Tellurium-125 Mössbauer spectra of some mixed oxides of tellurium(IV) and some mixed-valence oxides of tellurium(IV, VI)
Abstract
125
Te Mössbauer spectra of 10 tellurium(IV)-oxygen compounds of accurately known crystal structure and six other such compounds of unknown structure have been recorded. Data have also been obtained for the mixed-valence oxides Te2O5 and Te4O9. The results establish the oxidation states where these were uncertain and show that the mixed-valence oxides are TeIVTeVIO5 and TeIV3TeVIO9 respectively. Quadrupole splittings generated by the stereochemically active lone pair of electrons on TeIV have been correlated with the extent of distortion of the oxygen co-ordination polyhedra and decrease in the sequence type (A)(B)
(C). The 57Fe Mössbauer spectrum of Fe2Te3O9 shows that the compound is magnetically ordered at 4.2 K, but the 125Te spectrum indicates that there is no detectable transferred hyperfine field at the tellurium nucleus. The 119Sn Mössbauer spectrum of SnTe3O8 confirms the presence of SnIV in this compound.