A new layer-stacked porous framework showing sorption selectivity for CO₂ and luminescence

A new metal-organic framework, [Zn₃(μ₃-OH)(tzba)₂(bpy)(H₂O)]OH·DMF (1), was solvothermally synthesized by employing tetrazolate-carboxylate 4-(1H-tetrazol-5-yl) benzoic acid (H₂tzba) linker and 2,2'-bipyridine (bpy) chelating coligand. 1 contains novel Zn₆(μ₃-OH)₂(μ₂-H₂O)₂(COO)₄(N₄C)₂ hexanuclear clusters and reveals a three-dimensional (3D) microporous supramolecular framework based on the stacked 2D layers. The highly polar pores cause not only strong affinity towards CO₂ molecules but also a significant selective adsorption of CO₂ over CH₄. Meanwhile, the multiple binding sites for CO₂ in the framework were determined by Grand Canonical Monte Carlo (GCMC) simulations. 1 also shows strong blue luminescence from ligand-to-metal charge transfer (LMCT).