A natural abundance 77Se solid-state NMR study of inorganic compounds

Various inorganic selenium-based compounds were analysed by 77Se solid-state NMR, and a distinct difference in chemical shift ranges for compounds where selenium is present as selenide (Se2−) ionically and covalently bonded systems was observed. The selenides exhibit a shift range of approximately −700 to −100 ppm, as opposed to 700 to 1600 ppm for the compounds where there tends to be more direct covalent bonding to the selenium. The anisotropic hyperfine shift observed in NbSe2 is shown to be axially symmetric, where the H11 component is found to be normal to the Se3-trigonal plane.