October 2019
Article ID 0101 October 2019
YANMIN CHEN PEIJIAN SUN WEIWEI XING
Substituting low theoretical potential of the urea oxidation reaction (UOR) for the high theoretical potential of water splitting at the anode (oxygen evolution reaction) is meaningful for hydrogen energy storage and conversion. In this work, a bifunctional catalyst, cobalt nitride nanoflakes supported on Ni foam (CoN NF/NF), was synthesized for both UOR and hydrogen evolution reaction (HER). A two-electrode electrolyzer (CoN NF/NF||CoN NF/NF) was constructed. To drive 100 mA/cm2, the voltage of CoN NF/ NF||CoN NF/NF only 1.698 V is required, which is much lower than that of Pt/C||IrO2 (1.860 V) and the current density can be maintained for 30 h.
Article ID 0102 October 2019
A green synthesis of nitrones in glycerol
MONIRE SHARIATIPOUR MASOUMEH JADIDINEJAD AKBAR HEYDARI
An eco-friendly and efficient synthesis of nitrones is presented by condensation of an equimolar amount of aldehydes and N-substituted hydroxylamine hydrochlorides in glycerol as a recyclable solventcatalyst. This novel protocol provides rapid and mild access to a series of nitrone derivatives in good to excellent yields in the absence of catalyst and base.
Article ID 0103 October 2019
MOHAMMAD EL-KHATEEB QUSAY TANASH HASSAN ABUL-FUTOUH HELMAR GORLS WOLFGANG WEIGAND
The dithiocarbonato metal complexes M(k2S,S-S2CO)(k2P,P-dppf) {M= Ni, Pd, Pt; dppf=bis(diphenylphosphino)ferrocene} are obtained from the reaction of the metal(II) complexes [M(K2S,S-S2-COEt)2] with the dppf ligand or from the chloride substitution of M(k2P,P-dppf)Cl2 by the O-ethyldithiocabonatoanion. These complexes are produced by C-O bond cleavage by the O-ethyldithiocarbonato anion present in solution. These new complexes have been characterized by UV-Vis, NMR, IR spectroscopy and elemental analysis. The structures of the three complexes were further confirmed by single-crystal X-ray diffraction analysis.
Article ID 0104 October 2019
MARYAM JUYBAR MOHAMMADREZA KANMOHAMMADI KHORRAMI AMIR BAGHERI GARMARUDI
Catalytic conversion of methanol to gasoline range hydrocarbons, especially aromatics was carried out in a fixed bed reactor over nano-crystal composite H-ZSM-5/11 zeolite synthesized by hydrothermal method. The metals of Zn, Cu, Ga and Ag as bimetallic Zn-Cu and Ga-Ag with different concentrations (3: 2, 5: 3) and (1:1, 3:2) respectively were selected for loading into the prepared zeolitecatalysts. Direct synthesis method was used for incorporating metals. Prepared zeolites were characterized by XRD, SEM, TEM, N2 adsorption-desorption, ICP-OES, NH3-TPD and FT-IR. After incorporation of metal species into the zeolites framework, the particles crystalline size was reduced, the intercrystalline porositywas increased, causing the formation of new moderate acid sites. The catalytic results illustrated that the incorporation of metal species enhanced the activity and catalyst stability in MTA reaction. BTX yield in ZSM-5/11 reached up at 23.5% to 30.4% and 25.88% with Zn-Cu-ZSM-5/11(1) and Ga-Ag-ZSM-5/11(1), respectively whereas heavier aromatics production reduced. Also, the comparison of catalysts with different metals content showed that due to improvement in structure and properties, low metal content zeolites havebetter performance in converting methanol to aromatics
Article ID 0105 October 2019
Development of novel pyrazolones by using SiO2/ZnCl2 – green approach
G NEELIMA K LAKSHMI K SESHA MAHESWARAMMA
The present research work deals with the green synthesis of substituted pyrazolone derivatives 4(a–f) from 2,4-dinitrophenylhydrazine with various substituted aromatic aldehyde and ethyl acetoacetate in the presence of silica-supported zinc chloride (SiO2/ZnCl2) as a recyclable Lewis acid catalyst. The synthesized compounds were structurally characterized with IR, 1H NMR, Mass spectra and elemental analysis. All these compounds were tested for their antioxidant activity by using the DPPH radical scavenging method.
Article ID 0106 October 2019
JELENA PETRONIJEVIC NENAD JOKSIMOVIC ZORICA BUGARCIC ELVIRA ÐURÐIC NENAD JANKOVIC
The selected quinoxalinones and benzoxazinones derivatives, synthesized in our laboratory earlier, were explored by spectroscopic techniques (UV-Vis, IR, Raman and NMR) and theoretical study (DFT calculations). In order to understand the electronic properties of these compounds, the theoretical UV spectra have been investigated by TDDFT/B3LYP method with 6-311+G(d,p) basis set in ethanol as a solvent. For all compounds, the absorption of UV radiation with a wavelength around 415 nm with an oscillator strength f = 0.90 induces the intramolecular electronic transition (n→p*). The frontiers molecular orbitals are calculated, and contributions of the electronic transitions are determined. Also, we did quantumchemical calculations to investigate the corrosion inhibition properties of these molecules. The vibrational analysis was performed at the B3LYP/6-311+G(d,p) level of theory in vacuo. Obtained results are in very good agreement with experimental data. The calculated 13C NMR shifts in all cases are in good-to-excellent agreement. Also, 1H NMR predicted shifts are comparable with experimental results, but there are some deviations (for N–H shifts) probably as a consequence of intramolecular interactions.
Article ID 0107 October 2019
MOHD H AHMAD NOORSAADAH ABD RAHMAN FARKAAD A KADIR LINA A AL-ANI NAJIHAH M HASHIM WAGEEH A YEHYE
In the present study, a series of multipotent antioxidants (MPAOs), namely sulfur-containing BHT (S-BHT), derivatives were rationally designed and synthesized, and their inhibitory activities against free radicals and human cancer cell lines, HT29 (colon cancer) and MCF7 (breast cancer) were further evaluated. The experimental results showed that the Six out-of-eight S-BHT compounds had excellent antioxidant activity against DPPH radical with major enhancement compared to BHT. Among them, compounds 2b, 2a and 3b attained over 45% lower IC50 values than BHT. In vitro cytotoxicity, MTT assay was carried out using two human cancer cell lines, HT29 (colon cancer) and MCF7 (breast cancer) in addition to their non-tumorigenic counterparts to explore selectivity. In line with antioxidant activity, compounds 2a and 2b displayed the highest cytotoxicity effect on both cancer types. Interestingly, 2b not only exhibited superior cancer inhibition but also scored high selectivity index (SI = 5.2, 12.5) in colon and breast tissues, respectively, exceeding that of the standard chemotherapeutic drugs used 5-Fluorouracil (5-FU) and Tamoxifen (Tmx), with lower IC50 values. The results indicated that the symmetric S-BHT derivatives were significantlyenhanced by the antioxidant potency and their ability as useful and promising selective anticancer agents.
Article ID 0108 October 2019
K RAJAVENKATESH S SANTOSHKUMAR K PURNASAI S THENNARASU
A simple method for naked-eye detection of free amine groups during solid-phase peptide synthesis is reported. The technique involves base-catalyzed cyclization of 2-(2-oxo-2H-acenaphthylene-1-ylidene)-malononitrile (1) and subsequent oxidative substitution of aryl moiety by free amine group present atthe N-terminus of the peptide chain that leads to the formation of a chromophore, which distinguishes the deprotected peptide chain from the protected one. The reaction is fast, does not require heating, and allows N-terminal modification of peptides suitable for imaging specific cells.
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Volume 131 | Issue 11
November 2019
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