Rational design of phosphonocarboxylate metal–organic frameworks for light hydrocarbon separations

Metal–organic frameworks (MOFs) provoke intensive research interests on separations of small gas molecules. By introducing a coordinative phosphate group into a carboxylic acid linker, a ligand 4,4′-(hydroxyphosphoryl) dibenzoic acid (H 3 hpda) was successfully synthesized and used to construct microporous phosphonocarboxylate framework [Cu 3 (hpda) 2 ·DMF·2H 2 O]·3DMF·H 2 O (DMF = N , N -dimethylformamide) and [Mg 3 (μ 2 -OH 2 ) 2 (OH 2 ) 2 (hpda) 2 ]·3DMF·2H 2 O. Both of them possess narrow approachable channels and exhibit excellent performance on selective separation of light hydrocarbons (C 1 –C 2 ), presenting a promising ligand design strategy for the construction of porous material aiming for natural gas upgrading.