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1.
Mixed complexes of Pb(II) with some carboxylate ions, viz. tartrate (tart2?), malonate (mal2?) and citrate (citr3?); and imidazole (im) have been studied polarographically at 25°C and at constant ionic strength μ = 2.0 (NaNO3) and at pH 6. The polarographic reduction of the complexes in each case is reversible and diffusion-controlled. Pb(II) forms a single mixed complex with tartrate and imidazole, viz [Pb(tart)(im)] with stability constant log β11 = 4.19; with mal2? and im, three mixed complexes, [Pb(mal)(im)], [Pb(mal)(im)2] and [Pb(mal)2(im)]2? with stability constants log β11 = 4.3, log β12 = 7.3 and log β21 = 5.5 respectively are formed. With citr3? and im a single mixed species, [Pb(citr)(im)]? with stability constant log β11 = 8.0 is formed. Various equilibria involved in the mixed systems have been discussed. 相似文献
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The mixed complexes of Eu(III) with succinate (succ2?) and malonate (mal2?) and ethylenediamine (en) have been studied polarographically at 25°C and at constant ionic strength, μ = 0.1 (NaNO3) and pH 6. The reduction of the complexes in each case is quasi-reversible and diffusion-controlled. In each system three mixed complexes are formed, viz. [Eu(succ)(en)]+, [Eu(succ)(en)2]+ and [Eu(succ)2(en)]? with stability constants log β11 = 9.2, log β12 = 17.5 and log β21 = 11.7; and [Eu(mal)(en)]+, [Eu(mal)2(en)2]? and [Eu(mal)3(en)]3? with stability constants log β11 = 11.4, log β22 = 19.08 and log β31 = 13.5 respectively. 相似文献
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Ganeshpurkar Ankit Singh Ravi Shivhare Shalini Divya Kumar Devendra Gutti Gopichand Singh Ravibhushan Kumar Ashok Singh Sushil Kumar 《Molecular diversity》2022,26(3):1455-1479
Molecular Diversity - Structure-based drug design (SBDD) is an important in silico technique, used for the identification of enzyme inhibitors. Acetylcholinesterase (AChE), obtained from... 相似文献
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Summary The spectrophotometric determination of dimethyl formamide comprises hydrolysation to dimethyl amine and reaction with carbon disulphide to dithiocarbamate, which gives a yellow complex (max=430 nm) with copper(II). Standard deviation was ±0.0086 g/ml. There are no interferences from various copollutants. 相似文献
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Spectrophotometric determination of Zineb (a dithiocarbamate fungicide) by the methylene blue method
V. Agrawal P. Shivhare V. K. Gupta 《Fresenius' Journal of Analytical Chemistry》1992,344(7-8):350-352
Summary A spectrophotometric method has been developed for the determination of Zineb in water and vegetables. The method is based on the liberation of hydrogen sulphide from Zineb, which is trapped in an absorbing solution of triethanolamine, sodium hydroxide and ethylenediamine tetraacetic acid. The absorbing solution is treated with N-N-dimethyl-p-phenylene diamine sulphonate and ferric chloride to form methylene blue. Beer's law is obeyed over the concentration range of 3–32 ppm. The method is simple and can be used for the determination of Zineb in the presence of other dithiocarbamates. 相似文献
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Km Neha Shivhare 《Supramolecular chemistry》2019,31(1):52-61
An elegant, mild, and straightforward strategy for the synthesis of indole derivatives have been accomplished by the biomimetic catalysis for the first time in water under neutral conditions. This supramolecular catalyst oriented methodology provides a sustainable and green protocol for the synthesis of 6H-indolo[2,3-b]quinoxalines and 3H-spiro[benzo[d]thiazole-2,3’-indolin]-2’-one by the reaction of isatin derivatives with 1,2-difunctionalized benzene using β-cyclodextrin (β-CD) as a recoverable and reusable supramolecular catalyst. 相似文献
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Nazeef Mohd Shivhare Km Neha Ali Shabir Ansari Saif Siddiqui I. R. 《Molecular diversity》2021,25(4):2479-2486
Molecular Diversity - A new metal-free approach to construct medicinally valuable 1-aryl-1H,3H-thiazolo[3,4-a]benzimidazoles under visible light irradiation in aqueous ethanol medium at room... 相似文献
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Hafeesudeen Sahabudeen Dr. Haoyuan Qi Marco Ballabio Dr. Miroslav Položij Dr. Selina Olthof Rishi Shivhare Dr. Yu Jing SangWook Park Kejun Liu Dr. Tao Zhang Ji Ma Dr. Bernd Rellinghaus Prof. Dr. Stefan Mannsfeld Prof. Dr. Thomas Heine Prof. Dr. Mischa Bonn Prof. Dr. Enrique Cánovas Prof. Dr. Zhikun Zheng Prof. Dr. Ute Kaiser Dr. Renhao Dong Prof. Dr. Xinliang Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6084-6092
Single-layer and multi-layer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the long-range transport properties. Here we employ a surfactant-monolayer-assisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimine-based 2D polymer (PI-2DP) films with square and hexagonal lattices, respectively. The synthetic PI-2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200 nm and large crystalline domains (100–150 nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PI-2DP are investigated by time-resolved terahertz spectroscopy. Typically, the porphyrin-based PI-2DP 1 film exhibits a p-type semiconductor behavior with a band gap of 1.38 eV and hole mobility as high as 0.01 cm2 V−1 s−1, superior to the previously reported polyimine based materials. 相似文献
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A sensitive spectrophotometric method for the determination of paraquat using ascorbic acid (an easily available reducing agent) is described. Paraquat is reduced with ascorbic acid in alkaline solution to give a blue radical ion with an absorbance maximum at 600 nm. Beer's law is obeyed in the range 12-96 micrograms of paraquat in 10 ml of the final solution (1.2-9.6 ppm). The important analytical parameters and the optimum reaction conditions were evaluated. The method was applied successfully to the determination of paraquat in water, grain and plant materials. 相似文献