ELECTROCHEMICAL BEHAVIOUR OF SOME NOVEL μ-OXO DIMERIC FE(III) COMPLEXES IN DMF

Voltammetric behaviour of several μ-oxo dimers of Fe(III) of general formula [FeL] 2 O with ligands based on S-alkyl-1, 4-bis(substituted salicylidene)isothiosemicarbazide was studied at a glassy carbon electrode in DMF solutions with different supporting electrolytes (tetrabutylammonium perchlorate, LiC1O 4 , LiCl). In perchlorate medium the investigated compounds are reduced in three, basic, one-electron steps accompanied by complex decomposition. Oxidation takes place in 2-3 multi-electron processes causing decomposition of the complex and the ligand. The primary dimer decomposition products, both of the reduction and oxidation, are corresponding monomelic species, undergoing further electrochemical reactions. The study encompassed the effects of Li + (formation of ion pairs with reduced dimer species), Cl − and H + (phenol and HC1O 4 ) on the behaviour of the dimers at the electrode and in the solution. It was found that differences in the behaviour of the complexes are determined by the nature of the substituent in the benzene ring. A general reaction scheme is proposed.