Study of the laser-initiated chlorination of methyltrichlorogermane

Conclusions The high selectivity of the chlorination of CH₃GeCl₃with the formation of CH₂ClGeCl₃ by the action of a UV laser is independent of the emission wavelength in the range from 193 to 308 run. The quantum yield is not less than 10².Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2167–2170, September, 1988.     

硅胶负载钯催化剂对丙烯酸甲酯的催化加氢性能研究

本文报导一种新法制备的硅胶负载钯催化剂,其活性组份大部分负载于载体的表面。该催化剂在常温常压下对丙烯酸甲酯的液相加氢反应,即有很高的活性和良好的重复使用性能。 催化剂按下法制备:在圆底烧瓶中加入1.00g硅胶和20mL甲醇,抽真空置换出硅胶孔内的空气,在搅拌下加入一定浓度的吸附质(聚乙烯亚胺、正丙胺、正丁胺等),在25℃反应3—4小时,过滤,固体经甲醇充分洗涤后和一定浓度的氯化钯甲醇溶液反应6小时。过     

IR absorption spectra of some aminoalcohols in the gas phase

The IR spectra of aminoalcohols in the gas phase show that in practically all instances (with the exception of N-allylaminoethanol) they are present mainly as monomers, with or without intramolecular H-bonds (IHB), the former predominating in the vicinal compounds. In 1,4-aminoalcohols the concentrations of molecules with and without IHB are practically equalized. The strongest IHB occur in the seven-membered intramolecular rings which are formed in 4-aminobutan-1-o1, for which the greatest difference is observed between the frequencies of the free OH groups and those bound in IHB. Analysis of the effect of an increase in temperature on the intensities of the OH bands of the free OH groups and of those bound in IHB shows that the partial rupture of the IHB occurs to a greater extent in the unsubstituted aminoalcohols of the vicinal series than in aminoalcohols with two alkyl substituents on the amino group. The IHB exhibit less tendency to break with rise in temperature in the vicinal aminoalcohols than in the 1,3- and 1,4-aminoalcohols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1323–1333, June, 1990.     

金属有机化合物的分析（Ⅷ）：氢硼酸金属有机络合物的反相色谱机理

本文研究了具有特殊结构的氢硼酸金属有机络合物的反相色谱及机理。在MicropakC_(18)柱上,加入含离子试剂的甲醇-水作为流动相,通过用电导法测定流动相电性能,Break-through法测定离子试剂在固定相上的吸附量及制备色谱法研究各流分组成,认为此类化合物的保留机理为动态离子交换过程。     

The regioselectivity of the formation of 2-pyrazolylthiazoles and their precursors from the reaction of 2-hydrazinothiazoles with 4,4,4-trifluoro-1-hetaryl-1,3-butanediones

Reaction of 2-hydrazinothiazoles 1 with 1-thienyl- and 1-furyl-1,3-butanediones 2a,b in methanol in the presence of hydrochloric acid mainly leads to a mixture of pyrazoles 3 and pyrazolines 4 or pyrazoles 3 and 5 in strong acidic conditions. Isomeric hydrazones 6 and pyrazolines 4 were formed and isolated in these reactions in the absence of hydrochloric acid. It has been shown that the regioselectivity in the reaction of diketones 2 with hydrazine 1 is governed by both the concentration of acid and the nature of substituents in the 1,3-diketones 2. Cyclization of hydrazones 6 is shown to occur under milder conditions than dehydration for pyrazolines 4. The new heterocyclic compounds were prepared and fully characterized by NMR spectra and by X-ray analysis for 3c.     

Crystallographic parameters of 1-organylgermatranes

The crystallographic parameters and the translation groups of the elementary cells of the crystals of 1-methyl-, 1-ethyl-, 1-phenyl-, and 1--naphthylgermatranes have been determined by X-radiography. The volumes of the elementary cells (V), the number of molecules in them (N), the X-ray density of the crystals (x) and the packing coefficients for the molecules in the crystals (k) have been calculated from the linear and angular parameters.     

Experimental and modeling study on decomposition kinetics of methane hydrates in different media

The decomposition kinetic behaviors of methane hydrates formed in 5 cm3 porous wet activated carbon were studied experimentally in a closed system in the temperature range of 275.8-264.4 K. The decomposition rates of methane hydrates formed from 5 cm3 of pure free water and an aqueous solution of 650 g x m(-3) sodium dodecyl sulfate (SDS) were also measured for comparison. The decomposition rates of methane hydrates in seven different cases were compared. The results showed that the methane hydrates dissociate more rapidly in porous activated carbon than in free systems. A mathematical model was developed for describing the decomposition kinetic behavior of methane hydrates below ice point based on an ice-shielding mechanism in which a porous ice layer was assumed to be formed during the decomposition of hydrate, and the diffusion of methane molecules through it was assumed to be one of the control steps. The parameters of the model were determined by correlating the decomposition rate data, and the activation energies were further determined with respect to three different media. The model was found to well describe the decomposition kinetic behavior of methane hydrate in different media.