Highly Selective Sorption of Small Hydrocarbons and Photocatalytic Properties of Three Metal–Organic Frameworks Based on Tris(4-(1H‑imidazol-1-yl)phenyl)amine Ligand

By employing a tris­(4-(1H-imidazol-1-yl)­phenyl)­amine (Tipa) ligand, three new metal–organic frameworks, [Zn₂(Tipa)­(4,4′-bpdc)_1.5(H₂O)­(NO₃)]·2­(DMF)·H₂O (1; 4,4′-bpdc = 4,4′-biphenyldicarboxylate, DMF = N,N-dimenthylformamide), [Cd­(Tipa)­Cl₂]·2­(DMF)·H₂O (2), and [Co­(Tipa)­Cl₂(H₂O)]·DMF·H₂O (3), have been synthesized solvothermally. Compound 1 features a three-dimensional (3D) pillared-layer structure with low band gap and interesting photocatalytic properties. Compound 2 is a 2-fold interpenetrating (3,6)-connected porous framework, and it shows highly selective adsorption of C₂H₂, CO₂, and C₂H₄ over CH₄. Compound 3 with honeycomb-like layers exhibits unusual 2D + 2D→ 3D polycatenation (2D = two-dimensional). The luminescent properties for these compounds were also investigated.