An aryl-fused redox-active tetrathiafulvalene with enhanced mixed-valence and radical-cation dimer stabilities

作者：Schroeder Hendrik V; Witte Felix; Gaedke Marius; Sobottka Sebastian; Suntrup Lisa; Hupatz Henrik; Valkonen Arto; Paulus Beate; Rissanen Kari; Sarkar Biprajit; Schalley Christoph A^*

来源：Organic and Biomolecular Chemistry, 2018, 16(15): 2741-2747.

DOI：10.1039/c8ob00415c

Molecular recognition of stable organic radicals is a relatively novel, but important structural binding motif in supramolecular chemistry Here, we report on a redox-switchable veratrole-fused tetrathiafulvalene derivative VTTF which is ideally suited for this purpose and for the incorporation into stimuli-responsive systems As revealed by electrochemistry, UV/Vis measurements, X-ray analysis, and electrocrystallisation, VTTF can be reversibly oxidised to the corresponding radical-cation or dication which shows optoelectronic and structural propterties similar to tetrathiafulvalene and tetrakis(methylthio)tetrathiafulvalene. However, theoretical calculations, variable temperature ERR, and NIR spectroscopy indicate that the dispersion-driven binding in the mixed-valence dimer (VTTF2)(.+) (K-MV = 69 M-1 in CH2Cl2) and the radical-cation dimer (VTTF.+)(2) (K-Rc = 38 M- 1 in CH3CN) is significantly enhanced by the additional veratrole pi-surface in comparison to pristine tetrathiafulvalene.

• 出版日期2018-4-21