207Pb and 113Cd NMR and XPS characterization of PbO–PbCl2–CdCl2 glasses

A structural characterization of PbO–PbCl2–CdCl2 oxychloride glasses was achieved using 207Pb and 113Cd nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). 207Pb static NMR spectra exhibit two broad components, whose intensity change with oxygen–chlorine substitution in the glass composition. 207Pb phase-adjusted spinning sidebands (PASS) NMR shows that the lead first co-ordination sphere in PbO–PbCl2–CdCl2 glasses contains both oxygen and chlorine atoms and that the Pb bonding environment varies from an ionic environment to a more covalent bonding state. From the study of crystalline Pb3O2Cl2, the correlation between 207Pb isotropic and anisotropic chemical shift is extended to oxychloride compounds. Oxygen 1s photoelectron spectra contain two components that are consistent with a glass formation through Pb–O–Pb bonds. 113Cd NMR spectra show that Cd is mainly ionically bonded to chlorine and acts as network modifier for all glass compositions.