Hydrothermal synthesis and crystal and molecular structure of a binuclear dioxovanadium(V) species exhibiting abridging HPO4 2- ligand, [(VO2)2(HPO4)(2,2′-bipy)2] · H2O

The hydrothermal reaction of V₂O₅, CuO, 2,2′bipyridine, H₃PO₄, H₃Bu₄NOH, and H₂O in the mole ratio 1.0:0.86:2.05:3.54:1.40:449 at 160°C for 46 h yields [(VO₂)₂(HPO₄)(2,2′-bipy)₂] · H₂O (1). The binuclear species is constructed from two edge-sharing dioxovanadium(V) octahedra, exhibiting a {V₂O₄} core in the anti-coplanar orientation. Two binuclear units are linked through the hydrogen atoms of pendant {O≡P-OH} groups on adjacent dimers to give a dimer of dimers, in a manner reminiscent of carboxylic acids. Crystal data: [(VO₂)₂(HPO₄)(2,2′-bipy)₂] · H₂O (1): monoclinic P2₁/n, a = 9.244(6) Å, b = 16.197(3) Å, c = 15.334(2) Å, β = 99.35(3)^o, V = 2265(1) Å, Z = 4; 2900 reflections; R = 0.039, R_w = 0.046.