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Full-Text Articles in Physical Sciences and Mathematics
Bulky Thiolated Gold Nanomolecules: Synthesis, Characterization, Optical Properties, And Atomic Structure, Tanya Clorise Jones
Bulky Thiolated Gold Nanomolecules: Synthesis, Characterization, Optical Properties, And Atomic Structure, Tanya Clorise Jones
Electronic Theses and Dissertations
Gold nanomolecules (NMs) have a distinct number of gold atoms and thiolate ligands, Aux(SR)y, with unique spectroscopic, electrochemical, and chiral properties which are dependent on “x” and “y”. The properties of NMs are dictated by the type of capping ligand. The overall structure, size, surface percentage of ligands, and structure of an entire gold NM is changed based on the type of ligand used to synthesize it. Ligand type, such as aliphatic, aromatic or bulky play a crucial role in determining the size and composition of such NMs. A NM’s composition and properties vary widely depending on the type of …
Optical And Sensing Properties Of Various Shaped Gold Nanoplates And Highly Controlled Asymmetric Gold Nanoplate/Nanosphere Coupled Assemblies., Aiqin Fang
Electronic Theses and Dissertations
With the development of a strategy to correlate the dark-field light scattering spectra of individual nanostructures with scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the same nanostructures, we were able to investigate several interesting optical properties of Au nanoplates (NPs) and asymmetrically-coupled Au nanospheres (NSs) attached to Au NPs with a high level of control. The light scattering spectra of the NP/NS coupled structures depend strongly on the location of NS attachment on the NP. Attachment of multiple NSs at the edge/vertex sites leads to a unique synergistic effect. In contrast to the uniform distribution of …
Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties, Praneeth Reddy Nimmala
Gold Nanomolecules : Developing Synthetic Protocols, Characterization And Investigation Of Ligand Effects On Structure And Properties, Praneeth Reddy Nimmala
Electronic Theses and Dissertations
The term "Nano" in chemistry refers to particles/molecules in the size range 1 to 100 nm. Gold nanoparticles were used in ancient times in making decorative glass as they produce vibrant, size dependent, colors upon interaction with light. Gold is a preferred choice of metal for the synthesis of nanoparticles mainly due to its inertness to atmospheric conditions and most chemicals. Gold thiolate nanomolecules, which is the primary focus of this dissertation research, are chemical molecules with a fixed number of gold atoms and organo-thiolate ligands. They are of the form Aux(SR)y and possess molecule-like properties as a result of …
Mechanistic Insights And Functionalization Of Alkynes In Homogeneous Gold Catalysis., Manish Kumar
Mechanistic Insights And Functionalization Of Alkynes In Homogeneous Gold Catalysis., Manish Kumar
Electronic Theses and Dissertations
The focus of my dissertation work was to study the basic mechanistic insights of gold-catalyzed reactions. Although the various mechanistic pathways of gold catalysis are better understood nowadays, numerous questions still remain unanswered concerning the nature of deactivation of the catalyst's active species, high resistance towards protodeauration, and how we can solve these problems to improve the efficiency of gold catalysis. To address these challenges in gold catalysis we conducted first a detailed experimental study to understand the mechanism of deactivation of gold active species. Based on the combination of experimental data, we proposed that gold disproportionation is preferred as …
Expanding The Frontier Of Gold-Catalyzed Cyclizations And Rational Ligand Design., Deepika Malhotra
Expanding The Frontier Of Gold-Catalyzed Cyclizations And Rational Ligand Design., Deepika Malhotra
Electronic Theses and Dissertations
The focus of my dissertation work is to study the gold-catalyzed intramolecular and intermolecular cyclizations involving oxonium intermediates towards the application of synthetically interesting frameworks under ambient conditions and developing a rational approach for the effective catalyst design in gold catalysis. We explored the goldcatalyzed oxygen-transfer reactions of 2-alkynyl-1,5-diketones or 2-alkynyl-5-ketoesters to furnish five-membered rings bearing a quaternary carbon tethered to a carbonyl group. The detailed mechanistic investigation on the newly proposed intramolecular [4+2] cycloaddition mechanism was performed by means of isotopic experiments and quantum chemical calculations. The reactivity of alkynylenolate was investigated in the reactions of allenic ketones and …
Investigation Of Nanoceria-Modified Platinum-Gold Composite Electrodes For The Electrochemical Reduction Of Oxygen In Alkaline Media, Rahul Hegishte
Investigation Of Nanoceria-Modified Platinum-Gold Composite Electrodes For The Electrochemical Reduction Of Oxygen In Alkaline Media, Rahul Hegishte
Electronic Theses and Dissertations
Platinum-gold and nanoceria-modified platinum-gold electrodes were prepared on a platinum surface via electrochemical reduction of solutions of platinum and gold salts in the dispersion of nanoceria. The molar ratios of Pt and Au were varied in both PtAu and PtAu/CeO₂ electrodes while the total concentration of the metals was maintained at 2 x 10⁻³M and the concentration of nanoceria was maintained constant at 5 x 10⁻³M. The electrodes were characterized by their cyclic voltammetry curves in 0.5M sulfuric acid solution. The electrochemically active area of the electrodes was determined using the copper underpotential deposition method. The linear sweep voltammograms of …