Ab initio MO and SD-CI study of (carbon dioxide)bis(phosphine)nickel. Electron correlation effects on geometry, binding energy, and electronic structure

Abstract

Introduction of electron correlation lengthens the Ni-CO 2 coordinate bond distance of the η 2 -side-on complex and decreases the CO 2 binding energy. These correlation effects are opposite to those found in M(CO) (M=Ni, Pd, Pt), Ni(PH 3 ) 2 (η 1 -N 2 ), and Ni(PH 3 ) 2 (C 2 H 4 ). The difference in correlation effects between them comes from their different feature of the HOMO. The electronic structure of Ni(PH 3 ) 2 (η 2 -CO 2 ) is analyzed in detail at the Hartree-Fock and SD-CI levels