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41.
42.
Kaushik Sen Bhaskar Mondal Srimanta Pakhira Chandan Sahu Deepanwita Ghosh Abhijit K. Das 《Theoretical chemistry accounts》2013,132(8):1-17
The association reaction between silyl radical (SiH3) and H2O2 has been studied in detail using high-level composite ab initio CBS-QB3 and G4MP2 methods. The global hybrid meta-GGA M06 and M06-2X density functionals in conjunction with 6-311++G(d,p) basis set have also been applied. To understand the kinetics, variational transition-state theory calculation is performed on the first association step, and successive unimolecular reactions are subjected to Rice–Ramsperger–Kassel–Marcus calculations to predict the reaction rate constants and product branching ratios. The bimolecular rate constant for SiH3–H2O2 association in the temperature range 250–600 K, k(T) = 6.89 × 10?13 T ?0.163exp(?0.22/RT) cm3 molecule?1 s?1 agrees well with the current literature. The OH production channel, which was experimentally found to be a minor one, is confirmed by the rate constants and branching ratios. Also, the correlation between our theoretical work and experimental literature is established. The production of SiO via secondary reactions is calculated to be one of the major reaction channels from highly stabilized adducts. The H-loss pathway, i.e., SiH2(OH)2 + H, is the major decomposition channel followed by secondary dissociation leading to SiO. 相似文献
43.
Abhijit Chandra Roy V.S. Nisha Chetna Dhand Md. Azahar Ali B.D. Malhotra 《Analytica chimica acta》2013
We report results of the studies relating to the fabrication and characterization of a conducting polymer based molecularly imprinted para-nitrophenol (PNP) sensor. A water pollutant, para-nitrophenol is electrochemically imprinted with polyvinyl sulphonic acid (PVSA) doped polyaniline onto indium tin oxide (ITO) glass substrate. This PNP imprinted electrode (PNPI-PANI-PVSA/ITO) prepared via chronopotentiometric polymerization and over-oxidation is characterized by Fourier transform infra-red spectroscopy (FT-IR), UV–visible (UV–vis) spectroscopy, contact angle (CA), scanning electron microscopy (SEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies. The response studies of PNPI-PANI-PVSA/ITO electrode carried out using DPV reveal a lower detection limit of 1 × 10−3 mM, improved sensitivity as 1.5 × 10−3 A mM−1 and stability of 45 days. The PNPI-PANI-PVSA/ITO electrode shows good precision with relative standard deviation of 2.1% and good reproducibility with standard deviation of 3.78%. 相似文献
44.
A number of ortho -cyclohexenyl phenols 2(a–i) have been cyclised by treatment with one equivalent of m-chloroper-oxybenzoic acid in refluxing benzene for 4 h to furnish linearly fused 1-hydroxy-1,2,3,4,4a,9a-hexahydrodibenzofurans 3(a–i) (70–80%) and bicyclic 3-hydroxy-1,3-ethanochromans 4(a–f) (10–20%). Products 3(a–i) were oxidised with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (excess) in refluxing dry xylene for 6 h to give 2,3-dihydrodibenzofuran-1 (2H)-ones 6(a–i) (85–95%). 相似文献
45.
Antimony trichloride is an efficient catalyst for the cyclization of 2-amino chalcones to the corresponding 2-aryl-2,3-dihydroquinolin-4(1H)-ones under mild reaction conditions and in almost quantitative yields. 相似文献
46.
4-Cyclohex-2-enyl-3-hydroxy-1-methylquinolin-2(1H)-one (4) was prepared in 90% yield by the thermal [3,3]sigmatropic rearrangement of 3-cyclohex-2-enyloxy-1-methylquinolin-2(1H)-one (3) in refluxing chloroben-zene for 10 h. Compound (4) was cyclised through a sequence of reactions viz. i) acetylation ii) addition of bromine and iii) treatment of the acetyl dibromo compound (6) with base to give a bicyclic product (7) in 90% yield. Treatment of compound 4 with pyridine hydro-bromide perbromide in dichloromethane at 0–5° C afforded a cyclic product 8 in excellent yield. Compound 4 when treated with cold conc. sulphuric acid at 0–5° C furnished the bicyclic product 12 in 89% yield. 相似文献
47.
Arindam Maity Debanjana ChakrabortyAbhijit Hazra Yogesh P. BharitkarSandip Kundu Prakas R. MaulikNirup B. Mondal 《Tetrahedron letters》2014
An inexpensive one-pot green methodology has been developed for the synthesis of thiazolo[2,3-a]isoquinolin-4-ium derivatives by the reaction of different derivatives of isoquinoline and 2-bromoacetophenone/bromoacetonitrile with benzoyl isothiocyanate in aqueous micellar medium. 相似文献
48.
Linear {NiII–LnIII–NiII} Complexes Containing Twisted Planar Ni(μ‐phenolate)2Ln Fragments: Synthesis,Structure, and Magnetothermal Properties
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Sourav Das Atanu Dey Subrata Kundu Sourav Biswas Prof. Dr. A. J. Mota Prof. Dr. Enrique Colacio Prof. Dr. Vadapalli Chandrasekhar 《化学:亚洲杂志》2014,9(7):1876-1887
Sequential reaction of a multisite LH4 ligand {2‐[2‐hydroxy‐3‐(hydroxymethyl)‐5‐methylbenzylideneamino]‐2‐methylpropane‐1,3‐diol} with appropriate lanthanide salts followed by the addition of Ni(NO3)2 ? 6 H2O in a 4:1:2 stoichiometric ratio in the presence of triethylamine afforded four heterobimetallic trinuclear complexes [Ni2Gd(LH3)4] ? 3 NO3 ? 3 MeOH ? H2O ? CH3CN ( 1 ), [Ni2Tb(LH3)4] ? 3 NO3 ? 3 MeOH ? CH3CN ( 2 ), [Ni2Dy(LH3)4] ? 3 NO3 ? 3 MeOH ? H2O ? CH3CN ( 3 ), and [Ni2Ho(LH3)4] ? 3 NO3 ? 3 MeOH ? H2O ? CH3CN ( 4 ). Complexes 1 – 4 possess linear trimetallic cores with a central lanthanide ion. Magnetic studies revealed a predominant ferromagnetic interaction between the Ni and Ln centers. Alternating current susceptibility measurements of complex 3 showed a small frequency dependence of the out‐of‐phase signal, χ′′M , under zero direct current field, but without achieving a net maximum above 2 K. Magnetic studies on 1 revealed that it has a significant magnetocaloric effect. 相似文献
49.
Tailored Synthesis of Various Nanomaterials by Using a Graphene‐Oxide‐Based Gel as a Nanoreactor and Nanohybrid‐Catalyzed CC Bond Formation
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New graphene oxide (GO)‐based hydrogels that contain vitamin B2/B12 and vitamin C (ascorbic acid) have been synthesized in water (at neutral pH value). These gel‐based soft materials have been used to synthesize various metal nanoparticles, including Au, Ag, and Pd nanoparticles, as well as nanoparticle‐containing reduced graphene oxide (RGO)‐based nanohybrid systems. This result indicates that GO‐based gels can be used as versatile reactors for the synthesis of different nanomaterials and hybrid systems on the nanoscale. Moreover, the RGO‐based nanohybrid hydrogel with Pd nanoparticles was used as an efficient catalyst for C? C bond‐formation reactions with good yields and showed high recyclability in Suzuki–Miyaura coupling reactions. 相似文献
50.