ORGANOMETALLIC OXIDES - CONVENIENT, HIGH-YIELD SYNTHESES OF THE (PENTAMETHYLCYCLOPENTADIENYL)MOLYBDENUM OXO COMPLEXES (ETA-C5ME5)MOCL(O)2, ANTI-[(ETA-C5ME5)MOCL(O)]2(MU-O), (ETA-C5ME5)MOCL2(O), AND SYN-[(ETA-C5ME5)MO(O)(MU-O)]2

Convenient, high-yield syntheses of (pentamethylcyclopentadienyl)molybdenum oxo complexes are presented. Oxidation of [(eta-C5Me5)Mo(CO)2]2 with H2O2/HCl in CHCl3 solution gave (eta-C5Me5)MoCl(O)2. Oxygen abstraction from (eta-CrMe5)MoCl(O)2 with P(OMe)3 gave anti-[(eta-C5Me5)MoCl(O)]2(mu-O), which was converted into (eta-C5Me5)MoCl2(O) by treatment with Me3SiCl. Hydrolysis of [(eta-C5Me5)MoCl(O)]2(mu-0) in toluene containing Et3N gave syn-[(eta-C5Me5)Mo(O)(mu-O)]2. The physical properties of the oxo complexes are reported. It is noted that (eta-C5Me5)MoCl(O)2 is unstable both thermally and photochemically. X-ray diffraction showed that the Mo-O distance in (eta-C5Me5)MoC12(O) Was very short (1.683(2) angstrom). Crystal data: triclinic, P1BAR, a = 6.5752(4) angstrom, b = 8.6699(7) angstrom, c = 11.2425(8) angstrom, a = 85.937(8)-degrees, beta = 86.302(7)-degrees, gamma = 89.352(6)-degrees, Z = 2, R = 0.031 for 3476 observed reflections and 187 parameters.