ELECTROCHEMICAL-BEHAVIOR OF SOME NOVEL MU-OXO DIMERIC FE(III) COMPLEXES IN DMF

Voltammetric behaviour of several mu-oxo dimers of Fe(III) of general formula [FeL](2)O with ligands based on S-alkyl-1,4-bis(substituted sa licylidene)isothiosemicarbazide was studied at a glassy carbon electro de in DMF solutions with different supporting electrolytes (tetrabutyl ammonium perchlorate, LiClO4, LiCl). In perchlorate medium the investi gated compounds are reduced in three, basic, one-electron steps accomp anied by complex decomposition. Oxidation takes place in 2-3 multi-ele ctron processes causing decomposition of the complex and the ligand. T he primary dimer decomposition products, both of the reduction and oxi dation, are corresponding monomeric species, undergoing further electr ochemical reactions. The study encompassed the effects of Li+ (formati on of ion pairs with reduced dimer species), Cl- and H+ (phenol and HC lO4) on the behaviour of the dimers at the electrode and in the soluti on. It was found that differences in the behaviour of the complexes ar e determined by the nature of the substituent in the benzene ring. A g eneral reaction scheme is proposed.