M ig u el M o n g e O ro za, A n n ette S chierb, H u b ert S ch m id b au r1 ' "' Gold-Silicon Compounds, Silyl-Gold Compounds, (Phosphine)gold(I) Complexes M ononuclear coordination compounds of the type (R3P)AuSiR'3 with R = R' = Ph and R = Me, R' = Ph have been obtained from reactions of the corresponding halide complexes (RiPjAuCl with the silyllithium reagent LiSiPh.v The fully phenylated species undergoes ligand redistribution in solution to give homoleptic ionic species. (M e.^A u S iP h i is less susceptible to this process and crystallizes from solutions as the heteroleptic complex. The crystal structure of this compound has been determined by X-ray diffraction. In the crystal lattice the molecules are not associated.