Synthesis and gas sorption properties of cupric microporous metal-organicframework based on 1,1′-ethynebenzene-3,3′, 5,5′-tetracarboxylate

The synthesis, crystal structure, and sorption properties of [Cu2(EBTC)H2O2]·8H2O·DMF·DMSO(abbreviated as 1, EBTC=1,1′-ethynebenzene-3,3′, 5,5′-tetracarboxylate; DMF=N,N-dimethyl formamide; DMSO= dimethyl sulfoxide are reported. 1 features two kinds of cavities with a diameter of 0.85 nm and 0.85×2.15nm, which are enclosed respectively by six and twelve tetracarboxylate-bridged [Cu2(CO2)4] paddle-wheels and extended by the EBTC linkers into a three-dimensional 3D supramolecular structure with 1D channels accommodating the solvent molecules. It adopts the (3,4)-c net of fof (sqc 1575 topology, possesses very large solvent accessible pore volume which reaches 72.8% of the unit cell volume. After removal of the solvent molecules, the desolvated 1a exhibits permanent porosity verified by an N2 sorption isotherm with a Langmuir surface area of 2844 m²·g¹ and Brunauer-Emmett-Teller (BET) surface area of 1 852 m2·g^-1. It displays significant uptake of gases (H2, CO2, CH4, C2H2) and relatively high adsorption enthalpies. Especially, it is notable that 1a exhibits the highest acetylene storage of 252 cm³·g^-1 at 273 K under 1.0×10⁵ Pa with higher adsorption enthalpy (34.5 kJ·mol^-1 at the coverage of 1 mmol·g^-1) among all porous metal-organic materials reported to date. CCDC: 744108.