Chemistry Commons^™

Design, Synthesis And Application Of Janus Gold Nanoprisms For Directed Self-Assembly., Md. Emtias Chowdhury

Electronic Theses and Dissertations

Colloidal Janus particles that possess more than one type of surface chemistry or functionalities have drawn significant interest due to their enormous potential in bottom-up synthetic strategies for complex superstructures. Moreover, the property of molecular recognition, tunability, and predictability of the DNA-mediated interactions enable a high degree of control over particle assembly to generate highly ordered nanostructures with emergent applications. In this dissertation, we present our works on the synthesis of Janus particles from anisotropic gold nanoprisms, and DNA- mediated assembly of nanoprisms and polymer beads in four major areas: 1) Facet selective asymmetric functionalization of gold nanoprisms for Janus …

Photoelectrical And Photoelectrochemical Characterization Of The Materials Used In Dye-Sensitized And Perovskite Solar Cells., Pom Lal Kharel

Electronic Theses and Dissertations

Solar energy is one of the most important alternative renewable energy sources to fulfill the increasing demand of energy in the world. Third-generation solar cells like dye-sensitized solar cells, perovskite solar cells, quantum dot solar cells, and organic solar cells are extensively studied to increase their photoconversion efficiency, and ultimately for their large-scale implementation. A dye-sensitized solar cell consists of a photoanode of a mesoporous film of titania sensitized with dye sandwiched with a counter electrode, which is usually a platinum-coated transparent conducting oxide, and a redox couple injected between the photoanode and counter electrode. Doping titania with rare-earth metal …

The Utilization Of Metal-Ligand Cooperativity For Electrocatalytic Reduction And Catalytic Hydration., Steven Cronin

Electronic Theses and Dissertations

Small molecules are building blocks for developing larger materials. These small molecules could be extremely small, such as hydrogen, or larger such as a nitrile, but their impact on the global economy is massive. This dissertation describes a catalyst for three reactions involving small molecules; 1) the hydrogen evolution reaction, 2) the carbon dioxide reduction reaction, 3) nitrile hydration. The catalyst Zn(DMTH) (DMTH = diacetyl-2-(4-methyl-3-thiosemicarbazonate)-3-(2-pyridinehydrazonato)) use “metal-ligand cooperativity” between the Lewis acid Zn(II) metal ion and an uncoordinated Lewis base nitrogen in the ligand framework to activate substrates. The complex has been analyzed via NMR, UV/Vis, single crystal X-ray crystallography, …

Clean & Fast Amide Couplings In Water, Nicklas Buckbinder, Sudripet Sharma, Sachin Handa

Undergraduate Research Events

EDC

(1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide) is a carbodiimide that is well known reagent for the amide coupling reactions between an amine and carboxylic acid in the presence of a base. It is the commonly used coupling agent in industries because it produces a water-soluble urea byproduct, which can be easily removed by an aqueous work-up. However, our methodology, the desired amide product precipitates out of the reaction mixture, and no additional work-up is required.3 Using aqueous micelles of PS-750-M as a solvent dramatically increases the rate of reaction.2 The filtrate recovered can be recycled to perform several coupling runs after post-reaction manipulation.

(Pseudo)Phase Tuning In The Service Of Synthesis: Technologies For Sustainable Catalysis., Justin Douglas Smith

Electronic Theses and Dissertations

Strategies for manipulation of chemical phases were explored with emphasis on synthetic chemistry applications. Some strategies are fairly divergent from their origin, but all ultimately began from investigations of micellar media. Accordingly, Chapter 1 reviews the historical development of micellar catalytic processes. Chapters 2 and 3 detail development of synthetic methods in micellar solutions of designer surfactant PS-750-M. PS-750-M was designed to create benign micellar solutions which effectively mimic toxic organic solvents; it contains a proline-based linker between its hydrophobic and hydrophilic regions which imparts increased polarity to the micellar core. Chapter 2 details an interfacial nucleophilic substitution of perfluoroarenes …

Water Cluster Motifs In Structurally Similar N-(2-Aminoethyl)-1-Methylimidazole-2-Carboxamide Metal Complexes: Synthesis, Characterization, Thermal And Electrical Properties., Nina Saraei

Electronic Theses and Dissertations

Water is a remarkable molecule and in all of its forms exhibits an amazing collection of properties and functions. Besides its crucial role in life and many technological processes, water displays some unusual and anomalous properties at various interfaces and under different conditions. Although the role of hydrogen-bonding interactions and their fluctuations are well known to determine the properties of water, the main obstacle exists in the complexity of correctly describing the interactions between water molecules. The key to understanding the behavior of water is to collect precise structural data of various H-bonded water networks in diverse environments. In this …

Functional Nanomaterials By Combining Aminooxy Chemistry And Iodine Activation At Momolayer Protected Clusters., Tirtha Raj Sibakoti

Electronic Theses and Dissertations

Aminooxy (-ONH₂) groups are most commonly known for their chemoselective reaction with carbonyl compounds (aldehydes/ketones) under mild reaction conditions. Aminooxy-based click chemistry is a versatile means of ligation as evidenced by broad application in material science, biology, biochemistry, analytical chemistry, and nanoscience. Our work exploits the facile reaction of aminooxy groups presented on the surface of gold (Au) or palladium (Pd) monolayer protected clusters (MPCs) with various aldehydes via oximation reactions, which form the robust oxime ether adducts. The functionalization of hexanethiolate-stabilized Au MPCs with a newly developed trifunctional amine-containing aminooxy alkanethiol ligand by thiol place-exchange affords aminooxylated …

Computational Modeling Of Photolysis And Catalysis Reactions In Vitamin B12-Dependent Enzymes., Abdullah Al Mamun

Electronic Theses and Dissertations

Vitamin B₁₂ is a complex organometallic molecule, the derivatives of which such as adenosylcobalamin (AdoCbl) and methylcobalamin (CH₃Cbl) act as a cofactor in numerous enzymatic reactions. These two biologically active cofactors contain a unique organometallic Co-C σ bond. Important feature of this Co-C bond is that it can be activated by both thermally and photolytically inside the enzymatic environment as well as in the solution. In the case of enzymatic reactions where AdoCbl molecule act as a cofactor, the cleavage of the Co-C bond constitutes the key catalytic step. The most intriguing features of this cleavage is …

Electrochemical Reduction Of Carbon Dioxide And Carbon Monoxide For The Production Of Green Fuels And Chemicals., Jacob M. Strain

Electronic Theses and Dissertations

It has become apparent that closing the carbon cycle on this planet in order to mitigate disastrous consequences of runaway global warming has become one of the most pressing issues of our civilization. One of the ways we need to accomplish this goal is by finding news methods to generate fuels that will be carbon neutral. Renewable fuels and green chemicals will be a major component of closing the carbon cycle and restoring our planet’s ecosystem into a sense of balance. A method that can help achieve this goal is the reduction of CO₂. If CO₂ can …