高等学校化学学报2001，Vol.22Issue(2)：252-256,5.
第一过渡系金属硅烯配合物的理论研究
Theoretical Study of the Complexes of First-row Transition Metals with SiH2
摘要
Abstract
The HF/6-311+G* basis set was used to study the characteristics of molecular orbitals and bond dissociation energies of the complexes, MSiH2, of the first-row transition metals with SiH2. The atoms in MSiH2 are all coplanar, and M—Si bonds of ground state 3TiSiH2 and 4CoSiH2 show obviously the double bond characteristic. In 4VSiH2 and 5CrSiH2 there is the week single occupied π bond. The 8MnSiH2 with a high-spin eightet ground state has both of single occupied σ and π bonds, and chief component of its σ and π orbital are the Mn 4s and the Si 3px orbitals, respectively. Other ground state MSiH2 have only a double occupied σ single bond. The most of M—Si bonds are quite covalent. The formation of M—Si σ bonds can be considered as the interaction between one electron in 4s or 4pz, or 3d orbital of M and other electron in Si sp hybrid orbital. The double occupied π bonds are also considered as the pairing of one π electron of SiH2(3B1) with one 3d electron of M. All of the HSiH bond angles in MSiH2 are closed to that in SiH2(3B1). It means that the Si in MSiH2 still keeps a sp hybrid orbital similar to Si in SiH2(3B1 states). The Sc—Si, V—Si and Ni—Si bonds are longer because their formation involves mainly the 4s orbitals of M. On the contrary, the Cu—Si bond is shorter since its σ bond would involve primarily the M 3dZ2 \{obitals\}. The 3TiSiH2 and 4CoSiH2 have much shorter bond lengths and larger bond dissociation energies because of their double bond character. From Sc to Cu, the bond dissociation energies of M—Si change in periodic trend. There is an approximate linear relationship between the bond dissociation energies and the metal ion promotion energy.关键词
过渡系金属配合物/键解离能/硅烯/从头算分类
化学化工引用本文复制引用
李吉海,高建军,冯大诚,冯圣玉..第一过渡系金属硅烯配合物的理论研究[J].高等学校化学学报,2001,22(2):252-256,5.基金项目
国家自然科学基金 （）
