Hydrothermal synthesis and crystal and molecular structure of a binuclear dioxovanadium(V) species exhibiting a bridging HPO42− ligand, [(VO2)2(HPO4)(2,2′-bipy)2]·H2O

The hydrothermal reaction of V2O5, CuO, 2,2′bipyridine, H3PO4, n-Bu4NOH, 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)°, V=2265(1) Å, Z=4; 2900 reflections; R=0.039, Rw=0.046.