Ethylenedithio--Tetrathiafulvalene--Helicenes: Electroactive Helical Precursors with Switchable Chiroptical Properties

Thomas Biet (1) , Arnaud Fihey (1) , Thomas Cauchy (1) , Nicolas Vanthuyne (2) , Christian Roussel (2) , Jeanne Crassous (3) , Narcis Avarvari (1)

1 MOLTECH-Anjou
2 ISM2 - Institut des Sciences Moléculaires de Marseille
3 IPR - Institut de Physique de Rennes

Electroactive fused ethylenedithio-tetrathiafulvalene-[4]helicene and -[6]helicenes have been synthesized through a strategy involving the preparation of 2,3-dibromo-helicene derivatives as intermediates. The dihedral angles between the terminal helicenes, as determined by single crystal X-ray analyses, amount to 22.7° and 50.7° for the [4]helicene and [6]helicene, respectively. The solid state architectures show interplay between S···S and ··· intermolecular interactions. The chiroptical properties of the enantiopure EDT-TTF-[6]helicene derivatives have been investigated and supported by TD DFT calculations. Remarkable redox switching of the circular dichroism signal between the neutral and radical cation species has been achieved.

Domaines: Chimie organique

Thomas Biet, Arnaud Fihey, Thomas Cauchy, Nicolas Vanthuyne, Christian Roussel, et al.. Ethylenedithio--Tetrathiafulvalene--Helicenes: Electroactive Helical Precursors with Switchable Chiroptical Properties. Chemistry - A European Journal, 2013, 19 (39), pp.13160-13167. ⟨10.1002/chem.201301095⟩. ⟨hal-01086724⟩