NMR and cation-cation interactions involvings 2 lone pairs

The results of NMR spectroscopy on^203,205Tl,²⁰⁷Pb,¹²⁵Te, and other nuclei are used to characterize an anomalous effect of the s² lone pair on interatomic interactions in the fluorides, oxides, and chalcogenides of some elements of Groups 13–18 of the periodic table. Data for crystals of TISe structural type and related compounds, for various structural modifications of TIF, PbO, and TeO₂ crystals, and also for liquids and liquid solutions (TIOC₂H₅)₄, (XeF₆)₄, etc.], of vanadium tellurite and lead silicate glasses are considered. It is shown that the electronnuclear interactions and the structural peculiarities of compounds with underoxidated cations are due to the effect of the excited states of ions with the electronic configuration s². Translated fromZhumal Strukturnoi Khimii, Vol. 38, No. 1, pp. 173–195, January–February, 1997.