Molecular Scaffolding with Tetrathiafulvalene—Design and Synthesis of New Molecules for Molecular Electronics

Abstract

Since the field of molecular electronics originated in the 1970s, the sulfur-containing heterocycle tetrathiafulvalene (TTF) has played a leading role. The reason for this is its ability to undergo two reversible one-electron oxidation steps at potentials that can be finely tuned by either peripheral substitution or by insertion of a π-conjugated spacer between the two dithiole rings. This review summarizes our own efforts in developing the synthetic TTF chemistry for obtaining a variety of molecules with potential applications in molecular electronics devices, such as redox-controlled molecular wires incorporating vertically disposed extended TTFs (cruciform molecules), conjugated macrocycles (dehydroannulenes) with fused TTF units, TTF-perylene diimide donor–acceptor dyads with broken conjugation, and redox-controlled dihydroazulene photoswitches. The synthetic strategies are to a large extent based on acetylenic scaffolding with acetylenic dithiafulvene and tetrathiafulvalene building blocks, employing different metal-catalyzed coupling reactions.

Keywords:

• Macrocycles
• molecular electronics
• switches
• tetrathiafulvalene
• thiol

Acknowledgments

I acknowledge all group members and collaborators who contributed to the work described in this review and whose names appear in the publications listed in the references section. The Danish Research Council for Independent Research/Natural Sciences, The Carlsberg Foundation, and the European Community's Seventh Framework Programme (FP7/2007-2013) under the grant agreement “SINGLE” no. 213609 are gratefully acknowledged for financial support.