Uranium(VI) tetraoxido core coordinated by bidentate nitrate.

The synthesis and structural characterization of the compounds K[(UO(2))(2)(UO(4))(OH)(NO(3))(2)]H(2)O (1) and Ba[(UO(2))(4)(UO(4))(2)(OH)(2)(NO(3))(4)]H(2)O (2) have revealed that each contains sheets that are based upon the beta-U(3)O(8)-type topology and that these sheets are linked through low-valence interlayer cations. Consistent with other uranium(VI) compounds that have topologically identical sheets, one of the uranium(VI) sites exhibits a highly unusual (UO(4))(2-) tetraoxido core that is further coordinated by two bidentate (NO(3))(-) groups.