Construction and Properties of Six Metal–Organic Frameworks Based on the Newly Designed 2‑(<i>p</i>‑Bromophenyl)-Imidazole Dicarboxylate Ligand

The newly designed organic ligand 2-(<i>p</i>-bromophenyl)-1<i>H</i>-imidazole-4,5-dicarboxylic acid (<i>p</i>-BrPhH₃IDC) has been successfully prepared and its coordination features were explored. By the reactions of <i>p</i>-BrPhH₃IDC with main group or transition metals, six metal–organic frameworks (MOFs), namely, [Ca­(<i>p</i>-BrPhHIDC)­(H₂O)₂]_<i>n</i> (<b>1</b>), [Sr­(<i>p</i>-BrPhHIDC)­(H₂O)]_<i>n</i> (<b>2</b>), [Zn­(<i>p</i>-BrPhHIDC)­(H₂O)]_<i>n</i> (<b>3</b>), {[Co­(<i>p</i>-BrPhH₂IDC)₂]­·2H₂O}_<i>n</i> (<b>4</b>), [Cd_1.5(<i>p</i>-BrPhHIDC)­(<i>p</i>-BrPhH₂IDC)­(H₂O)]_<i>n</i> (<b>5</b>), and {[Cd₂(<i>p</i>-BrPhHIDC)₂­(4,4′-bipy)]­·4H₂O}_<i>n</i> (4,4′-bipy = 4,4′-bipyridine) (<b>6</b>) have been synthesized under hydro­(solvo)­thermal conditions. X-ray single-crystal analyses reveal that they have rich structural chemistry ranging from one-dimensional (1D) (<b>3</b>), two-dimensional (2D) (<b>1</b>,<b> 2</b>,<b> 4</b>, and <b>5</b>) to three-dimensional (3D) polymers (<b>6</b>). Furthermore, the existence of intermolecular hydrogen bonds and/or π···π stacking interactions between the aromatic groups supplies the additional stabilization for the solid-state supramolecular structures of polymers <b>3</b>, <b>4</b>, and <b>5</b>. The solid-state photoluminescence properties of the polymers <b>1</b>–<b>6</b> have been investigated as well