Au-197 Mossbauer spectroscopy studies of some cyclometalated gold dimers

The oxidation states and structures of a series of cyclometalated gold comp lexes derived from oxidative addition reactions of the digold(I) complex [A u-2(mu -C6H3-2-PPh2-6-Me)(2)] have been determined by (197)AU Mossbauer spe ctroscopy. The spectra for the binuclear gold(I)/gold(I) and gold(II)/gold( II) complexes indicate the presence of equivalent gold atoms, whereas the g old(I)/gold(III) and gold(III)/gold(III) spectra show signals due to two in equivalent metal centers. The coordination spheres of metal centers in the complexes have been determined from isomer shift and quadrupole splitting d ata.