电子光谱法研究不饱和酯类硅氢化的催化作用机理

Study on Catalytic Mechanism of Hydrosilylation of Unsaturated Esters by Electronic Spectroscopy

采用电子光谱法考察硅氢化反应中催化剂Pt(Ⅳ)或Pt(Ⅱ)物种和不饱和化合物的特征吸收,从而提出其催化作用的关键中间体和催化机理,实验表明:催化剂中ROH主要起溶剂作用,Pt(Ⅳ)催化物种容易被HSiR_3还原为动力学活性的Pt(Ⅱ)催化物种;反应诱导期是关镇中间体生成与增加的过程。

Specif ic absorption bands of catalytic species Pt(Ⅳ)or Pt(Ⅱ) and unsaturated reactant in hydrosilylation were studied by electronic spectroscopy. The key medium and the mechanism of the catalytic process in hydrosilylation were suggested. The experiment showed, a)ROH in the catalyst acts mainlg as a solveat; b) catalytic species Pt(Ⅳ) can be easily reduced by R3SiH tc another catalytic species Pt(Ⅱ) with high activity;c) the reaction induction period is the production and accumulation of the key medium.