TAOI2 - A CENTROSYMMETRIC VARIANT OF NBOI 2 STRUCTURE

The crystal structure of tantalum(IV) oxide diiodide was determined by single-crystal X-ray diffraction. TaOI2 contains sheets of distorted TaO2I4 octahedra which share trans I-I edges and trans O corners (cent rosymmetric MoOCl2 type). The Ta atoms are displaced from the centres of the octahedra forming Ta ... Ta pairs [3.100 (2) Angstrom]. The str ucture is closely related to the structure of NbOI2, which was reporte d as the non-centrosymmetric NbOCI2 type.