Amine-templated uranyl selenates with chiral [(UO2)(2)(SeO4)(3)(H2O)](2-) layers: topology, isomerism, structural relationships

作者：Krivovichev Sergey V^*; Gurzhiy Vladislav V; Tananaev Ivan G; Myasoedov Boris F

来源：Zeitschrift fur Kristallographie, 2009, 224(5-6): 316-324.

DOI：10.1524/zkri.2009.1145

• Uranyl selenate
• Topology
• Isomerism
• Structural control
• Chirality
• Single crystal structure analysis
• X-ray diffraction

Eleven new amine-templated uranyl selenate hydrates have been prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amines. The structures of the compounds have been solved by direct methods and refined using least-squares techniques. Each structure is based upon [(UO2)(2)(SeO4)(3)(H2O)](2-) layers of corner-sharing UO7 pentagonal bipyramids and SeO4 tetrahedra. The layers are based upon 4- and 6-membered rings arranged in different fashion. In topology I, 6-membered rings form edge-sharing chains, whereas, in topology II, they form corner-sharing chains. Layers with the topology II exist in two geometrical isomers that differ in the system of 'up' and 'down' orientations of tetrahedra relative to the plane of the layer. There are two isomers, one of which is chiral and the other is achiral. The layers with the topology H are chiral. Chirality is induced by the combination of orientations of tetrahedra and direction of the U -> H2O bond. The analysis of the relationships between composition and shape of amine molecules and layer topology reveals two important regularities. 1. Aliphatic components of amine molecules tend to associate with 6-MRs of the inorganic layers. 2. Molecules with longer and spacious aliphatic components favor formation of the layers with topology II, whereas those with shorter aliphatic components prefer layers with the topology I.

• 出版日期2009