Highly Selective Electrochemical Baeyer–Villiger Oxidation through Oxygen Atom Transfer from Water

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 13438 - 13444

Published: April 30, 2024

The Baeyer–Villiger oxidation of ketones is a crucial oxygen atom transfer (OAT) process used for ester production. Traditionally, accomplished by thermally oxidizing the OAT from stoichiometric peroxides, which are often difficult to handle. Electrochemical methods hold promise breaking limitation using water as source. Nevertheless, existing demonstrations electrochemical face challenges low selectivity. We report in this study strategy overcome challenge. By employing well-known catalyst, Fe2O3, we achieved nearly perfect selectivity cyclohexanone. Mechanistic studies suggest that it essential produce surface hydroperoxo intermediates (M-OOH, where M represents metal center) promote nucleophilic attack on ketone substrates. confining reactions catalyst surfaces, competing (e.g., dehydrogenation, carboxylic acid cation rearrangements, and hydroxylation) greatly limited, thereby offering high surface-initiated nature reaction confirmed kinetic spectroelectrochemical characterizations. This discovery adds toolbox organic synthesis.

Language: Английский

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Effect of multivalent ion doping on magnetic, electrical, and dielectric properties of nickel ferrite nanoparticles

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Nov. 28, 2024

The nanoscale spinel structured ferrites co-doped with multi-valence ions are of great interest and proving to be promising for numerous applications. In light this, herein we report tetravalent titanium (Ti4+) divalent zinc (Zn2+) nickel generic formula NiFe2 − 2xTixZnxO4 (x = 0.00 ≤ x 0.20 in step 0.05). sol gel self combustion method assistance citric acid as fuel was employed prepare the samples. X-ray diffraction (XRD) analysis Rietveld refinement performed confirm single-phase cubic structure. sphere type grain morphology samples revealed by SEM images. compositional studies carried out EDAX showed desired formation composition absence impurities characteristics bands belonging were appeared IR spectra confirming successive sample forming. different surface parameters including area pore volume estimated using Brunauer-Emmett-Teller (BET) analysis. low coercive nature soft magnetism observed co-doping M-H plots. electric dielectric decrementing behaviour increment Ti4+-Zn2+ co-doping. This study outcome signifies that could a prominent many nanoelectronics

Language: Английский

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Designing a Phenalenyl-Based Dinuclear Ni(II) Complex: An Electrocatalyst with Two Single Ni Sites for the Oxygen Evolution Reaction (OER)

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(21), P. 9771 - 9785

Published: May 13, 2024

A new dinuclear Ni(II) complex 1, [Ni2II(dtbh-PLY)2], is synthesized from 9-(2-(3,6-di-tert-butyl-2-hydroxybenzylidene)hydrazineyl)-1H-phenalen-1-one, dtbh-PLYH2 ligand, and structurally characterized by various analytical tools including the single-crystal X-ray diffraction (SCXRD) technique. In solid state, both metal centers in 1 exist a distorted square planar geometry display presence of rare Ni···H–C anagostic interactions to form one-dimensional (1-D) linear motif supramolecular array. Complex further stabilized state π–π-stacking between highly delocalized phenalenyl rings. The redox features have been analyzed cyclic voltammetry (CV) technique solution as well revealing crucial involvement for undergoing quasi-reversible oxidation reactions on application an anodic sweep. 1-modified glassy carbon electrode, GC-1, employed electrocatalyst oxygen evolution reaction (OER) 1.0 M KOH, giving OER onset at 1.45 V, very low overpotential, 300 mV vs reversible hydrogen electrode (RHE) reach 10 mA cm–2 current density. Furthermore, GC-1 displayed fast kinetics with Tafel slope 40 dec–1, significantly lower value than those previously reported molecular catalysts. situ electrochemical experiments postoperational UV–vis, Fourier transform infrared (FT-IR), scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS), photoelectron (XPS) studies were performed analyze stability nature gain reasonable insights into true catalyst.

Language: Английский

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Unmasking the Electrochemical Stability of N‐Heterocyclic Carbene Monolayers on Gold

Chemistry - A European Journal, Journal Year: 2023, Volume and Issue: 30(15)

Published: Dec. 20, 2023

N-heterocyclic carbene (NHC) monolayers are transforming electrocatalysis and biosensor design via their increased performance stability. Despite increasing use in electrochemical systems, the integrity of NHC monolayer during voltage perturbations remains largely unknown. Herein, we deploy surface-enhanced Raman spectroscopy (SERS) to measure stability two model NHCs on gold ambient conditions as a function applied potential under continuous voltammetric interrogation. Our results illustrate that exhibit over wide window (-1 V 0.5 vs Ag|AgCl), but they found degrade at strongly reducing (< -1 V) or oxidizing (>0.5 potentials. We also address interrogation between 0.2 -0.5 V, commonly used for sensing, showing stable up 43 hours. However, additionally find modifications backbone structure can lead significantly shorter operational lifetimes. While these highlight architectures electrode functionalization, reveal pitfalls have not been fully appreciated applications NHCs.

Language: Английский

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Exploring multi-stimuli-responsive Pt(ii) complexes: supramolecular self-assembly, lysosome-specific targeted photodynamic therapy and photodegradation of organic pollutants

Inorganic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(6), P. 1693 - 1702

Published: Jan. 1, 2024

Developing novel luminescent materials with multi-stimuli-responsiveness and multi-functional properties is vital.

Language: Английский

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Bifunctional low-Pt content nanocatalysts supported on carbons functionalized with a Cu-organometallic compound: Tailoring of d-band center with high catalytic activity for electrochemical oxygen reactions

International Journal of Hydrogen Energy, Journal Year: 2024, Volume and Issue: unknown

Published: March 1, 2024

Language: Английский

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Synthesis, properties, environmental stability and practical application of organometallic compounds: A comprehensive review

Inorganic Chemistry Communications, Journal Year: 2023, Volume and Issue: 158, P. 111567 - 111567

Published: Oct. 18, 2023

Language: Английский

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Non-covalent Immobilization of Metal N-Heterocyclic Carbene Complexes onto Carbon Cloth as Bifunctional Electrodes for Overall Water Splitting in Alkaline Medium

ACS Applied Energy Materials, Journal Year: 2024, Volume and Issue: 7(20), P. 9500 - 9511

Published: Oct. 16, 2024

The use of molecular complex-modified electrodes presents avenues for their rational and simplistic design to serve as efficient catalysts in emerging electrocatalytic applications. Herein, three electrocatalysts, CoLBr2, NiLBr2, PdLBr2, were synthesized from the pyridine-functionalized N-heterocyclic carbene (NHC) ligand (HLBr) physisorbed onto CC obtain free-standing electrodes. These investigated hydrogen evolution reaction (HER) oxygen (OER) activity 1 M KOH. Among electrodes, CoLBr2 electrode exhibited best HER with an overpotential −255 mV vs RHE at 10 mA/cm2 a Tafel slope 155 mV/dec. For OER activity, NiLBr2 performance 376 86 bifunctional nature enabled assembly symmetric alkaline electrolyzer, i.e., CoLBr2//CoLBr2, cell voltage 1.81 V mA/cm2. post-stability analysis revealed that complexes possessed chemical stability despite undergoing long-term tests high overpotentials. findings authenticate versatility metal NHC fabricating molecularly modified HER, OER, overall water splitting, paving way development sustainable energy conversion technologies.

Language: Английский

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Synergistic Innovations: Organometallic Frameworks on Graphene Oxide for Sustainable Eco-Energy Solutions

ChemEngineering, Journal Year: 2024, Volume and Issue: 8(3), P. 61 - 61

Published: June 12, 2024

Combining organometallic frameworks with graphene oxide presents a fresh strategy to enhance the electrochemical capabilities of supercapacitors, contributing advancement sustainable energy solutions. Continued refinement materials and device design holds promise for broader applications across storage conversion systems. This featured application underscores inventive utilization on oxide, shedding light creation superior devices eco-friendly review article delves into synergistic advancements resulting from fusion offering thorough exploration their utility in eco-energy encompasses various facets, including synthesis methodologies, amplified catalytic performances, structural elucidations. Through collaborative efforts, notable progressions photocatalysis, photovoltaics, are showcased, illustrating transformative potential these hybrids reshaping solar technologies. Moreover, environmentally conscious features organometallic–graphene underscored through contributions environmental remediation, addressing challenges pollutant elimination, water purification, air quality enhancement. The intricate characteristics expounded upon highlight role tailoring material properties specific applications. Despite promising advancements, such as scalability stability candidly addressed, pragmatic view current research landscape. manuscript concludes by providing insights prospective avenues, guiding scientific community towards surmounting hurdles fully leveraging energy-efficient future.

Language: Английский

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Mono- vs Tri-nuclear Silver(I) and Gold(I) N-Heterocyclic Carbene Complexes/Metallacycles as Free-Standing Carbon Cloth Electrodes for Hydrogen Evolution Reaction in Alkaline Medium

Energy & Fuels, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

The synthesis of a Au(I) chlorido mono-carbene complex (AuLCl), tri-nuclear Ag(I) tri-carbene metallacycle (Ag3L3·3PF6), and (Au3L3·3PF6) via direct or transmetalation route has been reported. new metal N-heterocyclic carbene (NHC) complexes are thoroughly characterized by 1H, 13C NMR, single crystal X-ray diffraction (SCXRD) technique. molecular structure analysis AuLCl Au3L3·3PF6 reveals that both these crystallize in monoclinic system possess linear coordination geometry. NHC fabricated as free-standing carbon cloth (CC) electrodes using simple dip-coating drying method. deposition the on CC is investigated field emission scanning electron microscopy (FE-SEM), it found they deposited distinct, fine microgranules with varying sizes shapes. (AuLCl, Ag3L3·3PF6, Au3L3·3PF6) studied for their potential electrochemical hydrogen evolution reaction (HER) an alkaline medium. activity enhanced incorporating conductive ink electrode fabrication to develop complex-carbon (AuLCl/C, Ag3L3·3PF6/C, Au3L3·3PF6/C). Among electrodes, Ag3L3·3PF6/C exhibits best HER overpotential 187 mV vs RHE reach current density 10 mA/cm2 Tafel slope value 169 mV/dec charge transfer resistance (Rct) 9.85 Ω. its long-term operational stability 24 h chronoamperometric technique exhibited significant retention. integrity after FE-SEM, exhibiting robust stable nature metallacycle-carbon composite electrode.

Language: Английский

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