Quaternary cerium(iv) containing fluorides exhibiting Ce3F16 sheets and Ce6F30 frameworks.

A series of new Ce(IV) based fluorides with two different compositions, Cs2MCe3F16 (M = Ni2+, Co2+, Mn2+, and Zn2+) and Na3MCe6F30 (M = Al3+, Ga3+, Fe3+, and Cr3+) were synthesized as high quality single crystals via a mild hydrothermal route. The compounds with the composition Cs2MCe3F16 (M = Ni2+, Co2+, Mn2+, and Zn2+) crystallize in the hexagonal crystal system with space group P63/mmc and are isotypic with the uranium analogs, whereas the Na3MCe6F30 (M = Al3+, Ga3+, Fe3+, and Cr3+) compounds crystallize in the trigonal space group P3 @#x0305;c1 and are isotypic with the uranium and thorium analogs NaxMM’6F30 (M’ = Th, U). The Cs2MCe3F16 compounds exhibit a complex 3D crystal structure constructed of edge-sharing cerium trimers, in which all three Ce atoms share a common µ3-F unit. The Na3MCe6F30 compounds are constructed of edge- and vertex-sharing cerium polyhedra connected to each other to form Ce6F306- framework, which can accommodate only relatively smaller trivalent cations (M3+ = Al3+, Ga3+, Fe3+, and Cr3+) as compared to uranium and thorium analogs. Magnetic susceptibility measurements were carried out on the samples of Cs2MCe3F16 (M = Ni2+ and Co2+), which exhibit paramagnetic behavior.