Structure study of bromocadmate and iodocadmate glasses by ¹¹³Cd MAS NMR spectroscopy

¹¹³Cd magic-angle spinning (MAS) NMR spectra have been measured for glasses of 50.0CdBr₂·xKBr·xCsBr·(50.0-2x)BaBr ₂ (x=17.5 and 20.0), 40CdI₂·40KI·20CsI, 50CdI₂·yKI·(50-y)CsI (y=10,20, and 30), 60CdI₂·10KI·30CsI, and (60-z)CdI₂·40CsI·zBaI₂ (z=0,5and10) in mol% to reveal the anion co-ordination environments around Cd²⁺ in the glasses. The bromocadmate and iodocadmate glasses gave isotropic chemical shift values of -27 ppm and 78∼121 ppm, respectively, indicating that the former and the latter glasses consist of CdBr₆ octahedra and CdI₄ tetrahedra, respectively. Moreover, the octahedral anion co-ordination around Cd²⁺ in the bromocadmate glasses has higher symmetry than that in the chlorocadmate glasses, and the iodine co-ordination environment around Cd²⁺ in the iodocadmate glasses is dependent on the CdI₂ content, but is independent of the kind of glass-modifying cation.