| Abstract
| - Synthetic strategies for preparing dimeric tetrathiafulvalenes (TTFs) linked by either one, two, orfour bridges have been developed. In particular, we report efficient few-step protocols for the preparation offace-to-face overlapped quadruple-bridged bis-TTFs. The ready interconversion of cis and trans TTFs in thepresence of catalytic amounts of acid was implemented in one synthetic protocol as a way to control theisomeric outcome. The compounds were characterized by NMR spectroscopy, mass spectrometry, and elementalanalysis. Moreover, the X-ray crystal structure of the macrocycle 4b is presented and compared to semiempirical(PM3) geometry optimizations. Cyclic voltammetry and spectroelectrochemistry were used to describe theinteractions established between two TTF units upon oxidation, that is, their ability to form mixed-valencecomplexes and π-dimers either intra- or intermolecularly. The length, flexibility, and number of bridging unitsin a bis-TTF, as well as the specific TTF positions being connected, determine the extent of these interactions.Thus, rigid linkers enhance the formation of intermolecular mixed-valence complexes. For 4b, the absorptionspectrum of this mixed-valence state of TTF in solution has been recorded for the first time. Finally, preliminarycomplexation experiments with different electron-deficient molecules are described.
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