Use of Thallium(I), Lead(II), and Bismuth(III) as Spectroscopic Probes for Ionic–Covalent Interaction in Glasses

Abstract

Ultraviolet spectra of thallium(I), lead(II), and bismuth(III) in chloride–sulfate and all‐sulfate glasses have been studied, and it is observed that the ${}^3{P}_1{\mathrm{\hspace{0.17em}\leftarrow \hspace{0.17em}}}^1{S}_0$ transition undergoes a blue shift as the sulfate: chloride ratio increases. This is interpreted in terms of increased ionicity of the probe metal ions in the all‐sulfate glass. Spectral data indicate comparable ionicity of the probe metal ions in phosphate glass, but more covalent interactions in silicate glass. It is suggested that the study of these spectral bands may be applied to the problems of oxide ion activity in glasses and of covalency in molten salt chemistry.