An ethynyl-modified interpenetrated metal–organic framework for highly efficient selective gas adsorption

Abstract

An ethynyl-modified interpenetrated MOF material with lvt topology, [Cu₂(BTEB)(NMF)₂]·NMF·8H₂O (compound 1, H₄BTEB = 4,4′,4′′,4′′′-(benzene-1,2,4,5-tetrayltetrakis(ethyne-2,1-diyl))tetrabenzoic acid, NMF = N-Methylformamide), was successfully synthesized by using an alkynyl-functionalized H₄BTEB organic ligand under solvothermal conditions. Structural analysis shows that compound 1, consisting of a tetradentate carboxylic acid ligand and classical [Cu₂(CO₂)₄] paddle-wheel structure building units, has a rare 4-connected lvt topology with dual interpenetrating structure, which can improve the framework stability, as well as the gas adsorption capacity and selectivity due to the restricted pore channel. According to the study of gas adsorption performance, compound 1 with a larger surface area, boasts a superior adsorption capacity for small gas molecules. Also, ideal adsorption solution theory (IAST) computational simulation shows that compound 1 has good gas adsorption selectivity for C₃H₈/CH₄, indicating its potential application in gas separation.