Uranyl Ion Coordination by Benzene-1,2,3-tricarboxylate: Building Chains and Networks from Binuclear Bricks

Benzene-1,2,3-tricarboxylic acid (123btcH(3)) was used to synthesize 7 uranyl ion complexes under hydro-solvothermal conditions, in the presence of different structure-directing agents. [Zn(phen)(3)][Zn-2(123btc)(phen)(4)][(UO2)(2)(123btc)(2)(OH)(CH3CN)] . 3H(2)O (1, phen=1,10-phenanthroline), the only discrete species in the series, crystallizes as a binuclear, cup-shaped dimer. Both [PPh3Me][UO2(123btc)] (2) and [C(NH2)(3)][UO2(123btc)] . 0.5H(2)O (3) contain anionic, monoperiodic coordination polymers based on quasi-planar, binuclear (UO2)(2)(123btc)(2)(2-) subunits in which two oxygen atoms of each ligand are uncoordinated. Similar chains are found in [UO2(123btc)K(18C6)] . H2O (4, 18C6=18-crown-6), the potassium cations being decorating groups bound to carboxylato and uranyl oxo donors. An analogous decorating role to monoperiodic polymers is played by UO2(DMF)(2)(H2O)(2)(2+) cations in [(UO2)(3)(123btc)(2)(DMF)(2)(H2O)(2)] (5), while bridging of chains by UO2(NMP)(3)(2+) cations in [(UO2)(3)(123btc)(2)(NMP)(3)] (6) yields a diperiodic network with V2O5 topology. [NH4][UO2(123btc)] (7), which does not contain the dimeric subunit found in the other cases, crystallizes as a diperiodic network with sql topology, the layers being associated through hydrogen bonding interactions with the ammonium counterions.

Automated summary

Benzene-1,2,3-tricarboxylic acid was utilized to synthesize 7 uranyl ion complexes, which exhibit various structures including discrete species, monoperiodic coordination polymers, and diperiodic networks.