Polyiodide chains in crystalline organic iodides: Ab initio Hartree–Fock crystal orbital study

Hartree–Fock crystal orbital calculations of two crystalline organic iodides, tetrathiafulvalenium triiodide (TTF∗︁I₃) and dipyridinium decaiodide (NHC₅H₅)₂∗︁I₁₀, were carried out. The former crystal contains no true polyiodide chains, whereas such chains are present in the latter crystal. In such a way, the effect of the polyiodide chain formation on the electronic structure of crystalline organic iodides was studied. The present calculations show that crystalline organic iodides with polyiodide chains could, in principle, be quasi-one-dimensional semiconductors. A polyiodide chain could be a carrier of semiconductivity only when it is formed by fully charged iodide anions (no charge transfer from the chain). © 1997 John Wiley & Sons, Inc. Int J Quant Chem 64 : 473–479, 1997