摘要
首次报导1,2,5 噻二唑衍生物3 氯 1,2,5 噻二唑(A)和3,4 二氯 1,2,5 噻二唑(B)化合物的紫外光电子能谱 (UPS).谱带的指认建筑在对谱带形状、相对强度、实验电离能 (IPs)的分析以及对研究分子的Gaussian94STO 6G从头计算电离能( -εi).化合物BUPS谱带的IPs比相应的化合物A的IPs均低,这归结为B分子中两个取代Cl原子上电子的拥挤效应.计算的B的总能量(Etol= -1501.1a.u.)比A分子(Etol= -1042.2a.u.)的低 ,也表明B有较高的热解能 ,这与其热解产生星际物种的结果相一致.
The HeI photoelectron spectra (UPS) of 3 chloro 1,2,5 thiadiazole (A)and 3,4 dichloro 1,2,5 thiadiazole (B) are reported for the first time. The assignment of the UPS bands for the compounds studied has been made by the band shapes,the relative intensity of the bands and the experimetal ionization energies as well as ab initio Gaussian 94 STO 6G calculations on the molecules studied. The lower ionization energy of B compound compared with that of A might be due to the “crowding effect”of two chlorine atoms in the B molecule. The total energy (Etot=-1501.1 a.u.) for B compound is lower than that (Etot=-1042.2 a.u.) of A compound. This means also that B has higher thermal pyrolysis energy which is consistence with the result of the interstellar species produced by pyrolysis of A and B.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2000年第6期491-495,共5页
Acta Physico-Chimica Sinica
基金
国家自然科学基金!资助项目 (29973051)
关键词
紫外光电子能谱
1
2
5-噻二唑衍生物
从头算
HeI photoelectron spectra(UPS), Derivatives 1,2,5 thiadiazole, Ab initio
