Chiral semiconductor phases: The optically pure D3[M III(S, S -EDDS)]2 (D = TTF, TSF) family

Abstract

A new family of optically pure tetrathiafulvalenium and tetraselenafulvalenium salts, D3[MIII(S,S-EDDS)] 2·nH2O (where D = TTF, TSF; M = Co, Fe, Cr; EDDS = ethylenediaminedisuccinato), were synthesized electrochemically. These phases are semiconductors with conductivities between 6.9 - 10-6 and 1.3 - 10-5 S·cm-1 (Eaca. 0.3 eV) for TTF and 2.8 - 10-4 to 2.8 - 10-5 S·cm-1 (E aca. 0.1 eV) for TSF compounds. While some crystals suffer from twinning, other well resolved structures consist of TTF/TSF stacks which, under the influence of the chiral anion, exhibit a periodic undulation described by an elliptical helix. The crystallographic data, along with computational work, indicate charge localization in the semiconducting motifs. © 2011 American Chemical Society.