Sc-2(MoO4)(3) and Sc-2(WO4)(3): Halide Flux Growth of Single Crystals and Sc-45 Solid-state NMR

Balamurugan S, Rodewald UC, Harmening T, van Wullen L, Mohr D, Eckert H, Pottgen R

Zusammenfassung

Single crystals of Sc-2(TO4)(3) with T = Mo and W were synthesized from Sc2O3, MoO3, and WO3 at 1223 K in NaCl/KCl as solvent. Both structures were refined from X-ray diffractometer data: Pbcn, a = 1325.1(1), h = 954.9(1), c = 964.4(1) pm, wR2 = 0.0425, .2097 F-2, 79 variables for Sc-2(MoO4)(3) and a = 1332.9(9), b = 959.4(7), c = 967.9(2) pm, wR2 = 0.0384, 1971 F-2, 79 variables for Sc-2(WO4)(3). The structures consist of a three-dimensional network of corner-sharing ScO6/2 octahedra and two crystallographically independent TO4/2 tetrahedra. Sc-45 MAS NMR spectra show sharp single resonances in accordance with the crystallographic data. The quadrupolar interaction parameters obtained from a simulation of the full Sc-45 MAS NMR spectra are found to be in good agreement with those obtained from DFT calculations of the electric field gradient.