对吡啶的邻、间、对位的双自由基体系的理论研究Theoretical study of biradical organic molecules with o,m,p-pyridine
储德清,王立敏,李聪,张景萍,王荣顺
摘要(Abstract)：
针对以吡啶为耦合单元,以·CH2、·NH2+、HNO·和·NH 4种自由基为自旋单元的5种体系,采用密度泛函方法进行计算,得到了双自由基之间磁性耦合的拓扑规则,即共轭体系中,两个自由基之间以偶数个碳(或氮)原子耦合,体系具有低自旋基态,表现为反铁磁耦合;两个自由基之间以奇数个碳(或氮)原子耦合,体系具有高自旋基态,表现为铁磁耦合．计算也说明,间位取代吡啶可以充当很好的铁磁耦合单元, 而邻位和对位取代吡啶不可以充当铁磁耦合单元．在2,6取代吡啶中以HNO·作自旋中心分子的高自旋基态有最稳定性,在3,5取代吡啶中以·NH作自旋中心分子的高自旋基态有最稳定性．
关键词(KeyWords)： 吡啶;自由基;UB3LYP;铁磁耦合
基金项目(Foundation): 天津工业大学校内基金资助项目(029307)和(029302) 天津大学博士后基金资助项目(413220)
作者(Author): 储德清,王立敏,李聪,张景萍,王荣顺
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