A series of enantiopure BEDT-TTF-acetamide derivatives with two stereogenic centres†

A method for the synthesis of twelve enantiopure derivatives of BEDT-TTF which have two stereogenic centres is reported comprising six diastereomeric pairs. The donors are derivatives of enantiopure (BEDT-TTF)-acetamide bearing a chiral substituent on the nitrogen (NCHMeR: R = 3-Cl-C₆H₄, 3-OMeC₆H₄, 4-Me-C₆H₄, cyclohexyl and 1-naphthyl, and NCH(CH₂Ph)CO₂Me), and structural assignments are supported by X-ray crystallography. All donors show two successive oxidations typical of BEDT-TTF. Two examples of charge transfer salts with members of this series are reported: a 2 : 1 salt with triiodide in which the anions lie in channels along the donor stacking direction and a 1 : 1 salt with TCNQ-F₂ in which the donors and acceptors lie side by side, and staggered with respect to the next layer. Hydrogen bonding between the donors’ amide groups is an important feature in the crystal structures.