Syntheses and structures of three supramolecular complexes based on 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid

Abstract Three new supramolecular compounds, [Cu( o -HPIDC)(bpy)(H 2 O)]·2H 2 O 1 , [Cu( o -H 2 PIDC)(phen)Cl]·[Cu(phen) 2 Cl]·10H 2 O·Cl 2 and {[Cd( o -H 2 PIDC)(H 2 O) 2 Cl]·H 2 O} 2 3 ( o -H 3 PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), were hydrothermally synthesized and characterized. In compound 1 , the adjacent two supramolecular layers are constructed from different types of helical chains with the same pitch. In compound 2 , the adjacent 2D water-chloride layers, {[(H 2 O) 10 Cl] − } n , are pillared by [Cu( o -H 2 PIDC)(phen)Cl] units to form the overall 3D supramolecular network with 1D channels through O H⋯O hydrogen bond interactions. In compound 3 , two Cd(II) are linked into a binuclear [Cd 2 ( o -H 2 PIDC) 2 (H 2 O) 4 Cl 2 ] with a ten-membered ring by two o -H 2 PIDC − ligands. The three compounds self-assemble into 3D supramolecular structures via hydrogen bond and π-π stacking interactions. The fluorescence properties of compound 3 was also investigated.