Syntheses, structures, characterizations and charge-density matching of novel amino-templated uranyl selenates

Five hybrid organic–inorganic uranyl selenates have been synthesized, characterized and their structures have been determined. The structure of (C2H8N)2[(UO2)2(SeO4)3(H2O)] (EthylAUSe) is monoclinic, P21, a=8.290(1), b=12.349(2), c=11.038(2) Å, β=104.439(4)°, V=1094.3(3) Å3, Z=2, R1=0.0425. The structure of (C7H10N)2[(UO2)(SeO4)2(H2O)]H2O (BenzylAUSe) is orthorhombic, Pna21, a=24.221(2), b=11.917(1), c=7.4528(7) Å, V=2151.1(3) Å3, Z=4, R1=0.0307. The structure of (C2H10N2)[(UO2)(SeO4)2(H2O)](H2O)2 (EDAUSe) is monoclinic, P21/c, a=11.677(2), b=7.908(1), c=15.698(2) Å, β=98.813(3)°, V=1432.4(3) Å3, Z=4, R1=0.0371. The structure of (C6H22N4)[(UO2)(SeO4)2(H2O)](H2O) (TETAUSe) is monoclinic, P21/n, a=13.002(2), b=7.962(1), c=14.754(2) Å, β=114.077(2)°, V=1394.5(3) Å3, Z=4, R1=0.0323. The structure of (C6H21N4)[(UO2)(SeO4)2(HSeO4)] (TAEAUSe) is monoclinic, P21/m, a=9.2218(6), b=12.2768(9), c=9.4464(7) Å, β=116.1650(10)°, V=959.88(12) Å3, Z=2, R1=0.0322. The inorganic structural units in these compounds are composed of uranyl pentagonal bipyramids and selenate tetrahedra. In each case, tetrahedra link bipyramids through vertex-sharing, resulting in chain or sheet topologies. The charge-density matching principle is discussed relative to the orientations of the organic molecules between the inorganic structural units.

Graphical abstractThe structures of five new inorganic–organic hybrid uranyl selenates present new structural topologies based upon chains and sheets of uranyl pentagonal bipyramids and selenate tetrahedra.Figure optionsDownload full-size imageDownload as PowerPoint slide