The coordination chemistryof vanadium, in particular compounds containing VO2+ ions, are of considerable interest because of their association with vanadium-dependent enzymes (eg, nitrogenase, haloperoxidase, phosphomutase, etc.). It was necessary to synthesize functional compounds for the detailed study of the structure and the chemical, and medical properties of these enzymes. (Thio)carbohydrazone ligands have a versatile coordinationability due to the presence of several donor centers, and tend to stabilize vanadium in its maximum oxidation states. Carbohydrazone based vanadium(V) complexes were previously applied as alternative selective homogeneous catalysts for the industrially significant oxidation of cyclohexane tocyclohexanol and cyclohexanone [1]. Herein a binuclear complex [Na(H2O)6][(VO2)2(HL)] (1), obtained from the reaction of VO(acac)2 and 1,5-bis(2-hydroxybenzaldehyde)carbohydrazone(H4L) in the presence of Na2CO3, is reported. Complex 1 was characterized by IR spectroscopy and single crystal X-ray crystallography. Spectral IR analysis of compound 1 showed the following: the very intense band in the 37003000 cm–1 region with a maximum of 3330 cm –1 is assigned to H2O, its broadened character being associated with multiple hydrogen interactions; other characteristic vibrations v(C=O) and v(C=N) appear as intense bands with maximums at approx. 1600 and 1558 cm –1 , respectively. As expected, these bands in compound 1 are shifted compared to those of the H4L ligand; the intense and wide band v(V=O) at 885 cm –1 supports the presence of cis-VO2 groups. According to the crystallographic data the asymmetric unit of complex 1 consists of the complex dinuclear anion [(VO2)2(HL)]^– and the [Na(H2O)6]⁺ cation. The triple-deprotonated hexadentate ligand HL^3–accommodates two V(V) atoms in the form of VO2+ entities by means of the two sets of donor atoms ONO and NNO. V1 and V2 atoms are five-coordinate and use cis-oxo ligands to complete their coordination sphere. The bond lengths in the carbohydrazide moiety indicate that the ligand adopts the enol tautomeric form. The hexaaquasodium cation in this complex, besides charge balancing, plays a more important role. Thus, in the solid state, the obtained compound has an extensive oligomeric structure, involving an alternative arrangement of cisdioxidovanadium( V) anionic units [(VO2)2(HL)]^– and [Na(H2O)6]+, held together by strong electrostatic interactions and hydrogen bonds, as determined by X-ray crystallographic analysis.