Structural chemistry of mixed-ligand carboxylate-fluoride and neutral fluoride complexes of uranyl (review)

Abstract

The crystal structures of mixed-ligand carboxylate-fluoride and neutral fluoride complexes of uranyl studied by the single-crystal X-ray diffraction method have been systematized and discussed. The crystal chemical features of the structures of this class of uranyl compounds were determined: the coordination polyhedron of the hexavalent uranium atom in the structures of the mixed-ligand carboxylate-fluoride and neutral fluoride complexes of uranyl (excluding three hexadentate-bipyramidal compound) has a pentagonal-bipyramidal structure: the oxygen atoms of the uranyl group are located on the vertical axis of the pentagonal bipyramid, perpendicular to the equatorial plane in which five atoms are located. In the crystal structures of dimeric and polymeric mixed-ligand carboxylate-fluoride and neutral fluoride complexes of uranyl (with the exception of one compound in which the bridging bonds in the dimer are formed by oxygen atoms) the fluoride bridges form fluoride atoms.