The chemistry of hydride, halide and alkyl niobocene complexes with coordinated diazoalkanes

Article abstract of DOI:10.1016/0022-328X(95)05450-4

The complexes Cp2Nb(H)(η¹-NNCPhAr) (Ar <*> Ph (1) or o-C6H4Br (2)) were found to undergo easy substitution of a hydride ligand for a halogen atom by the reaction of 1 with various alkylhalides with high yields of Cp2Nb(X)(η¹-NNCPh2) (X <*> Cl (4), Br (5) or I (6), Cp2Nb(Br)(η¹-NNC(Ph)-o-C6H4Br) (7) and 5 were found to be formed in a halgen exchange reaction, and also by the thermolysis of 2.Halide diazoalkane niobocene complexes clearly exhibit marked polarity of the metal centre.Nucleophilic substitution of bromine in 5 yielded Cp2Nb(Me)(η¹-NNCPh2) (8).The results of X-ray analysis of 7 are provided.Keywords: Niobium