A novel trigonal bipyramidal cage-based Zn(ii)-MOF featuring two types of trinuclear clusters with high gas sorption properties

Abstract

The cage-based MOFs have attracted widespread interest due to their large internal ordered cavities and small windows, which can selectively capture and separate the guest molecules. Herein, a unique trigonal bipyramidal cage-based MOF {[Zn₆(μ₃-OH) (tdpb)₂ (H₂O)₂] 6DMA 6H₂O}_n (1) (H₂tdpb = 1,3,5-tri (2,4-dicarboy i phenoxy) benzene) featuring linear trinuclear pin-wheel MBB of [Zn₃(COO)₆(H₂O)₂] and triangular trinuclear cluster MBB of [Zn₃(μ₃-OH)(COO)₃] was successfully synthesized. These MOFs can not only effectively capture CO₂ and C2-hydrocarbons but also separate CH₄ from CO₂ and C2-hydrocarbon mixtures. Besides, molecular simulations deeply analyzed the adsorption binding sites of C2-hydrocarbons and CO₂.