Crystal Engineering with the Uranyl Cation I. Aliphatic Carboxylate Coordination Polymers:  Synthesis, Crystal Structures, and Fluorescent Properties

Four novel U(VI) containing coordination polymers, UO 2 (C 7 H 10 O 4 ) ( 1 ), UO 2 (C 8 H 12 O 4 ) ( 2 ), UO 2 (C 9 H 14 O 4 ) ( 3 ), and UO 2 (C 10 H 16 O 4 ) ( 4 ), were synthesized from UO 2 (NO 3 ) 2 ·6H 2 O and aliphatic dicarboxylic acids (pimelic, suberic, azelaic, and sebacic acids, respectively) using hydrothermal techniques and were characterized by single-crystal diffraction. Compounds 1 and 4 consist of (UO 2 ) 2 O 8 dimers connected by the acid molecules to form layers, whereas 2 and 3 are constructed of chains of hexagonal bipyramids connected to form layers. These materials complete the series of aliphatic uranyl carboxylates to C 10 (sebacic acid) and may be considered to be carboxylate “end-members” of a series of dipyridyl/carboxylate structures described in part II of this investigation (following in this issue).