Complexation between vanadium(V) and citrate: spectroscopic and structuralcharacterization of a dinuclear vanadium(V) complex

Investigation of the aqueous coordination chemistry for citrate and vanadiu m(V) resulted in the isolation and characterization of a dinuclear vanadium (V) citrato complex (1) Na2K2[VO2(Hcit)](2). 9H(2)O. Complex (1) is an inte rmediate between the fully deprotonated and diprotonated citrate vanadate. It may represent an early mobilized precursor in the biosynthesis of FeV-co , as well as a relevant model in the proton transport relay process between P-cluster pair to M-cluster pair. The complex has been characterized by el emental analyses and i.r. spectroscopy. Its i.r. spectra are consistent wit h a oxo-bridged dinuclear structure as revealed by a single crystal X-ray d iffraction study.