PHOTO-INDUCED DEGRADATION REACTIONS OF SOME ALKYL- AND ARYL-CARBONYL DERIVATIVES OF MANGANESE, MOLYBDENUM AND TUNGSTEN

Article abstract of DOI:10.1016/0022-328X(85)80012-7

Photo-induced degradation of CH3Mn(CO)5 in pentane solution results in the formation of Mn2(CO)10, methane and carbon monoxide.Both CH3D and CH4 are formed when CH3Mn(CO)5 is photolyzed in C6D6.Photolysis of C6H5CH2Mn(CO)5 in pentane solution produces Mn2(CO)10, toluene and bibenzyl.Analogous photodegradation of C6H5Mn(CO)5 in pentane solution yields Mn2(CO)10, benzene and carbon monoxide, but not biphenyl.The thermally unstable complex C2H5Mn(CO)5 was studied by photolyzing it in solution at -40 degC.GC analysis indicates that both ethylene and ethane are formed, and that the mole ratio of these products is dependent on the initial concentration of C2H5Mn(CO)5.These results are consistent with a β-hydrogen elimination mechanism for this reaction.Photolysis of CpMo(CO)3CH2C6H5 in pentane solution produces 2 and toluene, whereas photolysis of CpW(CO)3CH2C6H5 affords 2, CpW(CO)2(η³-benzyl), toluene, and a small amount (2percent) of bibenzyl.When CpM(CO)2(η³-benzyl) (M=Mo, W) complexes are subjected to photolysis under similar conditions, the only identifiable product is toluene.CpW(CO)3C6H5 degrades photochemically in pentane solution to form 2 and benzene, together with a small amount (6percent) of biphenyl.