The Gas Phase Raman Spectrum and Molecular Structure of Dichlorodibromotellurium(IV) TeCl2Br2. Novel Penta- and Hexa-co-ordinate Mixed Halide Anions of Tellurium(IV). Synthesis and infrared and Raman Spectra of [Et4N]TeCl2Br3 and [Et4N]2TeCl2Br4

Abstract

The Raman spectrum of gaseous TeCl2Br2 at 310 °C is reported for the first time. The gas phase data is consistent with the presence of a monomolecular species haying C1 symmetry. A synthetic route for the preparation of penta- and hexa-co-ordinate mixed halide anions of tellurium(IV), under anhydrous conditions, is described for the first time. The infrared and Raman spectra for solid [Et4N]TeCl2Br3 and [Et4N]2TeCl2Br4 are reported. A stereochemistry based on a square pyramid, is favored for [Et4N]-TeCl2Br3. In the case of [Et4N]2TeCl2Br4 the vibrational data strongly suggests the presence of a cis-octahedral anion, having C2v symmetry.