EFFECT OF PHOSPHINE SUBSTITUENTS IN GOLD(I) COMPLEXES - A THEORETICAL-STUDY OF MEAUPR3, R = H, ME, PH

Electronic structure investigations on triphenylphosphine (PPh3) ligat ed gold clusters are commonly carried out with model phosphine ligands . To explore the validity and the limitations of this approach, we hav e studied the effects of phosphine substituents in a series of gold(I) compounds: MeAuPR3, R = H, Me, Ph. We used the recently developed sca lar-relativistic version of the linear combination of Gaussian-type or bitals (LCGTO) local density functional (LDF) method which allows an a ll-electron treatment of all systems under study. For structural prope rties the PH3 ligand provides a satisfactory model of the full PPh3 li gand. But the trimethylphosphine ligated models have to be employed if good agreement is desired for energy properties and for the dipole mo ment.