Bi16I4 – A New Bismuth Subiodide: An Analysis of Molecular Packing and Electronic Structures of the Compounds in the Bi_mI4 (m = 14, 16, 18) Family

Abstract

A new bismuth subiodide Bi₁₆I₄ was synthesized by high-temperature synthesis. Its structure was determined by single-crystal X-ray diffraction analysis [C2/m (No. 12), a = 25.948(6) Å, b = 4.354(1) Å, c = 13.259(3) Å, β = 104.48(2)°, Z = 2, R₁ = 0.041, wR_all(F²) = 0.109]. The compound belongs to the Bi_mI₄ (m = 14, 16, 18) family of low-dimensional subhalides that feature one-dimensional bismuth stripes of varying width, terminated by iodine atoms. Ab initio calculations at the DFT level were performed on 3D structures of all three Bi_mI₄ compounds of the family. According to the computational data all three compounds are expected to exhibit metallic behavior and Pauli paramagnetism, with a directional anisotropy of the properties indicated by the calculated band structures. The molecular packing in bismuth subiodides has been analyzed in detail and two homologous series – Bi_8+4nI₄ and Bi_10+4nI₄ (n = 0, 1, 2, ...) – are suggested to describe existing and possible structures of the compounds of the Bi_mI₄ family. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)