A Zinc Coordination Complex Mimicking Carbonic Anhydrase for CO₂ Hydrolysis and Sequestration

Abstract

Carbonic anhydrase (CA) mimicking is an effective and environmentally friendly strategy for carbon dioxide sequestration. Herein, we developed a nonanuclear CA-mimetic zinc coordination complex (1) which possesses a coordination environment similar to that of CA’s catalytically active zinc sites. Complex 1 exhibited excellent reusability, solvent and thermal stability, and gram-scale synthesis, which are essential for practical applications. It was found that complex 1 exhibited outstanding catalytic performance that is much better in comparison to that of the popular CA-mimetic compound Zn-cyclen and comparable to that of the reported metal–organic frameworks (e.g., CFA-1). Moreover, we found that its catalytic activity can be significantly improved via OAc–/OH– exchange and particle size reduction treatment. This study provides important guidance for the design of highly efficient CA-mimetic materials.

Amino Acid-Mediated Synthesis of the ZIF-8 Nanozyme That Reproduces Both the Zinc-Coordinated Active Center and Hydrophobic Pocket of Natural Carbonic Anhydrase

“…Biomimetic nanozymes are catalysts that mimic natural enzyme catalytic structures and functions, mainly including polypeptide metal complexes, small molecule metal complexes, , and nanomaterials. − Compared with natural enzymes, nanozymes not only have similar catalytic activity but also have the advantages of easy synthesis and high stability . Till now, several biomimetic CA analogues have been synthesized. ,− The zinc complex of 1,4,7,10-tetraazacyclododecane is considered one of the most representative functional models of biomimetic CA . Floyd et al found that the 1,4,7,10-tetraazacyclododecane chelate of zinc­(II) perchlorate (zinc rings) was highly stable and could be used as a powerful catalyst for industrial carbon capture .…”

Biomimetic Catalysis of CO2 Hydration: A Materials Perspective

“…The most efficient catalyst for the hydration of CO 2 is the enzyme carbonic anhydrase (CA). − CA is a metalloenzyme with a Zn 2+ ion active site, while some species of the enzyme also have Fe 2+ and Cd 2+ ion active site. − CA is found in most mammals and microbes for conversion of CO 2 to carbonic acid for pH regulation and CO 2 transportation . In nature CA is found as five different species that include α, β, γ, δ, and ζ .…”

Basically, nucleophilicity matters little: towards unravelling the supramolecular driving forces in enzyme-like CO2 conversion

“…18 Considering the prominent activities afforded by these biologic catalysts, numerous efforts have been devoted in the last years to design artificial systems able to mimic enzymatic activity, the so-called synzymes. 19,20 On this behalf, two different synzymatic approaches are currently established: (I) the development of abiotic systems that contain analogous groups to the ones found in the active-site of the enzyme, [21][22][23] and (II) the design of molecules that do not necessarily resemble the active pocket but are still capable to promote the desired function through properly arranged functionalities. [24][25][26][27] We have recently reported a simple macrocyclic system that promoted superior activity in the cycloaddition of CO 2 to terminal epoxides in the presence of halide anions (Fig.…”