Bioinspired Metal-Organic Framework for Trace CO2 Capture

A Zn benzotriazolate metal-organic framework (MOF), [Zn(ZnO2CCH3)(4)(bibta)(3)] (1, bibta(2-) = 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 alpha-carbonic anhydrase. The postsynthetically modified MOF, [Zn-(ZnOH)(4)(bibta)(3)] (2*), exhibits excellent performance for trace CO, 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.