Syntheses and structures of oxovanadium(V) and cobalt(III) complexes with salicylaldehyde p-nitrobenzoylhydrazone

The two title compounds containing the same ligand H2L (H2L = salicylaldehyde p-nitrobenzoylhydrazone), VOL(CH3OH)(CH3O) 1 (C16H16N3O7V, M-r = 413.26) and [CoL(C5H5N)(3)](NO3C5H5N)-N-.-C-. 2 (C34H29N8O7Co, M-r = 720.58) have been synthesized and characterized. Complex 1 belongs to monoclinic, space group P2(1)/c with a = 7.3253(3), b = 18.8237(9), c = 12.9014(5) Angstrom, beta = 91.672(1)degrees, V = 1778.2(1) Angstrom(3), Z = 4, F(000) = 848, mu(MoKalpha) = 0.603 mm(-1), R = 0.0470 and wR = 0.1312. Complex 2 is of monoclinic, space group P2(1)/c with a = 11.4196(8), b = 17.157(1), c = 17.081(1) Angstrom, beta = 96.8233(9)degrees, V = 3323.0(4) Angstrom(3), Z = 4, F(000) = 1488, mu(MoKalpha) = 0.578 mm(-1), R = 0.0455 and wR = 0.1311. The vanadium atom in 1 has a distorted octahedral VO(OON)(O)(O) coordination with a normal V=O bond of 1.583(3) Angstrom. Two oxygen and one nitrogen atoms of the tridentate hydrazone ligand L2-, and one oxygen atom of the deprotonated methanol CH3O- are coordinated to the vanadium(V) atoms, forming an equatorial plane. The axial position trans to the oxo group is occupied by the oxygen atom of the neutral methanol CH3OH. Every two molecules related by centrosymmetric operation in 1 are connected by pairs through intermolecular hydrogen bonds. The hydrogen bond length of (ON)-N-... is 2.861(4) Angstrom and bond angle of O-(HN)-N-... is 163.20degrees. Each two facial benzene rings form dimers via partial pi-pi stacking in the pairs. The cobalt atom in 2 is octahedrally coordinated by three ONO donors in L2- and three nitrogen atoms in three pyridine molecules.