Synthesis, structure and physical properties of charge-transfer complexes based on BET–TTF and M(mnt)2(M = Au, Pt)

Abstract

The crystalline complexes (BET–TTF)[Au(mnt)2] and (BET–TTF)2[Pt(mnt)2] have been obtained by electrocrystallization of BET–TTF [bis(ethylenethio)tetrathiafulvalene] in CH2Cl2 in the presence of M(mnt)2(M = Au, Pt). IR, UV and EPR spectroscopy indicate that both compounds are completely ionized and have diamagnetic anions. (BET–TTF)[Au(mnt)2] crystallizes in the triclinic P space group, a= 7.94(1)A, b= 13.56(2)A, c= 5.80(2)A, V= 586(4)A3 and Z= 1. The structure consists of mixed donor–acceptor stacks along the a axis with close intermolecular S ⋯ S and N ⋯ H contacts which lead to a strongly interlocked packing. The conductivity of (BET–TTF)[Au(mnt)2] parallel to a is 8 × 10–3 S cm–1 at 300 K and presents an activation energy of 0.090 eV, indicative of semiconducting behaviour.