Structural Tuning of Curved TTFAQ-AQ as a Redox-Active Supramolecular Partner for C70 Fullerene

• Published in: Journal of organic chemistry 2021-11, Vol.86 (21), p.14855-14865
• Main Authors: Abdollahi, Maryam F, Zhao, Yuming
• Format: Article
• Language: English
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/acs.joc.1c01633

A series of saddle-shaped donor–acceptor π-systems, termed TTFAQ-AQs, were designed and synthesized. The molecular structures of TTFAQ-AQs feature a π-fused framework containing an anthraquino­dimethane extended tetrathiafulvalene (TTFAQ) as the donor and an anthraquinone (AQ) unit as the acceptor. As such, TTFAQ-AQs show enhanced intramolecular charge-transfer properties, which result in amphoteric redox behavior and narrow electronic energy band gaps. Detailed structural and electronic properties were investigated by UV–vis absorption, cyclic voltammetric, and single-crystal X-ray diffraction (SCXRD) analyses. The supramolecular interactions of TTFAQ-AQs with C60 and C70 fullerenes were examined in both the solution and solid phases. Our results showed that the benzoannulated TTFAQ-AQ derivative favors interaction with C70 fullerene through complementary concave–convex interactions. Detailed energetics involved in the TTFAQ-AQ/C70 interactions were assessed by means of density functional theory (DFT) calculations.