77Se solid-state NMR spectra have been recorded with cross-polarization and magic-angle spinning on [M(Se4)2]2 complexes with [Me4N]+ (M = Zn, Cd, Hg) and [Et4N]+ (M = Cd, Hg). The large chemical shift anisotropies (of the order of 1000 ppm) mean that fast spinning speeds (9–11 kHz) are needed in order to reveal the number of crystallographic selenium sites present within the solid. The spectra enable the principal components of the 77Se shielding tensor to be calculated from the spinning sideband intensities. Differences between the 77Se isotropic chemical shifts observed for the [Et4N]+ complexes and for the [Me4N]+ complexes reflect small structural changes in the [M(Se4)2]2 geometry with cation, J-coupling to 199Hg and 111/113Cd are also observed. The solid-state NMR results are compared with similar work in solution. A single-crystal X-ray structure determination of [Me4N]2- [Hg(Se4)2]‧0.5DMF is reported (monoclinic crystal system, space group C2/c). The Hg atom is tetrahedrally coordinated by two chelating tetraselenide ligands with both HgSe4 rings adopting the envelope conformation. The FT Raman spectrum of [Me4N]2[Cd(Se4)2] is also reported.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry