Tetrathiafulvalene and Tetramethyltetraselenafulvalene Salts with [M(dcdmp)2] Anions (M = Au, Cu, and Ni): High Conductivity and Unusual Stoichiometries

Abstract

Four new charge transfer salts based on tetrathiafulvalene (TTF) or tetramethyltetraselenafulvalene (TMTSF) donors and transition metal complexes [M(dcdmp)2] (dcdmp = 2,3-dicyano-5,6-dimercaptopyrazine), TMTSF5[Cu(dcdmp)2]4 (1), (TMTSF)2[Ni(dcdmp)2] (2), and (TTF)7[M(dcdmp)2]6 (M = Au (3) and Cu (4)) were prepared by electrocrystallization. These compounds are characterized by a rich variety of crystal structures with unusual donor/acceptor stoichiometries. In spite of the uncommon structural types observed, these salts can be highly conducting. Compound 1 crystallizes with segregated TMTSF stacks, showing 1D metallic properties with a room temperature conductivity of 134 S/cm. Compound 2 crystallizes in an out-of-registry mixed column arrangement of donor dimers and acceptors. Compounds 3 and 4 appear in single crystal X-ray diffraction as isostructural and composed of columns of TTF hexamers that are disrupted by a single TTF layer and surrounded by [M(dcdmp)2]− monoanionic pairs, aligning perpendicular...