A flexible metal-organic framework with double interpenetration for highly selective CO2 capture at room temperature

A flexible metal-organic framework of 1a Cu(FMA)(4,4'-Bpe)(0.5) (FMA=fumarate; 4,4'-Bpe=trans-bis-(4-pyridyl)ethylene) that exhibits guest molecule-controlled gate-opening adsorption has been reported, in which the flexible pores can be enlarged by CO2 molecules rather than CH4 and N-2 under a certain gate-opening pressure. The CO2 uptake can be sharply improved from 6.85 cm(3) g(-1) at 0.60 atm to 33.7 cm(3) g(-1) at 1 atm due to the gate-opening effect, thus resulting in the notably enhanced adsorption selectivities for CO2/CH4 (32:1, v/v) and CO2/N-2 (48:1, v/v) separations at room temperature.