The iridathiabenzene analogues [η6-Cp*Ir(C,S-2,5-Me2T)]M(CO)3, where M = Cr (3), Mo (5), W (7), of (η6-arene)M(CO)3 are prepared from M(CO)3(NCMe)3 and Cp*Ir(C,S-2,5-Me2T) (2), where C,S-2,5-Me2T is ring-opened 2,5-dimethylthiophene. The high reactivity and coordination flexibility of the η6-Cp*Ir(C,S-2,5-Me2T) ligand leads to a variety of products upon reaction with phosphine ligands. The reaction of 3 with PEt3 leads to PEt3 adduct formation at the Ir in the product [η6-Cp*Ir(PEt3)(C,S-2,5-Me2T)] [Cr(CO)3] (17). On the other hand, reaction of the analogous tungsten complex 7 with PEt3 yields the adduct [η4-Cp*Ir(C,S2,5-Me2T)]W(CO)2(PEt 3)(μ-CO) (19), in which PEt3 adds to the W atom. These and other studies show that the iridathiabenzene ligand is capable of coordination to Cr, Mo, or W through one, four, five, or six of its ring atoms. When 7 is reacted with CF3SO3H, protonation occurs at the tungsten, as occurs in the protonation of the analogous arene complex (η6C6Me6)W(CO)3. Structures of four of the complexes were established by X-ray studies.