Self-Assembly of an Octa-uranate Cage Complex with a Rigid bis-Catechol Ligand

2,3,6,7-Tetrahydroxy-9,10-dimethyl-9,10-dihydro-9,10-ethanoanthracene, LH4, reacts with uranyl nitrate in the presence of NEt3 to give a highly symmetric octa-uranate complex with a molecular cage geometry, (HNEt3)8[(UO2)8(LH2)4(O2)8].22H2O. Four LH2 ligands act as bis-bidentate divergent and rigid bridges between two [(UO2)(O2)]4 squares. The resulting molecular container is surrounded by the H bonded triethylammonium ions and contains H bonded H2O mols. This complex is compared to a previously reported octa-uranate molecular box involving dicarboxylic acids and m-peroxo-ions as bridges. Both compdounds evidenced the potential of uranyl ions as supramolecular building blocks.