“Enzymatic” Photoreduction of Carbon Dioxide using Polymeric Metallofoldamers Containing Nickel–Thiolate Cofactors

Abstract

The photoreduction of CO 2 by using enzyme-mimicking polymeric metallofoldamers containing Ni-thiolate cofactors was explored. Metallofoldamers consisting of folded polymers incorporated with Ni-thiolate complexes were prepared by intramolecular Ni-thiolate coordination with thiol-functionalized linear copolymers. The folded polymer backbonem ay resemble the protein framework to provide as econd coordination environment to the active sites. We showedt hat Ni-metallofoldamers were superiorlya ctive and selective for CO 2 photoreduction. At 80 8C, the turnover frequency of the Ni-metallofoldamersc ould reach 0.69 s À1 ,w hich corresponds to 2500 turnovers per hour per Ni site. Our findings are expected to provide useful guidelines to investigate artificial enzymes and to understand the role of protein frameworks in photosynthesis.New catalytic materials that can effectively capture and sustainably convert CO 2 into carbon-based fuels are of great interest. [1] In nature, an umber of metalloenzymes [e.g.,c arbon monoxide dehydrogenase (CODH) and formate dehydrogenase] are known to be highly active for variousconversion pathways in the biological metabolism of CO 2 . [2] All of these metalloenzymes contain metal-thiolates as cofactors. [1g] For example, the CODH isolated from the anaerobic bacterium Carboxydothermus hydrogenoformans can catalyze thermodynamically reversible conversionsb etween CO 2 and CO at ac omplexN i-, Fe-, and S-containing metal-thiolate site, namely,t he [Ni-Fe 4 S 4 ] Cc luster. [3] The enzymatic conversion of CO 2 has advantages, for example, high binding affinity,e xcellent product selectivity, and minimum energy input. Inspired by metalloenzymes, considerable effort has been made to synthesize mimics that can catalyzea nalogoust ransformations found in naturals ystems. [4] However,t he overall efficiency of artificial photosynthetic sys- [a] Supporting Information and the ORCID identification number(s) for the author(s) of this article can be found under: http://dx.

Bioinspired Design of Hybrid Polymer Catalysts with Multicopper Sites for Oxygen Reduction

“…Our strategy to synthesizing polymer metal catalysts offers new insights into the design of bioinspired catalysts with multi metal centers. [26] Experimental Section , triethyl amine (TEA, > 99 %), copper nitrate trihydrate (Cu(NO 3 ) 2 3H 2 O)), manganese nitrate tetrahydrate (Mn(NO 3 ) 2 4H 2 O)), nickel nitrate hexahydrate (Ni(NO 3 ) 2 6H 2 O)), cobalt nitrate hexahydrate (Co(NO 3 ) 2 6H 2 O)), iron(II) chloride tetrahydrate (FeCl 2 4H 2 O) were purchased from Sigma Aldrich and used as received unless otherwise noted. Dipicolyl amine (DPA) was used from a previously synthesized batch reported in our previous paper.…”

“…The presence of multi‐T3Cu sites confined in polymer chains not only improves the local concentration of Cu but also enables the cooperative catalysis among Cu sites, that also preserves the ORR performance even at a low catalyst loading. Our strategy to synthesizing polymer metal catalysts offers new insights into the design of bioinspired catalysts with multi metal centers [26] …”

Local Domain Size in Single-Chain Polymer Nanoparticles

“…The precursor polymers were based on either PS or poly(methyl methacrylate) (PMMA), both having a similar value of chain stiffness 34 ( C ∞ (PS) = 9.5, C ∞ (PMMA) = 9.0). Estimations were carried out based on experimental R / R 0 data by assuming α ≈ 0.53 in eq 6aa, for Pt II -, Cu II -, and Ni II -containing SCNPs employed with success in amination of allyl alcohol, 20 selective alkyne homo-coupling reactions, 22 and photoreduction of carbon dioxide, 42 respectively.…”

Self‐Reporting of Folding and Aggregation by Orthogonal Hantzsch Luminophores Within a Single Polymer Chain

“…He et al. synthesized catalytic SCNPs containing Ni‐thiolate complexes with excellent thermal stability under aerobic conditions and remarkable activity and selectivity for the photocatalytic reduction of CO 2 to CO [12] . More recently, Zimmerman et al.…”