Tetraphenylphosphonium iodide–1,3,5- trifluoro-2,4,6-triiodobenzene–methanol (3/4/1)

0.040; wR factor = 0.081; data-to-parameter ratio = 12.4. The crystallization of a 1:1 molar solution of 1,3,5-trifluoro-2,4,6-diiodobenzene (TFTIB) and tetraphenylphosponium iodide (TPPI) from methanol produced tetragonal needles of pure TPPI and tabular pseudo-hexagonal truncated bipyramids of the title compound, 3C24H20P +3I-4C6F3I3CH4O or (TPPI)3(TFTIB)4MeOH. The asymmetric unit is composed of six TPPI molecules, eight TFTIB molecules and two methanol molecules, overall 16 constitu-ents. The formation of the architecture is essentially guided by a number of C—I I halogen bonds (XB), whose lengths are in the range 3.276 (1)–3.625 (1) Å. Layers of supramolecular polyanions are formed parallel to (101) wherein iodide anions function as penta-, tetra- or bidentate XB acceptors. The structure is not far from being P21/n, but the centrosymmetry is lost due to a different conformation of a single couple of cations and the small asymmetry in the formed supra-molecular anion. One methanol molecule is hydrogen bonded to an iodide anion, while the second is linked to the first one via an O—H O contact. This second methanol molecule is more loosely pinned in its position than the first and presents very high anisotropic displacement parameters and a seeming shortening of the C—O bond length. The crystal studied was refined as a perfect inversion twin. Related literature For the structure of pure TPPI, see: Schweizer et al. (1989), fo