ABINITIO MO AND SD-CI STUDY OF NI(PH3)2(CO2) - ELECTRON CORRELATION-EFFECTS ON GEOMETRY, BINDING-ENERGY, AND ELECTRONIC-STRUCTURE

Ab initio Hartree-Fock, single-reference single-double configuration interaction (SD-CI) and multireference SD-CI calculations were carried out for Ni(PH3)2(CO2). Introduction of electron correlation lengthens the Ni-CO2 coordinate bond distance of the η2-side-on complex and decreases the CO2 binding energy. These correlation effects are opposite to those found in M(CO) (M = Ni, Pd, Pt), Ni(PH3)2(η1-N2), and Ni(PH3)2(C2H4). The difference in correlation effects between them comes from their different feature of the HOMO. The electronic structure of Ni(PH3)2(η2-CO2) is analyzed in detail at the Hartree-Fock and SD-CI levels. © 1990, American Chemical Society. All rights reserved.