10 Vanadium, niobium and tantalum

Abstract

The chemistry of compounds of the Group 5 metals has been the subject of exciting and significant advances in 2004. Particular highlights are (i) the synthesis of cationic and neutral four-coordinate vanadium(IV) alkylidene complexes containing short VC bonds; (ii) the formation of phosphanylphosphinidenes via an anionic, terminal phosphide of niobium; (iii) the cross metathetical reaction between propane and methane mediated by a supported tantalum hydride; (iv) the formation of thermally-robust, single-site vanadium catalysts for alkene polymerisation; (v) the isolation of a molecular and highly-charged niobium-based Keggin ion; and (vi) the assessment of vanadium oxo complexes as cancer prevention agents.