A5022035352- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Electrocatalysts for Energy Conversion
- CO2 Reduction Techniques and Catalysts
- Electron and X-Ray Spectroscopy Techniques
- Machine Learning in Materials Science
- Field-Flow Fractionation Techniques
- Asymmetric Synthesis and Catalysis
- Crystallography and molecular interactions
- Catalytic Processes in Materials Science
- Electronic and Structural Properties of Oxides
- Advanced Electron Microscopy Techniques and Applications
- Fluorine in Organic Chemistry
- Ionic liquids properties and applications
- Inorganic Fluorides and Related Compounds
- Asymmetric Hydrogenation and Catalysis
- Molecular Junctions and Nanostructures
- Surface Chemistry and Catalysis
- Metal-Catalyzed Oxygenation Mechanisms
- Catalytic C–H Functionalization Methods
- Chemical synthesis and alkaloids
- Traditional and Medicinal Uses of Annonaceae
- TiO2 Photocatalysis and Solar Cells
- Radical Photochemical Reactions
- Advanced Photocatalysis Techniques
Yale University
2021-2024
University of Virginia
2017-2021
University of New Haven
2021
TiO2 thin films are often used as protective layers on semiconductors for applications in photovoltaics, molecule–semiconductor hybrid photoelectrodes, and more. Experiments reported here show that silicon electrochemically photoelectrochemically reduced buffered acetonitrile at potentials relevant to photoelectrocatalysis of CO2 reduction, N2 H2 evolution. On both n-type Si irradiated p-type Si, reduction is proton-coupled with a 1e–:1H+ stoichiometry, demonstrated by the Nernstian...
Eleven 2,2'-bipyridine (bpy) ligands functionalized with attachment groups for covalent immobilization on silicon surfaces were prepared. Five of the feature silatrane functional to metal oxide coatings surfaces, while six contain either alkene or alkyne hydrogen-terminated surfaces. The bpy coordinated Re(CO)5Cl form complexes type Re(bpy)(CO)3Cl, which are related known catalysts CO2 reduction. Six new characterized using X-ray crystallography. As proof principle, four molecular Re...
A high-surface-area p-type porous Si photocathode containing a covalently immobilized molecular Re catalyst is highly selective for the photoelectrochemical conversion of CO2 to CO. It gives Faradaic efficiencies up 90% CO at potentials −1.7 V (versus ferrocenium/ferrocene) under 1 sun illumination in an acetonitrile solution phenol. The photovoltage approximately 300 mV based on comparisons with similar n-type cathodes dark. Using estimate equilibrium potential reduction optimized reaction...
Multiple H2O2-forming mechanisms are accessible in Fe(porphyrin)-catalysed oxygen reduction, a key reaction both fuel cell technologies and oxygen-utilizing enzymes. Our kinetic analysis reveals that the porphyrin secondary structure dictates pathway for H2O2 formation. This approach is generalizable to other electrocatalytic processes provides insight into selectivity-determining steps.
Three molecular Re hydrides of the form (Rbpy)Re(CO)3H with 2,2′-bipyridine (bpy) ligands containing silatrane functional groups for surface attachment on metal oxide surfaces were synthesized. IR spectroscopy and cyclic voltammetry (CV) demonstrated that complexes have electronic properties similar to those a control compound, which did not contain attachment. Additionally, in fashion are electrocatalysts reduction CO2 CO solution. The immobilized thin layer TiO2 Si, resulting composites...
The effects of an electron-withdrawing group on the organic chemistry η2-bound benzene ring are explored using complex TpW(NO)(PMe3)(η2-PhCF3). This trifluorotoluene was found to undergo a highly regio- and stereoselective 1,2-addition reaction involving protonation ortho carbon followed by addition nucleophile. resulting 1,3-diene complexes can second nucleophilic with range nucleophiles including hydrides, amines, cyanide, protected enolates. Interestingly, proton nucleophile occurs in...
The dihapto-coordination of benzene to the π-basic fragment {TpW(NO)(PMe3)} (Tp = hydridotris(pyrazolyl)-borate) enhances basicity arene ligand point that it can be protonated with a mild Brønsted acid (diphenylammonium triflate; pKa ∼ 1). resulting η2-benzenium complex reacts wide range nucleophiles including protected enolates, cyanide, amines, methoxide, and aromatic form 5-substituted 3,4-η2-1,3-cyclohexadiene complexes in good yield (42–70%). These coordinated dienes were successfully...
The surface immobilization of molecular catalysts is attractive because it combines the benefits homogeneous and heterogeneous catalysis. However, determining coverage distribution a catalyst on solid support often challenging, inhibiting our ability to design improved catalytic systems. Here, we demonstrate that combination scanning transmission electron microscopy (STEM) image analysis individual positions heavy atoms in transition metal complexes via convolutional neural network (CNN)...
We report a series of isomeric, dicationic Re(bpy
Reactions are described for complexes of the form WTp(NO)(PMe3)(η2-arene) and various amines, where arene is benzene or with an electron-withdrawing substituent (CF3, SO2Ph, SO2Me). The complex first protonated to η2-arenium species, which then selectively adds amine. resulting η2-5-amino-1,3-cyclohexadiene can be subjected same sequence a second nucleophile 3-aminocyclohexene complexes, up three stereocenters originate from carbons. Alternatively, 1,3-cyclohexadiene containing ester group...
The surface immobilization of molecular catalysts is attractive because it combines the benefits homogeneous and heterogeneous catalysis. However, determining coverage distribution a catalyst on solid support often challenging, inhibiting our ability to design improved catalytic systems. Here, we demonstrate that combination scanning transmission electron microscopy (STEM) image analysis individual positions heavy atoms in transition metal complexes via convolutional neural network (CNN)...
The surface immobilization of molecular catalysts is attractive because it combines the benefits homogeneous and heterogeneous catalysis. However, determining coverage distribution a catalyst on solid support often challenging, inhibiting our ability to control catalytic performance. Here, we demonstrate that scanning transmission electron microscopy can image location metal center in surface-attached transition complexes with atomic resolution. Using machine learning model, analyze many...
Abstract The surface immobilization of molecular catalysts is attractive because it combines the benefits homogeneous and heterogeneous catalysis. However, determining coverage distribution a catalyst on solid support often challenging, inhibiting our ability to control catalytic performance. Here, we demonstrate that scanning transmission electron microscopy can image location metal center in surface-attached transition complexes with atomic resolution. Using machine learning model, analyze...