Bioinspired Metal–Organic Framework for Trace CO₂ Capture

A Zn benzotriazolate metal–organic framework (MOF), [Zn­(ZnO2CCH3)4(bibta)3] (1, bibta2– = 5,5′-bibenzotriazolate), has been subjected to a mild CH3CO2–/HCO3– ligand exchange procedure followed by thermal activation to generate nucleophilic Zn–OH groups that resemble the active site of α-carbonic anhydrase. The postsynthetically modified MOF, [Zn­(ZnOH)4(bibta)3] (2*), exhibits excellent performance for trace CO2 capture and can be regenerated at mild temperatures. IR spectroscopic data and density functional theory (DFT) calculations reveal that intercluster hydrogen bonding interactions augment a Zn–OH/Zn–O2COH fixation mechanism.