<b>Synthesis, characterization and anti-tumour activity of iron(III) Schiff base complexes with unsymmetric tetradentate ligands</b>

The synthesis and characterization of two new iron(III) complexes, [Fe(pythsalI)]Cl2 and [Fe(pythsalBr)]Cl2 with the NSNO-donor tetradentate Schiff base ligands pythsalHX [(5–X-N-(2pyridylethylsulfanylethyl) salicylideneimine] (X = I, Br)) obtained from the inserted condensation of 1-(2-pyridyl)-3-thia-5-aminopentane with the respective derivative salicylaldehyde in a 1:1 molar ratio is reported. The iron(III) complexes were characterized by several techniques using elemental analysis (C, H, N), FT-IR, electronic spectra and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:2 [M:L] ratio formation. The molar conductance measurements reveal the presence of 1:2 electrolytic nature complexes. Infrared spectral data agreed with the coordination to the central metal ion through deprotonated phenolic oxygen, imine and pyridine type nitrogens and the thioether sulfur atoms. From ligand field spectral data an octahedral geometry is assigned to the iron(III) ion in all these complexes. These new compounds have showed anti-tumour activity against two kinds of cancer cells that are K562 (human chronic myeloid leukemia) and Jurkat (human T lymphocyte carcinoma)