The stabilization energies of substituted lithium carbene cations were calculated by using ab initio molecular orbital theory, and the relationship between the stabilization energies and molecular orbitals was discuss...The stabilization energies of substituted lithium carbene cations were calculated by using ab initio molecular orbital theory, and the relationship between the stabilization energies and molecular orbitals was discussed. The substituents with pi donor engender strong stabilization to CH2Li+. The calculations show the Y-C* bond lengths of cations become shorter and H-Y bond lengths longer than those of corresponding neutral molecules.展开更多
The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH 2 + were investigated byab initio molecular orbital theory (HF/LAYL2DZ). All of MCH 2 k are coplanar. In the closed shel...The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH 2 + were investigated byab initio molecular orbital theory (HF/LAYL2DZ). All of MCH 2 k are coplanar. In the closed shell structures the C hlnds to M with double bonds:while in the open shell structures the partial double bonds are formed. because one of the σ and π orbitals is singly occupied. It is mainly the π-type overlap between the 2p x orbital of C and 4p x , 3d xx orbitals of M+ that forms the π orbitals. The dissociation energies of C—M bond appear in periodic trend from Sc to Cu. Most of the calculated band dissociation energies are close to the experimental ones.展开更多
文摘The stabilization energies of substituted lithium carbene cations were calculated by using ab initio molecular orbital theory, and the relationship between the stabilization energies and molecular orbitals was discussed. The substituents with pi donor engender strong stabilization to CH2Li+. The calculations show the Y-C* bond lengths of cations become shorter and H-Y bond lengths longer than those of corresponding neutral molecules.
基金Project supported by the National Natural Science Foundation of China (Grant No. 29170070)
文摘The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH 2 + were investigated byab initio molecular orbital theory (HF/LAYL2DZ). All of MCH 2 k are coplanar. In the closed shell structures the C hlnds to M with double bonds:while in the open shell structures the partial double bonds are formed. because one of the σ and π orbitals is singly occupied. It is mainly the π-type overlap between the 2p x orbital of C and 4p x , 3d xx orbitals of M+ that forms the π orbitals. The dissociation energies of C—M bond appear in periodic trend from Sc to Cu. Most of the calculated band dissociation energies are close to the experimental ones.
