HNO(HNS)与分子簇(HF)_(1≤n≤3)形成蓝移氢键的理论研究  

Theoretical Study on Blue-Shifted H-Bonds of HNO(HNS) with (HF)_(1≤n≤3)

作　　者：倪杰[1] 黎安勇[1] 闫秀花[1] 

机构地区：[1]西南大学化学化工学院,重庆400715

出　　处：《西南大学学报（自然科学版）》2009年第1期49-54,共6页Journal of Southwest University(Natural Science Edition)

基　　金：重庆市自然科学基金资助项目(230413515)

摘　　要：运用量子化学从头算方法研究了HNO(HNS)与(HF)1≤n≤3形成的蓝移氢键.计算结果表明:在HNO体系中,氢键NH…F的形成导致NH键收缩与伸缩振动频率蓝移,且随着n增大而增大;在HNS体系中,NH键是微小蓝移的,但键长增大,n相同时,NH键蓝移比HNO体系的小很多.电子密度拓扑(AIM)分析阐明了这些分子间相互作用的氢键性质.自然键轨道(NBO)分析表明,在HNO体系中,重极化和重杂化以及分子内超共轭大幅度减小导致了NH键的蓝移;而HNS体系中NH键蓝移很小主要是由于n(S)的超共轭给予能力比n(O)小,因而对σ*(NH)电子密度的调节能力小的缘故.The blue-shifted H-bonds between HNO（HNS） and （HF）1≤n≤3 are theoretically studied in this paper, using ab initio calculation. The calculated results show that in the HNO systems the H-bonds NH F lead to large contraction of NH bonds and large blue shifts of NH stretch frequency, which increase with n, and that in the HNS systems the blue shifts of NH stretch frequency are much smaller than those in the HNO system with the same n. Topological analysis of electron density demonstrates that these interactions are indeed H-bonds. Natural bond orbital analysis shows that in the HNO system, the blue-shifted H-bonds are caused by repolarization and rehybridization and by the great decrease in intramolecular hyper- conjugation, while in the HNS systems, the reason why the blue shifts of NH bonds are very small is that the ability of hyperconjugation donation and adjustability on electron density in σ＊ （NH） of n（S） is much smaller than that of n（O）.

关 键 词：蓝移氢键 电子密度拓扑分析 分子间与分子内超共轭 重杂化 

分 类 号：O641.2[理学—物理化学]