightly disfavored in comparison to that of the reduction channel. Moreover, the inclusion of base in this channel allows the silylated product become dominant. These findings offer a good explanation for the complex experimental observations. Designing reaction process, which allow the oxidative addition of Pd0 catalyst to aryl iodide occurs prior to hydrosilane, was thus suggested to improve reactivity and chemoselectivity for silylated product by pushing the catalytic cycle proceeds via Cycle B (monoligated Pd0 catalyst) or Cycle C (biligated Pd0 catalyst) instead of Cycle A.
      PubDate: 2017-04-28T00:20:37.563285-05:
      DOI: 10.1002/asia.201700174
       
  • Small Molecular Anion Recognition by a Shape-responsive Bowl-type
           Dodecavanadate
    • Authors: Sho Kuwajima; Yuji Kikukawa, Yoshihito Hayashi
      Abstract: A dodecavanadate, [V₁₂O₃₂]⁴¯, is an inorganic bowl-type host with a cavity entrance with a diameter of 4.4 Å in the optimized structure. The linear, bent, and trigonal planar anions, are tested as a guest anion and the formation of host-guest complexes, [V₁₂O₃₂(X)]⁵¯ (X = CN¯, OCN¯, NO₂¯, NO₃¯, HCO₂¯, and CH₃CO₂¯) were confirmed by X-ray crystallographic analyses and ⁵¹V NMR study. The degree of the distortion of the bowl from a regular bowl to an oval bowl depends on the shape of the guest anion, after host-guest complex formation. In ⁵¹V NMR spectroscopy, all the chemical shifts of the host-guest complexes are clearly shifted after the guest incorporation. The incorporation reaction rates for OCN¯, NO₂¯, HCO₂¯, and CH₃CO₂¯ are much larger than those of NO₃¯ and halides. The incorporated non-spherical molecular anions in the dodecavanadate host are easily dissociated or exchanged to other anions, while the spherical halides in the dodecavanadate host are preserved without dissociation even in the presence of the tested anions.
      PubDate: 2017-04-22T05:30:42.533474-05:
      DOI: 10.1002/asia.201700489
       
  • Effects of stoichiometry on the H2 storage properties of
           Mg(NH2)2-LiH-LiBH4 tri-component system
    • Authors: Han Wang; Hujun Cao, Claudio Pistidda, Sebastiano Garroni, Guotao Wu, Thomas Klassen, Martin Dorheim, Ping Chen
      Abstract: Hydrogen desorption pathways and storage properties of 2Mg(NH2)2-3LiH-xLiBH4 samples (x = 0, 1, 2 and 4) were investigated systematically by combination of Pressure-Composition-Isotherm (PCI), Differential scanning calorimetric (DSC) and volumetric release methods. Experimental results show that the desorption peak temperatures of 2Mg(NH2)2-3LiH-xLiBH4 samples are ca. 10-15 oC lower compared to that of 2Mg(NH2)2-3LiH. Especially the 2Mg(NH2)2-3LiH-4LiBH4 composite begins to release hydrogen at 90 oC, exhibiting a superior dehydrogenation performance. All the LiBH4 doped samples can be fully dehydrogenated and re-hydrogenated at the temperature of 143 oC. The high hydrogen pressure region (above 50 bar) of PCI curves for the LiBH4 doped samples rise with the increasing of the LiBH4 amount. LiBH4 changes the desorption pathway of the 2Mg(NH2)2-3LiH sample under 50 bar hydrogen pressure, resulting in the formation of MgNH and molten [LiNH2-2LiBH4], which is different from the dehydrogenation pathways of 2Mg(NH2)2-3LiH sample without LiBH4 forming Li2Mg2N3H3 and LiNH2 as reported before. In addition, DSC results show that the doped samples exhibit two independent endothermic events, which may be related to two different desorption pathways.
      PubDate: 2017-04-18T23:22:02.835459-05:
      DOI: 10.1002/asia.201700287
       
  • Stabilities and Biological Activities of Vanadium Drugs: What is the
           Nature of Active Species?
    • Authors: Aviva Levina; Peter Andrew Lay
      Abstract: Diverse biological activities of vanadium(V) drugs mainly arise from their abilities to inhibit phosphate-dependent enzymes and to alter cell signaling. Initial interest focused on anti-diabetic activities but has shifted to anti-cancer and anti-parasitic drugs. V-based anti-diabetics are pro-drugs that release active components (e.g., H₂VO₄¯) in biological media. By contrast, V anti-cancer drugs are generally assumed to enter cells intact; however, speciation studies indicate that nearly all drugs are likely to react in cell culture media during in-vitro assays and the same would apply in vivo. The biological activities are due to V(V) and/or V(IV) reaction products with cell culture media, or the release of ligands (e.g., aromatic diimines, 8-hydroxyquinolines or thiosemicarbazones) that bind to essential metal ions in the media. Careful consideration of the stability and speciation of V complexes in cell culture media and in biological fluids is essential to design targeted V-based anti-cancer therapies.
      PubDate: 2017-04-11T21:26:00.891775-05:
      DOI: 10.1002/asia.201700463
       
  • Symmetry Breaking in Pyrrolo[3,2-b]pyrroles: Synthesis,
           Solvatofluorochromism, and Two-photon Absorption
    • Authors: Daniel T Gryko; Aleksander Mikhaylov, Łukasz Łukasiewicz, Hye Gun Ryu, Aleksander Rebane, Kyo Han Ahn, Marzena Banasiewicz, Bolesław Kozankiewicz, Denis Jacquemin, Cloe Azarias
      Abstract: Five centrosymmetric and one dipolar pyrrolo[3,2-b]pyrroles, possessing, respectively, either two- or one strongly electron-withdrawing nitro groups have been synthesized in a straightforward manner from simple building blocks. In the symmetric compounds the nitroaryl groups induced spontaneous breaking of inversion symmetry in the excited-state, leading to large solvatofluorochromism. To study the origin of this effect, the series employed peripheral structural motifs that control the degree of conjugation via altering of dihedral angle between the 4-nitrophenyl moiety and the electron-rich core. We observed that for compounds with a larger dihedral angle, fluorescence quantum yield decreased quickly when exposed to even moderately polar solvents. Reducing the dihedral angle (i.e., placing the nitrobenzene moiety in the same plane as the rest of the molecule) moderated the dependence on solvent polarity so that the dye exhibited significant emission, even in THF. To investigate at what stage the symmetry breaking occurs, we measured two-photon absorption (2PA) spectrum and 2PA cross-sections (σ2PA) for all six compounds. The 2PA transition profile of the dipolar pyrrolopyrrole, followed the corresponding one-photon absorption (1PA) spectrum, which provided an estimate of the change of the permanent electric dipole upon transition ~18 D. The nominally symmetric compounds displayed an allowed 2PA transition in the wavelength range, 700-900 nm. In the S0S1 transition region, the symmetric structures also showed a partial overlap between 2PA and 1PA transitions in the long-wavelength wing of the band, from which a tentative, relatively small dipole moment change, 2-7 D, was deduced, thus suggesting that some slight symmetry breaking may be possible in the ground state, even before major symmetry breaking occurs in the excited-state.
      PubDate: 2017-04-11T08:20:27.9954-05:00
      DOI: 10.1002/asia.201700159
       
  • Porous Peptide Complexes by a Folding-and-Assembly Strategy
    • Authors: Tomohisa Sawada; Motoya Yamagami, Shuji Akinaga, Tatsuki Miyaji, Makoto Fujita
      Abstract: Concerted folding and assembly processes are necessary for protein self-assembly, yet such a concerted strategy has rarely been attempted by synthetic chemists. In this work, we have created a new porous peptide structure through a coordination-driven folding-and-assembly strategy. A porous framework with 1.5 nm-sized pores and a PII helical peptide scaffold was successfully obtained by complexation of AgNTf2 and tripeptide ligands containing the Gly-Pro-Pro sequence. The pores were modified in various ways with retention of the latent PII helical conformation of the peptide ligand.
      PubDate: 2017-04-05T11:21:20.630746-05:
      DOI: 10.1002/asia.201700458
       
 
 
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