A Fluent Transition from Triiodide, I 3 − , to Tris(trifluoromethyltellurate)(1−), [(TeCF 3 ) 3 ] − —A Structural Study

A complete series of compounds with the anions [(TeCF 3 ) 3− x I x ] − ( x =0–2) had been prepared and characterised in the solid state and by NMR spectroscopic methods. Dynamic behaviour in solution can be assumed for [(TeCF 3 ) 3 ] − and [(TeCF 3 ) 2 I] − , while in the solid state all three bis(triphenylphosphoranyliden)ammonium (PNP) salts resemble structures found in triiodides. The molecular structures of [PNP][(TeCF 3 ) 3− x I x ] − ( x =0–2) are discussed in comparison with [PNP]I 3 , I 2 , and Te 2 (CF 3 ) 2 . On this basis, the structures of the [(TeCF 3 ) 3 ] − and [(TeCF 3 )I 2 ] − ions are comparable to symmetric I 3 − ions, while the [(TeCF 3 ) 2 I] − ion resembles an asymmetric I 3 − unit.