Oxidized states of methoxy- and hexyl-oligothiophenes with ferrocenyl groups

Quater-, quinque-, and sexithiophene with two ferrocennyl groups were prepared as model compounds for molecular wires attached terminals. The oligothiophenes, wire moieties, were substituted with methoxy and/or hexyl groups for the purpose of increase in the oxidized ability and the solubility, respectively. The oxidation processes and the oxidized states of the compounds were investigated by cyclic voltammetry, coulometry, and electronic absorption spectroscopy. The electrochemical measurements of quinque- and sexithiophene derivatives show that the oxidized species produced in a ferrocene moiety, terminal, interacts with other ferrocene moiety. The electronic absorption spectra of the one-electron-oxidized oligothiophenes indicate that the oxidized species are spread in the oligothiophene moiety.