A technique for determining the HMO parameters with MS-Xα-SCF method has been de- veloped. The ionization potentials of even polyenes and condensed benzene compounds have been calculated. The average deviation from t...A technique for determining the HMO parameters with MS-Xα-SCF method has been de- veloped. The ionization potentials of even polyenes and condensed benzene compounds have been calculated. The average deviation from the existent experimental values is 0.34 eV.展开更多
The role of the sulfur 3d orbitals in bond formation is discussed by taking into account the influence of the environment on the orbitals of the sulfur atom in the molecules. The ca cula- tion results of a series of p...The role of the sulfur 3d orbitals in bond formation is discussed by taking into account the influence of the environment on the orbitals of the sulfur atom in the molecules. The ca cula- tion results of a series of prototype molecules containing sulfur such as SF_2, SF_4, NSF_3, SF_1, H_2S are reported. It is convincingly shown that in highly electronegative environment the energy levels of the sulfur 3d orbitals are reduced to the vicinity of those of the ligand valence orbitals and their spatial distributions are contracted to the bonding area, and therefore they can participate in bond formation to a certain extent, which is enhanced by the formation of the d-p π back bonds. It seems that the result reported in this paper is helpful for the solution of the long-standing debate about the sulfur 3d orbital participation in bond formation.展开更多
基金This research was supported by the National Natural Science Foundation of China.
文摘A technique for determining the HMO parameters with MS-Xα-SCF method has been de- veloped. The ionization potentials of even polyenes and condensed benzene compounds have been calculated. The average deviation from the existent experimental values is 0.34 eV.
文摘The role of the sulfur 3d orbitals in bond formation is discussed by taking into account the influence of the environment on the orbitals of the sulfur atom in the molecules. The ca cula- tion results of a series of prototype molecules containing sulfur such as SF_2, SF_4, NSF_3, SF_1, H_2S are reported. It is convincingly shown that in highly electronegative environment the energy levels of the sulfur 3d orbitals are reduced to the vicinity of those of the ligand valence orbitals and their spatial distributions are contracted to the bonding area, and therefore they can participate in bond formation to a certain extent, which is enhanced by the formation of the d-p π back bonds. It seems that the result reported in this paper is helpful for the solution of the long-standing debate about the sulfur 3d orbital participation in bond formation.
