Interaction of half-sandwich alkylmolybdenum(III) complexes with B(C6F5)3. The X-ray structure of [CpMo(η4-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3]

The reactions of the half-sandwich molybdenum(III) complexes CpMo(η4-C4H4R2)(CH3)2, where Cpη5-C5H5 and RH or CH3, with equimolar amounts of B(C6F5)3 have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe3. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η4-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3], indicate that the borane attack has occurred at the methyl position.