ELECTROCHEMICAL REDOX REACTIONS OF HEMIN DERIVATIVES HAVING THIENYLENE GROUPS IN ION CONDUCTIVE PEO OLIGOMERS

Hemin derivative having thienylene groups, hemin thienyl ester (HTE), was synthesized and its electrochemical behavior was analyzed in poly( ethylene oxide) (PEG) oligomers. A cyclic voltammogram of the HTE diss olved in dimethylformamide (DMF) showed redox peaks (E(1/2) = - 0.10 V vs. Ag) based on the heme (iron protoporphyrin IX). The HTE also show ed the same redox behavior in PEO(200) (molar mass of 200). Symmetrica l redox waves were observed in the cyclic voltammogram of the HTE adso rbed on the indium tin oxide (ITO) coated glass electrode in PEO(200). Its peak separation was about 10 mV and the quantity of electricity w as constant and both were independent of the scan rate. These results indicated that HTE molecules were fixed on the ITO electrode as a mono layer. The thienylene group was confirmed to be effective to fix the r edox active molecules on the ITO electrode suitable for the electron t ransfer even in the PEO oligomers.