Soft–Soft Interactions of Iodide and Triiodide Ions with Triphenyltelluronium Cations

Abstract

The crystal structures of triphenyltelluronium iodide and of triphenyltelluronium triiodide were solved by X-ray diffraction. Triphenyltelluronium iodide consists of ladder-like tetrameric units involving dicoordinated iodine atoms, bridging penta- and hexacoordinated tellurium atoms, and tri-coordinated central iodines that bridge one pentacoordinated and two hexacoordinated tellurium atoms. Triphenyltelluronium triiodide is made up of extended chains that are generated by pairwise interaction of Ph₃Te-I₃ units through weak Te···I contacts involving one terminal atom from each triiodide ion, and by connection of these four-membered units through both terminal atoms of the triiodide ions. This asymmetric contribution of the two terminal iodine atoms of the triiodide ion to the soft–soft network correlates with a significant difference of the two I‒I bond lengths (2.847 and 2.984 A).

Keywords:

• Secondary interactions
• soft–soft interactions
• telluronium salts
• triiodide
• X-ray crystallography

Acknowledgments

Dedicated to Professor Naomichi Furukawa on the occasion of his 70th birthday.