New scu topological MOF based on azolyl-carboxyl bifunctional linker: Gas adsorption and luminescence properties

The self-assembly of Zn2+ ion and an azolyl-carboxyl bifunctional ligand, 4,6-bis(triazol-1-yl)isophthalic acid (H2btzip), give rise to one three-dimensional (3D) porous metal-organic framework (MOF), [Zn(btzip)(H2O)0.5]·H2O (1). The MOF shows a rare (4,8)-connected scu net containing 1D channels, based on 4-connecetd ligands and 8-connected [Zn(COO)2(H2O)] dimers. Owing to the decoration of uncoordinated N atoms in porous walls, 1 can selectively capture CO2 molecules over CH4 with high adsorption heat and considerable selectivity. The different adsorption sites for CO2 in 1 were deeply explored by simulations. In addition, 1 also displays strong solid-state luminescence that is from the intraligand charge transfer.