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 NiAc2.4H2O, 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.