Kekulé-based Valence Bond Model.I. The Ground-state Properties of Conjugated π-Systems

• 来源期刊: 中国化学(英文版)
• 年，卷（期）: 2002,（11）
• 页码范围: 1168-1179
• 页数: 12页
• 语种: 英文

摘要

The Kekulé-based valence bond ( VB ) method, in which the VB model is solved using covalent Kekulé structures as basis functions, is justified in the present work. This method is dimonstrated to provide satisfactory descriptions for resoance energies and bond ang lengths of benzenoid hydrocarbons, being in good agreement with SCF-MO and experimental results. In additicn, an alternative way of discyssing characters of localizedsubstructures within a polyclic benzenoid system is suggested based upon such sunokufied VB calculations. Finally,the symmetries of VB ground states for nonalternant conjugated systems are also illustrated to be obtainable through these calculations, presenting very useful information for understanding the chemical behaviors of some nonalternant conjugated molecules.