Crystal Structure and Physical Properties of (TTM-TTF)I2.47

Abstract

Abstract The X-ray crystal structure analysis of a novel organic conductor (TTM-TTF)I2.47 (TTM-TTF: tetrakis(methylthio)tetrathiafulvalene) shows that the donors with an almost flat structure are stacked face-to-face to form columns. The iodine lattice composed of I3− columns is incommensurate with the donor lattice. The measurements of resistivity, thermoelectric power, and ESR show a metal-insulator transition around 100 K. This transition is attributed to the Peierls type phase transition. The quasi-one-dimensional electronic structure is supported by the arrangement of the donor molecules in the crystal and the calculated anisotropy of transfer integrals.