Electronic structures of transition-metal four-co-ordinated complexes. Part 3. Theoretical ab initio and ultraviolet photoelectron spectroscopy study of nickel(II), palladium(II), and platinum(II) bis(O,O′-diethyl dithiophosphate) square-planar complexes

Abstract

The electronic structures of [Ni(dtp)₂], [Pd(dtp)₂], and [Pt(dtp)₂][dtp = S₂P(OEt)₂] have been studied using pseudopotential valence-only ab initio methods, and He I and He II photoelectron spectroscopy. For [Ni(dtp)₂] and [Pd(dtp)₂], correlation and relaxation effects have been included in the calculation of the ionization energies by means of the extended two particle–hole Tamm–Dancoff method. The deviations from Koopmans' theorem were found to be considerably greater for the nickel than for the palladium complex. Consistent assignments of the photoelectron spectra have been proposed with the aid of these calculations.