The solid-state MU8Q17 compounds ScU 8S17, CoU8S17, NiU8S 17, TiU8Se17, VU8Se17, CrU8Se17, CoU8Se17, and NiU 8Se17 were synthesized from the reactions of the elements at 1173 or 1123 K. These isostructural compounds crystallize in space group C2h 3 - C2/m of the monoclinic system in the CrU 8S17 structure type. X-ray absorption near-edge structure spectroscopic studies of ScU8S17 indicate that it contains Sc3+, and hence charge balance is achieved with a composition that includes U3+ as well as U4+. The other compounds charge balance with M2+ and U4+. Magnetic susceptibility measurements on ScU8S17 indicate antiferromagnetic couplings and a highly reduced effective magnetic moment. Ab Initio calculations find the compound to be metallic. Surprisingly, the Sc-S distances are actually longer than all the other M-S interactions, even though the ionic radii of Sc3+, low-spin Cr2+, and Ni2+ are similar.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry