TRANSITION-METAL COMPLEXES WITH THE THIOSEMICARBAZIDE-BASED LIGANDS .16. NOVEL IRON(IV) COMPLEXES WITH PENTANE-2,4-DIONE BIS(S-METHYLISOTHIOSEMICARBAZONE)

Several square-pyramidal iron(IV) complexes with the quadridentate ligand pentane-2,4-dione bis(S-methylisothiosemicarbazone) (H-3L) of the type [Fe(L)X], where X = Cl, Br, NCO or NCS, were synthesized and their physicochemical characteristics. together with those of previously reported [Fe(L)I] and [Fe(L)]2O, are described. The complexes were characterized by elemental analysis, molar conductivity and magnetic measurements, IR and electronic spectra. In addition, cyclic voltammetry is used to study the redox behaviour of the complexes in their DMF solutions and especially of the dimer-monomer equilibria influenced by the acidity of the solution.