1,2,5-噻二唑衍生物电子结构的紫外光电子能谱研究

首次报导了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）的分析以对研究分子Ｇａｕｓｓｉａｎ ９４ＳＴ０－６Ｇ从头计算电离能（－ε１）。化合物Ｂ ＵＰＳ谱带的ＩＰＳ比相应的化合物Ａ的ＩＰＳ均你芝归结为Ｂ分子中两个取代Ｃ１原子上电子的拥挤效应。计算的Ｂ的 有量（

HeI Photoelectron Spectroscopic Study on the Electronic Structure of the Derivatives of 1,2,5-thiadiazole

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.