Rational Design of Microporous MOFs with Anionic Boron Cluster Functionality and Cooperative Dihydrogen Binding Sites for Highly Selective Capture of Acetylene

Abstract

AbstractSeparation of acetylene (C2H2) from carbon dioxide (CO2) or ethylene (C2H4) is important in industry but limited by the low capacity and selectivity owing to their similar molecular sizes and physical properties. Herein, we report two novel dodecaborate‐hybrid metal–organic frameworks, MB12H12(dpb)2 (termed as BSF‐3 and BSF‐3‐Co for M=Cu and Co), for highly selective capture of C2H2. The high C2H2 capacity and remarkable C2H2/CO2 selectivity resulted from the unique anionic boron cluster functionality as well as the suitable pore size with cooperative proton‐hydride dihydrogen bonding sites (B−Hδ−⋅⋅⋅Hδ+−C≡C−Hδ+⋅⋅⋅Hδ−−B). This new type of C2H2‐specific functional sites represents a fresh paradigm distinct from those in previous leading materials based on open metal sites, strong electrostatics, or hydrogen bonding.