Tetraethylammonium Hexafluoro Uranate(IV), Hafnate(IV), and Cerate(IV) Salts: Preparation and Solid-state Structure

The {N(C2H5)(4)}(2)[UF6]center dot 2H(2)O (1), {N(C2H5)(4)}(2)[HfF6]center dot 2H(2)O (2), and {N(C2H5)(4)}(2)[CeF6]center dot 6H(2)O (3) salts were prepared in high yield (ca. 80 %) from the reaction of MF4 with tetraethylammonium fluoride in propylene carbonate and for the first time their solid-state structures characterized by single-crystal X-ray diffraction. The compounds 1, 2 and 3 crystallize in the space groups Pcca, P2(1)/n(1) and Pca2(1), respectively. In 1, 2, and 3 the MF62- anions are almost octahedral with average M-F distances of 2.16, 1.999, and 2.148 angstrom.