FORMATION OF A HETEROBIMETALLIC COMPOUND BY REDUCTIVE ELIMINATION OF CH4 AND OXIDATIVE CLEAVAGE OF AN ARYL PHOSPHORUS BOND IN REACTION OF TRANS-MEIR(CO)[P(PARA-TOLYL)3]2 WITH HMOCP(CO)3 - CRYSTAL AND MOLECULAR-STRUCTURES OF CPMO(CO)2[MU-P(PARA-TOLYL)2]IR(PARA-TOLYL)[P(PARA-TOLYL)3](CO)2(MO-IR) AND CPMO(CO)2[MU-P(PARA-TOLYL)2]IR(H)[P(PARA-TOLYL)3](CO)2(MO-IR)

Reaction of HMoCp(CO)3 with trans-MeIr(CO)[P(p-tolyl)3]2 results in quantitative elimination of CH4 and formation of a heterobimetallic complex, Cp(CO)2Mo[mu-P(p-tolyl)2]Ir(p-tolyl)[P(p-tolyl)3](CO)2, by activation of the phosphorus-carbon bond. This complex has been fully characterized, including by X-ray crystallography. Cp(CO)2Mo[mu-P(p-tolyl)2]Ir(p-tolyl)[P(p-tolyl)3](CO)2(Mo-Ir) crystallizes in the centrosymmetric monoclinic space group P2(1)/n (No. 14) with a = 13.108 (5) angstrom, b = 11.892 (5) angstrom, c = 30.165 (11) angstrom, beta = 102.52 (3)-degrees, V = 4590 (3) angstrom 3, and Z = 4. Diffraction data (Mo K-alpha, 2-theta = 5-45-degrees) were collected with a Siemens R3m/V diffractometer and the structure was refined to R = 7.68% and R(w) = 6.05% for all 6023 reflections (R = 3.62%, R(w) = 4.63% for those 3586 reflections with F-omicron > 6.0-sigma(F-omicron)). The molecule contains a molybdenum-iridium bond (Mo-Ir = 2.976 (2) angstrom, which is bridged by a mu-P(p-tolyl)2 ligand (Mo-P = 2.412 (3) and Ir-P = 2.376 (3) angstrom). The molybdenum atom is bonded to an eta-5-C5H5 ligand (Mo-C = 2.306 (11)-2.377 (11) angstrom) and two terminal carbonyl ligands (Mo-CO = 1.937 (10)-1.942 (15) angstrom); the iridium atom is bonded to mutually trans carbonyl ligands (Ir-CO = 1.899 (14)-1.907 (12) angstrom) and mutually cis P(p-tolyl)3 and sigma-(p-tolyl) ligands (Ir-P = 2.355 (3) and Ir-C(ipso) = 2.168 (10) angstrom). The heterobimetallic complex is surprisingly unreactive to CO, CH3I, and PhC = CPh; however, reaction with H-2 causes elimination of toluene and formation of a trihydride and a monohydride. Both have been separated and fully characterized. These hydrides are fluxional at room temperature and appear to be reactive. The monohydride, CpMo(CO)2[mu-P(p-tolyl)2]Ir(H)[P(p-tolyl)3](CO)2(Mo-Ir), crystallizes in the centrosymmetric orthorhombic space group Pbca (No. 61) with a = 12.934 (2) angstrom, b = 23.890 (3) angstrom, c = 26.615 (3) angstrom, V = 8224 (2) angstrom 3, and Z = 4. The structure was refined to R = 8.18% and R(w) = 6.56% for all 5390 reflections (R = 3.41%, R(w) = 3.59% for those 2861 reflections with F(o) > 6.0-sigma(F(o)). This molecule has Mo(1)-Ir(1) = 2.957 (1) angstrom and a bridging mu-P(p-tolyl)2 ligand associated with Mo-P = 2.391 (3) and Ir-P = 2.334 (3) angstrom. The molybdenum atom is bonded to an eta-5-C5H5 ligand (Mo-C = 2.283 (14)-2.383 (15) angstrom) and two terminal carbonyl ligands (Mo-CO = 1.940 (13)-1.953 (14) angstrom); the iridium atom is now bonded to mutually cis carbonyl ligands (Ir-CO = 1.899 (13)-1.912 (15) angstrom) and mutually cis P(p-tolyl)3 and hydride ligands (Ir-P = 2.333 (3) angstrom and Ir-H = 1.67 (9) angstrom).