Hydrogen Donor Research Articles

Resorcinol–Formaldehyde Resin and Sodium Dodecyl Sulfate Co-assisted Mesoporous TiO2 Supported Ni3Sn2 Intermetallic Compound Catalysts for In-Situ Hydrodeoxygenation of Methyl Palmitate with Methanol as the Hydrogen Donor in Water

Resorcinol–Formaldehyde Resin and Sodium Dodecyl Sulfate Co-assisted Mesoporous TiO2 Supported Ni3Sn2 Intermetallic Compound Catalysts for In-Situ Hydrodeoxygenation of Methyl Palmitate with Methanol as the Hydrogen Donor in Water

Controlled Defluorinative Carboxylation Cascade of Sterically Hindered CF3-Alkenes with Formate Salt via Photocatalysis.

A controlled cleavage of double C-F bonds in sterically hindered tetrasubstituted CF3-alkenes using formate salt has been achieved through a photoinduced electron transfer approach. Diverse γ-branched multifunctionalized gem-difluoroalkenes and α-fluoroacrylic acids are obtained sequentially via hydrodefluorination and C-F bond carboxylation with good-to-high yields. Precisely controlling the quantity of formate salt and the reaction time is crucial for obtaining divergent defluorinative products. Formate serves as the C1 source, hydrogen donor, and reducing agent.

Turning the band alignment of carbon dots for visible-light-driven enzymatic asymmetric reduction of aromatic ketone.

Turning the band alignment of carbon dots for visible-light-driven enzymatic asymmetric reduction of aromatic ketone.

Renewable diesel and bio-aromatics production from waste cooking oil using ethanol as a hydrogen donor in deoxygenation reaction

Renewable diesel and bio-aromatics production from waste cooking oil using ethanol as a hydrogen donor in deoxygenation reaction

Kinetic studies of the rich interaction of cannabinoids with oxygen-centered radicals and excited carbonyl compounds.

Kinetic studies of the rich interaction of cannabinoids with oxygen-centered radicals and excited carbonyl compounds.

Highly Effective Hydrodeoxygenation of Sulfoxides and Pyridinic-N-Oxides Using Biomass-Derived Ethanol as the Hydrogen Donor

Highly Effective Hydrodeoxygenation of Sulfoxides and Pyridinic-N-Oxides Using Biomass-Derived Ethanol as the Hydrogen Donor

Metal Nanoclusters as Highly Efficient, Versatile Type‐II Photoinitiators via Generating Radicals from Non‐Conventional Hydrogen Donors

AbstractDevelopment of highly efficient photocatalysis or photoinitiation systems that are applicable to various types of illumination source is critical to virtually all the light‐driven applications. Here, we report a generalizable strategy to achieve highly sensitive, versatile photoinitiation systems based on the combination of metal nanoclusters with non‐conventional hydrogen donors (co‐initiators). Discovery of this type‐II photoinitiation pathway in metal nanoclusters not only improves their two‐photon initiation sensitivity by up to three‐orders‐of‐magnitude, it further opens the door for metal nanoclusters to trigger the photopolymerization using the low‐power UV light‐emitting diodes. Different from molecular type‐II photoinitiators, we found that the selection rules of hydrogen donors for metal nanoclusters are largely dependent on their ligand structures. More importantly, using electron paramagnetic resonance and mass spectroscopy, we for the first time demonstrate that the photoexcited metal nanoclusters can function as versatile hydrogen atom abstractors which generate various types of previously unreported thiyl and nitrogen‐centered radicals. This finding indicates the broad opportunity of the future application of metal nanoclusters in light‐driven organic synthesis and radical chemistry.

Synthesis and crystal structure of 5,10-dihy-droxy-9-meth-oxy-2,2-dimethyl-12-(2-methyl-but-3-en-2-yl)-2H,6H-pyrano[3,2-b]xanthen-6-one.

5,10-Dihy-droxy-9-meth-oxy-2,2-dimethyl-12-(2-methyl-but-3-en-2-yl)-2H,6H-pyrano[3,2-b]xanthen-6-one, C24H24O6 (2), is a prenylated xanthone that was synthesized from 5,9,10-trihy-droxy-2,2-dimethyl-12-(2-methyl-but-3-en-2-yl)-2H,6H-pyrano[3,2-b]xanthen-6-one or macluraxanthone (1), a known compound isolated from Garcinia schomburgkiana Pierre. The present study describes the synthesis of compound 2 by methyl-ation reaction of 1, and its crystallographic characterization. Compound 2 features a planar xanthone core and a bent pyrano ring adopting a half-boat conformation. An intermolecular O-H⋯O hydrogen bond between the hydroxyl hydrogen donor and the ketone acceptor organizes the molecules into a one-dimensional network along the b-axis direction. Perpendicular to this network, π-π stacking interactions form the three-dimensional supramolecular architecture. These two key intermolecular interactions are distinctly revealed in the Hirshfeld surface analysis.

Kelvin Probe Force Microscopy Imaging of Plasticity in Hydrogenated Perovskite Nickelate Multilevel Neuromorphic Devices.

Ion drift in nanoscale electronically inhomogeneous semiconductors is among the most important mechanisms being studied for designing neuromorphic computing hardware. However, nondestructive imaging of the ion drift in operando devices directly responsible for multiresistance states and synaptic memory represents a formidable challenge. Here, we present Kelvin probe force microscopy imaging of hydrogen-doped perovskite nickelate device channels subject to high-speed electric field pulses to directly visualize proton distribution by monitoring surface potential changes spatially, which is also supported with finite element-based electric field distribution studies. First-principles calculations provide mechanistic insights into the origin of surface potential changes as a function of hydrogen donor doping that serves as the contrast mechanism. We demonstrate 128 (7-bit) nonvolatile conductance levels in such devices relevant to in-memory computing applications. The synaptic plasticity measurements are implemented in spiking neural networks and show promising results for classification (SciKit Learn's Iris and Wine data sets) and control (OpenAI's CartPole-v1 and BipedalWalker-v3) simulation tasks.

Metal Nanoclusters as Highly Efficient, Versatile Type-II Photoinitiators via Generating Radicals from Non-Conventional Hydrogen Donors.

Development of highly efficient photocatalysis or photoinitiation systems that are applicable to various types of illumination source is critical to virtually all the light-driven applications. Here, we report a generalizable strategy to achieve highly sensitive, versatile photoinitiation systems based on the combination of metal nanoclusters with non-conventional hydrogen donors (co-initiators). Discovery of this type-II photoinitiation pathway in metal nanoclusters not only improves their two-photon initiation sensitivity by up to three-orders-of-magnitude, it further opens the door for metal nanoclusters to trigger the photopolymerization using the low-power UV light-emitting diodes. Different from molecular type-II photoinitiators, we found that the selection rules of hydrogen donors for metal nanoclusters are largely dependent on their ligand structures. More importantly, using electron paramagnetic resonance and mass spectroscopy, we for the first time demonstrate that the photoexcited metal nanoclusters can function as versatile hydrogen atom abstractors which generate various types of previously unreported thiyl and nitrogen-centered radicals. This finding indicates the broad opportunity of the future application of metal nanoclusters in light-driven organic synthesis and radical chemistry.

Cobalt-Catalyzed Reductive Heck Cyclization Using Water as Hydrogen Donor to Access Oxindoles

Cobalt-Catalyzed Reductive Heck Cyclization Using Water as Hydrogen Donor to Access Oxindoles

Hydrogenation of Organic Molecules via Direct Mechanocatalysis.

Mechanochemical hydrogenation of unsaturated C-C and C-O, as well as N-O and C-X bonds is successfully achieved without the use of solvents, ligands, or catalyst powders via ball milling. A variety of catalysts are electroplated onto the walls of the milling vessel, allowing for simple recycling and reuse of the catalytic material. Hydrogen gas is directly introduced into the milling vessel, eliminating the need for hydrogen donor compounds which contribute to waste production and suboptimal atom economy. This approach enables the quantitative hydrogenation of unsaturated carbon-carbon bonds, achieving near-complete conversion within just 20 minutes at ambient temperature and pressures as low as 1.5 bar. Carbonyls, nitro groups, and organohalides were converted within reaction times of up to 12 hours. Mechanistic investigations suggest the reaction to be following established mechanisms for hydrogenation. Finally, chemoselective hydrogenation of various reducible functional groups was explored, demonstrating the versatility and efficiency of this solvent-free mechanochemical approach with simple catalyst recycling for hydrogenation reactions.

Hydrogenation of Organic Molecules via Direct Mechanocatalysis

Mechanochemical hydrogenation of unsaturated C‐C and C‐O, as well as N‐O and C‐X bonds is successfully achieved without the use of solvents, ligands, or catalyst powders via ball milling. A variety of catalysts are electroplated onto the walls of the milling vessel, allowing for simple recycling and reuse of the catalytic material. Hydrogen gas is directly introduced into the milling vessel, eliminating the need for hydrogen donor compounds which contribute to waste production and suboptimal atom economy. This approach enables the quantitative hydrogenation of unsaturated carbon‐carbon bonds, achieving near‐complete conversion within just 20 minutes at ambient temperature and pressures as low as 1.5 bar. Carbonyls, nitro groups, and organohalides were converted within reaction times of up to 12 hours. Mechanistic investigations suggest the reaction to be following established mechanisms for hydrogenation. Finally, chemoselective hydrogenation of various reducible functional groups was explored, demonstrating the versatility and efficiency of this solvent‐free mechanochemical approach with simple catalyst recycling for hydrogenation reactions.

Isolation, synthesis and structure-activity relationships of gallotannin derivatives as cathepsin C inhibitor.

Isolation, synthesis and structure-activity relationships of gallotannin derivatives as cathepsin C inhibitor.

Nitrogen-doped Porous Carbon Supported Nickel Catalysts for Efficient Hydrodeoxygenation of Lignin-derived Vanillin to 2-methoxy-4-methylphenol in Ethanol

Nitrogen-doped Porous Carbon Supported Nickel Catalysts for Efficient Hydrodeoxygenation of Lignin-derived Vanillin to 2-methoxy-4-methylphenol in Ethanol

Hydrogenic and Non-Hydrogenic Donor Impurity in Quantum Dot with an inverse parabolic plus a parabolic potential under magnetic field effect

Hydrogenic and Non-Hydrogenic Donor Impurity in Quantum Dot with an inverse parabolic plus a parabolic potential under magnetic field effect

Product distribution and free radical reaction behavior during coal liquefaction in solvents with different hydrogen donor indexes

Product distribution and free radical reaction behavior during coal liquefaction in solvents with different hydrogen donor indexes

Fabrication of lignin-MOF derived spherical carbon supported NiCo-bimetallic catalysts for selective hydrogenolysis lignin derived ether.

Fabrication of lignin-MOF derived spherical carbon supported NiCo-bimetallic catalysts for selective hydrogenolysis lignin derived ether.

Direct photodegradation of aromatic carbamate pesticides: Kinetics and mechanisms in aqueous vs. non-aqueous media.

The direct photodegradation quantum yields (Φ) of five representative aromatic carbamate pesticides - carbaryl, carbofuran, propoxur, isoprocarb, and metolcarb - were examined in both aqueous and non-aqueous solutions, the latter mimicking hydrophobic environments such as leaf surfaces. For carbaryl, carbofuran, isoprocarb, and metolcarb, the Φ values generally followed the order Φwater < ΦMeOH < Φn-hexane, while propoxur showed a different trend, ΦMeOH < Φn-hexane < Φwater. Scavenging and laser flash photolysis experiments, combined with quantum chemical calculations, were used to clarify the photodegradation mechanisms. Photodegradation is primarily initiated by the singlet excited state (S*), with the triplet state (T * ) also contributing in compounds with conjugated structures, such as carbaryl. Upon excitation, methylcarbamate aromatic esters (MCAEs) generated both radical cations (S•+) and phenoxyl radicals (S-O•), and S•+ would convert to S-O• subsequently. S-O• is predominantly generated through the cleavage of C-O bonds in ester groups, subsequently abstracting hydrogen from solvent molecules. The reactivity of hydrogen donors in these solvents follows the order: -CH2- > -CH3 > -OH. For propoxur, the ether group also contributes to the formation of S-O•, which further reacts with H2O and enhances degradation in aqueous environments. Solvent polarity had a minimal effect on photodegradation. This comparative study of degradation in aqueous and nonaqueous phases provides insights for designing and selecting pesticides that are effective during use in nonaqueous environments, such as on leaf surfaces, yet degrade rapidly in aqueous environments in the post-application phase.

Are Polycyclic Aromatic Hydrocarbons in the Hydro-Liquefaction Products of Lignin Derived from the Lignin or Hydrogen Donor Solvent?

Are Polycyclic Aromatic Hydrocarbons in the Hydro-Liquefaction Products of Lignin Derived from the Lignin or Hydrogen Donor Solvent?