Novel mixed valence U(VI)/U(IV) dipicolinate

Mixed valence U(VI)/U(IV) compound with organic anionic ligand bridging uranium atoms in different oxidation states was synthesized at room temperature. Coordination polyhedron of U(VI) atom is a pentagonal bipyramide whose equatorial positions are occupied by nitrogen and two oxygen atoms of one DPA2− anion, oxygen atom of another DPA2− anion and a water molecule. Second uranium atom U(IV) is surrounded by three DPA2− anions, one of which is tetradentate and acts as bridging ligand connecting metal centers, while other two DPA2− anions are tridentate. The crystal structure is confirmed by UV–vis and IR spectroscopic data.