Combinatorial topology of uranyl molybdate sheets: syntheses and crystal structures of (C6H14N2)(3)[(UO2)(5)(MoO4)(8)](H2O)(4) and (C2H10N2)[(UO2)(MoO4)(2)]

摘要

Two new mixed organic-inorganic uranyl molybdates, (C6H14N2)(3)[(UO2)(5)(MoO4)(8)](H2O)(4) (1) and (C2H10N2)[(UO2)(MoO4)(2)] (2), have been obtained by hydrothermal methods. The structure of I [triclinic, P (1) over bar, Z = 1, a = 11.8557(9), b = 11.8702(9), c = 12.6746(9) Angstrom, alpha = 96.734(2)degrees beta = 91.107(2)degrees, gamma = 110.193(2)degrees, V = 1659.1(2)Angstrom] has been solved by direct methods and refined on the basis of F-2 for all unique reflections to R1 = 0.058, which was calculated for the 5642 unique observed reflections (F greater than or equal to 4sigma(F))The structure contains topologically novel sheets of uranyl square bipyramids, uranyl pentagonal bipyramids, and MoO4 tetrahedra, with composition [(UO2)(5)(MoO4)(8)](6-), that are parallel to (-101). H2O groups and 1,4-diazabicyclo [2.2.2]-octane (DABCO) molecules are located in the interlayer, where they provide linkage of the sheets. The structure of 2 [triclinic, P (1) over bar, Z = 2, a = 8.4004(4), b = 11.2600(5), c = 13.1239(6) Angstrom, alpha = 86.112(1)degrees, beta = 86.434(1)degrees; gamma = 76.544(1)1degrees, V = 1203.14(10)Angstrom] has been solved by direct methods and refined on the basis of F-2 for all unique reflections to R1 = 0.043, which was calculated for 5491 unique observed reflections (F-o greater than or equal to 4sigma(F)). The structure contains topologically novel sheets of uranyl pentagonal bipyramids and MoO4 tetrahedra, with composition [(UO2)(MoO4)(2)](2-), that are parallel to (I 10). Ethylenediamine molecules are located in the interlayer, where they provide linkage of the sheets. All known topologies of uranyl molybdate sheets of corner-sharing U and Mo polyhedra can be described by their nodal representations (representations as graphs in which U and Mo polyhedra are given as black and white vertices, respectively). Each topology can be derived from a simple black-and-white graph of six-connected black vertices and three-connected white vertices by deleting some of its segments and white vertices. (C) 2002 Elsevier Science (USA). All rights reserved. [References: 45]