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Several five‐membered heterocyclic molecules were studied theoretically as organic hydride donors. The density functional theory and ab initio methods are employed to study the direct one‐step or multistep sequence suggested for the hydride transfer from the selected molecules: H atom/electron, electron/proton/electron or electron/H atom. Out of the three multistep mechanisms, electron/H atom seems to be a probable pathway in the presence of suitable catalyst/photoreaction that can cause ionization. In the lack of such catalyst/photoreaction, the direct hydride transfer seems to be most probable with the presence of suitable hydride acceptor. A detailed mechanism of the hydride transfer from the five‐membered heterocylic compounds is important in understanding chemical and biological reactions and required for scientifically designing and synthesizing new desired five‐membered heterocyclic compounds as organic hydride donor. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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A two-dimensional analytical model for channel potential and threshold voltage of short channel dual material gate lightly doped drain MOSFET 下载免费PDF全文
Shweta Tripathi 《中国物理 B》2014,(11):624-629
An analytical model for the channel potential and the threshold voltage of the short channel dual-material-gate lightly doped drain (DMG-LDD) metal-oxide-semiconductor field-effect transistor (MOSFET) is presented using the parabolic approximation method. The proposed model takes into account the effects of the LDD region length, the LDD region doping, the lengths of the gate materials and their respective work functions, along with all the major geometrical parameters of the MOSFET. The impact of the LDD region length, the LDD region doping, and the channel length on the channel potential is studied in detail. Furthermore, the threshold voltage of the device is calculated using the minimum middle channel potential, and the result obtained is compared with the DMG MOSFET threshold voltage to show the improvement in the threshold voltage roll-off. It is shown that the DMG-LDD MOSFET structure alleviates the problem of short channel effects (SCEs) and the drain induced barrier lowering (DIBL) more efficiently. The proposed model is verified by comparing the theoretical results with the simulated data obtained by using the commercially available ATLASTM 2D device simulator. 相似文献
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Gananadhamu Samanthula Debasish Swain Gayatri Sahu Shweta Bhagat P. V. Bharatam 《Journal of Analytical Chemistry》2018,73(6):560-569
The fixed dose combination of azilsartan medoxomil potassium and chlorthalidone has been introduced for the effective treatment of hypertension. In the present work a rapid, simple and accurate stability indicating ultra HPLC assay method has been developed. The separation of azilsartan medoxomil, chlorthalidone and their degradation products were accomplished on an Acquity UPLC BEH C18 (100 mm × 2.1 mm, 1.7 μm) column using mobile phase combination of 0.02% trifluoroacetic acid in water and acetonitrile in gradient mode. The forced degradation products were identified using liquid chromatography?electrospray ionisation-quadrupole time of flight-tandem mass spectrometry (LC?ESIQTOF–MS/MS) and accurate mass experiments. The in silico toxicities of the degradation products for both the drugs were evaluated. The proposed method was validated as per the ICH Q2 (R1) guideline for selectivity, linearity, precision, accuracy and robustness. 相似文献
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We describe the integration of a small-molecule hydrogen-bond-donor template into a cascade reaction that is comprised of a combination of molecular and supramolecular events. The cascade is performed mechanochemically and in the presence of μL amounts of water. The small-molecule template is generated (molecular) using water-assisted vortex grinding and is then used to assemble an alkene (supramolecular) to undergo an intermolecular [2 + 2] photodimerization reaction (molecular). The chemical cascade results in a cyclobutane photoproduct that we show serves as a building block of a hydrogen-bonded network with a topology that conforms to T-silica. Remarkably, the molecular–supramolecular–molecular chemical cascade occurs stepwise and entirely regioselectively within the continuous mechanochemical conditions employed.Mechanochemistry is applied to molecular and supramolecular chemistry to support a template-directed photochemical reaction. 相似文献
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A. Sarkar Shweta Hegde T. Mukherjee S. Kapoor 《Research on Chemical Intermediates》2010,36(3):309-318
The effect of silver ions and silver nanoparticles on the rate of polymerization of acrylamide and N-isopropylacylamide was investigated. Composites of silver particles of diameter around 30 nm and polyacrylamide were prepared
by the photochemical method in the absence of any photosensitizer. The particles formed were characterized by UV–visible spectrophotometry,
XRD, and TEM. It was shown that the presence of metal ions such as Ag+, Co2+, and Ni2+ in the acrylamide monomer is essential for photoinduced polymerization. 相似文献
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Jamble Shweta N. Ghoderao Karuna P. Kale Rohidas B. 《Research on Chemical Intermediates》2019,45(3):1381-1399
Research on Chemical Intermediates - Photocatalytic degradation of toxic dyes is an important topic across the globe. This paper reports the photocatalytic degradation of methylene blue (MB) dye... 相似文献
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Mazaahir Kidwai Kavita Singhal Shweta Rastogi 《Journal of heterocyclic chemistry》2006,43(5):1231-1236
An expeditious and convenient solid supported synthesis of 1,3,7‐triaryl‐6‐phenyl‐2‐thioxo‐1,2,3,7‐tetrahydropyrrolo [2,3‐d]pyrimidin‐4‐one derivatives from readily accessible N,N‐disubstituted thiobarbituric acids under microwaves utilising Paal Knorr reaction is described. 相似文献
40.
An end-to-end assembly of spherical Ag nanoparticles takes place in the presence of biotin to form long fiberlike microstructures. These microstructures are about 4 mum long with a thickness of 1 mum, obtained from SEM studies. TEM studies showed the presence of spherical silver nanoparticles having an average size of 20 nm. ATR-FTIR studies revealed that silver ions interact with biotin involving the carboxylate group. A weak binding of the silver particles with the thioether and ureido groups helps in connecting the Ag nanoparticles to form long fiberlike structures. Elucidation of the mechanism of formation of the spherical Ag clusters was done by pulse radiolysis. 相似文献