The task is to provide a method for producing straight-chain trisiloxane with a hydroxyl group at one end of the molecular chain and a hydroxyl group or alkoxy group at the other end, using an easily accessible cyclic trisiloxane as a raw material, with high yield and in a single step. The solution involves reacting various cyclic trisiloxanes with water or alcohol in the presence of hydrogen gas and/or a hydrogen generator, as well as a transition metal catalyst, to produce the desired trisiloxane compound. No figures are included.
Rates and mechanism of solvolysis of N-phenylcyclosilazoxanes
作者:Zygmunt Lasocki、Małgorzata Witekowa
DOI:10.1016/0022-328x(84)85132-3
日期:1984.3
The rates of solvolysis of some N-phenyl-1-aza-3,5-dioxa-2,4,6-tris(dimethylsily)cyclohexanes, substituted in the benzene ring, have been measured spectrophotometrically in methanol containing a small quantity of water. The reaction is subject to general acid catalysis and is inhibited by weak bases. Electron-donating substituents accelerate the solvolysis. The ϱ-constant, derived from the linear relation
已用分光光度法在含有少量水的甲醇中分光光度法测定了一些被苯环取代的N-苯基-1-氮杂-3,5-二氧杂-2,4,6-三(二甲基甲硅烷基)环己烷的溶剂分解速率。该反应经受一般的酸催化并被弱碱抑制。给电子的取代基加速了溶剂分解。由速率常数和Hammettσ常数的对数之间的线性关系得出的ϱ常数为-1.2(在中性介质中为ϱ = -1.0)。发现了氘的反向同位素效应(k H / k D= 0.82)。所提出的SiN键裂解和相关的开环机理涉及溶剂分子对硅的同时亲核攻击和通过质子从催化酸转移到氮的亲电辅助。
Alkylalkoxypolysiloxanes. IV. Lower Members of Methoxy End-blocked Dimethylpolysiloxanes with One to Six Silicon Atoms
作者:Toshio Tanaka、Rokuro Okawara
DOI:10.1246/bcsj.28.364
日期:1955.5
(1) Methoxy end-blocked dimethylpolysiloxanes have been prepared by the reaction of sodium bicarbonate with partially methanolyzed dimethyldichlorosilane.(2) Distribution of the lower polymers was determined in regard to the composition of the partially methanolyzed dimethyldichloro-silane.(3) Methoxy end-blocked dimethylpolysiloxanes from monomer (dimethyldimethoxysilane) to hexamer have been characterized.