An unsymmetrical tricarboxylate ligand with linking alkyne moiety has been used to construct a highly porous metal–organic framework with agw topology. The obtained Cu(II) MOF exhibits a high BET surface area of 3337.0 m² g⁻¹, a large capacity of CO₂ (21.2 mmol g⁻¹ at 298 K and 20 bar) and a good H₂ adsorption (5.8 wt% at 77 K and 20 bar).