五元硫氮环与硼氮环的从头算比较研究

A COMPARATIVE AB INITION STUDIES ON FIVE-MEMBEREDSULFUR NITROGEN RINGS AND BORON NITROGEN RINGS

本文用从头算方法 ,在 4～ 3 1 G基组水平上 ,对系列平面 S-N环、B-N环分子 ,包括实验上已知的分子和未知分子的几何构型进行了全优化 ,得出了平面稳定构型 .根据 Mulliken重迭布居 ,原子净电荷和轨道布居讨论并比较了构型相似的 S-N与 B-N环分子的电子结构 ,揭示了富电子环与缺电子环成键情况的实质不同 ,以及 B、S、N原子上加

the theoretical studies have been carried out for planar sulfur nitrogen rings and boron-nitrogen rings by using AB INITIO method at the 4～31G set levels.All these molecules,include known and unknown rings have been full optimized and their planar geometric configurations were obtained.Elecronic structures of similar configurations sulfur-nitrogen rings and boron-nitrogen rings were determined using Mulliken overlap populations,net charges and orbital populations,it is indicated that the natures of the chemical bonds in electron-rich rings and electron-deficient rings are different.If the boron or/and nitrogen atoms and sulfur or/and nitrogen atomsare linked with hydrogen atoms,bheir effects on the stabilities of rings are also different.