METAL-COMPLEXES OF 5-ACETYL-2,2'-PYRIDYLTHIOPHENE AROYLHYDRAZONES - CRYSTAL-STRUCTURE OF A COBALT(II) DERIVATIVE

The new potentially tetradentate aroylhydrazone ligands, Hbitp and Hsi tp, produced by condensation of 5-acetyl-2,2'-pyridylthiophene with be nzoyl- and salicyloylhydrazine, respectively, have been reacted with s everal metal(II) acetates. Deprotonation at the amide nitrogen occurs and neutral complexes of the type [M(bitp)2L2] and [M(sitp)2L2] are ob tained, where L is a solvent molecule. An X-ray crystal structure dete rmination carried out on [Co(bitp)2(dmso)2] (1) revealed that these li gands behave as bidentate through the -(O)C-N-N= hydrazide moiety, ass uming the Z configuration around the C = N hydrazone bond. The coordin ation environment is distorted octahedral, the solvent molecules occup ying the axial positions. The crystal structure of the ligand Hbitp (I I) has also been determined for comparison.