title: Coordination Polymers and Cage-Containing Frameworks in Uranyl Ion Complexes with rac- and (1R,2R)-trans-1,2-Cyclohexanedicarboxylates: Consequences of Chirality.
abstract: Racemic and enantiopure (1R,2R) forms of trans-1,2-cyclohexanedicarboxylic acid (H2chdc and R-H2chdc, respectively) have been used in the synthesis of a series of 13 uranyl ion complexes, all obtained under solvo-hydrothermal conditions and in the presence of additional metal cations and/or N-donor ligands. While the homometallic complex [UO2(R-chdc)] (1) was only obtained with the enantiopure ligand, complexes [UO2(chdc)(THF)] (2), [UO2(chdc)(DMF)] (3), and [UO2(chdc)(NMP)] (4), with a coordinated solvent molecule, were obtained from the racemic form only; all crystallize as two-dimensional (2D) assemblies. The two complexes [UO2(chdc)(bipy)](5) and [UO2(R-chdc)(bipy)] (6), where bipy is 2,2'-bipyridine, are isomorphous since 5 crystallizes as a racemic conglomerate; they are both one-dimensional (1D) homochiral, helical polymers. The heterometallic complexes [UO2Cu(chdc)2(bipy)(H2O)]·H2O (7) and [UO2Cu(R-chdc)2(bipy)]·3H2O (8) crystallize as a 1D or a 2D species, respectively, while [UO2Cd(R-chdc)2(H2O)2]·H2O (9) displays a 2D arrangement with the unusual Cairo pentagonal tiling topology. The four complexes [(UO2)2Na2(chdc)3(H2O)2] (10), [(UO2)2Ag2(chdc)3(H2O)2] (11), [(UO2)2Na2(R-chdc)3(H2O)2] (12), and [(UO2)2Pb(R-chdc)3(H2O)4] (13) are closely related, all of them containing tetranuclear, pseudotetrahedral [(UO2)4(chdc/R-chdc)6]4-cage motifs, that are assembled into a three-dimensional (3D) framework by bridging counterions (Na+, Ag+, or Pb2+). These cages define a new pathway to assembly of such species based on the unique coordination geometry of uranyl ion, differing from the widely exploited use of octahedral metal ions.
authors.affiliation: NIMBE, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France.
authors.forename: Pierre
authors.identifier: http://orcid.org/0000-0003-1683-570X
authors.initials: P
authors.lastname: Thuéry
authors.affiliation: ISIS, Université de Strasbourg , 8 allée Gaspard Monge, 67083 Strasbourg, France.
authors.forename: Jack
authors.initials: J
authors.lastname: Harrowfield