Uranyl Ion-Containing Polymeric Assemblies with $cis/trans$ Isomers of 1,2-, 1,3- and 1,4-Cyclohexanedicarboxylates, Including a Helical Chain and a Sixfold-Interpenetrated Framework
Abstract
Diverse isomers of cyclohexanedicarboxylic acid (chdcH$_2$) have been used to synthesize uranyl ion complexes in the presence of various possible counterions and, but for one case, under (solvo-)hydrothermal conditions. The cis isomer of 1,2-chdcH$_2$ gives the complex [UOV$_2$(c-1,2-chdc)(H$_2$O)2]·H$_2$O (1), which crystallizes as an enantiomerically pure helical monoperiodic structure, while partial isomerization of the cis into the trans form yields [PPh$_4$]$_2$[(UO$_2$)$_3$(c-1,2-chdc)$_2$(rac-t-1,2-chdc)(H$_2$O)]·$_2$H$_2$O (2), a ladderlike monoperiodic assembly. The pure (1R,2R) enantiomer of t-1,2-chdcH$_2$ gives [UO$_2$(R-t-1,2-chdc)(H$_2$O)] (3) containing a diperiodic assembly of hcb topological type. When reacted at room temperature, its racemic counterpart produces [UO$_2$(rac-t-1,2-chdc)(EtOH)]·H$_2$O (4), a diperiodic species with the fes topological type isomorphous to other similar solvates. Using a mixture of the cis and trans isomers of 1,3-chdcH$_2$ gives [NH$_4$][NBu$_4$][(UO$_2$)$_2$(c-1,3-chdc)$_2$(t-1,3-chdc)] (5), the first instance of a triperiodic uranyl-containing framework obtained with this ligand. Finally, the complex [H$_2$NMe$_2$]$_2$[(UO$_2$)$_2$(t-1,4-chdc)$_3$] (6), containing the trans isomer of 1,4-chdc 2-, crystallizes as a triperiodic framework with ths topology, and displays sixfold-interpenetration, the highest degree found up to now in a uranyl ion complex. These results are discussed together with previous ones obtained with this highly versatile family of cyclohexanedicarboxylate ligands.
Domains
Cristallography
Origin : Files produced by the author(s)
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