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化学学报
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化学学报 ›› 2002, Vol. 60 ›› Issue (9): 1564-1570. 上一篇    下一篇

研究论文

硫叶立德化合物优势构型和键结构的量子拓扑研究

曾艳丽;郑世钧;孟令鹏   

  1. 河北师范大学化学学院计算量子化学研究所,石家庄(050091)
  • 发布日期:2002-09-15

Topological Studies on the C-S Bond of S-Ylide Compounds

Zeng Yanli;Zheng Shijun;Meng Lingpeng   

  1. Institute of Quantum Chemistry at College of Chemistry, Hebei Normal University,Shijiazhuang(050091)
  • Published:2002-09-15

PDF

449

被引次数

25 | 4

采用MP4（SDTQ）/6-311++G（d,p）和B3LYP/6-311++G（d,p）对所选四种化合 物进行构型优化，从量子拓扑学的角度对各稳定构型进行电子密度拓扑分析，讨论 了C-S键的特性。研究发现：（1）类硫叶立德自由基（·CHSH_2）和硫叶立德（ CH_2SH_2）基态的稳定构型都不具有C_s对称性；（2）类硫叶立德自由基和硫叶立 德中C-S键的性质类似，硫叶立德中π键由两个电子形成，类硫叶立德自由基中π 键由一个电子形成，所以前者的π键性质明显，后者的π键性质不明显；（3）类 硫叶立德自由基（·CHSH_2）中单电子π键中的电子主要在碳原子附近运动，属于 单电子π（C → S）配键，所以其C-S键的强度比相应的产物要弱。

关键词: 硫叶立德, 拓扑, 化学键, 电子密度, 构型

MP4(SDTQ)/6-311++G(d,p) and B3LYP/6-311++G(d,p) calculations were carried out to optimize the structures of S-ylide compounds. The C-S bond characters were discussed by topological analysis of the electronic density. The following conclusions are drawn: (1) Neither the S-ylide nor the S-ylide-like radical has C_s symmetry. (2) The C-S bond character of S-ylide-like radical is similar to that of S-ylide, there exist π bonds in both types of ylide compounds. However, there are two electrons in the π bond of S-ylide, while there is only one electron in the π bond of S-ylide-like radical. (3) The electron in the π bond of S-ylide-like radical appears mainly near the C atom. It has π(C → S) bond character, therefore it is weaker than the C-S bond in the corresponding product.

Key words: S-ylide, TOPOLOGY, CHEMICAL BONDS, ELECTRON DENSITY, CONFIGURATION

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