Synthesis and structural study of tris(2,6-diaminopyridinium) bis(oxalato)dioxidovanadate(V) 2.5-hydrate.

Crystals of the title compound, (C5H8N3)3[VO2(C2O4)2]·2.5H2O, a mononuclear VV complex, were obtained by slow evaporation at room temperature of an aqueous solution containing vanadium pentoxide, oxalic acid and 2,6-di­amino­pyridine. The asymmetric unit contains one bis­(oxalato)dioxovanadate(V) anionic complex, three 2,6-di­amino­pyridinium cations and two and a half uncoordinated water mol­ecules. The mononuclear vanadium(V) anions are connected to the organic cations and water mol­ecules through a strong N--H...O and O--H...O hydrogen-bond network, consolidated by π-π stacking inter­actions, to form a three-dimensional structure. [ABSTRACT FROM AUTHOR]