TRANSITION-METAL COMPLEXES WITH THE THIOSEMICARBAZIDE-BASED LIGANDS .23. SYNTHESIS, PHYSICOCHEMICAL PROPERTIES AND VOLTAMMETRIC CHARACTERIZATION OF IRON(III) COMPLEXES WITH TERDENTATE AND QUADRIDENTATE THIOSEMICARBAZIDE DERIVATIVES

Two iron(III) complexes with the terdentate ONS and ONN ligands benzoy lacetone thiosemi- and S-methylisothiosemicarbazone, respectively, of the general formula [Fe(HL)Cl2], were synthesized. Besides, the iron(I II) complexes of the general formula [Fe(L)Cl] involving the quadriden tate ONNO ligands N(1)-benzoylisopropilidene-N(4)-salicylidene (5-chlo ro-, 3,5-dichloro-, or 5-nitro-salicylidene) S-methylisothiosemicarbaz ide were also prepared. The complexes were characterized by elemental analysis, molar conductivity and magnetic measurements, IR and electro nic spectra, as well as by cyclic voltammetry. It was found that the c omplexes are high-spin pentacoordinated. In addition, a detailed volta mmetric study in DMF solutions has shown that the electrochemical proc esses are frequently accompanied by various chemical reactions.