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  Subjects -> CHEMISTRY (Total: 845 journals)
    - ANALYTICAL CHEMISTRY (51 journals)
    - CHEMISTRY (595 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (25 journals)
    - INORGANIC CHEMISTRY (41 journals)
    - ORGANIC CHEMISTRY (45 journals)
    - PHYSICAL CHEMISTRY (67 journals)

CHEMISTRY (595 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: 24)
ACS Medicinal Chemistry Letters     Full-text available via subscription   (Followers: 39)
ACS Nano     Full-text available via subscription   (Followers: 246)
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: 8)
Adsorption Science & Technology     Full-text available via subscription   (Followers: 5)
Advanced Functional Materials     Hybrid Journal   (Followers: 51)
Advanced Science Focus     Free   (Followers: 3)
Advances in Chemical Engineering and Science     Open Access   (Followers: 56)
Advances in Chemical Science     Open Access   (Followers: 13)
Advances in Chemistry     Open Access   (Followers: 15)
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: 16)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 9)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 21)
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: 17)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
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: 27)
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: 199)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 218)
Annales UMCS, Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
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: 310)
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: 5)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 118)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 91)
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: 4)
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: 7)
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: 14)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 72)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 24)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Full-text available via subscription   (Followers: 20)
Chemical Reviews     Full-text available via subscription   (Followers: 181)
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: 58)
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: 146)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 15)
Chemistry and Materials Research     Open Access   (Followers: 20)
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: 255)
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: 4)
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: 3)
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: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 5)
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 9)
Current Opinion in Molecular Therapeutics     Full-text available via subscription   (Followers: 17)
Current Research in Chemistry     Open Access   (Followers: 8)
Current Science     Open Access   (Followers: 61)
Dalton Transactions     Full-text available via subscription   (Followers: 23)
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: 3)
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: 3)
Environmental Chemistry     Hybrid Journal   (Followers: 7)
Environmental Chemistry Letters     Hybrid Journal   (Followers: 4)
Environmental Science & Technology Letters     Full-text available via subscription   (Followers: 5)

        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]
  • A tribute to T.K. Sham
    • Authors: G. Michael Bancroft
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 11, Page v-vi, November 2017.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-10-26T01:27:26Z
      DOI: 10.1139/cjc-2017-0530
       
  • T.K....where amazing happens
    • Authors: Robert Lamb
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 11, Page vii-vii, November 2017.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-10-26T01:27:25Z
      DOI: 10.1139/cjc-2017-0531
       
  • This special issue is dedicated to Professor T.K. Sham / Numéro spécial
           en homage aux Professor T.K. Sham
    • Abstract: Canadian Journal of Chemistry, Volume 95, Issue 11, Page iii-iii, November 2017.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-10-26T01:27:10Z
      DOI: 10.1139/cjc-2017-0483
       
  • High-loaded and transparent LaxCe1-xF3 — polystyrene nanocomposite
           scintillators for radiation detection
    • Authors: Sunil Sahi, Michael Groza, Wei Zhang, PhuongAnh Do, Rasool Kenarangui, Arnold Burger, Junying Zhang, Wei Chen
      Pages: 1233 - 1240
      Abstract: Canadian Journal of Chemistry, Volume 95, Issue 11, Page 1233-1240, November 2017.
      For radiation detection, sensitivity, response time, and energy resolution are important. Scintillating nanoparticles, in principle, can have enhanced light output in comparison with their bulk materials due to quantum size confinement and increased overlap of electron and hole wave function. However, the aggregation and the loss of transparency at high loading into polymers are the challenging issues for practical applications. Here, for the first time, we report a new method to fabricate the blue-emitting nanocomposites with up to 30 wt% nanoparticle loading. First, the polymerizable surfactant coated La0.6Ce0.4F3 nanoparticles are synthesized, and then, they are loaded up to 30 wt% in a polystyrene matrix. The nanocomposites show an intense luminescence and a good transparency, performing much better than the commercial EJ-200 plastic scintillator. The gamma spectra acquired with the nanocomposite show a photopeak for the Co-57 isotope. The gamma spectra of Cs-137 show a full energy peak at around 622 keV, due to the escape of La and Ce Kα X-rays. The observation of the photopeaks is attributed to the enhanced photoelectric effect as a result of increased effective atomic number (Zeff). All these indicate that the high loaded nanocomposites are promising for radiation detection and nuclear material surveillance for homeland security.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-10-17T07:00:00Z
      DOI: 10.1139/cjc-2017-0211
       
  • Catalytic asymmetric Friedel–Crafts synthesis of
           1,1′-diaryl-2-substituted 4-pentenes enables stereoselective access to
           functionalized tetrahydronaphthalenes
    • Authors: Étienne Chénard, Jean-Philippe Cusson, Stephen Hanessian
      Pages: 1 - 9
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A series of electron-rich arenes were reacted with 1-alkyl or 1-aryl 1′-allyl benzylic alcohols to give the corresponding 1,1′-diarylalkanes, in the presence of Lewis and Brønsted acids as catalysts. In the presence of HBF4, 1,1′-diarylalkanes containing an allylic chain were shown to form tetrahydronaphthalenes through a rearrangement involving spirocyclic intermediates. The mechanism of the cyclization is discussed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-11-10T11:50:32Z
      DOI: 10.1139/cjc-2017-0393
       
  • The bioactive lipid (S)-sebastenoic acid impacts motility and dispersion
           in Vibrio cholerae
    • Authors: Christopher J.A. Warner, Mauro Salinas, David Zamorano-Sánchez, Walter M. Bray, R. Scott Lokey, Fitnat H. Yildiz, Roger G. Linington
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Although Gram-negative bacterial pathogens continue to impart a substantial burden on global healthcare systems, much remains to be understood about aspects of basic physiology in these organisms. In recent years, cyclic-diguanylate (c-di-GMP) has emerged as a key regulator of a number of important processes related to pathogenicity, including biofilm formation, motility, and virulence. In an effort to discover chemical genetic probes for studying Vibrio cholerae we have developed a new motility-based high-throughput screen to identify compounds that modulate c-di-GMP levels. Using this new screening platform, we tested a library of microbially derived marine natural products extracts, leading to the discovery of the bioactive lipid (S)-sebastenoic acid. The evaluation of the effect of this new compound on bacterial motility, vpsL expression, and biofilm formation implied that (S)-sebastenoic acid may alter phenotypes associated to c-di-GMP signaling in V. cholerae.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-11-10T11:43:41Z
      DOI: 10.1139/cjc-2017-0334
       
  • Simultaneous determination of nifedipine and atenolol in combined dosage
           forms using a boron-doped diamond electrode with differential pulse
           voltammetry
    • Authors: Jessica Scremin, Elen Romão Sartori
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Combinations of nifedipine (NIF) and atenolol (ATN) are used for the treatment of arterial hypertension. Dosages values different from those presented on the label of pharmaceuticals can significantly impact a consumer’s health. To control the quality of the pharmaceuticals effectively, a method for the simultaneous determination of these both drugs using an anodically pretreated boron-doped diamond electrode coupled to differential pulse voltammetry technique was developed. The influence of supporting electrolyte, pH and scan rate on the current response of these both antihypertensives was examined to select the optimum experimental conditions. It was found that NIF and ATN provided two well-shaped and reproducible oxidation peaks at 0.97 V and 1.36 V (vs. Ag/AgCl electrode), respectively, in TRIS buffer solution (pH 8.0). At optimized differential pulse voltammetric parameters, the current response of NIF and ATN was proportionally linear in the concentration range of 3.98–107 μmol L–1 and 1.99–47.2 μmol L–1, with detection limit of 0.612 and 0.999 μmol L−1, respectively. The proposed method was successfully applied in analysis of several commercial combined dosage forms, whose accuracy was attested by good agreement of the results (paired t test at a 95% confidence level) with those obtained using high performance liquid chromatography.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-11-10T11:30:31Z
      DOI: 10.1139/cjc-2017-0302
       
  • Synthesis and characterization of a stable non-cyclic bis(amino)arsenium
           cation
    • Authors: Marcus Kuprat, Axel Schulz, Max Thomas, Alexander Villinger
      Pages: 1 - 11
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The reaction of Li[Mes*NH] (1, Mes* = 2,4,6-tri-tert-butylphenyl) with aminoarsane Mes*N(H)AsCl2 (2, Mes* = 2,4,6-t-Bu3C6H2) at −80 °C resulted in the formation of bisamino(chloro)arsane (Mes*NH)2AsCl (3Cl) by elimination of LiCl. 3Cl reacted with the Lewis acids such as AlCl3, GaCl3, and Ag[X] (X = AsF6−, OTf−, BF4−; OTf = trifluoromethanesulfonate = OSO2CF3−) upon chloride ion abstraction to give salts bearing the cation [(Mes*NH)2As]+ (3[X]; X = AsF6−, OTf−, BF4−, ECl4; E = Al, Ga). 3+ represents the first NH-functionalized acyclic bis(amino)arsenium cation. The formation of the salts bearing 3+ could also be observed in the reaction of cyclo-1,3-diarsa-2,4-diazane [ClAs(μ-NMes*)]2 (4) with Lewis acids (AlCl3, GaCl3) in the presence of proton sources in solution. All presented salts 3[X] were stable at room temperature and fully characterized.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-28T07:00:00Z
      DOI: 10.1139/cjc-2017-0420
       
  • An investigation of hybridization and the orbital models of molecular
           electronic structure for CH4, NH3, and H2O
    • Authors: C.E. Brion, Saul Wolfe, Zheng Shi, Glyn Cooper, Yenyou Jeff Zheng
      Pages: 1 - 9
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Observations of the physical behaviour (motions) of the valence (frontier) electrons in the iconic benchmark hydride molecules CH4, NH3, and H2O are used to provide a direct experimental evaluation of hybridization and of the localized and delocalized orbital models of molecular electronic structure, after more than 80 years since the initial proposals of these theoretical concepts. Our previously published experimental measurements of valence (frontier) electron momentum probability distributions, made by electron momentum spectroscopy (EMS), are compared with those calculated using the localized molecular orbital (LMO) model and a range of hybrid orbital models, as well as with the delocalized canonical molecular orbital (CMO) and density functional theory Kohn–Sham orbital (KSO) models. In all cases, the electron momentum probability distributions calculated with LMOs and localized hybrid orbital type models are inconsistent with the experimental observations. In contrast, those calculated with the delocalized CMOs and KSOs are in very good agreement with the experimental measurements. These findings are of importance in those research applications such as reactivity, drug and novel material design, and also in molecular electronics, where the shapes and orientations of particular valence (frontier) orbital electron density probability distributions (and not the total electron densities) are considered to be key determining factors. These findings and their implications are also of pedagogical significance in chemistry and molecular physics.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0450
       
  • An efficient, room temperature, oxygen radical anion (O2•−) mediated,
           one-pot, and multicomponent synthesis of spirooxindoles
    • Authors: Somaiah Gajaganti, Shivam Bajpai, Vandana Srivastava, Sundaram Singh
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      The present report highlights an efficient use of oxygen radical anion to promote a room temperature multi-component synthesis of spirooxindoles (4a–4l) under mild reaction conditions. The potassium superoxide (KO2) and tetraethylammonium bromide (TEAB) combination generate the oxygen radical anion in situ to promote this transformation. This method offers a sustainable and direct access to the biologically important spirooxindole derivatives in good to excellent yields.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0432
       
  • An analogy study on ESIPT reaction for 3BHC sensor between polar DMF and
           nonpolar toluene
    • Authors: Dapeng Yang, Min Jia, Jingyuan Wu, Xiaoyan Song, Qiaoli Zhang
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A comparison about excited state intramolecular proton transfer (ESIPT) mechanism of a new sensor 3-(1,3-benzothiazol-2-yl)-2-hydroxynaphthalene-1-carbaldehyde (3BHC) in polar solvent dimethylformamide (DMF) and nonpolar solvent toluene have been investigated within the framework of the time-dependent density functional theory (TD-DFT) method. The reproduced previous experimental absorption and emission spectra via our calculations reveals the reasonability of the DFT and TD-DFT theoretical level. The staple bond lengths, bond angles, and corresponding infrared vibrational spectra demonstrate that the intramolecular hydrogen bond of 3BHC should be strengthened in both polar DMF and nonpolar toluene. Two kinds of ESIPT mechanisms for different solvents have been put forward; there is a low potential barrier in the ESIPT process in the DMF solvent, whereas there is almost a nonbarrier for the ESIPT process in the toluene solvent. Hence, we could conclude that the ESIPT process of 3BHC sensor is more likely to occur in the nonpolar solvent upon the photoexcitation, based on which, the excited state behavior of 3BHC could be controlled.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-26T07:00:00Z
      DOI: 10.1139/cjc-2017-0463
       
  • Corrigendum: Analytical quantification of electrochemical ferrates for
           drinking water treatments
    • Authors: Macarena A. Cataldo Hernández, Andrew May, Arman Bonakdapour, Madjid Mohseni, David P. Wilkinson
      Pages: 1 - 1
      Abstract: Canadian Journal of Chemistry, e-First Articles.

      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-23T10:04:53Z
      DOI: 10.1139/cjc-2017-0583
       
  • Integrating regression and classification-based QSARs with molecular
           docking analyses to explore the structure-antiaromatase activity
           relationships of letrozole-based analogs
    • Authors: Nilanjan Adhikari, Sk. Abdul Amin, Tarun Jha, Shovanlal Gayen
      Pages: 1 - 11
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Aromatase is a multienzyme complex responsible for the biosynthesis of estrogen and its level has been found higher in breast cancer. Although the designing strategy of aromatase inhibitors (AIs) has continued for more than four decades, it may still be in demand to design highly effective and less toxic AIs. In this study, several chemometric approaches have been used to explore the important structural features of a series of letrozole-based analogs for their promising aromatase inhibitory activity. All techniques are statistically validated individually and in turn, validated with each other along with the structure–activity relationship (SAR) observations. The imidazole ring has been found to interact with the heme iron, whereas the triazole ring system has not shown any interaction. Moreover, imidazole function is better than 1,2,3-triazole, whereas 1,2,3-triazole is better than the 1,2,5-triazole ring system. Additionally, a bulky aryl substitution in the azole ring along with the orientation of the azole nitrogens and the cyanophenyl function has an essential role in the inhibition of aromatase. Furthermore, a cyano group substituted at the phenyl moiety interacts with Arg115, Met374, and Ser478 at the enzyme active site to form hydrogen bonding interactions. These observations are useful for designing potential AIs in the future.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0419
       
  • Genetically modified human type II collagen for N- and C-terminal covalent
           tagging
    • Authors: Andrew Wieczorek, Clara K. Chan, Suzana Kovacic, Cindy Li, Thomas Dierks, Nancy R. Forde
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Collagen is the predominant structural protein in vertebrates, where it contributes to connective tissues and the ECM; it is also widely used in biomaterials and tissue engineering. Dysfunction of this protein and its processing can lead to a wide variety of developmental disorders and connective tissue diseases. Recombinantly engineering the protein is challenging due to post-translational modifications generally required for its stability and secretion from cells. Introducing end labels into the protein is problematic, because the N- and C-termini of the physiologically relevant tropocollagen lie internal to the initially flanking N- and C-propeptide sequences. Here, we introduce mutations into human type II procollagen in a manner that addresses these concerns and purify the recombinant protein from a stably transfected HT1080 human fibrosarcoma cell line. Our approach introduces chemically addressable groups into the N- and C-telopeptide termini of tropocollagen. Simultaneous overexpression of formylglycine generating enzyme (FGE) allows the endogenous production of an aldehyde tag in a defined, substituted sequence in the N terminus of the mutated collagen, whereas the C-terminus of each chain presents a sulfhydryl group from an introduced cysteine. These modifications are designed to enable specific covalent end-labelling of collagen. We find that the doubly mutated protein folds and is secreted from cells. Higher order assembly into well-ordered collagen fibrils is demonstrated through transmission electron microscopy. Chemical tagging of thiols is successful; however, background from endogenous aldehydes present in wild-type collagen has thus far obscured the desired specific N-terminal labelling. Strategies to overcome this challenge are proposed.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0335
       
  • P-arylation of aryl halides by an environmentally compatible method
    • Authors: Sara Sobhani, Zahra Vahidi
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      In this paper, palladium–DABCO complex supported on magnetic nanoparticles was successfully used as a new magnetically recoverable heterogeneous catalyst for the synthesis of arylphosphonates via P-arylation of different types of aryl halides (aryl iodides/bromides/chlorides and benzene boronic acid/sulfonate), with phosphite esters (triethyl/triphenyl/tri-iso-propyl/diethyl/diphenyl/di-iso-propyl phosphite) in neat water without using any additive. The heterogeneous catalyst was easily isolated from the reaction mixture by an external magnet and reused five times without significant degradation in its activity.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0364
       
  • Medium effect (water versus MeCN) on reactivity and reaction pathways for
           the SNAr reaction of 1-aryloxy-2,4-dinitrobenzenes with cyclic secondary
           amines
    • Authors: Ik-Hwan Um, Min-Young Kim, Julian M. Dust
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A kinetic study on SNAr reactions of 1-aryloxy-2,4-dinitrobenzenes (1a–1h) with a series of cyclic secondary amines in 80 mol% water – 20 mol% DMSO at 25.0 ± 0.1 °C is reported. The plots of kobsd versus amine concentration curve upward except for the reactions of substrates possessing a strong electron-withdrawing group in the leaving aryloxide with strongly basic piperidine. The curved plots indicate that the reactions proceed through both uncatalytic and catalytic routes. Linear Brønsted-type plots have been obtained for the uncatalyzed and catalyzed reactions of 1-(4-nitrophenoxy)-2,4-dinitrobenzene (1a) with βnuc = 0.84 and 0.78, respectively. The Yukawa–Tsuno plot for the uncatalyzed reactions of 1a–1h with piperidine results in an excellent linear correlation with ρ = 1.66 and r = 0.31. In contrast, rate constants for catalyzed reactions are independent of the electronic nature of the substituent in the leaving group. The current SNAr reactions have been proposed to proceed via a zwitterionic intermediate (MC±) that partitions to products through uncatalytic and catalytic routes. The catalyzed reaction from MC± has been concluded to proceed through a concerted mechanism with a six-membered cyclic transition state (TScycl) rather than via a stepwise pathway with a discrete anionic intermediate (MC−), the traditionally accepted mechanism. Medium effects on the reactivity and reaction mechanism are discussed. Particularly, hydrogen bonding of the amines to water precludes formation of kinetically significant dimers found in some aprotic solvents; no explicit role for water in the catalytic transition state is required or proposed. The specific stabilization of the leaving aryloxides substituted with strong electron-withdrawing groups accounts for the lack of the catalytic pathway in these systems (1a–1c) with piperidine nucleophile.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-19T07:00:00Z
      DOI: 10.1139/cjc-2017-0454
       
  • Theoretical analysis of high-pressure effects on conformational equilibria
    • Authors: Jacob Spooner, Heather Wiebe, Miranda Louwerse, Brandon Reader, Noham Weinberg
      Pages: 1 - 12
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Along with temperature, pressure is the most important physical parameter determining the thermodynamic properties and reactivity of chemical systems. In this work, we discuss the effects of high pressure on conformational properties of organic molecules and propose an approach toward calculation of conformational volume changes based on molecular dynamics simulations. The results agree well with the experimental data. Furthermore, we demonstrate that pressure can be used as an instrument for fine-tuning of molecular conformations and to propel a properly constructed molecular rotor possessing a suitable combination of energy and volume profiles.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0411
       
  • Thiol-ene click microcontact printing of gold nanoparticles onto silicon
           surfaces
    • Authors: Casey M. Platnich, Abhinandan Banerjee, Vinayaraj Ozhukil Kollath, Kunal Karan, Simon Trudel
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      We report a novel process to selectively pattern nanomaterials, specifically gold nanoparticles, onto a silicon surface through “click” chemistry, to consistently and efficiently join together small units through a quick and simple reaction. We employed the UV-initiated thiol-ene reaction, which is used in tandem with microcontact printing. Dithiol-capped nanoparticles were used as a printing ink and were grafted onto ene-terminated Si(100) wafers by pressing a nanoparticle-impregnated poly(dimethylsiloxane) stamp, while irradiating with ultraviolet light to activate a radical initiator. The resulting structures were characterized using scanning electron microscopy and atomic force microscopy.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-18T07:00:00Z
      DOI: 10.1139/cjc-2017-0321
       
  • 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
       
  • A simple and sensitive sensor for silver ions based on unmodified gold
           nanoparticles by using dynamic light scattering techniques
    • Authors: Zhiyou Xiao, Anjiang Tang, Hongsheng Huang, Ze Wang
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      A simple and sensitive assay for Ag+ was developed with unmodified gold nanoparticles (AuNPs) by using dynamic light scattering techniques. Ag+ could induce the oligonucleotide (5′-ATC ACT ATA TCA TAT ACT CAT-3′) to change from a single-stranded structure to a double-stranded structure and desorb from the surface of AuNPs, which triggered the aggregation of AuNPs in the salt solution. The average hydrodynamic diameter of aggregated AuNPs could be detected by using dynamic light scattering techniques. Under the optimum conditions, the average hydrodynamic diameter of AuNPs is proportional to the concentration of Ag+ within the range of 13.3–100.0 nmol/L, with a detection limit of 3.2 nmol/L. The method is easy to operate and has low sample consumption, high sensitivity and selectivity.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-13T07:00:00Z
      DOI: 10.1139/cjc-2017-0241
       
  • Correlation of pheromone-binding protein–ligand equilibrium dissociation
           constants with electroantennogram response patterns
    • Authors: Mailyn Terrado, Yang Yu, Erika Plettner
      Pages: 1 - 10
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Pheromone-binding proteins (PBPs) are water-soluble proteins found at high concentration in the lymph fluid of pheromone-sensing hairs on insect antennae. PBPs could function as pheromone transporters, ferrying the hydrophobic odorants to their cognate odorant receptors. However, it is also possible for these proteins to bind the odorants near the dendritic membrane of pheromone-sensing neurons and, therefore, function as scavengers. The two functions are not mutually exclusive. In this paper, the transporter and (or) scavenger roles of PBPs in pheromone perception were investigated using the pheromone of the gypsy moth (7R, 8S)-epoxy-2-methyloctadecane and analogues with heteroatom (O or S) substitutions in the hydrocarbon chain. PBP–ligand equilibrium dissociation constants (Kd) were correlated with electroantennogram (EAG) response patterns of male gypsy moth antennae to the pheromone, its enantiomer, and their respective analogues. EAG measures the potential drop across the antenna due to odorant receptor activation and subsequent ion channel opening. Three quantifiable properties of the EAG responses were used: lag times from stimulus to response onset, depolarization rates (rate of receptor activation), and repolarization rates (rate of receptor deactivation). Negative correlations were observed between Kd and lag times and between Kd and repolarization rates. Positive correlations were seen with Kd against depolarization rates. The inverse relationship of Kd constants with lag times and the direct relationship with depolarization rates strongly supports transporter function of PBPs. Interestingly, the inverse correlation of Kd constants with repolarization rates suggests a scavenger effect. These results indicate that PBP affects odorant receptor activity through both odorant transport and scavenger functions. Through differences in ligand binding affinities, PBPs influence pheromone availability for receptor activation.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-09-13T07:00:00Z
      DOI: 10.1139/cjc-2017-0339
       
  • Michael addition at neutral pH: a facile synthesis of 1,3-dinitroalkanes
    • Authors: Porag Bora, Pranjal P. Bora, Barisha Wahlang, Ghanashyam Bez
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Base-catalyzed Michael addition of nitroalkane to conjugated nitroalkene suffers serious practical difficulties due to the formation of oligomeric byproduct. Given its importance for synthesis of pharmacologically relevant organic compounds, a scalable synthesis of 1,3-dinitroalkane is developed by addition of nitroalkane to nitroalkene in aqueous phosphate buffer at pH 7.0 with no added traditional base catalyst.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-25T07:00:00Z
      DOI: 10.1139/cjc-2017-0257
       
  • Analysis of the interaction between the cocaine-binding aptamer and its
           ligands using fluorescence spectroscopy
    • Authors: Aron A. Shoara, Sladjana Slavkovic, Logan W. Donaldson, Philip E. Johnson
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      We used fluorescence spectroscopy to measure the binding affinity and provide new insights into the binding mechanism of cocaine and quinine with the cocaine-binding DNA aptamer. Using the intrinsic fluorescence of quinine and cocaine, we have observed quenching of ligand fluorescence upon binding of the aptamer. Quantification of this quenching provides an easy method to measure the binding constant using small amounts of sample. The observed quenching coupled with a red shift of the Stokes shift in the emission spectrum indicates that quinine and cocaine interact with the aptamer through stacking interactions.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0380
       
  • Cr doped ZnO nanostructures: synthesis, electronic structures, and
           magnetic properties
    • Authors: Michael W. Murphy, William R. Diebel, Yun-Mui Yiu, Tsun-Kong Sham
      Pages: 1 - 8
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      In this experiment, we have attempted to dope Cr into ZnO nanostructure as a function of dopant concentration using sol-gel method, followed by controlled thermal annealing with some success. We have also examined the samples thus prepared with scanning electron microscopy (SEM), X-ray powder diffraction (XRD), near edge X-ray absorption fine structure (NEXAFS), both theoretical and experimental, and magnetic measurements. We found that low concentration of Cr can indeed be doped in ZnO and is substitutional, occupying the tetrahedral site. However, upon increasing dopant concentration and annealing temperature, a secondary phase with Cr occupying an octahedral site precipitates out, which was evident from SEM, XRD, and NEXAFS. Ferromagnetism at room temperature was not observed in any samples, although at low Cr concentration and 400 °C processing temperature, antiferromagnetism can be seen; however, at higher concentrations or processing temperatures, the samples show only paramagnetism.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-22T07:00:00Z
      DOI: 10.1139/cjc-2017-0143
       
  • 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
       
  • Experimental and modelling liquid–liquid equilibrium for the system
           2-ethyl-1-hexanol + glycerol
    • Authors: A.L. Araujo, M.O. Ferreira, C.P. Souza, L. Cardozo Filho, E.M.B.D de Sousa
      Pages: 1 - 6
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      This work presents experimental data on liquid–liquid equilibrium (LLE) for the system 2-ethyl-1-hexanol + glycerin. Equilibrium data were obtained through “cloud point” method, at temperatures of 298.15 K, 313.15 K, 333.15 K, 368.15 K, 383.15 K, 403.15 K, and 433.1 K. For the experimental data, a UNIQUAC model was used to describe the phase’s equilibrium performance. Posteriorly, a phase split stability test was done to validate the parameters found in this model. The system presented “upper critical solution temperature” (UCST), and the parameters of the UNIQUAC model were satisfactorily adjusted (1.27% standard deviation). The stability phase test (phase split) proved the validation of the tested model.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-16T07:00:00Z
      DOI: 10.1139/cjc-2017-0003
       
  • Collective and single-particle degrees of freedom in rotating nuclei
    • Authors: Anish Verma, Krzysztof Starosta
      Pages: 1 - 10
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      In 1937, Hermann Jahn and Edward Teller published their research describing a mechanism of symmetry breaking in nonlinear polyatomic molecules resulting in a lifting of orbital degeneracy of an electronic state (Proc. R. Soc. London, Ser. A 1937, 161, 220), yielding insight into molecular structure. The impact of symmetry breaking on the energy and structure of quantum states is not unique to molecules and may be applied to nuclei, involving degenerate nucleon states as opposed to electronic states. Reinhard and Otten showed that the nuclear Jahn–Teller effect provides a mechanism applicable to describe the commonly observed collective quadrupole surface motion (Nucl. Phys. A 1984, 420, 173). To take into account single-particle effects, it is important to properly model the valence nucleons, especially those occupying large angular momenta orbitals near the Fermi level. In this work, a model has been developed in which two valence nucleons of the same kind are coupled to an axially symmetric quadrupole deformed rotor of the D2 symmetry and interact through the nuclear delta force. To test this model, the band of the lowest-energy state at a given spin for 126Ce is reproduced. The resultant wavefunctions are then used to calculate the g factor, reduced electric quadrupole transition probability, and spectroscopic quadrupole moment all as a function of spin. This method lays the groundwork to explore higher order symmetries following the multipole expansion.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-16T07:00:00Z
      DOI: 10.1139/cjc-2017-0275
       
  • Application of Fe3O4@SiO2/(CH2)3-[imidazolium-SO3H]Cl as a robust,
           magnetically recoverable solid acid catalyst for the facile preparation of
           arylbispyranylmethanes
    • Authors: Mohammad Ali Zolfigol, Mahdiyeh Navazeni, Meysam Yarie, Roya Ayazi-Nasrabadi
      Pages: 1 - 5
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      In this study, Fe3O4@SiO2/(CH2)3-[imidazolium-SO3H]Cl shows robust promoting capability in the synthesis of arylbispyranylmethane derivatives under mild and green conditions. Arylbispyranylmethanes were synthesized via efficient three-component reaction of various aromatic aldehydes with 4-hydroxy-6-methyl-2H-pyran-2-one. The nanomagnetic core-shell catalyst presented effective potential of at least eight times recycling applicability in the described synthetic procedure.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-16T07:00:00Z
      DOI: 10.1139/cjc-2017-0232
       
  • Hydrogen evolution at conjugated polymer nanoparticle electrodes
    • Authors: Patrick Fortin, Subash Rajasekar, Pankaj Chowdhury, Steven Holdcroft
      Pages: 1 - 10
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      Organic polymer nanoparticles have been gaining attention in photovoltaics as a means to control the morphology of polymer composite films for the purpose of studying bulk heterojunction, photoactive layers. This work investigates the preparation of nanostructured organic thin films from P3HT:PC61BM nanoparticles and their characterization as photoelectrodes for the photoelectrochemical reduction of hydrogen in acidic solutions. The morphology and optoelectronic properties of the nanostructured photocathodes are compared with conventional, solution-cast thin films of P3HT:PC61BM. The nanostructured photoelectrodes provide increased surface area compared with solution-cast films through control of the nanoscale morphology within each nanoparticle, leading to enhanced P3HT:PC61BM phase segregation. The photo-assisted deposition of platinum nanoparticles as hydrogen evolution reaction (HER) catalysts onto the nanostructured P3HT:PC61BM photocathodes facilitates the photoreduction of protons to H2.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-14T07:00:00Z
      DOI: 10.1139/cjc-2017-0329
       
  • Adsorption of methanol, methanal, toluene, ethylbenzene, and styrene in
           zeolites: a grand canonical Monte Carlo simulation study
    • Authors: Fei Zhao, XiShang Sun, Ruifeng Lu, Lihua Kang
      Pages: 1 - 7
      Abstract: Canadian Journal of Chemistry, e-First Articles.
      In this study, the adsorption behaviors of methanol, methanal, toluene, ethylbenzene, and styrene molecules in FAU, FER, CON, and MWW zeolites were investigated. The adsorption isotherms of the five adsorbates in the four zeolites at 298 and 350 K were simulated using grand canonical Monte Carlo simulations. Moreover, binary component adsorptions were considered. The results revealed that the saturated adsorption capacity of single components in different zeolites decreased in the order of FAU> MWW> CON> FER, and the adsorption capacity of the five adsorbates in the same zeolite decreased in the order of methanal> methanol> toluene> styrene> ethylbenzene. The equilibrium adsorption capacity slightly decreased with increasing temperature. In terms of binary component adsorption, intense competition existed between the smaller adsorbed molecules. As the differences among the molecular structures increased, the competition in adsorption became more intense.
      Citation: Canadian Journal of Chemistry
      PubDate: 2017-08-01T07:00:00Z
      DOI: 10.1139/cjc-2017-0218
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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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