A highly stable multifunctional three-dimensional microporous framework: excellent selective sorption and visible photoluminescence

Abstract

A Cd(II)–MOF [Cd(L)(DMF)] (1) (H₂L = 5-(4-pyridyl)-isophthalic acid) featuring high thermal and chemical stability has been solvothermally synthesized and characterized. Complex 1 is a robust multifunctional three-dimensional (3D) microporous framework possessing an unusual (4,5)-connected topological net. Activated 1 shows high-efficiency for the selective capture of CO₂ over N₂ and CH₄ under ambient conditions, which ranks it among MOFs with the highest selectivity. In addition, desolvated 1 exhibits good separation ratios of H₂ over N₂ at lower temperature, as well as alcohols from water. In particular, desolvated 1 demonstrates significantly higher adsorption enthalpies for CO₂ and CH₄ gas molecules, which are in the range of the highest Q_st values reported to date. Furthermore, complex 1 displays visible photoluminescence in the solid state under UV irradiation.