Diaminogermylene and diaminostannylene derivatives of gold(I): novel AuM and AuM2 (M = Ge, Sn) complexes

The reactions of AuCl(THT)] (THT = tetrahydrothiophene) with 1 equiv of the group 14 diaminometalenes M(HMDS)(2) M = Ge, Sn; HMDS = N(SiMe(3))(2)] lead to Au{MCl(HMDS)(2)}(THT)] M = Ge (1), Sn (2)], which contain a metalate(II) ligand that arises from insertion of the corresponding M(HMDS)(2) reagent into the Au-Cl bond of the gold(I) reagent. While compound 1 reacts with more Ge(HMDS)(2) to give the germanate-germylene derivative Au{GeCl(HMDS)(2)}{Ge(HMDS)(2)}] (3), which results from substitution of Ge(HMDS)(2) for the THT ligand of 1, an analogous treatment of compound 2 with Sn(HMDS)(2) gives the stannate-stannylene derivative Au{SnCl(HMDS)(2)}{Sn(HMDS)(2)(THT)}] (4), which has a THT ligand attached to the stannylene tin atom and which, in solution at room temperature, participates in a dynamic process that makes its two Sn(HMDS)(2) fragments equivalent (on the NMR time scale). A similar dynamic process has not been observed for the AuGe(2) compound 3 or for the AuSn(2) derivatives Au{SnR(HMDS)(2)}{Sn(HMDS)(2)(THT)}] R = Bu (5), HMDS (6)], which have been prepared by treating complex 4 with LiR. The structures of compounds 1 and 3-6 have been determined by X-ray diffraction.