摘要
HNO和CH_2O可在λ_(EXC)≥645nm和λ_(EXC)=345 nm的光照射下,生成顺式和反式亚硝基甲醇。对于这个光反应,实验工作者提出了两种机理。本文用ab initio方法(STO-3G基组),通过求得反应的S_0、S_1和T_1态的过渡态及反应途径(IRC),并用GUGA CI方法(基于图形酉群理论的CI方法)计算能量,支持了实验提出的两种机理之一,即在两种入射光照射下,第一步都生成反式亚硝基甲醇,在λ_(EXC)≥645nm的入射光继续照射下,第一步生成的反应产物光异构化为顺式的机理。
Two different mechanisms have been put experimently forward for the photoreaction, in which HNO and CH_2O under both irradiation conditions at λ_(EXC)≥645 nm or λ_(EXC)=345 nm can produce cis and trans nitrosomethanol. In present paper, we located the S_0, S_1 and T_1 transition state and traced the IRC's of the reaction based on the ab initio method with STO-3G basis set. Using the GUGA CI method, we also calculated reactive and exciting energies of the reaction system. Our theoretical results support one of the two possible mechanisms suggested by experimentalists. We showed that whether the reactants are irradiated by light of λ≥645 nm or by light of λ=345 nm, in the first step of the reaction, the product formed will be trans nitrosomethanol.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
1989年第3期340-347,共8页
Acta Physico-Chimica Sinica
基金
The project supported by National Natural Science Foundation of China
