几种硫醚化合物的紫外光电子能谱及量子化学研究

Hel Photoelectron Spectroscopical and Theoretical Studies of the Electronic Structure and Molecular Obital Character in some Alkyl Thioether Compounds

报导了硫酸系列化合物DMS（二甲基硫酸），DpCPS（二对氯苯硫酸），DpTS（二对甲基苯硫醚）气相HcI紫外光电子能谱（UPs），其中DpCPS，DpTS的UPS谱为首次获得．对各体系利用MNDO方法进行了分子构型优化，对优化得到的优势构型实施RHF／6－31G量子化学计算，并利用计算结果对各个分子体系的UPS谱进行了指认，计算结果分析显示：a）S原子的孤对电厂在DpCPS和DpTS中起到阻碍形成遍及整个分子体系π轨道的阻断作用，故此不存在遍及整个分子体系的π轨道；b）通过对三体系第一电高能的对比分析表明，第一电高能所激发出的电子主要是受S原子的束缚；c）还得到另一个有意义的结论──各分子体系的第一电离能大小与HOMO中3Pz轨道所占成份成有很好的线性关系．

The HeI photoelectron spectra of dimethyl thioether, di-p-chlorphenyl thioether and di-p-tolyl thioether have been studied. To assign these spectra MNDO optimization and RHF/6-31G molecular Orbital calculation for the named molecules have also been performed. The results show that: a) The lonc-pair electrons of the sulfur atoms can be considered as an obstructor forcomplete molecular conjugation and so there is no conjugated π bond in the whole molecules;b)The electron which has been ionized by the lowest ionization potentials is bound mainly to thesuflur atom, according to the features analysis of the lowest lonization potentials for the namedsystem; c)The RHF/6-31G calclation results show that the lowest ionization potentials of thenamed compound are directly proptional to the composition of 3Pz of sulfur atom in the HOMO.