摘要
采用ＵＨＦ及ＵＭＰ＿２方法，对~１Σ~＋Ｎｉ─ＣＯ分子簇的成键机制进行了从头算研究。计算表明，在σ空间，Ｎｉ~１Ｓ（ｄ^（１０））导出态的主要成键特征是ＣＯ５σ→Ｎｉ４ｓ的授键作用；而Ｎｉ~１Ｄ（ｄ~９ｓ~１）导出态的主要特征是４ｓｐ＿σ极化。在~１Σ~＋Ｎｉ─ＣＯ分子簇中总的成键机制是：ｄ^（１０）导出态中π反馈作用大于σ授键作用；而ｄ~９ｓ~１导出态中σ授键作用强于π反馈作用。由于接受配键机制一定伴随着轨道之间的重叠，因而为了给出合理的Ｍ─Ｌ作用分析，进行补偿计算是重要的。
UHF and UMP_2 are employed to investigate the bonding mechanism of￣1Σ￣+Ni-CO molecular cluster.The calculation results show that, in￣1Σ+Ni─CO σ subspace,CO 5σ→Ni 4s σ donation dominates in Ni￣1 S(d￣(10))derived state,while 4sp_σpolarization dominates in Ni￣1D(d￣9s￣1)derived state.The π backdonation is greater than σ donation in d￣(10)derived state,while σ donation is more important than π backdonation in d￣9s￣1 derived state, The calculation results demonstrate that it is important to perform a counterpoise calculation because there must exist an orbital overlapping in a donor-acceptor bonding mechanism.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1994年第10期1534-1537,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金重大项目资助课题
