Syntheses and Crystal Structures of Two VO(IV) Schiff Base Complexes with Oxyammonia Ligand

Two novel VO(IV) Schiff base complexes, VO(SALHA)2[SALHA: salicyaldehyde- oxyammonia] and VO(o-VANHA)2 [o-VANHA: o-vanillin-oxyammonia], have been synthesized with salicyaldehyde or o-vanilline, hydroxylammonium chloride and vanadyl sulfate in absolute methanol, and their crystal structures were determined by single-crystal X-ray diffraction. The vanadium(IV) centers in both complexes are five-coordinate in a distorted square pyramidal geometry. VO(SALHA)2 (C14H12N2O5V, Mr = 339.20) crystallizes in the monoclinic system, space group P21/n with a = 14.716(9), b = 7.175(5), c = 14.716(9) ? b = 113.130(7), V = 1428.8(15) 3, Z = 4, Dc = 1.577 g/cm3, l = 0.71073 ? m(MoKa) = 0.720 mm-1, F(000) = 692, the final R = 0.0466 and wR = 0.0829 for 1561 observed reflections (I > 2s(I)). VO(o-VANHA)2 (C16H16N2O7V, Mr = 399.25) is of monoclinic, space group P21/n with a = 11.386(12), b = 10.405(10), c = 14.627(15) , b = 93.654(19), V = 1729(3) 3, Z = 4, Dc = 1.533 g/cm3, l = 0.71073 , m(MoKa) = 0.615 mm-1, F(000) = 820, the final R = 0.0513 and wR = 0.1129 for 1235 observed reflections (I > 2s(I)).