Abstract Inspired by nature's orchestra of chemical subtleties to activate and reduce CO 2 , we have developed a family iron porphyrin derivatives in which introduced urea groups functioning as multipoint hydrogen‐bonding pillars on the periphery porphyrinic ring. This structure closely resembles hydrogen‐bond stabilization scheme carbon dioxide (CO ) adduct monoxide dehydrogenase (CODH). We found that such changes second coordination sphere significantly lowered overpotential for reduction...

Research in the development of new molecular catalysts for selective transformation CO2 to reduced forms carbon is attracting enormous interest from chemists. Molecular catalyst design hinges on elaboration ligand scaffolds manipulate electronic and structural properties fine tuning reactivity pattern. A cornucopia sets have been designed along this line more are being reported. In quest, porphyrin platform has under intensive focus due unmatched catalytic metalloporphyrins. There rapid...

Abstract The manipulation of the second coordination sphere for improving electrocatalytic CO 2 reduction has led to breakthroughs with hydrogen bonding, local proton source, or electrostatic effects. We have developed two atropisomers an iron porphyrin complex urea functions acting as multiple hydrogen‐bonding tweezers lock metal‐bound in a similar fashion found carbon monoxide dehydrogenase (CODH) enzyme. αα topological isomer groups on same side provides stronger binding affinity tether...

Iron porphyrins are among the best molecular catalysts for electrocatalytic CO2 reduction reaction. Powering these with help of photosensitizers comes along a couple unsolved challenges that need to be addressed much vigor. We have designed an iron porphyrin catalyst decorated urea functions (UrFe) acting as multipoint hydrogen bonding scaffold towards substrate. found spectacular photocatalytic activity reaching unreported TONs and TOFs high 7270 3720 h-1 , respectively. While Fe0 redox...

Iron porphyrins are among the most studied molecular catalysts for carbon dioxide (CO

Abstract Downsizing the graphdiyne (GDY) network to shape quantum dots (QDs) will provide attractive optical and electronic properties associated with confinement edge effects. Here, it is demonstrated that defect introduction allow using GDY in donor–acceptor photocatalytic systems for solar‐to‐hydrogen conversion. The defect‐rich QDs (GDYO‐QDs) exhibit a blue‐to‐green excitation‐dependent photoluminescence behavior, demonstrating their ability harvest light over wide energy range....

An efficient and selective four-electron plus four-proton (4e(-)/4H(+)) reduction of O(2) to water by decamethylferrocene trifluoroacetic acid can be catalyzed a synthetic analog the heme a(3)/Cu(B) site in cytochrome c oxidase ((6)LFeCu) or its Cu-free version ((6)LFe) acetone. A detailed mechanistic-kinetic study on homogeneous catalytic system reveals spectroscopically detectable intermediates that rate-determining step changes from O(2)-binding process at 25 °C room temperature (RT) O-O...

In this study we report a strategy to attach methylimidazolium fragments as ionic liquid units on an established iron porphyrin catalyst for the selective reduction of CO₂ CO in water, precluding need external proton source.

At the core of carbon monoxide dehydrogenase (CODH) active site two metal ions together with hydrogen bonding scheme from amino acids orchestrate interconversion between CO2 and CO. We have designed a molecular catalyst implementing bimetallic iron complex an embarked second coordination sphere multi-point hydrogen-bonding interactions. found that, when immobilized on paper electrode, dinuclear enhances up to four fold heterogeneous reduction CO in water improved selectivity stability...

Harvesting sunlight to drive carbon dioxide (CO2) valorisation represents an ideal concept support a sustainable and carbon-neutral economy. While the photochemical reduction of CO2 monoxide (CO) has emerged as hot research topic, full CO2-to-CO conversion remains often-overlooked criterion that prevents productive direct CO into high-value-added chemicals. Herein, we report photocatalytic process unlocks fast (<10 min) its straightforward human health related field radiochemistry with...

The nature of the ligand is an important aspect controlling structure and reactivity in coordination chemistry. In connection with our study heme−copper−oxygen relevant to cytochrome c oxidase dioxygen-reduction chemistry, we compare molecular electronic structures two high-spin heme−peroxo−copper [FeIIIO22−CuII]+ complexes containing N4 tetradentate (1) or N3 tridentate (2) copper ligands. Combining previously reported new resonance Raman EXAFS data coupled density functional theory...

The synthesis of a new cross-bridged 1,4,8,11-tetraazacyclotetradecane (cb-cyclam) derivative bearing picolinate arm (Hcb-te1pa) was achieved by taking advantage the proton sponge properties starting constrained macrocycle. structure reinforced ligand as well its acid–base and coordination with Cu2+ Zn2+ investigated. X-ray free showed completely preorganized conformation that lead to very fast copper(II) complexation under mild conditions (instantaneous at pH 7.4) or even in acidic (3 min...

Abstract In his pioneering work to unravel the catalytic power of enzymes, Warshel has pertinently validated that electrostatic interactions play a major role in activation substrates. Implementing such chemical artifice molecular catalysts may help improve their properties. this study, series tetra‐, di‐, and mono‐substituted iron porphyrins with cationic imidazolium groups were designed. Their presence second coordination sphere helped stabilize [Fe−CO 2 ] intermediate through...

The development of efficient hydrogen production technologies is fundamental for replacing fossil-fuel-based energies. As such, electrocatalysts derived from Earth-abundant metal complexes are appealing, and interesting performances have typically been disclosed under acidic conditions in organic solvents. However, their applicability relevant pH-neutral has underexplored. Herein, we demonstrate that nonionic, dimeric cobalt-dithiolene supported on a multiwalled carbon nanotube...

All's well that ends well: The geometric and electronic structure of the first end-on heme–peroxo–copper adduct (see picture) was elucidated using UV/Vis, resonance Raman, X-ray absorption spectroscopy is supported by DFT calculations. Coordination axial base correlated to a spin-state change, leading enhanced biomimetic reactivity, gives insight into OO bond cleavage cytochrome c oxidase. Detailed facts importance specialist readers are published as "Supporting Information". Such documents...

The export of second coordination effects from homogeneous to heterogeneous catalysis through catalyst immobilization on the surface an electrode greatly boosts catalytic performances for CO 2 electroreduction in water.

New synthesis of bifunctionalised cyclams and⁶⁴Cu-PET imaging study.

We describe an easy synthesis of original C-functionalized cyclam derivatives based on the efficient bisaminal template method. In perspective developing bifunctional chelating agents (BCAs), this new synthetic strategy offers possibility introducing various coupling functions one carbon atom in β-N position macrocycle, leaving four nitrogen atoms available for introduction pendant coordinating arms. The methodology is a keystone oxo-cyclam intermediate that obtained by cyclization...

Abstract Inspired by nature's orchestra of chemical subtleties to activate and reduce CO 2 , we have developed a family iron porphyrin derivatives in which introduced urea groups functioning as multipoint hydrogen‐bonding pillars on the periphery porphyrinic ring. This structure closely resembles hydrogen‐bond stabilization scheme carbon dioxide (CO ) adduct monoxide dehydrogenase (CODH). We found that such changes second coordination sphere significantly lowered overpotential for reduction...

Understanding the reactivity landscape for activation of water until formation O–O bond and O2 release in molecular chemistry is a decisive step guiding elaboration cost-effective catalysts oxygen-evolving reaction (OER). Copper(II) complexes have recently caught attention chemists as 4e–/4H+ oxidation process. While copper(IV) intermediate has been proposed reactive species, no spectroscopic signature reported so far. Copper(III) ligand radical species also formulated supported by...

// Cl&eacute;ment Bailly 1, 2, * , S&eacute;bastien Gouard Marie Lacombe 3 Patricia Remaud-Le Sa&euml;c 2 Benjamin Chalopin Micka&euml;l Bourgeois 4 Nicolas Chouin 5 Rapha&euml;l Tripier 6 Zakaria Halime Ferid Haddad Alain Faivre-Chauvet Fran&ccedil;oise Kraeber-Bod&eacute;r&eacute; Michel Ch&eacute;rel 3, 4, and Caroline Bodet-Milin 1 Nuclear Medicine Department, University Hospital, Nantes, France Nantes-Angers Cancer Research Center CRCINA, of INSERM UMR1232, CNRS-ERL6001, ICO-Ren&eacute;...

Abstract The [Re(bpy)(CO) 3 Cl] catalyst pioneered by Lehn for the two‐electron reduction of CO 2 has constantly revealed unique facets in mechanistic understanding selective transformation . A novel triazole‐linked ruthenium photosensitizer and a rhenium dyad was synthesized investigated photo‐induced charge accumulation using time‐resolved absorption spectroscopy. triazole bridging ligand promoted weak electronic communication between two units, resulting an anodic shift potentials Re...

To efficiently capture, activate, and transform small molecules, metalloenzymes have evolved to integrate a well-organized pocket around the active metal center. Within this cavity, second coordination sphere functionalities are precisely positioned optimize rate, selectivity, energy cost of catalytic reactions. Inspired by strategy, an artificial distal defined preorganized 3D strap is introduced on iron-porphyrin catalyst (sc-Fe) for CO2-to-CO electrocatalytic reduction. Combined...

Strapped in: Insertion of PbII into a porphyrin bearing 5,15 straps with pendant carboxylate group led to the first homobimetallic complex divalent metal ion, which belongs class III/type M in Buchler's classification metalloporphyrins (see picture). Since ligand also readily coordinates isoelectronic BiIII it is potential interest as chelator for 212Pb/212Bi isotope generators. Supporting information this article available on WWW under...