One-dimensional array of two- and three-center cation-cation bonds in the structure of Li4[(UO2)10O10(Mo2O8)]

Dark-red crystals of the new compound Li-4[(UO2)(10)O-10(Mo2O8)] (1) have been obtained by high-temperature solid-state reactions. The structure of 1 (monoclinic, P2(1)/c, a = 7.9426(4) angstrom, b = 19.9895(9) angstrom, c = 10.0796(5) angstrom, beta = 90.575(2)degrees, V = 1600.24(13) angstrom(3), Z = 4) consists of a framework of U and Mo polyhedra with Li+ cations in the channels, The framework contains seven-polyhedrawide uranium oxide tapes interlinked by dimers of edge-sharing [4 + 1]-distorted MoO5 polyhedra. The U-O tapes are parallel to the a axis, and their planes are oriented parallel to (021) and (02 (1) over bar) so that they are cross-linked within the framework. The core of the tapes consists of unprecedented one-dimensional arrays of cation-cation-bonded uranyl ions. The arrays are constructed from eight-membered cycles with ulranyl ions linked through two- and three-center cation-cation interactions.