One-Dimensional Array of Two- and Three-Center Cation−Cation Bonds in the Structure of Li₄[(UO₂)₁₀O₁₀(Mo₂O₈)]

Abstract

Dark-red crystals of the new compound Li(4)[(UO(2))(10)O10(Mo(2)O(8))] (1) have been obtained by high-temperature solid-state reactions. The structure of 1 (monoclinic, P2(1)/c, a = 7.9426(4) A, b = 19.9895(9) A, c = 10.0796(5) A, beta = 90.575(2) degrees, V = 1600.24(13) A(3), Z = 4) consists of a framework of U and Mo polyhedra with Li+ cations in the channels. The framework contains seven-polyhedra-wide uranium oxide tapes interlinked by dimers of edge-sharing [4 + 1]-distorted MoO(5) polyhedra. The U-O tapes are parallel to the a axis, and their planes are oriented parallel to (021) and (02) 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 uranyl ions linked through two- and three-center cation-cation interactions.