Investigation on the complex of diperoxovanadate with picolinamide

A novel diperoxovanadate complex NH4[OV(O2)2(picolinamide)]·H2O was synthesized from aqueous solution under physiological conditions. The solution structure of the complex was characterized by multinuclear (1H, 13C, 14N, and 51V), variable temperature as well as two-dimensional (DOSY) NMR techniques in the interaction system of NH4VO3/H2O2/picolinamide at room temperature. The crystal structure of the complex was determined at 223 K by single-crystal X-ray diffraction method. It belongs to the monoclinic space group P21/c with a = 7.323(3) Å, b = 14.255(7) Å, c = 10.022(5) Å, β = 99.524(9)°, V = 1031.7(8) Å3, and Z = 4. The crystal is composed of ammonium ions, picolinamide oxodiperoxovanadate(V) ions, and water molecules, which are held together by ionic and hydrogen bond forces. The species [OV(O2)2(picolinamide)]− is seven-coordinated with a distorted pentagonal bipyramidal geometry both in solution and in crystal.