Efficient routes towards a series of 5,5 '-bithiazolidinylidenes as pi-electron acceptors

• Published in: Organic & biomolecular chemistry Vol. 13; no. 31; pp. 8479 - 8486
• Main Authors: Le Gal, Y., Ameline, D., Bellec, N., Vacher, A., Roisnel, T., Dorcet, V., Jeannin, O., Lorcy, D.
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 21.08.2015; Royal Society of Chemistry
• Subjects: Chemical Sciences; Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; THIN-FILM TRANSISTORS; DESIGN; ORGANIC SEMICONDUCTORS; COMPLEXES
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/c5ob01169h

Different approaches have been studied in order to prepare efficiently the sulfur rich electron acceptor, DEBTTT. Among the various routes used, the one going through the synthesis of a bicyclic derivative, where the thiazole-2-chalcogenone is fused with a 1,3-dithiole-2-one, leads to the target molecule under milder conditions and better yield. Thus, this approach has been explored for the synthesis of a series of acceptors either by modifying the substituent on the thiazole core or by changing the exocyclic chalcogen atoms. All these sulfur rich electron acceptors exhibit short intra-and intermolecular S center dot center dot center dot S contacts in the solid state. Electrochemical investigations show that the nature of the exocyclic chalcogen atom of the thiazole ring has a significant influence on the accepting ability as a cathodic shift of about 220 mV is observed just by changing sulfur for oxygen. This structural modification enables the tuning of the redox properties.