Imido‐Supported Borohydrides of Titanium, Vanadium and Molybdenum

New imido bis(borohydride) complexes [(RN=)M(PMe 3 ) 2 (η 2 ‐BH 4 ) 2 ] [R = Ar, M = Ti ( 3 ); R = Ar, M = V ( 5 ); R = Ar, M = Mo ( 6 ); R = Ar′, M = Mo ( 7 ); Ar = 2,6‐ i Pr 2 C 6 H 3 , Ar′ = 2,6‐Me 2 C 6 H 3 ] were prepared by the reaction of dichlorides [(RN=)MCl 2 (PMe 3 ) n ] (M = Ti, n = 2; M = V, n = 2, M = Mo, n = 3) with LiBH 4 (2 equiv) in THF. Compounds 3 , 5 , 6 and 7 were studied by IR spectroscopy and X‐ray diffraction, and an EPR spectroscopy study was performed for paramagnetic compound 5 . In 3 , the two borohydride units are orthogonal to each other as a result of the overlap of an antiphase combination of B–H orbitals with the empty d xy orbital of Ti. In contrast, the d xy orbital of the metal atom is singly occupied in 5 and fully occupied in 6 and 7 , and both borohydride ligands are oriented in the same way, with the B(μ‐H 2 )M moieties orthogonal to the P–M–P vector.