Counter-ion control of structure in uranyl ion complexes with 2,5-thiophenedicarboxylate

2,5-Thiophenedicarboxylic acid (H2TDC) was reacted with uranyl nitrate under solvo-hydrothermal conditions with acetonitrile or N-methyl-2-pyrrolidone as organic co-solvents and different combinations of d-block metal ions and N-donating chelators. The complexes [Ni(bipy)(3)][(UO2)(2)(TDC)(2)(HTDC)(NO3)]center dot NMP center dot H2O (1) and [Co((NH2)(2)sar)][(UO2)(2)(TDC)(2)(HTDC)(2)]center dot Cl center dot 6H(2)O (2) (bipy = 2,2'-bipyridine, sar = sarcophagine = 3,6,10,13,16,19-hexaazabicyclo.6.6.6]icosane), the latter containing the enantiomerically pure Lambda-isomer of the counter-ion, crystallize as one-dimensional coordination polymers in which the TDC2- ligands are bis-chelating and the HTDC- ones are mono-chelating and terminal. Two-dimensional (2D) honeycomb networks with all ligands bis-chelating are generated in the two isomorphous complexes [Fe(phen)(3)](2)[(UO2)(4)(TDC)(6)][UO2(NMP)(2)(NO3)(2)]center dot 2NMP (3) and [Ni(phen)(3)](2)[(UO2)(4)(TDC)(6)][UO2(NMP)(2)(NO3)(2)] center dot NMP (4) (phen = 1,10-phenanthroline), while a 2D assembly with a tessellation of 4- and 8-membered rings (fes topological type) is formed in [Ag(CH3CN)(3)](2)[(UO2)(2)(TDC)(3)]center dot H2O (5). Finally, [Ag(bipy)(2)](5)[(UO2)(4)(TDC)(6)]center dot NO3 center dot 6H(2)O (6) comprises planar honeycomb networks which generate a three-dimensional (3D) architecture through inclined 2D -> 3D polycatenation; the [Ag(bipy)(2)](+) cations are assembled into columns held by pi-stacking and weak argentophilic interactions, which occupy the channels formed by the intersecting layers. Complete quenching of uranyl luminescence occurs in complexes 1-4 and only 6 displays an emission spectrum in the solid state showing the usual well-resolved vibronic fine structure.