A Family of Capsule-Based Coordination Polymers Constructed from a New Tetrakis(1,2,4-triazol-ylmethyl)resorcin[4]arene Cavitand and Varied Dicarboxylates for Selective Metal-Ion Exchange and Luminescent Properties

A series of novel capsule-based coordination polymers (CPs), namely, [Cd(TTR4A)(L1)].2.5H(2)O (1), [Cd(TTR4A)(L2)].2DMF.2H(2)O (2), [Cd(TTR4A)(L3)].2DMF.1.5H2O (3), [Cd(TTR4A)(L4)].1.5H(2)O (4), and [Zn(TTR4A)(L1)].DMF.H2O (5), have been synthesized via the reaction of a bowl-like tetrakis(1,2,4-triazol-ylmethylresorcin[4]arene (TTR4A) ligand with d(10) metal salts in the presence of varied dicarboxylates (H(2)L1 = fumaric acid, H2L2 = 1,3-benzenedicarboxylic acid, H2L3 = 5-hydroxy-1,3-benzenedicarboxylic acid, H(2)L4 = biphenylethene-4,4'-dicarboxylic acid, and DMF = N,N-dimethylformamide). CPs 1-3 show rare two-dimensional (2D) capsule-based network structures. In 1-3, two TTR4A bowls share two Cd(II) cations to give a capsule, which is further extended by the dicarboxylates into 2D networks. CP 4 features a fascinating three-dimensional 3-connected framework structure constructed from bowl-like [Cd(2)TTR4A] units and L4 anions. In 5, each TTR4A coordinates with two Zn(II) cations by using two 1,2,4-triazole groups to generate a capsule, which is further connected by L1 ligands to afford a 2D network structure. Significantly, solid-state emissions and temperature variable luminescence were studied for 1-4. In particular, the remarkable metal-ion exchange property of CP 1 was investigated.