Selective Sorption of Light Hydrocarbons on a Family of Metal–Organic Frameworks with Different Imidazolate Pillars

Four
isostructural pillared-layer metal–organic frameworks
(as 1-ims series) are successfully synthesized via the
charge-balance approach, where trigonal [Zn2(CO2)3] cluster-based cationic layers [Zn2(NH2–BTB)]+ (NH2–H3BTB = 1,3,5-(3-benzoic acid) aniline) are connected by a series of
2-substituted imidazolates. The 1-ims supply a systematic
platform to explore the adsorption of light hydrocarbons. Especially, 1-ims shows good adsorption selectivity of C3/C1 and C2/C1, and the selectivities of
C3H8/CH4 are all over 100 at room
temperature. These results demonstrate that introduction of functional
group plays a key role on tuning the channel and pore size as well
as improving the adsorption selectivity.