Counter-ion control of structure in uranyl ion complexes with 2,5-thiophenedicarboxylate †
Résumé
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 [NiIJbipy)3]ij(UO2)2IJTDC)2IJHTDC)IJNO3)]·NMP
·H2O (1) and [CoIJ(NH2)2sar)]ij(UO2)2IJTDC)2IJHTDC)2]·Cl·6H2O (2) (bipy = 2,2′-bipyridine, sar = sarcophagine =
3,6,10,13,16,19-hexaazabicycloij6.6.6]icosane), the latter containing the enantiomerically pure Λ-isomer of
the counter-ion, crystallize as one-dimensional coordination polymers in which the TDC2− ligands are bischelating
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
[FeIJphen)3]2ij(UO2)4IJTDC)6]ijUO2IJNMP)2IJNO3)2]·2NMP (3) and [NiIJphen)3]2ij(UO2)4IJTDC)6]ijUO2IJNMP)2IJNO3)2]
·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 [AgIJCH3CN)3]2ij(UO2)2IJTDC)3]·H2O (5). Finally,
[AgIJbipy)2]5ij(UO2)4IJTDC)6]·NO3·6H2O (6) comprises planar honeycomb networks which generate a threedimensional
(3D) architecture through inclined 2D → 3D polycatenation; the [AgIJbipy)2]+ cations are assembled
into columns held by π-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.