Syntheses and structures of one-and two-dimensional copper(I) coordination polymers with tetrakis(ethylthio)tetrathiafulvalene (TTC 2-TTF) and the properties of their iodine-doped compounds

Abstract

Two copper(I) complexes with tetrakis(ethylthio)tetrathiafulvalene (TTC 2-TTF), [(CuCl) 2TTC 2-TTF] ( 1) and [(CuBr) 2TTC 2-TTF] ( 2), have been synthesized and characterized by spectroscopic and X-ray crystallographic methods. Both 1 and 2 are neutral 2:1 (metal/ligand) complexes in which each metal ion is coordinated in a distorted tetrahedral geometry to two bridging halide ions and two sulphur atoms from TTC 2-TTF. The crystal of 1 has a two-dimensional structure in which TTC 2-TTF molecules are connected between novel helical CuCl frames, while the crystal of 2 has a one-dimensional polymeric chain structure. The average CuCl and CuS bond lengths are 2.282(2) and 2.405(2) Å in 1 and CuBr and CuS bond lengths are 2.445(2) and 2.349(1) Å in 2, respectively. Compounds 1 and 2 were doped with iodine to afford [(CuCl) 2TTC 2-TTF]I ( 3) and [(CuBr) 2TTC 2-TTF]I ( 4) which exhibit electrical conductivities of 6 × 10 −7 and 3 × 10 −7 S cm −1, respectively, at 25°C for compacted pellets.