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  Subjects -> CHEMISTRY (Total: 841 journals)
    - ANALYTICAL CHEMISTRY (50 journals)
    - CHEMISTRY (593 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (41 journals)
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CHEMISTRY (593 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: 34)
ACS Chemical Neuroscience     Full-text available via subscription   (Followers: 18)
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: 233)
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: 55)
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 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: 15)
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: 68)
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: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Analyst     Full-text available via subscription   (Followers: 40)
Angewandte Chemie     Hybrid Journal   (Followers: 222)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 213)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 3)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
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: 15)
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: 4)
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: 295)
Biochemistry Insights     Open Access   (Followers: 6)
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: 121)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 98)
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: 3)
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: 66)
Catalysis for Sustainable Energy     Open Access   (Followers: 7)
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: 8)
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: 13)
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: 176)
Chemical Science     Open Access   (Followers: 22)
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: 57)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 26)
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: 142)
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: 44)
Chemistry of Materials     Full-text available via subscription   (Followers: 258)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 9)
Chemistry World     Full-text available via subscription   (Followers: 22)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
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)
Clay Minerals     Full-text available via subscription   (Followers: 10)
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: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
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   (Followers: 1)
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: 12)
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: 58)
Dalton Transactions     Full-text available via subscription   (Followers: 22)
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: 8)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)
Environmental Science : Nano     Partially Free   (Followers: 1)
Environmental Toxicology & Chemistry     Hybrid Journal   (Followers: 17)

        1 2 3 | Last

Journal Cover Canadian Journal of Chemistry
  [SJR: 0.364]   [H-I: 57]   [10 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0008-4042 - ISSN (Online) 1480-3291
   Published by NRC Research Press Homepage  [21 journals]
  • In memoriam of Prof. Dr. Fritz Vögtle (1939–2017)
    • Authors: Donald A. Tomalia
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page ix-x, September 2017.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-01T11:55:37Z
      DOI: 10.1139/cjc-2017-0265
       
  • Dendrimers: syntheses, toxicity, and applications toward catalysis,
           environmental sciences, and nanomedecine
    • Authors: Abdelkrim Azzouz, René Roy
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page v-vii, September 2017.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0537
       
  • Peptide dendrimers: drug/gene delivery and other approaches
    • Authors: S.S. Santos, R.V. Gonzaga, J.V. Silva, D.F. Savino, D. Prieto, J.M. Shikay, R.S. Silva, L.H.A. Paulo, E.I. Ferreira, J. Giarolla
      Pages: 907 - 916
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 907-916, September 2017.
      Dendrimers are versatile hyperbranched molecules, which have deserved attention especially for their potential in many applications, including biological. Peptide dendrimers comprise interesting classes of dendrimers, and their use has been emphasized as a drug/bioactive compound delivery system, mostly in the antineoplastic area. The bioactive molecules can be covalently linked or entrapped inside the peptide derivative. Self-assembled nanocarriers are a recent trend in the design of potential delivery systems, and pH-sensitive carriers, one of their methods, have been designed to control their systems. In addition, the use of targeting peptides or other specific groups that direct the drug/bioactive compounds to specific organs is an important trend in the search for better drug delivery systems. Recent examples have been given in the literature, showing that gene delivery as another important peptide dendrimer application. It is worth emphasizing that some peptide dendrimers show activity per se, without bioactive compounds. Immune compounds and vaccines are presented herein, as well as uses of other peptide dendrimers are briefly discussed in this review, which encompasses around 10 years of work.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-14T07:00:00Z
      DOI: 10.1139/cjc-2017-0242
       
  • Exploring the in vivo toxicity of nanoparticles
    • Authors: L. Romero-Castillo, I. Posadas, V. Ceña
      Pages: 917 - 926
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 917-926, September 2017.
      Toxicological tests of a xenobiotic play a key role to determine the safety of the new compound before it reaches the market. In this review article, we describe the main types of toxicological studies that can be performed in vivo to detect a possible undesired effect of a xenobiotic with especial emphasis on the data available for the different types of nanoparticles. The different procedures described in this review allow to obtain valuable information about the possible toxic effects of a xenobiotic to minimize the possible risks for patients once the compound has been approved for therapeutic use.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-21T07:00:00Z
      DOI: 10.1139/cjc-2017-0203
       
  • Accelerated hydrolysis of boronic acid in a modified poly(amidoamine)
           dendrimer: identification of a factor leading to the production of an
           impurity in boronic acid containing poly(amidoamine) dendrimers
    • Authors: Ching-Hua Tsai, Yu-Wen Fang, Hui-Ting Chen, Chai-Lin Kao
      Pages: 984 - 990
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 984-990, September 2017.
      The preparation of boronic acid containing dendrimers is still a difficult task in dendrimer chemistry. In this investigation, an unanticipated hydrolysis product (4) was identified during the preparation of (G:2)-PAMAM-dendri-(4-phenyl boronic acid)14 (3) by acquiring its 1H NMR, 13C NMR, and UV–vis absorption spectra and IR spectra and comparing them with those of 4-hydroxylbenzoic acid (5). Furthermore, an Alizarin Red S staining analysis, ICP-MS, and 11B NMR spectrum indicated the lack of boronic acid in 4. Finally, treatment of 3 with hydrogen peroxide gave a product that was determined to be identical to dendrimer 4. By analyzing the formation of 4 under various conditions, the presence of numerous primary amines in a PAMAM dendrimer did accelerate the hydrolysis of peripheral boronic acid. This investigation revealed an apparent intrinsic problem that needs to be overcome during the preparation of boronic acid containing dendrimers and related boronic acid containing macromolecules.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-06-14T07:00:00Z
      DOI: 10.1139/cjc-2017-0209
       
  • PAMAM dendrimer: a pH-controlled nanosponge
    • Authors: Prabal K. Maiti
      Pages: 991 - 998
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 991-998, September 2017.
      Using fully atomistic molecular dynamics simulation that are several hundred nanoseconds long, we demonstrate the pH-controlled sponge action of PAMAM dendrimer. We show how at varying pH levels, the PAMAM dendrimer acts as a wet sponge; at neutral or low pH levels, the dendrimer expands noticeably and the interior of the dendrimer opens up to host several hundreds to thousands of water molecules depending on the generation number. Increasing the pH (i.e., going from low pH to high pH) leads to the collapse of the dendrimer size, thereby expelling the inner water, which mimics the ‘sponge’ action. As the dendrimer size swells up at a neutral pH or low pH due to the electrostatic repulsion between the primary and tertiary amines that are protonated at this pH, there is dramatic increase in the available solvent accessible surface area (SASA), as well as solvent accessible volume (SAV).
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-06-19T07:00:00Z
      DOI: 10.1139/cjc-2017-0244
       
  • Improved carbon dioxide storage over clay-supported perhydroxylated
           glucodendrimer
    • Authors: Saadia Nousir, Gerlainde Yemelong, Sameh Bouguedoura, Yoann M. Chabre, Tze Chieh Shiao, René Roy, Abdelkrim Azzouz
      Pages: 999 - 1007
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 999-1007, September 2017.
      Low-cost biosourced hybrid microporous adsorbents with improved affinity towards carbon dioxyde (CO2) were prepared through the incorporation of various amounts of glucosylated dendrimer into bentonite- and montmorillonite-rich composite materials. Characterization by nitrogen adsorption–desorption isotherms, surface specific and pore size analyses (BET and BJH), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) revealed changes in the interlayer spacing and textural structure of the materials. Thermal programmed desorption measurements (TPD) showed significant improvements of the retention capacity of CO2 (CRC) and water (WRC). This was explained in terms of enhancement of both surface basicity and hydrophilic character due to the incorporation of terminal polyhydroxyl groups. The CRC was found to vary according to the previous saturation time with CO2 and the carrier gas throughput. CO2 was totally released upon temperature not exceeding 80 °C or even at room temperature upon strong carrier gas stream, thus providing evidence that CO2 capture involves almost exclusively physical interaction with the OH groups of the dendrimer. This result opens promising prospects for the reversible capture of carbon dioxide with easy release without thermal regeneration, more particularly when extending this concept to biosourced dendrimers.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-06-20T07:00:00Z
      DOI: 10.1139/cjc-2017-0219
       
  • Convergent dendrimer synthesis by olefin metathesis and studies toward
           glycoconjugation
    • Authors: Roberto Guizzardi, Mattia Vacchini, Carlo Santambrogio, Laura Cipolla
      Pages: 1008 - 1012
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 1008-1012, September 2017.
      The synthesis of novel hyperbranched monodisperse linear dendrimers, based on 2,2-bis-(hydroxymethyl)-propionic acid (bis-MPA), has been achieved by convergent metathesis-mediated coupling between the alkene-terminated focal point of bis-MPA dendrons. On their surface, dendrimers present 4, 8 and 16 functional groups. Glycodendrimers exposing multiple saccharide moieties have also been obtained. To the best of our knowledge, this is the first example of the use of metathesis for focal point coupling.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0146
       
  • Intramolecular energy transfer and photoisomerization in stilbene
           dendrimers
    • Authors: Masahiro Taima, Yuka Ishida, Tatsuo Arai
      Pages: 1013 - 1023
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 9, Page 1013-1023, September 2017.
      Stilbene dendrimers with energy harvesting chromophores, such as naphthalene and benzophenone, have been prepared and their photochemical and photophysical properties have been examined. These dendrimers underwent trans–cis mutual photoisomerization on excitation of the core stilbene or the peripheral naphthalene and benzophenone chromophores through several energy transfer processes, and photophysical processes such as intersystem crossing finally resulted in cis-trans isomerization of the core stilbene.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-25T07:00:00Z
      DOI: 10.1139/cjc-2017-0137
       
  • Application of sequential proline-catalyzed α-chlorination and aldol
           reactions in the total synthesis of 1-deoxygalactonojirimycin
    • Authors: Michael Meanwell, Mathew Sutherland, Robert Britton
      Pages: 1 - 4
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A short enantioselective total synthesis of 1-deoxygalactonojirimycin (migalastat) has been achieved that does not rely on chiral pool starting materials or biocatalysis. Instead, this synthesis exploits a one-pot proline-catalyzed α-chlorination and aldol reaction of a commercially available aldehyde to assemble the entire carbon skeleton in a single step. The key role played by a nitrogen protecting group in the final epoxide opening reaction is highlighted as is the amenability to access structural analogues using this route.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-14T06:46:17Z
      DOI: 10.1139/cjc-2017-0318
       
  • Erratum: Nano-rod ZnO as a novel and reusable catalyst for C−P bond
           formation and hydrophosphonation of isatin derivatives under solvent-free
           conditions
    • Authors: Mona Hosseini-Sarvari, Mina Tavakolian
      Pages: 1 - 1
      Abstract: Canadian Journal of Chemistry, e-First Articles.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-11T06:28:56Z
      DOI: 10.1139/cjc-2016-0520
       
  • Bonding properties of FCC-like Au44(SR)28 clusters from X-ray absorption
           spectroscopy
    • Authors: Rui Yang, Daniel M. Chevrier, Chenjie Zeng, Rongchao Jin, Peng Zhang
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Thiolate-protected gold clusters with precisely controlled atomic composition have recently emerged as promising candidates for a variety of applications because of their unique optical, electronic, and catalytic properties. The recent discovery of the Au44(SR)28 total structure is considered as an interesting finding in terms of the face-centered cubic (FCC)-like core structure in small gold-thiolate clusters. Herein, the unique bonding properties of Au44(SR)28 is analyzed using temperature-dependent X-ray absorption spectroscopy (XAS) measurements at the Au L3-edge and compared with other FCC-like clusters such as Au36(SR)24 and Au28(SR)20. A negative thermal expansion was detected for the Au–Au bonds of the metal core (the first Au–Au shell) and was interpreted based on the unique Au core structure consisting of the Au4 units. EXAFS fitting results from Au28(SR)20, Au36(SR)24, and Au44(SR)28 show a size-dependent negative thermal expansion behavior in the first Au–Au shell, further highlighting the importance of the Au4 units in determining the Au core bonding properties and shedding light on the growth mechanism of these FCC-like Au clusters.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0169
       
  • Efficient and selective iron-mediated reductive Claisen rearrangement of
           propargyloxyanthraquinones to anthrafurandiones in ionic liquids
    • Authors: Samaneh Nadali, Ghasem Aghapour, Zahra Rafieepour
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      An efficient and rapid method is described for the reductive Claisen rearrangement of different propargyloxyanthraquinones to anthra[1,2-b]furan-6,11-diones for first time using iron powder in a mixture of two ionic liquids, namely 1-methylimidazolium tetrafluoroborate [Hmim]BF4 and 1-benzyl-3-methylimidazolium chloride [Bzmim]Cl. The present method is able to execute single or double Claisen rearrangements of 1,4- or 1,5-bispropargyloxyanthraquinones selectively, so that the desired anthra(mono)furandiones or anthra(bis)furandiones are produced, respectively, as the major product.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-08T02:33:39Z
      DOI: 10.1139/cjc-2017-0328
       
  • Pressure-selected reactivity between 2-butyne and water induced by
           two-photon excitation
    • Authors: Jiwen Guan, Roshan Daljeet, Yang Song
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      High-pressure photochemistry between 2-butyne (H3CC≡CCH3) and trace amount of H2O was investigated at room temperature using multiline UV radiation at λ ≈ 350 nm and monitored by FTIR spectroscopy. Instead of the expected polymerization of 2-butyne, the IR spectral analysis suggests the formation of cis- and trans-2-butene, as well as 2-butanone, as the primary products. The possible reaction mechanisms and production pathways of these products were examined, where the dissociation of water molecule as the other reactant is believed as the essential step of the photochemical reaction. We further found that initial loading pressure of the mixture can not only substantially influence the reaction kinetics, but also regulate the accessibilities to some reaction channels, which was evidenced by quantitative analysis of the characteristic IR bands of 2-butene and 2-butanone. The relative abundance of two products is found to be highly dependent on pressure and radiation time. This study provides attractive physical routes in the absence of solvents, catalysts, and radical initiators, to synthesis the relevant products with a great selectivity and feasibility.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-28T07:00:00Z
      DOI: 10.1139/cjc-2017-0155
       
  • optPBE-vdW density functional theory study of liquid water and
           pressure-induced structural evolution in ice Ih
    • Authors: Xue Yong, John S. Tse, Niall J. English
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The accuracy of several local and non-local van der Waals (vdW) corrected exchange correlation functionals on the description of the effect of pressure on ice has been investigated. In a preliminary survey, the non-local vdW correction used in conjunction with the optPBE functional was shown to provide the best overall agreement on the structural parameters of ice Ih with experiments. More importantly, this combination reproduced correctly the recently observed crystal → crystal transformation in ice Ih at 80 K prior to amorphisation. The predicted transition pressure of 1.9 GPa is somewhat higher, showing that the current generation of vdW functionals are still not sufficiently accurate for the ice system. The existence of an intermediate crystalline state with a shear-hexagonal structure confirms the earlier prediction that the collapse of crystalline structure under compression originates from the softening of phonon modes in ice Ih’s basal plane.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-28T07:00:00Z
      DOI: 10.1139/cjc-2017-0201
       
  • From HCOOH to CO on Pd catalyst: theoretical study
    • Authors: Yingying Wang, Zijiao Chen
      Pages: 1 - 4
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The present theoretical and experimental results in the literature for formic acid (HCOOH) oxidation into CO on Pd(111) cannot rationalize the well-known, easy CO poisoning. The present study reexamines HCOOH oxidation on Pd(111) by performing density functional theory calculations. Upon a thorough search, we present a new adsorption configuration of HCOOH on Pd(111). From the calculated energy pathway, we proposed that CO arises from the reduction of the hydrogenation product CO2 and direct dehydration of formic acid during HCOOH oxidation on Pd(111), with latter step being energetically easier. The present theoretical study rationalizes the early experimental findings and provides insights into the deactivation problem of Pd catalyst in the process of HCOOH oxidation.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-27T07:00:00Z
      DOI: 10.1139/cjc-2017-0266
       
  • Simulating the phase II metabolism of raloxifene on a screen-printed
           electrode
    • Authors: Rafaela Vasiliadou, Kevin J. Welham
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Raloxifene (RLX) is a selective estrogen receptor modulator widely used for the treatment of osteoporosis in post-menopause women. Toxicological in vitro studies suggested the reactivity of RLX through phase I metabolism. Herein, we describe a simple and inexpensive method for monitoring the reactive metabolism and detoxification of RLX by electrochemistry (EC) and mass spectrometry (MS). The phase I metabolite was synthesized electrochemically on a screen-printed electrode (SPE) and subsequently reacted with glutathione (GSH). The resulted GSH-adducts and GSH disulfides were characterized off-line by electrospray ionization (ESI)–MS.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-27T07:00:00Z
      DOI: 10.1139/cjc-2017-0279
       
  • Investigating the cheletropic reaction between sulfur dioxide and
           butadiene-containing linkers in UiO-66
    • Authors: Jinfeng Zhang, Jared B. DeCoste, Michael J. Katz
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      UiO-66 and a muconic acid functionalized derivative of UiO-66 (UiO-66-MA) were synthesized via the solvothermal method to determine if the muconic acid could undergo a cheletropic reaction in the presence of sulfur dioxide inside the metal-organic framework (MOF). Both MOFs were exposed to a constant flow of sulfur dioxide, and UiO-66-MA was observed to take up three times more sulfur dioxide than unfunctionalized UiO-66. Despite the improved uptake of sulfur dioxide in UiO-66-MA, NMR and IR data indicate that no chemical change occurred to the muconic acid indicating that a cheletropic reaction did not occur. We thus propose that the increased adsorption is due to either an interaction between the sulfur dioxide and unbound carboxylic acid from the muconic acid or a favourable interaction between the butadiene of muconic acid and sulfur dioxide.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-25T07:00:00Z
      DOI: 10.1139/cjc-2017-0306
       
  • Palladium stabilized on poly and mono sulfonamide ligands as novel,
           simple, effective, and recyclable nano catalysts for C–C cross-coupling
           reactions
    • Authors: Ramin Ghorbani-Vaghei, Narges Sarmast
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Poly and mono sulfonamide ligands were successfully used for the stabilization of palladium nanoparticles. The prepared nano catalysts that appeared to be heterogeneous and novel were characterized with various analytical tools. To establish the catalytic activity of the prepared catalysts, they were used in the Suzuki–Miyaura and Sonogashira–Hagihara coupling reactions of aryl halides under low palladium loading conditions. The catalysts showed good stability and could be recovered and reused for seven reaction cycles without significant loss of catalytic activity.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-25T07:00:00Z
      DOI: 10.1139/cjc-2017-0353
       
  • One-dimensional hydroxyapatite materials: preparation and applications
    • Authors: Bing-Qiang Lu, Ying-Jie Zhu
      Pages: 1 - 12
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      As one of the biominerals, hydroxyapatite (HAP) plays important roles in biology, and inspires researchers to investigate HAP-based materials for the applications in various biomedical fields. Among them, one-dimensional (1-D) micro-/nanostructured HAP materials have attracted great interest in the last decades. This review summarizes the preparation and applications of 1-D HAP materials, and discusses different aspects of 1-D HAP materials. Various synthetic methods have been developed to prepare 1-D HAP materials with different morphologies, sizes, surface properties and crystallinities. In addition, elements-substituted 1-D HAP materials and composites have also been prepared. Surfactants and additives are usually adopted to control the nucleation and growth of 1-D HAP materials, but the related mechanisms are not very clear yet. The applications of 1-D HAP materials have been widely investigated, and the biomedical applications show great prospect but still need further improvements. A new kind of highly flexible fire-resistant inorganic paper made of ultralong HAP nanowires has been developed and is a promising alternative of the traditional cellulose paper for valuable archives and important documents. Regardless of the advances, further studies should be made for preparing 1-D HAP materials with controlled structures, sizes and morphologies and for boosting their various applications.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-24T06:29:14Z
      DOI: 10.1139/cjc-2017-0144
       
  • Electronic energy pooling in organic systems: a cross-disciplinary
           tutorial review
    • Authors: Ronald P. Steer
      Pages: 1 - 16
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Electronic energy pooling via excited state (exciton) annihilation, primarily in organic systems, is reviewed in tutorial form. Cross-disciplinary terminologies and references are used and reference is made to the historical origins of the phenomena. Applications in organic photovoltaic and electroluminescent devices are addressed. Particular attention is paid to the kinetics of the processes involved; a standard format for all systems is developed. Within the organic materials framework, all triplet–triplet, triplet–singlet, and singlet–singlet annihilation processes are discussed. Examples from gas, liquid, and solid phase systems, including both homo- and hetero-species interactions, are employed. Particular attention is given to triplet–triplet annihilation processes in which product states other than the lowest excited singlet state are formed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-21T07:00:00Z
      DOI: 10.1139/cjc-2017-0369
       
  • An affinity-based probe for methyltransferase enzymes based on sinefungin
    • Authors: Matthew A. Lafreniere, Geneviève F. Desrochers, Kedous Mekbib, John Paul Pezacki
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Epigenetics control numerous cellular processes such as gene transcription, signal transduction, and protein stabilization. An understanding of epigenetic mechanisms can lead to the development of therapeutic agents for various diseases. Herein, we report the design and synthesis of a sinefungin affinity-probe (BpyneSF) that targets methyltranferase enzymes and proteins involved in recognition of methylation. This probe contains a bioorthogonal alkyne residue for conjugation using the copper-catalyzed azide–alkyne cycloaddition and a photoactivatable crosslinker group for covalent attachment of the probe to its proteomic targets. We investigate the efficiency and selectivity of the probe to inhibit and label methyltransferase enzymes, and we demonstrate, through in-gel fluorescence, on-bead digestion, and tandem mass spectrometry, that BpyneSF can label methyltransferase SETD2 and reader proteins in vitro. These results establish the utility of BpyneSF as a tool for affinity-based protein profiling in complex biological environments.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-20T07:00:00Z
      DOI: 10.1139/cjc-2017-0168
       
  • The impact of molecular symmetry and shape on the stability of discotic
           liquid crystals
    • Authors: Emilie Voisin, Vance E. Williams
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Three series of dibenzo[a,c]phenazines were prepared in an order to assess the impact of side chain position on the phase stability of columnar liquid crystals. Each series was composed of four isomeric compounds differing only in the disposition of hexyloxy and decyloxy chains around the central aromatic core, giving rise to electronically similar compounds with varying shapes and symmetries. The substitution pattern was found to have a moderate effect on the clearing transition of the liquid crystal but a larger impact on the melting temperatures. These observations suggest a viable strategy for controlling the phase range of liquid crystals via judicious choice of peripheral chain structure and location.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0317
       
  • Fukushima-derived radioactivity measurements in Pacific salmon and soil
           samples collected in British Columbia, Canada
    • Authors: Thomas Domingo, Krzysztof Starosta, Aaron Chester, Jonathan Williams, Sarah J. Lehnert, Nikolaus Gantner, Juan José Alava
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Despite the many studies that have shown minimal health risks to individuals living outside of Japan following the Fukushima Nuclear Accident, there are persisting concerns regarding the consumption of Pacific seafood that may be contaminated with radioactive species from Fukushima. To address these concerns, the activity concentrations of anthropogenic 134Cs and 137Cs, as well as naturally occurring 40K, were measured in Pacific salmon collected from Kilby Provincial Park, British Columbia (BC), in 2013 and from the Quesnel River, BC, in 2014 using low-background gamma-ray spectroscopy. In addition, soil samples and a single roof-debris sample were collected and analysed to provide a record of Fukushima-derived contamination in BC. Cesium-134 was not detected in the salmon samples. Cesium-137 was not detected in any of the sockeye or chum samples, although it was detected in all of the Chinook samples. The weighted average (±1σ) 137Cs activity concentration in the Chinook salmon collected in 2013 and 2014 was 0.23 (3) and 0.20 (3) Bq/kg fresh weight, respectively. A conservative annual dose estimate for an adult who consumes the average Canadian quantity of seafood per year, contaminated with radiocesium at the maximum concentrations measured in this campaign, was calculated to be 0.054 μSv per year. Cesium-134 was detected in all but two of the soil samples. A weak positive correlation was observed between presence of 134Cs and of 7Be suggesting that the 134Cs arrived via atmospheric deposition. Cesium-137 was present in every soil sample, although the total radiocesium activity concentrations measured were significantly less than action levels set by Health Canada.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0272
       
  • Anharmonic effect of the rate constant of the reactions of CH3SCH2OO
           system in high-temperature combustion
    • Authors: Yu Hao, Xinxiang Pan, Liguo Song, Yang Ding, Wenwen Xia, Shiye Wang, Hongjing Yu, Liqiang Kang, Li Yao
      Pages: 1 - 9
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The study mainly focuses on the anharmonic effect of the reactions of CH3SCH2OO system. The geometries of the reactants and the transition states are optimized with Gaussian 09. The barrier heights are calculated with the energy of the reactants and the transition states. The RRKM theory is utilized to calculate the anharmonic and harmonic rate constants of the reactions. The anharmonic effect of these reactions can be clearly demonstrated by our results. Generally speaking, in the study, for most reactions, the rate constants increase with the temperature in the canonical case and the total energy in the microcanonical case, and the anharmonic effect of these reactions is significant and should not be neglected in high-temperature combustion. In CH3SCH2OO system, CH3SCH2OO → CH2SCH2OOH → CH2S + CH2O + OH is the main reaction channel. After a series of calculations, the anharmonic effect is remarkable, especially in high-temperature combustion. By analyzing other meaningful reactions that followed that channel above, the anharmonic effect of these reactions is generally obvious enough, especially for those reactions whose barrier heights are relatively low.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0216
       
  • Rh(III)-catalyzed oxidative ortho-C–H alkylation of
           2,4-diarylquinazoline with potassium alkyltrifluoroborates
    • Authors: Wei Gao, Chun Gong, Qin Yang, Jianjun Yuan, Linchu Xu, Yiyuan Peng
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Alkyltrifluoroborates were used for Rh(III)-catalyzed ortho-alkylation of 2,4-disubstituted quinazoline via C–H bond activation. The reaction proceeded well with a broad substrate scope, providing a direct way to access high functional quinazoline core structure derivatives in yields up to 95%.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0258
       
  • Syntheses, characterization, and electrochemical behavior of alkylated
           2-(2′-quinolylbenzimidazole) complexes of rhenium (I)
    • Authors: Samuel S. Hanson, Jeffrey J. Warren
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A series of ClRe(CO)3-containing complexes with 1-methyl-1H-benzo[d]imidazol-2-yl)quinoline (Me-QuBIm), 1-benzyl-1H-benzo[d]imidazol-2-yl)quinoline (Bn-QuBIm), and 2-(1-(4-methoxybenzyl)-1H-benzo[d]imidazol-2-yl)quinoline (OMeBn-QuBIm) ligands were prepared and characterized. Each complex was characterized using 1H and 13C NMR, infrared, UV–vis, and fluorescence spectroscopies, and cyclic voltammetry. The physical properties of each complex are similar to the parent ClRe(CO)3(2-(1H-benzo[d]imidazol-2-yl)quinoline) complex. However, the electrochemical behavior is distinct from the parent, showing reversible voltammograms and poor CO2 reduction activity. Addition of K+ or Mg2+ as Lewis acids modestly increases catalytic currents, but at large overpotentials. The work presented here is consistent with a mechanism that involves rhenium reduction and deprotonation of imidazole and benzimidazole prior to CO2 reduction electrocatalysis.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0320
       
  • Exploration of the 150 cavity and the role of serendipity in the discovery
           of inhibitors of influenza virus A neuraminidase
    • Authors: Sankar Mohan, B. Mario Pinto
      Pages: 1 - 11
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Influenza pandemics are an ongoing threat for the human population, as the avian influenza viruses H5N1 and H7N9 continue to circulate in the bird population and the chance of avian to human transmission increases. Neuraminidase, a glycoprotein located on the surface of the influenza virus, plays a crucial role in the viral replication process and, hence, has proven to be a useful target enzyme for the treatment of influenza infections. The discovery that certain subtypes of influenza neuraminidase have an additional cavity, the 150 cavity, near the substrate binding site has triggered considerable interest in the design of influenza inhibitors that exploit this feature. Currently available antiviral drugs, neuraminidase inhibitors oseltamivir and zanamivir, were designed using crystal structures predating this discovery by some years. This mini review is aimed at summarizing our group’s efforts, together with related work from other groups, on neuraminidase inhibitors that are designed to exploit both the catalytic site and the 150 cavity. The design of a parent scaffold that yields a potent inhibitor that is active in cell culture assays and retains activity against several neuraminidases from mutant strains is also described. Finally, the role of serendipity in the discovery of a new class of potent neuraminidase inhibitors with a novel spirolactam scaffold is also highlighted.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0343
       
  • XEOL spectroscopy of lanthanides in aqueous solution
    • Authors: Astrid Jürgensen
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      As part of an ongoing study of the electronic interactions between solute and solvent molecules, a method for X-ray excited optical luminescence (XEOL) analysis of aqueous solutions was developed at the double-crystal monochromator beamline (DCM) of the Canadian Synchrotron Radiation Facility (CSRF). It was tested using a series of solutions containing lanthanide ions. The samples were contained in a sample holder for liquids with a 3 μm Mylar window separating them from the vacuum (≤3 × 10−6 torr, 1 torr = 133.3224 Pa) in the solid state absorption chamber of the DCM beamline. Terbium, samarium, and dysprosium have 4 intense and narrow luminescence peaks between 450 and 700 nm, well separated from the luminescence peak of the Mylar window between 300 and 425 nm. The intensity of the rare earth (RE3+) luminescence peaks was lower for the solutions than for solid RECl3·6H2O. In part, this was caused by the lower RE3+ concentration in the solutions than in the solid. In addition, the solvent (water) acts as a quencher. The disorder and the molecular motion in the solution increase the availability of nonradiative de-excitation pathways. A high concentration of SO42− in the solution enhanced the luminescence intensity, probably by inhibiting some nonradiative de-excitation pathways. This study has shown that it is in principle possible to investigate the luminescence of aqueous solutions with XEOL spectroscopy. Furthermore, it is possible to use this technique as a quantitative analytical tool for concentrated luminescent solutions and to study the shielding effects of anions in the solution that increase the luminescence intensity.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-13T12:32:12Z
      DOI: 10.1139/cjc-2017-0038
       
  • Synthesis, characterization, and application of palladium complexes
           containing bis(aminophosphine) ligands
    • Authors: Christina Jones, Matthew Timm, Jason D. Masuda, Aibing Xia
      Pages: 1 - 4
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Two palladium complexes containing bis(aminophosphine) ligands have been prepared and characterized. Their solid structures were determined by X-ray single crystal diffraction studies. They were successfully employed in the Suzuki coupling reactions of phenylboronic acid and various aryl chlorides.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-13T07:00:00Z
      DOI: 10.1139/cjc-2017-0349
       
  • Octahedral Co(III) salen complexes: the role of peripheral ligand
           electronics on axial ligand release upon reduction
    • Authors: Chen Zhang, Mathew Sutherland, Khrystyna Herasymchuk, Ryan M. Clarke, John R. Thompson, Linus Chiang, Charles J. Walsby, Tim Storr
      Pages: 1 - 9
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A series of octahedral CoIII salen complexes (where salen represents a N2O2 bis-Schiff-base bis-phenolate framework) were prepared with axial imidazole ligating groups. When using 1-methylimidazole (1-MeIm) axial ligands, the CoIII/CoII reduction potential could be altered by 220 mV via variation of the electron-donating ability of the para-ring substituents (R = H (1), OMe (2), tBu (3), Br (4), NO2 (5), and CF3 (6)). In addition, the irreversibility of the reduction process suggested substantial geometrical changes and axial ligand exchange upon reduction to the more labile CoII oxidation state. Installing an imidazole-coumarin conjugate as the axial ligands resulted in fluorescence quenching when bound to the CoIII centre (R = H (7), OMe (8), and CF3 (9)). The redox properties and fluorescence increase upon ligand release for 7–9 were studied under reducing conditions and in the presence of excess competing ligand (1-MeIm). It was determined that the Lewis acidity of the CoIII centre was the dominant factor in controlling axial ligand exchange for this series of complexes.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-07-04T07:00:00Z
      DOI: 10.1139/cjc-2017-0277
       
  • “Onion peel” glycodendrimer syntheses using mixed triazine and
           cyclotriphosphazene scaffolds
    • Authors: Rahul S. Bagul, Maryam M. Hosseini, Tze Chieh Shiao, René Roy
      Pages: 1 - 9
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      An expeditious synthetic protocol for the construction of glycodendrimers is illustrated using the newly discovered “onion peel” strategy. The onion peel approach and orthogonal coupling strategies were accomplished with rationally design sequential modifications of cyanuric acid. Carefully chosen building blocks and their effective attachment by chemoselective atom economical click reactions, namely Cu (I) azide–alkyne cycloaddition reaction (CuAAC) and photocatalyzed thiol-ene reaction (TEC), allowed rapid build-up of glycodendrimers in contrast to traditional dendrimers syntheses that are based on the repetitive use of identical building blocks to form each layer. The newly formed glycodendrimers were evaluated for their capacity to cross-link carbohydrate-lectin interactions using dynamic light scattering (DLS). Rapid increase in particle size was observed as a function of time when compared to their monomer counterparts resulting from the multivalent lectin cross-linking ability of the new glycodendrimers.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0220
       
  • Radiation chemistry of molecular compounds and polymers by soft X-ray
           spectroscopy and microscopy
    • Authors: Jianjun Yang, Jian Wang
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Soft X-ray-induced radiation chemistry in selected Fe molecular compounds and some aliphatic polymers was studied using soft X-ray absorption spectroscopy, and scanning transmission X-ray microscopy. X-ray absorption near-edge structure (XANES) spectroscopy was used to elucidate the radiation chemistry. The results show that damage to the Fe molecular complexes involves Fe-ligand bond breaking, ligand damage, and subsequent photoreduction of Fe(III) if it is not tightly bonded to oxygen. Upon radiation damage, polymer PAN primarily undergoes chemical structure changes without mass loss, PECA experiences chemical structure changes as well as small mass loss, while PPC and PEC suffer large mass loss with chemical structure changes. These studies are not only important to X-ray analysis of radiation sensitive materials but also are valuable to the applications of X-ray lithography and other types of nanofabrication involving photoresist.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0140
       
  • Easy but not straightforward: base and solvent effect on the synthesis of
           luminescent europium 1,3-di(thien-2-yl)propane-1,3-dionate coordination
           complexes
    • Authors: Lidia Armelao, Alice Carlotto, Federica Mian, Jacopo Tessarolo, Gregorio Bottaro, Marzio Rancan
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Reaction between EuCl3 and the ligand 1,3-di(thien-2-yl)propane-1,3-dione (L) leads to luminescent coordination compounds [EuL3(EtOH)2] (1), [EuL2(i-PrOH)4]Cl (2) and [EuL3(i-PrOH)2] (3), isolated as single crystals in high yield (70%–95%). The Eu/β-diketonate ratio is tuned from 1:2 to 1:3 through the variation of the alcoholic solvent (ethanol and isopropanol) or the base (pyridine and NaOH). In all compounds, Eu3+ ions are eight-coordinated, and in 2, the molecules are arranged in an H-bond supported supramolecular 1D chain. These compositional and structural differences are reflected also on the absorption and emission properties.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0200
       
  • High-performance reduced graphene oxide – red phosphorous composites
           anodes for lithium batteries and soft X-ray near-edge structure studies
    • Authors: Dongniu Wang, Lucia Zuin, David Muir
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A solution method was developed to synthesize reduced graphene oxide (RGO) – red phosphorous (RP) composites. The uniform distribution of RP particles into three-dimensional conductive RGO network was obtained. Due to both improved electronic structure and mechanical properties, the hybrids delivered a high lithium storage capacity with superior rate performance. For the first time, the electronic structure, as revealed by phosphorous (P) L-edge and lithium (Li) K-edge X-ray absorption near-edge structure (XANES), provides spectroscopic evidence to identify the lithiated products and solid electrolyte interphase. Charge distribution in between RP and RGO was also found by XANES, facilitating the anchoring of active RP into RGO surface.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-24T07:00:00Z
      DOI: 10.1139/cjc-2017-0121
       
  • Successive outermost-to-core shell directionality of the protonation of
           poly(propyl ether imine) dendritic gene delivery vectors
    • Authors: Abirami Lakshminarayanan, Narayanaswamy Jayaraman
      Pages: 1 - 10
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The protonation behaviour of polycationic compounds has direct relevance to their ability to condense and deliver nucleic acids. This report pertains to a study of the protonation behaviour of polycationic poly(propyl ether imine) (PETIM) dendritic gene delivery vectors that are constituted with tertiary amine core moiety and branch sites, n-propyl ether linkages, and primary amine peripheries. The ability of this series of dendrimers to condense nucleic acids and mediate endosomal escape was studied by unravelling the protonation behaviour of the dendrimers aided by pH metric titrations and 1H and 15N NMR spectroscopies. The results demonstrate protonation of the primary and tertiary amines of outermost-to-core shells occurring in a successive stepwise fashion, in contrast to other polycationic vectors. Theoretical calculations based on the Ising model rationalize further the finer details of protonation at each shell. The protonation pattern correlates with the endosomal buffering and nucleic acid condensation properties of this PETIM-based dendritic gene delivery vectors. The study establishes that the protonation behaviour is a critical and essential parameter to assess the gene condensation and delivery vector properties of a polycationic compound.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-24T07:00:00Z
      DOI: 10.1139/cjc-2017-0153
       
  • Investigation of amorphous to crystalline phase transition of sodium
           titanate by X-ray absorption spectroscopy and scanning transmission X-ray
           microscopy
    • Authors: Jian Liu, Biqiong Wang, Mohammad N. Banis, Zhiqiang Wang, Ruying Li, Jian Wang, Yongfeng Hu, Tsun-Kong Sham, Xueliang Sun
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Nanostructured sodium titanate has great potential for various applications such as sodium-ion batteries, photocatalysts, and waste treatment. Understanding the phase-transition mechanism in sodium titanate after annealing is fundamentally important to tune the structure, morphology, and property for targeted applications. In this work, we adopted amorphous sodium titanate grown on carbon nanotubes by an atomic layer deposition technique as a reference and used X-ray absorption spectroscopy (XAS) and scanning transmission X-ray microscopy (STXM), as well as a high-temperature in situ X-ray diffraction (XRD) technique, to elucidate the phase-transition mechanism of sodium titanate from amorphous to crystalline upon annealing from 25 °C to 900 °C. XAS and XRD analysis disclosed that anatase TiO2 first formed in the matrix of amorphous sodium titanate at 500 °C and then recrystallized into Na0.23TiO2 at 700 °C and 900 °C. XAS studies also revealed that the Ti atoms in sodium titanate were oxidized during the annealing process and reached an oxidation state about 3.8+ for Na0.23TiO2. The elevated annealing temperature increased the coordination number of Ti atoms and the crystallinity of sodium titanate. STXM chemical map provided spatial information and visualized evidence on the phase transition among amorphous sodium titanate, anatase TiO2, and Na0.23TiO2 in the samples annealed at intermediate temperatures (500 °C and 700 °C). This work provides a comprehensive understanding on the evolution of sodium titanate, in terms of crystal structure, electronic structure, chemical environment, and morphology, under different post annealing conditions.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-17T07:00:00Z
      DOI: 10.1139/cjc-2017-0132
       
  • Investigation of solvation effects on iron(II) and iron(III) salt
           solutions by X-ray absorption spectroscopy
    • Authors: Aimee Maclennan, Yongfeng Hu
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The effects of solvation on iron salts has been studied by in situ X-ray absorption spectroscopy (XAS). It was seen that the solvated iron is significantly different from the solid precursor when dissolved in a variety of common solvents. Changes in the chemical and electronic properties of the solvated species make it essential to understand what is happening in solution prior to choosing appropriate reference materials for the interpretation of X-ray absorption near edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS) data. An understanding of the complexity of analyzing liquid systems by XAS is gained from this research.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-17T07:00:00Z
      DOI: 10.1139/cjc-2017-0141
       
  • The application of XANES for the examination of silver, gold, mercury, and
           sulfur on the daguerreotype surface
    • Authors: M.S. Kozachuk, R.R. Martin, T.K. Sham, M. Robinson, A.J. Nelson
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      X-ray absorption near edge structure (XANES) spectroscopy was used to study a freshly prepared reference daguerreotype surface as the first step in devising improved methods for the conservation of these important historic artifacts. The results are consistent with the formation of alloy image particles. Interdiffusion of gold and silver has led to the development of a silver–gold alloy; the composition varies with depth. The amount of gold appeared to be elevated in the highlighted regions of the image, whereas shadow regions have lower levels of gold on the surface. The apparent increase in gold within the highlighted region may be due to the larger surface area presented by an array of small image particles. The mercury used to develop the daguerreian image showed no evidence of oxidation while a mercury–silver alloy was detected. Sulfur-based contaminants are also detected. The implications of these findings are discussed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-15T07:00:00Z
      DOI: 10.1139/cjc-2017-0062
       
  • Large-scale hollow nanoparticle identification by X-ray absorption
           spectroscopy
    • Authors: Yuanhong Tang, Zhiqiang Wang, Dongniu Wang, Jian Wang, Tsun-Kong Sham
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Large-scale SiO2 hollow nanoparticles were synthesized by a sol-gel method. The composition, morphology, and chemical bonding information of SiO2 hollow nanoparticles were studied by X-ray absorption near edge structure (XANES) and scanning transmission X-ray microscopy (STXM). XANES at the Si L-edge and K-edge reveal the characteristics of hollow nanoparticles, which are essentially amorphous SiO2 with a slightly longer Si–O bond than SiO2 nanoparticles on average and deficiencies in oxygen. Individual SiO2 hollow spheres were also examined using STXM, which provides spectromicroscopic information, as well as the absolute thickness, of the sample.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-15T07:00:00Z
      DOI: 10.1139/cjc-2017-0104
       
  • Dendrimer and dendrimer–conjugate protein complexes and protein
           coronas
    • Authors: Junjie Chen, Mark M. Banaszak Holl
      Pages: 1 - 4
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Dendrimers and dendrimer conjugates are widely employed for biological applications such as bio-imaging and drug delivery. Understanding the interaction between dendrimers and their biological environment is key to evaluating the efficacy and safety of these materials. Proteins can form an adsorbed layer, termed a “protein corona”, on dendrimers in either a non-specific or specific fashion. A tight-binding, non-exchangeable corona is defined as a “hard” corona, whereas a loosely bound, highly exchangeable corona is called a “soft” corona. Recent research indicates that small molecules conjugated to the polymer surface can induce protein structural change, leading to tighter protein–dendrimer binding and further protein aggregation. This “triggered” corona formation on dendrimer and dendrimer conjugates is reviewed and discussed along with the existing hard or soft corona model. This review describes the triggered corona model to further the understanding of protein corona formation.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-15T07:00:00Z
      DOI: 10.1139/cjc-2017-0198
       
  • PAMAM dendrimers in drug delivery: loading efficacy and polymer morphology
    • Authors: P. Chanphai, L. Bekale, S. Sanyakamdhorn, D. Agudelo, G. Bérubé, T.J. Thomas, H.A. Tajmir-Riahi
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The binding efficacy of anticancer drugs doxorubicin and tamoxifen with polyamidoamine (PAMAM-G4) dendrimers was studied in aqueous solution at physiological pH. The results of multiple spectroscopic methods, transmission electron microscopy (TEM), and molecular modeling of conjugated drug–polymer were examined. Structural analysis showed that drug–polymer conjugation occurs mainly via H-bonding and hydrophilic and hydrophobic contacts. Doxorubicin forms a more stable conjugate with PAMAM-G4 than tamoxifen. The drug loading efficacy was 40%–50%. The TEM images showed major changes in the PAMAM morphology upon drug encapsulation. Modeling showed that drug is located in the polymer surface and in the internal cavities. PAMAM nanoparticles are capable of transporting doxorubicin and tamoxifen in vitro. This minireview presents the most recent work performed with the dendrimers demonstrating their usefulness for drug delivery in cancer therapy.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-11T07:00:00Z
      DOI: 10.1139/cjc-2017-0115
       
  • Scanning transmission X-ray microscopy studies of chromium hydroxide
           hollow spheres and nanoparticles formed by gamma radiation
    • Authors: Zhiqiang Wang, Leena Alrehaily, Jiju Joseph, Jungsook Clara Wren, Jian Wang, Tsun-Kong Sham
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Amorphous chromium-containing solid nanoparticles and hollow spheres were formed as the intermediate product during the synthesis of Cr2O3 by gamma radiolysis of dichromate solution. Scanning transmission X-ray microscopy (STXM) is applied to investigate the electronic structure and chemical composition of this intermediate product (solid nanoparticles and hollow spheres). The STXM result obtained at O K-edge and Cr L3,2-edge confirms that chromium in the sample exists as Cr3+ and that the solid nanoparticles and hollow spheres are both Cr(OH)3. Combined with other techniques, a mechanism for gamma radiation induced formation of Cr2O3 nanoparticles via Cr(OH)3 intermediates from dissolved dichromate is proposed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-11T07:00:00Z
      DOI: 10.1139/cjc-2017-0142
       
  • Dendrimers for ocular drug delivery
    • Authors: Michael G. Lancina, Hu Yang
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Existing methods of administering ocular drugs are limited in either their safety or efficiency. Nanomedicine therapies have the potential to address this deficiency by creating vehicles that can control drug biodistribution. Dendrimers are synthetic polymeric nanoparticles with a unique, highly organized branching structure. In recent years, promising results using dendrimer vehicles to deliver ocular drugs through different routes of administration have been reported. In this minireview, we briefly summarize these results with emphasis on the dendrimer modifications used to target different ocular structures.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-05-11T07:00:00Z
      DOI: 10.1139/cjc-2017-0193
       
  • Defect specific luminescence dead layers in CdS and CdSe
    • Authors: R.A. Rosenberg
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      CdS and CdSe are often used in optoelectronic devices whose effectiveness may be dictated by defects in the near surface region. Luminescence is one of the main tools for studying such defects. The energy dependence of the X-ray excited optical luminescence (XEOL) spectra of these materials enables the extraction of the depth dependence of the defect distribution. Normal and time-gated XEOL spectra were obtained from these materials in the energy range 600–1500 eV. We find that the results can best be understood in terms of a luminescence dead layer whose width depends on the position of the defect level in the band gap.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-28T07:00:00Z
      DOI: 10.1139/cjc-2017-0126
       
  • Improved large-scale synthesis and characterization of small and medium
           generation PAMAM dendrimers
    • Authors: Mario Ficker, Valentina Paolucci, Jørn B. Christensen
      Pages: 1 - 11
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Dendrimers are promising polymers for biomedical applications; however, most dendrimer formulations have failed to move from laboratory science to upscaled products for preclinical testing or GMP production. This publications reports on an improved large-scale PAMAM dendrimer synthesis that is suitable to manufacture large amounts of highly pure and monodisperse dendrimers of generations G0–G5. Furthermore, an extended analytical guideline how to characterize PAMAM dendrimers with NMR, HPLC, SEC-MALS, ESI, MALDI, UV–vis, fluorescence, and IR spectroscopy is provided.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-24T07:00:00Z
      DOI: 10.1139/cjc-2017-0108
       
  • BF2 complexes of 1,3-diketones on the surface of phosphorus dendrimers:
           synthesis and study of the photoluminescence properties
    • Authors: Cédric Rouxel, Olivier Mongin, Aurélien Hameau, Armelle Ouali, Mireille Blanchard-Desce, Jean-Pierre Majoral, Anne-Marie Caminade
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Difluoroboron complexes of monomeric and dimeric diketones and of generations 0–4 of phosphorus dendrimers ended by diketone ligands are synthesized and characterized. Their photoluminescence properties are measured. All compounds exhibit an intense absorption band in the near UV region. Both model dimers and dendrimers show a marked hypsochromic shift of this absorption band compared with the monomeric difluoroboron complex. The fluorescence of the dioxaborine complex subunit in the multichromophoric dendritic architectures is quenched compared with the emission of the isolated monomeric fluorophore, presumably due to interactions between the terminal groups of dendrimers.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-19T07:00:00Z
      DOI: 10.1139/cjc-2017-0135
       
  • From optimized monovalent ligands to size-controlled dendrimers: an
           efficient strategy towards high-activity DC-SIGN antagonists
    • Authors: Stefania Ordanini, Giulio Goti, Anna Bernardi
      Pages: 1 - 10
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      This short review describes our work on the development of dendrimeric antagonists of DC-SIGN, a dendritic cells (DCs) receptor recognizing highly mannosylated structures and primarily involved in the recognition of viruses such as HIV. The structure of pseudo-di-mannoside and pseudo-tri-mannoside compounds was first finely modified to obtain DC-SIGN ligands that were more stable and selective than mannose. Their DC-SIGN affinity differences were amplified once presented on multivalent dendrimer-like scaffolds, including poly-alkyne terminated and phenylene-ethynylene rod-like ones. Libraries of mannosylated dendrimers were synthesized, improving their stability and maximizing their monodispersity. The effect of the dendrimers valency, structure, and size on DC-SIGN affinity and antiviral potency was investigated. Both the valency and the topology of the architectures were revealed as key parameters for activity optimization, together with the intrinsic affinity of the monovalent ligand. The stability, rigidity, and length of the scaffolds were also tuned. The design of geometrically adapted scaffolds afforded one of the most potent inhibitors of DC-SIGN mediated HIV infections to date. This monodispersed, not cytotoxic, and highly active compound was also tested with DCs; its internalization into endolysosomal compartments and its ability to induce the overexpression of signaling molecules makes it a good precursor to produce pathogen-entry inhibitors with immunomodulant properties.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-19T07:00:00Z
      DOI: 10.1139/cjc-2017-0138
       
  • Effect of antifouling dendrimers and Au DENPs on the enhancement of PCR
           amplification
    • Authors: Haixia Zhang, Chen Peng, Aijun Li, Xiangyang Shi, Xueyan Cao
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The polymerase chain reaction (PCR) has been considered as one of the most fundamental techniques to amplify and analyze specific DNA fragments in the field of molecular biology and clinical medicine. Recently, a variety of nanoparticles (NPs) have been regarded as a novel method to enhance both the quality and yield of PCR technique. Herein, we report the use of generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers and dendrimer-entrapped gold nanoparticles (Au DENPs) modified with polyethylene glycol (PEG) moieties and (or) acetyl groups as a novel class of enhancers to improve the PCR amplification. We set up the nonspecific PCR and two-round PCR as model systems to investigate mechanisms of enhanced PCR. Our results show that dendrimer-based derivatives seem to enhance the PCR specificity. It is worth noting that the modification of antifouling PEG significantly lowered the optimization capability of the corresponding dendrimers, although this inhibition effect can be remarkably compromised by the entrapment of Au NPs. Furthermore, we found that in the presence of Au NPs, the thermal conductivity induced by Au NPs could play the dominant role in the PCR optimization, whereas in the absence of Au NPs, the electrostatic interaction of the dendrimers with PCR components may be the major factor affecting the PCR system. Our results also showed that the optimal concentrations of the materials in the two test systems were very close, which indicates that the developed dendrimer derivatives with good thermal stability may be the efficient PCR additives for enhancing different PCR systems.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-05T07:00:00Z
      DOI: 10.1139/cjc-2017-0055
       
  • Synthesis of a poly(amidoamine) dendrimer having a
           1,10-bis(decyloxy)decane core and its use in fabrication of carbon
           nanotube/calcium carbonate hybrids through biomimetic mineralization
    • Authors: Shunichi Nishimura, Tomoyuki Tajima, Tatsuki Hasegawa, Tomoaki Tanaka, Yutaka Takaguchi, Yuya Oaki, Hiroaki Imai
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A new dendritic dispersant of carbon nanotubes (CNTs) was synthesized and applied for the noncovalent functionalization of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). The 1,10-bis(decyloxy)decane core of the poly(amidoamine) dendrimer strongly adhered to the sidewalls of CNTs to form CNT/dendrimer supramolecular nanocomposites having many carboxyl groups (–COOH) on the surface. Then, crystallization of calcium carbonate (CaCO3) by the CO2 diffusion technique in aqueous environments using the CNT/dendrimer supramolecular nanocomposites as scaffolds afforded monodisperse spherical CNT/CaCO3 nanohybrids consisting of CNTs and calcite nanocrystals. The morphologies of the SWCNT/CaCO3 hybrids and MWCNT/CaCO3 hybrids were almost the same.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-04-04T07:00:00Z
      DOI: 10.1139/cjc-2017-0022
       
  • Dye rejection membranes prepared from oxidized graphite particles
    • Authors: Anastasia Colomba, Mark C. Biesinger, Ranjith Divigalpitiya, Frank A. Brandys, Joe B. Gilroy
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      This article reports the comparison of different chemical methods to produce graphite-based particles with varying degrees of oxidation, as well as graphene oxide (GO) and pristine graphite (PG). Detailed physicochemical characterization of the resulting materials was carried out, highlighting structural differences and variable oxygen content. The particles were then used to produce supported membranes that were tested for the rejection of three different organic dyes (Rhodamine B, Methyl Blue, and Congo Red), and their performance was rationalized in terms of a combination of properties of the membranes and dyes. In particular, membranes produced using edge-oxidized graphite (EOG) showed comparable performance with those derived from GO in the removal of Congo Red, providing a promising alternative to the aforementioned membranes.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-03-27T12:56:07Z
      DOI: 10.1139/cjc-2016-0628
       
  • Strategies for penicillin V dendronization with cationic carbosilane
           dendrons and study of antibacterial properties
    • Authors: Elena Fuentes-Paniagua, José M. Hernández-Ros, Juan Soliveri, José L. Copa-Patiño, Rafael Gómez, Javier Sánchez-Nieves, F. Javier de la Mata
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Strategies to synthesize a cationic carbosilane dendron containing the antibiotic penicillin V potassium salt (PenVK) at the focal point are discussed. The preparation of such a compound requires the use of systems with no donor atoms such as N or S in their framework, because their presence favours the rupture of the penicillin β-lactam ring. The antibacterial activity of the new dendron containing ammonium groups, at the periphery, and the PenV moiety, at the focal point, against gram-positive Staphylococcus aureus strains was evaluated. These results were compared with those obtained for free PenVK, a related cationic dendron without a penicillin moiety at the focal point, and also compared with an equimolar mixture of this last dendron with free PenV. The data obtained indicate that, on one hand, the conjugation or interaction of PenV with cationic dendrons reduces its activity in comparison with free PenVK. On the other hand, the penicillin dendron is able to release the antibiotic in the presence of esterease, due to the breaking of the ester bond in this derivative.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-03-14T07:00:00Z
      DOI: 10.1139/cjc-2017-0059
       
  • Effects of polymer intercalation in calcium silicate hydrates on drug
           loading capacities and drug release kinetics: an X-ray absorption near
           edge structure study
    • Authors: Xiaoxuan Guo, Jin Wu, Yun-Mui Yiu, Yongfeng Hu, Ying-Jie Zhu, Tsun-Kong Sham
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Different calcium silicate hydrate (CSH)/polymer composites are synthesized by using a controlled precipitation reaction between calcium salt and silicate salt, followed by the addition of various polymer solutions at room temperature. X-ray absorption near edge structure (XANES) spectroscopy has been used to extensively investigate the structural changes after hybrid biomaterials formation and the drug–carrier interactions on the molecular level. We find that the polymers alter the structure of CSH to various degrees and that this behaviour further influences the drug loading capacities and drug release kinetics.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-03-08T08:00:00Z
      DOI: 10.1139/cjc-2016-0660
       
  • Impact of room temperature on pentacene thin film growth and electronic
           structure
    • Authors: Ru-Ru Ji, Qi Wang, Jia-Xin Hu, Steffen Duhm
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The electronic structure and transport properties of organic thin films depend critically on the film structure. We have shown by means of ultraviolet photoelectron spectroscopy that the growth of vacuum-sublimed pentacene on highly oriented pyrolytic graphite substrates depends significantly on the room temperature and the substrate cleanness. At T = 291 K, all molecules adopt a flat lying orientation in the contact layer to a clean (vacuum-annealed) substrate, whereas at T = 303 K, some molecules are standing upright. On defect-rich substrates, the thin films are rather disordered for both temperatures and comprise standing and lying molecules.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-03-08T08:00:00Z
      DOI: 10.1139/cjc-2017-0021
       
  • Colloidal synthesis of Pt–In bimetallic nanoparticles for propane
           dehydrogenation
    • Authors: Xuchun Wang, Di Yang, Yong Xu, Jun Zhong, Qiao Zhang
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Recently, Pt-based bimetallic nanoparticles have drawn much attention because of their great catalytic performance and wide applications in diverse fields. In this work, we report that bimetallic Pt–In nanoparticles with uniform size distribution and controllable composition can be synthesized through a one-step, facile colloidal approach. Various characterization tools such as XRD, TEM, XPS, and synchrotron techniques have been used to characterize the as-obtained nanoparticles. It is demonstrated that the Pt and In elements are homogeneously distributed in the whole nanoparticle. The bimetallic Pt–In nanoparticles have shown great catalytic performance, including high activity, high selectivity, and high stability, for the propane dehydrogenation reaction to produce propene, one of the most important chemicals. The excellent catalytic performance makes Pt–In bimetallic nanoparticles promising catalysts in future industrial application.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-03-03T08:00:00Z
      DOI: 10.1139/cjc-2017-0033
       
  • Investigation of CeTi2O6- and CaZrTi2O7-containing glass–ceramic
           composite materials
    • Authors: Elham Paknahad, Andrew P. Grosvenor
      Pages: 1 - 12
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Glass–ceramic composite materials are being investigated for numerous applications (i.e., textile, energy storage, nuclear waste immobilization applications, etc.) due to the chemical durability and flexibility of these materials. Borosilicate and Fe–Al–borosilicate glass–ceramic composites containing brannerite (CeTi2O6) or zirconolite (CaZrTi2O7) crystallites were synthesized at different annealing temperatures. The objective of this study was to understand the interaction of brannerite or zirconolite-type crystallites within the glass matrix and to investigate how the local structure of these composite materials changed with changing synthesis conditions. Powder X-ray diffraction (XRD) and Backscattered electron (BSE) microprobe images have been used to study how the ceramic crystallites dispersed in the glass matrix. X-ray absorption near edge spectroscopy (XANES) spectra were also collected from all glass–ceramic composite materials. Examination of Ti K-, Ce L3-, Zr K-, Si L2,3-, Fe K-, and Al L2,3-edge XANES spectra from the glass–ceramic composites have shown that the annealing temperature, glass composition, and the loading of the ceramic crystallites in the glass matrix can affect the local environment of the glass–ceramic composite materials. A comparison of the glass–ceramic composites containing brannerite or zirconolite crystallites has shown that similar changes in the long range and local structure of these composite materials occur when the synthesis conditions to form these materials or the composition are changed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-02-21T08:00:00Z
      DOI: 10.1139/cjc-2016-0633
       
 
 
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