EPR/UV-VIS-NIR Spectroelectrochemical Examination of the Association Properties of Thienoacene-Bridged Tetrathiafulvalenes Supported by DFT Calculations

This work was focused on the EPR/UV-VIS-NIR spectroelectrochemical examination of\nassociation properties of radical cations electrochemically produced from tetrathiafulvalene\n(TTF) derivatives, in relation to the molecular structure, mainly the number and orientation of\nthiophene rings in the spacer between fulvalene redox centers. Results from EPR/UV-VIS-NIR\nspectroelectrochemistry were supported by DFT calculations

Interactions between tetrathiafulvalene units in dimeric structures – the influence of cyclic cores

A selection of cyclic and acyclic acetylenic scaffolds bearing two tetrathiafulvalene (TTF) units was prepared by different metal-catalyzed coupling reactions. The bridge separating the two TTF units was systematically changed from linearly conjugated ethyne, butadiyne and tetraethynylethene (trans-substituted) units to a cross-conjugated tetraethynylethene unit, placed in either acyclic or cyclic arrangements. The cyclic structures correspond to so-called radiaannulenes having both endo- and exocyclic double bonds. Interactions between two redox-active TTF units in these molecules were investigated by cyclic voltammetry, UV–vis–NIR and EPR absorption spectroscopical methods of the electrochemically generated oxidized species. The electron-accepting properties of the acetylenic cores were also investigated electrochemically