A New Modification of TeI₄ Possessing the Crystal Structure Proposed for WI₄

Abstract

A modification of TeI 4 (ζ-TeI 4 ) was discovered in an attempt to reproduce a reported synthesis of WI 4 , beginning from WTe 2 and iodine. The crystal structure of ζ-TeI 4 was solved from single-crystal data in the triclinic space group P1, isotypic with the structure of the previously reported WI 4 . The crystal structure of ζ-TeI 4 contains isolated tetrameric Te 4 I 16 molecules, in which tellurium atoms are coordinated by six iodine atoms. Electron microprobe and ICP-OES measurements confirm the identity of the new phase and make the formation of WI 4 via this synthesis route implausible. A comparison of ζ-TeI 4 with all other TeI 4 polymorphs is drawn by DFT calculations and structural relationships. Special conditions regarding the formation of ζ-TeI 4 as well as the phase transition from δ-TeI 4 into ζ-TeI 4 are reported.