[Fe-3(mu(3)-O)(CO)(9)](2-) dianion as a suitable material for the preparation of homo- and heterometallic carbonyl clusters

Reactions of the [Fe-3(mu(3)-O)(CO)(9)](2-) dianion (I) with a series of me tal-containing compounds were studied. It was established that the reaction between I and [(AuPPh3)(3)O]+BF4- proceeded with the retention of the mu(3 )-O ligand and formation of the [Fe-3(mu(3)-O)(AuPPh3)(2)(CO)(9)] cluster. Heating of I in the presence of an excess of Fe(CO)(5) in diglyme gave only the carbido-carbonyl cluster [Fe6C(CO)(16)](2-) (II), whose structure was confirmed by the isolation of the [Fe6C(AuPPh3)(CO)(16)](-) monoanion (III) in the reaction of II with AuPPh3Cl in the presence of TIBF4. The new hete rometallic [Fe4Rh2C(AuPPh3)(2)(CO)(15)] cluster (IV) was prepared by reacti ng III with [Rh(CO)(2)Cl](2) in dichloromethane and structurally characteri zed. X-ray structural analysis of (IV) (MoKalpha radiation, graphite monoch romator, omega scan, R-1 = 0.056 for 4608 reflections) suggested that, in c rystal (a = 26.695, b = 13.560, c = 22.041 Angstrom, beta = 136.36 degrees, space group C2/c, Z = 4), the heterometallic cluster skeleton is comprised of the edge-sharing Au2Rh2 tetrahedron and Fe4Rh2 octahedron.