Reactions of organometallic oxometal complexes with B(C6F5)3: synthesis, structure, bonding and reactivity of [Mo(η5-C5H4Me)2{OB(C6F5)3}]

Abstract

Organometallic oxo complexes [M(C₅H₄R)₂O] reacted with the strong Lewis acid B(C₆F₅)₃ at their oxo functionality to yield [M(C₅H₄R)₂{OB(C₆F₅)₃}] (M = Mo, R = Me 1; M = W, R = H 2). The structure of 1 has been determined by X-ray crystallography. Density functional theory (DFT) calculations on [Mo(C₅H₅)₂O] and [Mo(C₅H₅)₂(OBF₃)] have been used to model the changes in geometry to the [Mo(C₅H₅)₂O] fragment on co-ordination by B(C₆F₅)₃ and indicate that this process is charge rather than orbitally controlled. Compound 1 reacted with PhNCO to yield [Mo(C₅H₄Me)₂{OC(O)NPh}{B(C₆F₅)₃}]; spectroscopic evidence and DFT calculations suggest that the Lewis acid is bound to the molybdenum oxygen atom.