Ethylenedithio end-capped oligothiophenes (bEDTnT); Dimer, trimer and tetramer

Two new ethylenedithio substituted thiophenes have been synthesized, 2,3-Dihydrothieno[2,3-b][1,4]dithiine(EDTT) 3 and 6-Bromo-2,3-dihydrothieno[2,3-b][1,4]dithiine 4. Starting from 4; oligomers 5 (bEDT2T, dimer), 8 (bEDTST, trimer) and 4 (bEDT4T, tetramer) were synthesized. Their cyclovoltammetric behaviour and electronic structure (by UV-Vis) have been recorded. Low oxidation potentials, and small differences between first and second oxidation potential were found. In the UV-Vis spectra large red shifts compared to other end-capped oligomers were observed.