New Three-Fold Interpenetrated Uranyl Organic Framework Constructed by Terephthalic Acid and Imidazole Derivative

A new 3-fold interpenetrated uranyl organic framework, UO₂(bdc)­(dmpi), was hydrothermally synthesized using 1,4-benzenedicarboxylic acid (H₂bdc) and 1-(4-(1<i>H</i>-imidazol-1-yl)-2,5-dimethylphenyl)-1<i>H</i>-imidazole (dmpi). This framework, which was determined by synchrotron radiation X-ray, exhibited a new 3-fold interpenetrated (2,4)-connected topology with the Schläfli symbol of (12⁶)­(12)₂. Additionally, large incurvation happened to the bond angle of [OUO]²⁺, which was always arranged in a rigorous line. Computational results based on density functional theory (DFT) indicated that the bent geometry of uranyl in UO₂(bdc)­(dmpi) was mainly due to the higher charge populations in the valence 6d shells of uranium, rendered by the electronegative imidazoles.