Two isomeric structures of oxovanadium(V) complexes with hydrazone and 8-hydroxyquinoline ligands

Two new oxovanadium(V) complexes [VOL 1 (HQ)] ( 1 ) and [VOL 2 (HQ)] ( 2 ) are prepared by the reaction of [VO(acac) 2 ] (where acac = acetylacetonate), 8-hydroxyquinoline (HHQ) with 4-bromo- N ′- (3-ethoxy-2-hydroxybenzylidene)benzohydrazide (H 2 L 1 ) and 2-bromo- N ′-(3-ethoxy-2- hydroxybenzylidene)benzohydrazide (H 2 L 2 ), respectively, in methanol. Crystal and molecular structures of the complexes are determined by elemental analysis, infrared spectroscopy, and single crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P 2 1 / c , with unit cell dimensions a = 12.5236(13) Å, b = 22.5260(15) Å, c = 16.7029(13) Å, β = 90.054(2)°, V = 4712.0(7) Å 3 , Z = 8, GOOF = 1.024, R 1 = 0.0586 and wR 2 = 0.0835. Complex 2 crystallizes in the triclinic space group P -1, with unit cell dimensions a = 7.4344(12) Å, b = 10.8677(16) Å, c = 14.687(2) Å, α = 85.327(5)°, β = 77.357(5)°, γ = 84.896(5)°, V = 1150.9(3) Å3, Z = 2, GOOF = 1.153, R 1 = 0.0917 and wR 2 = 0.3014. The V atoms are in the octahedral coordination. Thermal stability of the complexes is also studied.