Synthesis and X-ray crystal structures of some isothiosemicarbazone complexes

Four complexes of a new isothiosemicarbazone ligand have been prepared and characterized as mu(2)-pip-(NiL)(2) (1), MnL2 (2), UO2L(BrSal)BuOH (3) and (mu(2)-MoO2L)(2) (4) (H2L = 2-hydroxyacetophenone S-allyl isothiosemicarbazone.hydrobromide, BrSal = 5-bromosalicylaldehyde, pip = piperazine). All four complexes were characterized by X-ray crystallography, IR and elemental analyses. Complex 1 has a square planar coordination geometry in a binuclear arrangement such that both Ni atoms are coordinated to the phenolic-O, azomethine-N and thioamide-N atoms of L, and the bridging piperazine occupies the fourth position. For complex 2, the Mn atom connects to two N2O tridentate ligands in a distorted octahedron. The pentagonal bipyramidal geometry of complex 3 is provided by the tetradentate N2O2 ligand, n-butanol, and two oxo ligands around the uranium center. Finally, in the binuclear Mo complex (4), two N2O ligands coordinate to each molybdenyl center, together with the phenoxide-O donor of the adjacent molecule.