STRUCTURE AND REACTIVITY OF (ETA-C(5)R(5))MO(NO)(2)-HALIDE, (ETA-C(5)R(5))MO(NO)(2)-HALOMETHYL, AND (ETA-C(5)R(5))MO(NO)(2)-ALKYL COMPLEXES- CONSECUTIVE AEROBIC METHYLENE AND NITROSYL LIGAND OXIDATION

Cp'Mo(NO)(2)(CH(2)X) complexes are isolated in 80-90% yield after the treatment of the Cp'Mo(NO)(2)X complexes in CH2Cl2 with ethereal diazo methane in the presence of Cu powder (Cp' = eta-C5H5 (CP), eta-C-5(CH3 )(5)(Cp); X = Cl, Br). The Cp'Mo(NO)(2)(CH2I) derivatives are obtaine d in over 90% yield by treating the Cp'Mo(NO)(2)(CH2Cl) derivatives wi th NaI in THF. Four new halomethyl complexes have been characterized b y X-ray crystallography and are compared to the related CpMo(NO)(2)Br, CpMo(NO)(2)Cl, and Cp*Mo(NO)(2)(CH3) derivatives. The structural dat a and IR data indicate the donor properties of the halomethyl ligands to be intermediate between halide and alkyl ligands. The Cp'Mo(NO)(2)( CH(2)X) complexes react initially with O-2 to give CH2O and the regene ration of the parent Cp'Mo(NO)(2)X complexes. The Cp'Mo(NO)(2)Cl compl exes react with O-2 after an induction period to give the well-known C p'MoO2Cl complexes, NO2, NOCl, and N2O. Exposure of CpCr(NO)(2)(CH(CH3 )Br) to O-18(2) gives O-18=CH(CH3) and O-16-labeled CpCr(NO)(2)Br. The Cp'Mo(NO)(2)-alkyl complexes react with O-2 to give the corresponding Cp'MoO2-alkyl derivatives in 40-70% yield (alkyl = CH3, CH2CH3). Elec trochemical data show the Mo complexes to oxidize at 0.2-0.3 V lower t han the Cr congeners.