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991.
F. N. Guseinov R. N. Burangulova E. F. Mukhamedzyanova B. P. Strunin O. G. Sinyashin I. A. Litvinov A. T. Gubaidullin 《Chemistry of Heterocyclic Compounds》2006,42(7):943-947
Heterocyclization of 2-chloroepoxy-1,1-diethoxy-2.3-butane with 2-amino-4-methylpyridine occurred with participation of all
three potential electrophilic centers to give 3,7-dimethyl-2-[N-(4-methylpyridyl-2)-4-hydroxy-3-methyl-5-oxopyrrolen-3-yl]imidazo[1,2-a]pyridine,
the structure of which was determined by X-ray crystallography.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 1089–1094, July 2006. 相似文献
992.
Vaishali Tiwari 《Thermochimica Acta》2006,443(2):206-211
Densities ρ and viscosities η of two hydroxamic acids, N-phenyl-2-chlorobenzo- and N-o-tolyl-4-chlorobenzo-, have been determined as a function of their concentration in aqueous acetone solution at temperatures 303.15 and 313.15 K. Apparent molar volumes, standard-state partial molar volumes and relative viscosities have been calculated. The viscosity data have been analyzed using Jones-Dole equation. The activation thermodynamic parameters of viscous flow have been evaluated using Feakins equation. These were obtained to throw light on the mechanism of viscous flow. Thermodynamic interactions in solutions have been studied in terms of a number of excess functions calculated from the experimental data. The effect of hydroxamic acid concentration and temperature on these parameters has been discussed. The results were interpreted in the light of solute-solvent interactions in aquo-organic media. 相似文献
993.
A new catalyst has been prepared by coprecipitation sedimentation method developed in our laboratory. It exhibits excellent
catalytic activity, selectivity and stability for conversion of synthesis gas to dimethyl ether: conversion of CO 92%, selectivity
of dimethyl ether 98%. Catalytic properties of the catalyst show no evident change after being used for 100 h. 相似文献
994.
Yi Bo ZHOU Jun An MA Li Xin WANG Qi Lin ZHOU* State Key Laboratoratory Institute of Elemento-Organic Chemistry Nankai University Tianjin 《中国化学快报》2002,13(10)
During the last decade, 1-aminocyclopropanecarboxylic acid and its derivatives (ACCS) have attracted increasing attention of organic and bioorganic chemists due to their outstanding biological properties, ranging from antimicrobial, insecticidal, plant growth and fruit ripening controls, etc.1. Moreover, the three-membered carbocycle provides building blocks of unprecedented synthetic potential because it undergoes selective ring opening, ring enlargement or cycloaddition reactions2. The mo… 相似文献
995.
Glass capillaries coated with Chirasil-Val, a chirally functionalised polysiloxane, are capable in principle of resolving all protein amino-acid enantiomers in a single run and within a short analysis time, thus allowing for example the quantitative amino acid determination by enantiomer labelling. The elution characteristics of the individual amino acids however are also dependent upon the chemical nature of the capillary wall surface, and a surface pretreatment is found to be necessary if all protein amino acids are to be analysed. Of the various methods of pretreatment tested, etching of borosilicate glass with gaseous HCl followed by deposition of colloidal silicic acid is considered to be the most suitable. 相似文献
996.
碱处理笼形聚偕氨肟树脂(BCAO)对羧酸表现出强的吸附能力。一元羧酸在BCAO树脂上以多层吸附为主要特征。二元和三元羧酸则以单层吸附占优势。后者可能是以双阴离子的一个负极吸着在BCAO树脂表面,形成了对其他羧酸阴离子起排斥作用的负离子场。另外,双阴离子也有可能和两个氨基结合形成次级交联,妨碍着其他离子迁移和扩散。 相似文献
997.
Raman phonon spectroscopy has been used to study photodimerization reaction inp-chloro cinnamic acid (pCCA) crystal. The β-form of the crystal yields the 4,4′-dichloro-β-truxinic acid dimer. Six distinct low frequency phonon
bands are observed in thepCCA monomer crystal. On reaction progress, these bands show a monotonic shift to lower frequencies and broaden out. Finally,
in the dimer crystal the phonon spectrum shows two weak broad bands. These results suggest that the reaction is homogeneous
in the initial stages and, as the product concentration increases, the lattice becomes highly disordered. The reactant and
the product were characterised by infrared and Raman spectroscopy. The disappearance of aliphatic C=C bond stretching vibration
and appearance of cyclobutane ring deformation and cyclobutane ring-breathing vibrations on reaction confirm photodimerization
by cyclobutane ring formation. The large Stoke's shift between the absorption and emission band suggest strong exciton-phonon
coupling in the monomer lattice. This reaction seems to be phonon-mediated. 相似文献
998.
999.
Y. E. Kuznetsov N. L. Sukhov F. V. Pichugin B. G. Ershov 《Russian Chemical Bulletin》1996,45(12):2816-2819
Reactions ofmyo-inositiol hexa-O-nitrate with ammonia and primary amines yield tetrahydroxy-1,4-benzoquinone derivatives,viz., its tetraammonium salt and its diimines, respectively. Reactions with secondary and tertiary amines give salts of rhodizonic acid, which are converted into salts of croconic acid under certain conditions. The reactions with secondary amines involve intermediate formation of radical species, which were dectected by ESR spectroscopy. A scheme for the chemical transformations ofmyo-inositol hexa-O-nitrate under the action of amines was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2962–2967, December, 1996. 相似文献
1000.
Ruo Zhong WANG Lang Tao XIAO Ming Hui YANG Jun Hui DING Feng Li QU Guo Li-SHEN 《中国化学快报》2006,17(12):1585-1588
Platinum nanowire (PtNW) can be grown by electrodeposition in polycarbonate membrane, with the average diameter of the nanowires about 250 nm. The PtNW and multiwalled carbon nanotubes (CNT) are then dispersed into chitosan (CHIT) solution. The resulting PtNW-CNT-CHIT material brings new capabilities for electrochemical devices by using the synergistic action of the electrocatalytic activity of PtNW and CNT. By dropping the PtNW-CNT-CHIT film onto the glassy carbon (GO) electrode surface, and after evaporation an amperometric sensor for the determination of indole-3-acetic acid (IAA) was developed. The oxidation current of IAA increased significantly at the PtNW-CNT-CHIT film coated GC electrode, in contrast to that at the CNT-CHIT modified GC. The linear response of the sensor is from 50 ng/ml to 50 μg/ml with a detection limit of 25 ng/mL. 相似文献