Microporous Metal–Organic Framework Based on a Bifunctional Linker for Selective Sorption of CO₂ over N₂ and CH₄

Abstract

A bifunctional organic linker 4-(4-carboxyphenyl)-1,2,4-triazole (HCPT), incorporating both carboxylate and triazole groups, has been successfully used in the construction of a 2-fold interpenetrated dynamic metal-organic framework (MOF), {[Cu3(CPT)4(μ3-OH)]·NO3·7H2O·EtOH}n (1) based on a triangular Cu(II)-hydroxo cluster as secondary building unit (SBU). Upon solvation/desolvation and temperature, the crystal cell parameters of 1 could be fine-tuned. More importantly, a transformation from disordered phase to a more ordered phase after activation was observed via a single-crystal-to-single-crystal mode. Gas sorption studies reveal that the activated 1 exhibits highly selective sorption of CO2 over N2 and CH4 at room temperature.