Showing papers in "Canadian Journal of Chemistry in 2018"
TL;DR: In this paper, a method for simultaneous determination of nifedipine and atenolol using an anodically pretreated boron-doped diamond electrode coupled to differential pulse voltammetry technique was developed.
Abstract: 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 μmo...
18 citations
TL;DR: In this article, the authors introduce the concept of monoterpenes, which are prevalent organic compounds emitted to the atmosphere via biogenic activities in various types of plants, and undergo atmospheric decomposition reactions derived by the p...
Abstract: Monoterpenes are prevalent organic compounds emitted to the atmosphere, via biogenic activities in various types of plants. Monoterpenes undergo atmospheric decomposition reactions derived by the p...
17 citations
TL;DR: In this paper, charge transfer (CT) and charge transport (CTr) are at the core of life-sustaining biological processes and of processes that govern the performance of electronic and energy conversion devices.
Abstract: Charge transfer (CT) and charge transport (CTr) are at the core of life-sustaining biological processes and of processes that govern the performance of electronic and energy-conversion devices. Ele...
16 citations
TL;DR: The fundamental value of obtaining an electron density matrix that is N-representable is that it ensures consistency with an underlying properly antisymmetrized wavefunction, a requirement of quantum mechanical validity.
Abstract: Quantum crystallography (QCr) is a branch of crystallography aimed at obtaining the complete quantum mechanics of a crystal given its X-ray scattering data. The fundamental value of obtaining an electron density matrix that is N-representable is that it ensures consistency with an underlying properly antisymmetrized wavefunction, a requirement of quantum mechanical validity. However, X-ray crystallography has progressed in an impressive way for decades based only upon the electron density obtained from the X-ray scattering data without the imposition of the mathematical structure of quantum mechanics. Therefore, one may perhaps ask regarding N-representability “why bother?” It is the purpose of this article to answer such a question by succinctly describing the advantage that is opened by QCr.
14 citations
TL;DR: In this article, the interface dynamics of nanocrystalline NiO thin films sensitized with two ruthenium polypyridyl chromophores have been investigated to examine the influence that excited-state dipole orientation and...
Abstract: Interface dynamics of nanocrystalline NiO thin films sensitized with two ruthenium polypyridyl chromophores have been investigated to examine the influence that excited-state dipole orientation and...
13 citations
TL;DR: Four novel fluorescence sensors bearing a quinolylbenzothiazole platform showed excellent selectivity and highly sensitive fluorescence response to Fe3+ ion in H2O/DMSO buffer solution and the binding stoichiometry between sensors L1, L2, L3, or L4 and Fe3- was observed to be 1:1.
Abstract: Four novel fluorescence sensors bearing a quinolylbenzothiazole platform were synthesized and characterized. The sensors displayed excellent selectivity and highly sensitive fluorescence response t...
13 citations
TL;DR: In this article, the Tb(dipicCbz)3]3− (dipICBz = 4-(9H-carbazol-9-yl-pyridine-2,6-dicarboxylato) complex was isolated and evaluated as a temperature sensor in water.
Abstract: The water soluble [Tb(dipicCbz)3]3− (dipicCbz = 4-(9H-carbazol-9-yl-)pyridine-2,6-dicarboxylato) complex was isolated and evaluated as a temperature sensor in water. The 1:3 (TbIII:dipicCbz2−) stoichiometry in solution was confirmed by luminescence titration and high-resolution mass spectrometry. The quantum yield of sensitized emission is 3.8% ± 0.4% at 25.0 ± 0.1 °C, and the emission intensity depends on the temperature in the range of 5–70 °C with a relative thermal sensitivity of 3.4% °C−1 at 35 °C and temperature resolution < 0.01 °C in the range of 30–40 °C. The reversibility of this behavior was demonstrated for three heating–cooling cycles. Calculations of the energy gap between donor and acceptor show that the temperature dependence of the emission intensity is due to back-energy transfer from the Tb 5D4 excited state to the triplet and twisted intramolecular charge transfer (TICT) states of the dipicCbz. The assignment of one of the energy levels as a TICT state was confirmed by the temperature-...
13 citations
TL;DR: In this article, an innovative electrochemical nicotine modified sensor was created by chemically mixing a carbon paste with silver nano powder to prepare an Ag nanoparticle modified carbon paste electrode. Differe...
Abstract: An innovative electrochemical nicotine modified sensor was created by chemically mixing a carbon paste with silver nano powder to prepare an Ag nanoparticle modified carbon paste electrode. Differe...
12 citations
TL;DR: In this paper, phase change materials (PCMs) offer a promising technology for thermal energy storage, load leveling, and peak shifting applications, and a desirable PCM has a melting temperature within the temperatur...
Abstract: Phase change materials (PCMs) offer a promising technology for thermal energy storage, load leveling, and peak shifting applications. A desirable PCM has a melting temperature within the temperatur...
12 citations
TL;DR: In this paper, the excited-state proton transfer (ESPT) dynamical behavior of aloesaponarin I (ASI) was studied using density functional theory (DFT) and time-dependent DFT (TDDFT).
Abstract: The excited-state proton transfer (ESPT) dynamical behavior of aloesaponarin I (ASI) was studied using density functional theory (DFT) and time-dependent DFT (TDDFT) methods. Our calculated vertica...
12 citations
TL;DR: In this article, a mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO3)3·9H2O as the single catalyst and molecular...
Abstract: A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO3)3·9H2O as the single catalyst and molecular...
TL;DR: The addition of 4-ethyl-3-thiosemicarbazide to benzaldehyde and boronic acid containing derivatives afforded the corresponding thIosemicarazones (1−3) or benzodiazaborines (4−6) depending on the p...
Abstract: The addition of 4-ethyl-3-thiosemicarbazide to benzaldehyde and boronic acid containing derivatives afforded the corresponding thiosemicarbazones (1–3) or benzodiazaborines (4–6) depending on the p...
TL;DR: In this paper, PANI/MnCo2O4 nanocomposite was prepared via in-situ chemical polymerization method using FTIR spectroscopy, X-ray diffraction, and scanning elec...
Abstract: In this work, PANI/MnCo2O4 nanocomposite was prepared via in-situ chemical polymerization method. Materials synthesized were characterized by FTIR spectroscopy, X-ray diffraction, and scanning elec...
TL;DR: Evidence is provided that PNA probes are superior to DNA probes in term of sensitivity and adaptability, as PNA immobilization and PNA–RNA hybridization are less affected by salt content in the reaction...
Abstract: Herein, we report that peptide nucleic acid sequences (PNAs) have been used as the probe species for detection of RNA and that a microfluidic microarray (MMA) chip is used as the platform for detec...
TL;DR: Spherical gold nanoparticles have been supported onto the surface of potassium niobium oxide perovskites, an underdeveloped class of semiconductor in photocatalytic organic transformations as mentioned in this paper.
Abstract: Spherical gold nanoparticles have been supported onto the surface of potassium niobium oxide perovskites, an underdeveloped class of semiconductor in photocatalytic organic transformations The nan
TL;DR: In this article, a carbon dots based dual-emission nanosensor for chromium speciation analysis was developed for ratiometric fluorescent nanosensors using a simple and effective strategy.
Abstract: A simple and effective strategy for designing a ratiometric fluorescent nanosensor was described. A carbon dots (CDs) based dual-emission nanosensor for chromium speciation analysis was developed b...
TL;DR: Two new boron-capsaicin derivatives containing either a short or long chain aliphatic tail group using an iridium catalyzed hydroboration reaction with pinacolborane showed considerable activity against two Gram-positive bacteria, including Vancomycin-resistant Enterococcus.
Abstract: This preliminary study reports on the synthesis of two new boron-capsaicin derivatives containing either a short or long chain aliphatic tail group using an iridium catalyzed hydroboration reaction...
TL;DR: In photovoltaics, organic polymer nanoparticles have been used as a means to control the morphology of polymer composite films for the purpose of studying bulk heterojunction, photoacti... as mentioned in this paper.
Abstract: 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, photoacti...
TL;DR: Three extremely bulky 1,3,5-triazapentadienes, ArNNNH (ArNNN = N{C(But)=N(Ar)}2; Ar = Mes (mesityl), Dep (2,6-diethylphenyl), or Dip (2.6-diisopropyl-phenyl)) have been prepared and structurally constructed as discussed by the authors.
Abstract: Three extremely bulky 1,3,5-triazapentadienes, ArNNNH (ArNNN = N{C(But)=N(Ar)}2; Ar = Mes (mesityl), Dep (2,6-diethylphenyl), or Dip (2,6-diisopropylphenyl)) have been prepared and structurally cha...
TL;DR: In this article, the authors examined the potential for two plants grown on Canadian soil, Symphytum officinale L. (common comfrey) and Panicum virgatum L.(switchgrass), to produce 5-hydroxymethylfurfural usi...
Abstract: The present work examined the potential for two plants grown on Canadian soil, Symphytum officinale L. (common comfrey) and Panicum virgatum L. (switchgrass), to produce 5-hydroxymethylfurfural usi...
TL;DR: Ligand L6 (i.e., the P(Me2Ad)2 variant of L5) proved superior to all other ligands in the monoarylation of acetone and was the most broadly useful of the Mor-DalPhos ligands surveyed herein.
Abstract: The competitive catalytic screening of 18 known and newly prepared Mor-DalPhos ligand variants in the palladium-catalyzed cross-coupling of chlorobenzene with aniline, octylamine, morpholine, indol...
TL;DR: A number of new neutral bis-2-(4-dimethylamino)pyridinylidene electron donors featuring N-akyl groups of varying lengths (propyl, butyl, hexyl, dodecyl) have been prepared from 4-Dimethylaminopyrid as discussed by the authors.
Abstract: A number of new neutral bis-2-(4-dimethylamino)pyridinylidene electron donors featuring N-akyl groups of varying lengths (propyl, butyl, hexyl, dodecyl) have been prepared from 4-dimethylaminopyrid...
TL;DR: The engineered one-site adenosine aptamer showed excellent signaling properties with a 2.6-fold stronger signal intensity and also a 4.2-fold increased detection limit compared with the wild-type two-site aptamer.
Abstract: The 27-nucleotide DNA aptamer for adenosine and ATP, originally selected by the Szostak lab in 1995, has been a very popular model system for biosensor development. This unique aptamer has two targ...
TL;DR: Fluorescence spectroscopy provides an excellent technique for investigating heterogeneous systems, due to its high sensitivity and the large effect of the local environment on molecular emission as mentioned in this paper. But it is not suitable for high-dimensional data.
Abstract: Fluorescence spectroscopy provides an excellent technique for investigating heterogeneous systems, due to its high sensitivity and the large effect of the local environment on molecular emission. I...
TL;DR: In this paper, the equilibrium bond lengths of 41 small molecules are calculated by Gaussian09 and ADF2013 programs using five different basis sets: 6-31G*, cc-pVDZ, 6-311G+(2d,p), cc- pVTZ, and cc pVQZ, for six different methods: Hartree-Fock, MP2, MP3, CCSD, cCSD(T), and B3LYP.
Abstract: The equilibrium bond lengths of 41 small molecules are calculated by Gaussian09 and ADF2013 programs. We use five different basis sets: 6-31G*, cc-pVDZ, 6-311G+(2d,p), cc-pVTZ, and cc-pVQZ, for six different methods: Hartree-Fock, MP2, MP3, CCSD, CCSD(T), and B3LYP. The reliability of each level of theory on 89 bond lengths compared with CCSD(T)/cc-pVQZ is examined in terms of the mean absolute deviation. In particular, basis set dependence of the relative reliability of the two popular methods MP2 versus B3LYP is important to computational chemists. In addition, the efficient even-tempered basis set of Slater-type orbital called et-pVQZ, available in the ADF2013 program, is tested with the popular density functional B3LYP.
TL;DR: Thiourea formaldehyde calcium alginate (TFCA) composite was successfully synthesized and used for removal of Reactive Black 5 (RB5) dye in this article.
Abstract: Thiourea formaldehyde calcium alginate (TFCA) composite was successfully synthesized and used for removal of Reactive Black 5 (RB5) dye. The synthesized composite was applied and characterized by F...
TL;DR: The hypothesis that bed bugs biosynthesize some pheromone components from amino acid precursors in human blood, namely DMDS and DMTS from L-methionine and histamine from histidine is tested.
Abstract: We have recently shown that the aggregation pheromone of the common bed bug, Cimex lectularius, comprises a six-component blend of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), (E)-2-hexenal, (E)-2-octenal, 2-hexanone, and histamine. Here, we tested the hypothesis that bed bugs biosynthesize some pheromone components from amino acid precursors in human blood, namely DMDS and DMTS from L-methionine and histamine from histidine. We tested this hypothesis by (i) allowing bed bugs to feed on and metabolize sheep blood enriched with 13C-labelled histidine or 2H-labelled methionine, (ii) extracting bed bug feces (a source of the aggregation pheromone), and (iii) analyzing feces extracts by GC-MS, HPLC-MS and NMR spectroscopy. The analyses revealed that bed bugs converted 2H-methionine to 2H-DMDS and 2H-DMTS, and 13C-histidine to 13C-histamine. There is not enough histidine in human blood to account for the amount of histamine that bed bugs produce and excrete with their feces, and only a small proporti...
TL;DR: In this article, the first determination of how electronic excitation affects molecular C6 London dispersion coefficients from the exchange-hole dipole moment (XDM) dispersion model is presented.
Abstract: Atomic and molecular dispersion coefficients can now be calculated routinely using density-functional theory. In this work, we present the first determination of how electronic excitation affects molecular C6 London dispersion coefficients from the exchange-hole dipole moment (XDM) dispersion model. Excited states are typically found to have larger dispersion coefficients than the corresponding ground states, due to their more diffuse electron densities. A particular focus is both intramolecular and intermolecular charge-transfer excitations, which have high absorbance intensities and are important in organic dyes, light-emitting diodes, and photovoltaics. In these classes of molecules, the increase in C6 for the electron-accepting moiety is largely offset by a decrease in C6 for the electron-donating moiety. As a result, the change in dispersion energy for a chromophore interacting with neighbouring molecules in the condensed phase is minimal.
TL;DR: In this article, a series of novel N1-anthraquinon-2-yl amidrazones incorporating N-piperazines and related congeners were synthesized via reaction of the hydrazonoyl chloride derived from 2-qaminoanthrasquinone.
Abstract: A new series of novel N1-anthraquinon-2-yl amidrazones incorporating N-piperazines and related congeners were synthesized via reaction of the hydrazonoyl chloride derived from 2-qaminoanthraquinone...
TL;DR: In this paper, the rate constants for reactions involved in the radiolysis of water under relevant thermodynamic conditions in supercritical water-cooled reactors were estimated for inputs in simulations of the radiodynamic conditions.
Abstract: The rate constants for reactions involved in the radiolysis of water under relevant thermodynamic conditions in supercritical water-cooled reactors are estimated for inputs in simulations of the ra...