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Single crystals of four novel uranyl selenate and selenite-selenate oxysalts with protonated ethylamine molecules, (C 2 H 8 N) 2 [(UO 2 )(SeO 4 ) 2 (H 2 O)](H 2 O) ( I ), (C 2 H 8 N) 3 [(UO 2 )(SeO 4 ) 2 (HSeO 4 )] ( II ), (C 2 H 8 N)[(UO 2 )(SeO 4 )(HSeO 3 )] ( III ), and (C 2 H 8 N)(H 3 O)[(UO 2 )(SeO 4 ) 2 (H 2 O)] ( IV ) have been prepared by isothermal evaporation from aqueous solutions. Uranyl-containing 1D and 2D units have been investigated using topological approach and information-based complexity measurements that demonstrate the evolution of structural units and the increase of topological complexity with the decrease of H 2 O content. [ABSTRACT FROM AUTHOR]

Single crystals of seven novel uranyl oxysalts of selenium with protonated methylamine molecules, [C 2 H 8 N] 2 [(UO 2 )(SeO 4 ) 2 (H 2 O)] ( I ), [C 2 H 8 N] 2 [(UO 2 ) 2 (SeO 4 ) 3 (H 2 O)] ( II ), [C 4 H 15 N 3 ][H 3 O] 0.5 [(UO 2 ) 2 (SeO 4 ) 2.93 (SeO 3 ) 0.07 (H 2 O)](NO 3 ) 0.5 ( III ), [C 2 H 8 N] 3 [H 5 O 2 ][(UO 2 ) 2 (SeO 4 ) 3 (H 2 O) 2 ] 2 (H 2 O) 5 ( IV ), [C 2 H 8 N] 2 [H 3 O][(UO 2 ) 3 (SeO 4 ) 4 (HSeO 3 )(H 2 O)](H 2 SeO 3 ) 0.2 ( V ), [C 4 H 12 N] 3 [H 3 O][(UO 2 ) 3 (SeO 4 ) 5 (H 2 O)] ( VI ), and [C 2 H 8 N] 3 (C 2 H 7 N)[(UO 2 ) 3 (SeO 4 ) 4 (HSeO 3 )(H 2 O)] ( VII ) have been prepared by isothermal evaporation from aqueous solutions. Their crystal structures have been solved by direct methods and their uranyl selenate and selenite–selenate units investigated using black-and-white graphs from the viewpoints of topology of interpolyhedral linkages and isomeric variations. The crystal structure of IV is based upon complex layers with unique topology, which has not been observed previously in uranyl selenates. Investigations of the statistics and local distribution of the U–O br –Se bond angles demonstrates that shorter angles associate with undulations, whereas larger angles correspond to planar areas of the uranyl selenite layers. [ABSTRACT FROM AUTHOR]