Synthese und Struktur chiraler Heterometallatetrahedrane des Typs [Re2(M1PPh3)(M2PPh3)(μ‐PCy2)(CO)7C≡CPh] (M1 = Ag, Au; M2 = Cu, Ag, Au)

Syntheses and Structure of Chiral Metallatetrahedron Complexes of the Type [Re2(M1PPh3)(M2PPh3)(μ‐PCy2)(CO)7C≡CPh] (M1 = Ag, Au; M2 = Cu, Ag, Au) From the reaction of Li[Re2(μ‐H)(μ‐PCy2)(CO)7(C(Ph)O)] (1) with Ph3AuC≡CPh both benzaldehyde and the trinuclear complex Li[Re2(AuPPh3)(μ‐PCy2)(CO)7C≡CPh] (2a) were obtained in high yield. The complex anion was isolated as its PPh4‐salt 2b. The latter reacts with coinage metal complexes PPh3M2Cl [M2 = Cu, Ag, Au] to give chiral heterometallatetrahedranes of the general formula [Re2(AuPPh3)(M2PPh3)(μ‐PCy2)(CO)7C≡CPh] (M2 = Cu 3a, Ag 3b, Au 3c). The corresponding complex [Re2(AgPPh3)2(μ‐PCy2)(CO)7C≡CPh] (3d) is obtained from the reaction of [Re2(AgPPh3)2(μ‐PCy2)(CO)7Cl] (4) with LiC≡CPh. 3d undergoes a metathesis reaction in the presence of PPh3CuCl giving [Re2(AgPPh3)(CuPPh3)(μ‐PCy2)(CO)7C≡CPh] (3e) and PPh3AgCl. Analogous metathesis reactions are observed when 3c is reacted with PPh3AgCl or PPh3CuCl giving 3a or 3b, respectively. The reaction of 1 with PPh3AuCl gives benzaldehyde and Li[Re2(AuPPh3)(μ‐PCy2)(CO)7Cl] (5a) which upon reaction with PhLi forms the trinuclear complex Li[Re2(AuPPh3)(μ‐PCy2)(CO)7Ph] (6a). Again this complex was isolated as its PPh4‐salt 6b. In contrast to 2b, 6b reacts with one equivalent of Ph3PAuCl by transmetalation to give Ph3PAuPh and PPh4[Re2(AuPPh3)(μ‐PCy2)(CO)7Cl] (5b). The X‐ray structures of the compounds 3a, 3b, 3e and 4 are reported.