Amphiphilic polymeric micelles as microreactors: improving the photocatalytic hydrogen production of the [FeFe]-hydrogenase mimic in water

Abstract

An amphiphilic polymeric micelle is utilized as a microreactor to load a hydrophobic [FeFe]-hydrogenase mimic in water. The local concentration enhancement and strong interaction between the mimic and the photosensitizer as well as the water-mediated fast proton migration caused by the microreactor improve photocatalytic hydrogen production remarkably in water.

Catalytic Metallopolymers from [2Fe‐2S] Clusters: Artificial Metalloenzymes for Hydrogen Production

“…An amphiphilic polynorbornene random copolymer bearing a hydrophobic alkyl moiety and three hydrophilic oligo(ethyleneglycol) chains (P‐NB) was used to generate a polymeric micelle as a microreactor to encapsulate a hydrophobic diiron complex in its core (Figure ) . This amphiphilic polymeric micelle successfully encapsulated the small‐molecule HER catalysts, enabling phase transfer of the [2Fe‐2S] into the aqueous milieu and improved catalytic activity for H 2 generation.…”

Hydrophilic Quaternary Ammonium‐Group‐Containing [FeFe]‐Hydrogenase Models: Synthesis, Structures, and Electrocatalytic Hydrogen Production

“…The first approach is to introduce a hydrophilic ligand or group to the hydrophobic butterfly {Fe 2 S 2 } cluster core of the [FeFe]H 2 ase models (e.g., Darensbourg group and Wu group introduced a hydrophilic phosphatriazaadamantane (pta) ligand) or a hydrophilic sulfonate group to the butterfly {Fe 2 S 2 } cluster core, respectively. The second approach is self‐assembly in which a hydrophobic butterfly {Fe 2 S 2 } cluster core is loaded into the cavity of a water‐soluble cyclodextrin, as reported by Darensbourg and Sun, or embedded into an amphiphilic polymeric micelle microreactor to construct a water‐soluble supramolecular system, as reported by Wu and co‐workers . To develop a synthetic methodology for water‐soluble [FeFe]H 2 ase models further and to examine their electrocatalytic H 2 ‐producing ability in the presence of water, we decided to prepare (PDT)‐type (PDT = propanedithiolate) [FeFe]H 2 ase models containing quaternary ammonium groups and azadiphosphine (PNP) ligands.…”

“…In addition,h ydrophilic models 2 and 4 act as electrocatalysts and achieve higher i cat /i p values and turnover numbers (TONs) in MeCN/ H 2 Oa sasolvent than in MeCN for the production of hydrogen from the weak acid HOAc.[a] Prof.amphiphilic polymeric micelle microreactor to construct aw ater-soluble supramolecular system, as reported by Wu and co-workers. [49] To develop as ynthetic methodology for watersoluble [FeFe]H 2 ase modelsf urthera nd to examinet heir electrocatalytic H 2 -producing ability in the presence of water,w e decidedt op repare (PDT)-type (PDT = propanedithiolate)[ Fe-Fe]H 2 ase modelsc ontaining quaternary ammonium groups and azadiphosphine (PNP) ligands. That we chose to synthesize such at ype of [FeFe]H 2 ase mimic is based on the following reasons: 1) the parent PDT type of diiron complex [(m-PDT)Fe 2 (CO) 6 ] [50,51] is more stable and more easily prepared than heteroatom-containing analogues such as [(m-ADT)-Fe 2 (CO) 6 ]( ADT = azadithiolate) [52,53] and [(m-ODT)Fe 2 (CO) 6 ] (ODT = oxadithiolate); [54] 2) the CO substitution of [(m-PDT)Fe 2 (CO) 6 ]w ith an azadiphosphine ligand can make the diiron subsite more electron-rich and thus more able to accept protons;3 )the nitrogen atom in aP NP ligand can serve as proton relay for catalytic H 2 productionw ith high efficiency; [55] and 4) the quaternary ammonium group is aw ell-known water-soluble group.…”

A Heterogeneous Hydrogen‐Evolution Catalyst Based on a Mesoporous Organosilica with a Diiron Catalytic Center Modelling [FeFe]‐Hydrogenase

“…To model the diiron complex installed inside [FeFe]‐hydrogenase, synthetic diiron complexes with bridging dithiolate and carbonyl ligands have been investigated as highly active and inexpensive catalysts for H 2 evolution . However, despite these advantages, diiron complexes are limited by their low solubility in aqueous solutions, thus requiring efforts to solubilize the catalyst by either introducing a hydrophilic moiety to the diiron catalyst or embedding the catalyst into a supramolecular cage, such as an amphiphilic polymer or a protein matrix …”