Synthesis, structural characterization and biological activity of p-fluorobenzaldehyde thiosemicarbazones and of a nickel complex

New thiosemicarbazones (1-7), derived from p-fluorobenzaldehyde and differently substituted thiosemicarbazides, were synthetized and characterized by means of NMR and IR techniques. The p-fluorobenzaldehyde thiosemicarbazone Hfbt (1), the p-fluorobenzaldehyde 4-phenylthiosemicarbazone Ph-Hfbt (4) and complex [Ni(fbt)(2)] (8) were also characterized by X-ray diffractometry. Molecules 1 and 4 consist of two units: the p-fluorobenzaldehyde residue and the thiosemicarbazonic chain. In the reaction of 1 with NiAc2.4H(2)O, complex 8 was afforded. The molecular structure of 8 consists of the neutral molecules [Ni(fbt)(2)] with the metal placed on a symmetry centre, The coordination results in a square planar configuration and involves the sulphur atom and the hydrazine nitrogen atom of the two ligands in a trans configuration. Moreover, for compounds 1, 2, 4, and 8. assays of proliferation inhibition and apoptosis tests in vitro on human leukemia cell line U937 were carried out. (C) 2000 Elsevier Science S.A. All rights reserved.