Yongbao Zhu, M. O. Wolf
Sep 25, 1999
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0
Influential Citations
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Journal
Chemistry of Materials
Abstract
The new complexes 1,1‘-bis(5-(2,2‘-bithienyl))ferrocene (2) and 1,1‘-bis(5-(2,2‘:5‘,2‘ ‘-terthienyl))ferrocene (3) have been synthesized by coupling 1,1‘-bis(2-thienyl)ferrocene (1) with 2-bromothiophene and 5-bromo-2,2‘-bithiophene, respectively. The cyclic voltammograms of 1−3 contain a reversible FeII/III wave with E1/2 between 0.37 and 0.46 V vs SCE and irreversible thiophene-based oxidation waves at higher potentials. These compounds can be electrochemically oxidized to yield solutions of the monocations 1+−3+. The visible−near-IR spectra of these monocations all contain low-energy bands due to an oligothienyl group to FeIII charge-transfer transition. The absorption maxima and intensities of these bands correlate to the length of the conjugation in the oligothienyl group. Above the thiophene oxidation potential and by careful exclusion of water, 2 and 3 electropolymerize resulting in the deposition of electrochromic films on the electrode surface. The films are golden-red and stable when neutral and...