四元硫氮环与硼氮环的从头算比较研究

A COMPARATIVE AB INITIO STUDIES ON FOUR-MEMBERED SULFUR-NITROGEN RINGS AND BORON-NITROGEN RINGS

本文用从头算方法,在4～31G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,得出了它们的平面稳定构型.根据Malliken重速布居,原子净电荷和轨道布居讨论并比较了构型相似的S-N环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H对环的稳定性影响的不同.

The theoretical studies have been carried out for planar sulfur-nitrorgen 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 popu!ations,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 atoms are linked with hydrogen atoms, their effects on the stabilities of rines are also different.