瞬态吸收光谱研究水相中三苯基锡与·OH自由基反应机理

Study on the Reaction Mechanism of Triphenyltin with ·OH Radical in Aqueous Phase by Transient Absorption Spectra

利用激光闪光光解技术进行了有氧和无氧条件下氯化三苯基锡与亚硝酸水溶液的紫外光解反应研究.结果表明,·OH和三苯基锡阳离子(SnPh+3)反应生成了瞬态粒子SnPh+3-OHadduct,其二级生成速率常数为(7.9±1.2)×109L·mol-1·s-1.在N2饱和时,SnPh+3-OHadduct以单分子反应方式衰减,衰减速率常数为(1.15±0.15)×105s-1;在O2饱和时,表观一级衰减常数增加为(1.87±0.25)×105s-1,这是由于SnPh+3-OHadduct能够与O2发生作用生成SnPh+3-OHO2,其二级反应速率常数为(6.0±2.9)×107L·mol-1·s-1.

The reaction of triphenyltin with nitrous acid in aqueous phase in the presence and absence of O2 was studied by a laser flash photolysis technique. The main characteristic peaks in these transient absorption spectra were attributed and the build-up/decay trends were investigated. Triphenyltin cation reacts with ,OH radical to produce SnPh3^＋-OH adduct and the reaction rate was measured to be （7.9±1.2）×10^9L·mol^-1·s^-1. SnPh3^＋-OH adduct decayed at a constant of （1.87±0.25）×10^5 and （1.15±0.15）×10^5s^-1 in the presence and absence of O2 respectively. The decay rate in the presence of O2 was higher due to the reaction between SnPh3^＋ -OH and O2 which produces SnPh3^＋ -ono2 at a rate constant of （6.0±2.9）×10^7L·mol^-1·s^-1.