Hydrothermal synthesis and crystal and molecular structure of a binuclear dioxovanadium(V) species exhibiting a bridging HPO4(2-) 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 degrees 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 P2(1)/n, a=9.244(6) Angstrom, b=16.197(3) Angstrom, c=15.334(2) Angstrom, beta=99.35(3)degrees, V=2265(1) Angstrom, Z=4; 2900 reflections; R=0.039, R-w=0.046.