Ligand-Bound CO₂ as a Nonclassical Route toward Efficient Photocatalytic CO₂ Reduction with a Ni N-Confused Porphyrin

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(15), P. 10550 - 10558

Published: April 8, 2024

Implementing the synergistic effects between metal and ligand has successfully streamlined energetics for CO2 activation gained high catalytic activities, establishing important breakthroughs in photocatalytic reduction. Herein, we describe a Ni(II) N-confused porphyrin complex (NiNCP) featuring an acidic N–H group. It is readily deprotonated exists anion form during catalysis. Owing to this functional site, NiNCP gave rise outstanding turnover number (TON) as 217,000 with 98% selectivity reduction CO, while parent (NiTPP) was found be nearly inactive. Our mechanistic analysis revealed nonclassical reaction pattern where effectively activated via attack of Lewis-basic ligand. The resulting ligand-bound adduct could further reduced produce CO. This new metal–ligand effect anticipated inspire design highly active catalysts small molecule activations.

Language: Английский

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Unveiling the role of proton concentration in dinuclear metal complexes for boosting photocatalytic CO ₂ reduction

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(20)

Published: May 7, 2024

The reaction kinetics of photocatalytic CO 2 reduction is highly dependent on the transfer rate electrons and protons to molecules adsorbed catalytic centers. Studies uncovering proton effect in catalysts activity are significant but rarely reported. In this paper, we, from molecular level, revealed that closely related availability catalysts. Specifically, four dinuclear Co(II) complexes based Robson-type ligands with different number carboxylic groups (– n COOH; = 0, 2, 4, 6) were designed synthesized. All these show for a water-containing system upon visible-light illumination. Interestingly, yields increase positively carboxylic-group complexes. one containing –6COOH shows best CO, TON value reaching as high 10,294. 1.8, 3.4, 7.8 times higher than those –4COOH, –2COOH, –0COOH, respectively. also makes complex outstanding among reported homogeneous reduction. Control experiments density functional theory calculation indicated more catalyst endow relays, thus accelerating boosting This study, at elucidates beneficial

Language: Английский

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Sensitized and Self-Sensitized Photocatalytic CO₂ Reduction to HCO₂^– and CO under Visible Light with Ni(II) CNC-Pincer Catalysts

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(9), P. 6589 - 6602

Published: April 15, 2024

Robust earth-abundant transition metal-based photocatalysts are needed for photocatalytic CO2 reduction. A series of six Ni(II) complexes have been synthesized with a tridentate CNC pincer ligand composed two imidazole or benzimidazole-derived N-heterocyclic carbene (NHC) rings and pyridyl ring different R substituents (R = OMe, Me, H) para to N the pyridine ring. These characterized by using spectroscopic, analytic, crystallographic methods. The electrochemical properties all were studied cyclic voltammetry under N2 atmospheres. Photocatalytic reduction CO HCO2– was analyzed in presence absence an external photosensitizer (PS). All these active as without PS appreciable turnover numbers (TONs) formate (HCO2–) production typically lower amounts CO. Notably, CNC-pincer this also self-sensitized photocatalysts. Complex 4Me found be most photocatalyst. Ultrafast transient absorption spectroscopy (TAS) experiments computational studies performed understand mechanism catalysts. Whereas sensitized catalysis involves halide loss produce more complexes, requires some remain coordinated allow favorable electron transfer between excited nickel complex sacrificial donor. This then allows undergo via NiI Ni0 catalytic cycles. species (NiI Ni0) demonstrate distinct reactivity selectivity which influences formation vs product.

Language: Английский

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Photocatalysts for CO2 reduction and computational insights

Fuel, Journal Year: 2023, Volume and Issue: 344, P. 128101 - 128101

Published: March 12, 2023

Language: Английский

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Synergistic Porosity and Charge Effects in a Supramolecular Porphyrin Cage Promote Efficient Photocatalytic CO₂Reduction**

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 62(5)

Published: Dec. 20, 2022

We present a supramolecular approach to catalyzing photochemical CO

Language: Английский

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Redox-active ligand promoted multielectron reactivity at earth-abundant transition metal complexes

Inorganic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(18), P. 5795 - 5809

Published: Jan. 1, 2024

This review highlights the application of redox-active ligands for achieving substrate activation and reactivity through multielectron transfer at earth-abundant transition metal complexes.

Language: Английский

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Charge Transfer Chromophores Derived from 3d-Row Transition Metal Complexes

Molecules, Journal Year: 2022, Volume and Issue: 27(23), P. 8175 - 8175

Published: Nov. 24, 2022

A series of new charge transfer (CT) chromophores "α-diimine-MII-catecholate" type (where M is 3d-row transition metals-Cu, Ni, Co) were derived from 4,4'-di-tert-butyl-2,2'-bipyridyl and 3,6-di-tert-butyl-o-benzoquinone (3,6-DTBQ) in accordance with three modified synthetic approaches, which provide high yields products. square-planar molecular structure inherent for monomeric [CuII(3,6-Cat)(bipytBu)]∙THF (1) NiII(3,6-Cat)(bipytBu) (2) chromophores, while dimeric complex [CoII(3,6-Cat)(bipytBu)]2∙toluene (3) units two substantially distorted heteroleptic D-MII-A D, M, are donor, metal acceptor, respectively) parts through a donation oxygen atoms catecholate dianions. Chromophores 1-3 undergo an effective photoinduced intramolecular (λ = 500-715 nm, extinction coefficient up to 104 M-1·cm-1) concomitant generation less polar excited species, the energy finely sensitive towards solvent polarity, ensuring pronounced negative solvatochromic effect. Special attention was paid energetic characteristics CT interacting HOMO/LUMO orbitals that explored by synergy UV-vis-NIR spectroscopy, cyclic voltammetry, DFT study. The current work sheds light on dependence peculiarities nature centers various groups periodic law. Moreover, base "late" elements differences d-level's electronic compared first time.

Language: Английский

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Mechanistic Insights into Photochemical CO₂ Reduction to CH₄ by a Molecular Iron–Porphyrin Catalyst

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(24), P. 9400 - 9417

Published: June 6, 2023

Iron tetraphenylporphyrin complex modified with four trimethylammonium groups (Fe-p-TMA) is found to be capable of catalyzing the eight-electron eight-proton reduction CO2 CH4 photochemically in acetonitrile. In present work, density functional theory (DFT) calculations have been performed investigate reaction mechanism and rationalize product selectivity. Our results revealed that initial catalyst Fe-p-TMA ([Cl-Fe(III)-LR4]4+, where L = ligand a total charge -2, R4 +4) undergoes three steps, accompanied by dissociation chloride ion form [Fe(II)-L••2-R4]2+. [Fe(II)-L••2-R4]2+, bearing Fe(II) center ferromagnetically coupled diradical, performs nucleophilic attack on produce 1η-CO2 adduct [CO2•--Fe(II)-L•-R4]2+. Two intermolecular proton transfer steps then take place at moiety [CO2•--Fe(II)-L•-R4]2+, resulting cleavage C-O bond formation critical intermediate [Fe(II)-CO]4+ after releasing water molecule. Subsequently, accepts electrons one generate [CHO-Fe(II)-L•-R4]2+, which finally successive four-electron-five-proton methane without forming formaldehyde, methanol, or formate. Notably, redox non-innocent was play an important role since it could accept electron(s) during catalysis, thus keeping ferrous relatively high oxidation state. Hydrogen evolution via Fe-hydride ([Fe(II)-H]3+) turns out endure higher barrier than reaction, therefore providing reasonable explanation for origin

Language: Английский

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Bioinspired motifs in proton and CO₂ reduction with 3d-metal polypyridine complexes

Chemical Communications, Journal Year: 2023, Volume and Issue: 60(6), P. 658 - 673

Published: Dec. 15, 2023

The synthesis of active and efficient catalysts for solar fuel generation is nowadays high relevance the scientific community, but at same time poses great challenges. Critical requirements are mainly associated with kinetic barriers due to multi-proton multi-electron nature hydrogen evolution reaction (HER) CO

Language: Английский

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Ideal octahedral geometry leads to poor H2 evolution performance: Theoretical insights on reaction intermediates of cobalt–pentapyridyl molecular catalyst

International Journal of Hydrogen Energy, Journal Year: 2025, Volume and Issue: 106, P. 864 - 873

Published: Feb. 8, 2025

Language: Английский

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