Electrochemical studies of a new, low-band gap inherently chiral ethylenedioxythiophene-based oligothiophene

• Published in: Electrochimica acta 2018-09, Vol.284, p.513-525
• Main Authors: Benincori, Tiziana, Gámez-Valenzuela, Sergio, Goll, Miriam, Bruchlos, Kirsten, Malacrida, Claudia, Arnaboldi, Serena, Mussini, Patrizia Romana, Panigati, Monica, López Navarrete, Juan T., Ruiz Delgado, M. Carmen, Appoloni, Giulio, Ludwigs, Sabine
• Format: Article
• Language: English
• Subjects: Absorption spectra; bisEDOT; Cyclic oligomers; Electrodes; Energy gap; Light emitting diodes; Low-band gap monomer; Mixed valence conductivity; Oligomers; Oxidation; Photovoltaic cells; Resistance; Self-rigidification; Voltammetry
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.07.147

In the present paper, the synthesis and characterization of 2,2′-bis{bi[2,2’-(3,4-ethylenedioxy)thiophen-5-yl]}-3,3′-bithianaphthene, nicknamed BT2E4, is reported. We show that electrooligomerization of BT2E4 leads to electroactive films which are evaluated by cyclic voltammetry (CV), UV/vis spectroelectrochemistry and CV coupled with in-situ conductance measurements. Direct comparisons to the properties of the oligomers obtained from the atropisomeric all-thiophene analogue BT2T4 show that the introduction of EDOT leads to a strong reduction of the band-gap, an overall red-shifted absorption spectrum and a rigidification of the structure. Finally, DFT and TD-DFT calculations were performed in parallel to investigate and to compare the electronic and molecular structures of neutral and charged monomer and oligomer species.