Attainment of an eighteen-electron configuration by means of hydrogen bridging in a purported sixteen-electron pyrazolylborate complex of molybdenum; the structure of (3,5-dimethylpyrazolylborato)dicarbonyl-trihapto-(cycloheptatrienyl)molybdenum

Abstract

The structural and dynamic properties of [H₂B(3,5-dimethylpyrazolyl)]Mo(CO)₂C₇H₇, studied by X-ray crystallography and spectroscopy, show that the molecule is asymmetric with a trihapto-C₇H₇ ring, a severely bent boat form of the chelate ring, and a 2-electron, 3-centre B–H–Mo bond.