Reactions of the isomers Cp*Ir(η4-2,5-Me2T) (1) and Cp*Ir(C,S-2,5-Me2T) (2), where 2,5-Me2T is 2,5-dimethylthiophene, with Ru3(CO)12, Re2(CO)10, Mn2(CO)10, and [(η6-C6H6)RuCl2]2 yield a remarkable diversity of products. With Ru3(CO)12, both 1 and 2 give the CO-substituted product Cp*Ir(η4-2,5-Me2T·Ru3(CO) 11) (4), in which the 2,5-Me2T group is η4-coordinated to the Ir and S-coordinated to a Ru in the plane of the triangular Ru3(CO)11 cluster. With Re2(CO)10, 1 reacts to give the CO-substituted product Cp*Ir(η4-2,5-Me2T·-Re 2(CO)9) (6), in which 1 is S-coordinated in an equatorial position of the metal-metal dimer Re2(CO)9. However, another product of this reaction is Cp*Ir(η4-SC3H2MeC(=O)Me)[Re 2-(CO)9] (7), in which the 2,5-Me2T ligand has been converted to a ring-opened acyl-thiolate unit that is S-coordinated to Re2(CO)9. Compound 7 is the major product of the reaction of 2 with Re2(CO)10. The reaction of 2 with Mn2(CO)10 gives Cp*Ir(η4-SC3H2MeC(=O)Me)[Mn 2-(CO)9] (9), the Mn analog of 7. The reaction of [(η6-C6H6)RuCl2]2 with 1 gives the product Cp*Ir(η4-2,5-Me2T·Ru(η 6-C6H6)Cl2) (10), which illustrates again the strong S-donor ability of the Cp*Ir(η4-2,5-Me2T) (1) group. Structures of 4, 6, and 7 were established by X-ray diffraction studies.