A structurally-characterized NbCl5–NHC adduct

The selective reactions of niobium pentachloride with two bulky NHC carbenes afforded NbCl5(NHC) complexes, bearing the highest oxidation state ever found for a metal centre in a transition metal halide-NHC adduct. The X-ray structure of 2a is the first one reported for a monodentate NHC-niobium species, and exhibits an abnormally long Nb-C bond. © 2014 The Partner Organisations.The selective reactions of niobium pentachloride with two bulky NHC carbenes afforded NbCl5(NHC) complexes, bearing the highest oxidation state ever found for a metal centre in a transition metal halide–NHC adduct. The X-ray structure of 2a is the first one reported for a monodentate NHC–niobium species, and exhibits an abnormally long Nb–C bond