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Full-Text Articles in Physical Sciences and Mathematics

Thermodynamic Analysis Of Pamam Dendrimer Synthesis, Ryutaro Einar Jacobson Apr 2021

Thermodynamic Analysis Of Pamam Dendrimer Synthesis, Ryutaro Einar Jacobson

Honors Theses

The objective of this research was to determine kinetic and thermodynamic data about the reaction between ethylene diamine and methyl acrylate which is used in the production of PAMAM dendrimers. Establishing a rate law and finding values such as rate constant, activation energy, and Arrhenius coefficient will help in determining the best possible conditions for the reaction. A rate law was established through the method of initial rates, comparing the rates of reactions with different initial concentrations to one another. Additional reactions were run with active cooling to observe the effects on rate and reaction progress, and finally reactions were …


Synthesis Of The Complex Salt With Triphenylphosphine Bromide, Х Haitbayev,, X. Babaev, I Yuldashev, Aug 2018

Synthesis Of The Complex Salt With Triphenylphosphine Bromide, Х Haitbayev,, X. Babaev, I Yuldashev,

Scientific journal of the Fergana State University

This article affirms that one of the main factors for increasing the yield of fruit trees is their protection from pests and diseases. In recent years, plant protection has paid great attention to the use of harmless biological control methods for the environment, humans and animals. An example is the use of the use of pheromones, which can be separated from different insects. Practical significance is the production and use in practice of pheromones of insect pests by chemical methods, which adversely affect the plant world.


Synthesis Of The Complex Salt With Triphenylphosphine Bromide, Х Haitbayev,, X. Babaev, I Yuldashev, Aug 2018

Synthesis Of The Complex Salt With Triphenylphosphine Bromide, Х Haitbayev,, X. Babaev, I Yuldashev,

Scientific journal of the Fergana State University

This article affirms that one of the main factors for increasing the yield of fruit trees is their protection from pests and diseases. In recent years, plant protection has paid great attention to the use of harmless biological control methods for the environment, humans and animals. An example is the use of the use of pheromones, which can be separated from different insects. Practical significance is the production and use in practice of pheromones of insect pests by chemical methods, which adversely affect the plant world.


A Novel Method For Synthesis Of Hydroxytyrosol, Emmanuel Onobun Aug 2017

A Novel Method For Synthesis Of Hydroxytyrosol, Emmanuel Onobun

Electronic Theses and Dissertations

Hydroxytyrosol, 3,4-dihydroxyphenolethanol, a naturally occurring polyphenol most common in olive tree (Olea europaea), is one of the most effective member of the polyphenols family, because of its remarkable antioxidant activity, its ability to inhibit oxidation of low density lipids (LDL), and its protection against DNA oxidative damage. Hydroxytyrosol, which is widely used in cosmetics and food supplements industries, can be purchased as an olive oil extract that contains low concentration of hydroxytyrosol besides other polyphenols. The price and low natural abundance of hydroxytyrosol make alternative synthetic sources very attractive. In this research, a novel method for the synthesis of pure …


The Investigation And Characterization Of The Reaction Of 2-Methylfuran And 2-Methyl-3-Buten-2-Ol With O(3p) And The Photodissociation Of Xylyl Bromide Isomers, Yasmin Fathi May 2017

The Investigation And Characterization Of The Reaction Of 2-Methylfuran And 2-Methyl-3-Buten-2-Ol With O(3p) And The Photodissociation Of Xylyl Bromide Isomers, Yasmin Fathi

Master's Theses

This thesis has studied the oxidation behavior of different biofuels or additives, 2-methyl-3-buten-2-ol and 2-methylfuran, in combustion experiments at the Chemical Dynamics Beamline held at the Advanced Light Source of the Lawrence Berkley National Laboratory. The oxidation of these fuels were initiated through O(3P) and the combustion experiments were analyzed using a multiplexed chemical kinetics photoionization mass spectrometer with tunable synchrotron radiation. Products of the different reactions were identified using kinetic profiles and further characterized using the photoionization spectra. The amount of each species was calculated using branching fractions.

Additionally, the unimolecular dissociation of the xylyl bromide isomers …


Environmental Fullerene Chemistry: Elucidating Critical Reaction Pathways And Resulting Products In The Aqueous Phase, Jiewei Wu May 2016

Environmental Fullerene Chemistry: Elucidating Critical Reaction Pathways And Resulting Products In The Aqueous Phase, Jiewei Wu

McKelvey School of Engineering Theses & Dissertations

As the production of fullerenes and fullerene-based materials approaches industrial scale, there are increasing interests/concerns regarding their (potential) environmental impact(s) upon release. To date, a number of critical, aqueous-based fullerene transformation pathways under environmentally relevant conditions remain poorly understood. Comprehensive, fundamental, and quantitative understanding of the potential (major) reaction pathways and resulting products of fullerene materials, particularly in aquatic systems, is now crucial for their accurate fate, transport, life cycle, risk assessment(s), and thus ultimate material sustainability.

Herein, this dissertation is focused on identifying and elucidating aqueous transformation pathways of fullerene materials, focused on C60 as a model fullerene, under …


Selective Iodination Using Diaryliodonium Salts, William H. Miller Iv Nov 2015

Selective Iodination Using Diaryliodonium Salts, William H. Miller Iv

Department of Chemistry: Dissertations, Theses, and Student Research

Aryl iodides have become widely recognized as versatile synthetic intermediates, owing to aromatic iodine’s excellent ability to participate in oxidative addition reactions. Iodoarenes readily undergo a variety of synthetic transformations including metal catalyzed cross-coupling reactions, diaryliodonium chemistry, formation of organometallics through reduction or metal-halogen exchange, as well as classical SN2 type chemistry. Because a wide array of transformations are available for aryl iodides, organic molecules containing this moiety often serve as vital precursors to highly desirable pharmaceuticals.

This thesis describes a simple and selective two-step approach to the formation of aryl iodides. This method proceeds through an easily …


The Potlib Library Of Potential Energy Functions And A New Global Analytic Pes For The H + O2 Reaction, Ronald Duchovic Oct 2014

The Potlib Library Of Potential Energy Functions And A New Global Analytic Pes For The H + O2 Reaction, Ronald Duchovic

Ronald J. Duchovic

No abstract provided.


On The Origin Of Mode- And Bond-Selectivity In Vibrationally Mediated Reactions On Surfaces, Daniel Killelea, Arthur L. Utz Oct 2013

On The Origin Of Mode- And Bond-Selectivity In Vibrationally Mediated Reactions On Surfaces, Daniel Killelea, Arthur L. Utz

Chemistry: Faculty Publications and Other Works

The experimental observations of vibrational mode- and bond-selective chemistry at the gas–surface interface indicate that energy redistribution within the reaction complex is not statistical on the timescale of reaction. Such behavior is a key prerequisite for efforts to use selective vibrational excitation to control chemistry at the technologically important gas–surface interface. This paper outlines a framework for understanding the origin of non-statistical reactivity on surfaces. The model focuses on the kinetic competition between intramolecular vibrational energy redistribution (IVR) within the reaction complex, which in the long-time limit leads to statistical behavior, and quenching, scattering, or desorption processes that restrict the …


Selective Nitration Of Chlorobenzene By No2 In The Alkali Zeolite Nazsm-5, Scott J. Kirkby Dec 2012

Selective Nitration Of Chlorobenzene By No2 In The Alkali Zeolite Nazsm-5, Scott J. Kirkby

Scott J. Kirkby

Chlorobenzene was reacted with NO2, in the initially acid-free zeolite NaZSM-5, to yield para-chloronitrobenzene exclusively. The precursors were loaded sequentially into self-supporting pellets of the zeolite, contained within a stainless steel cell, from the gas phase. The reaction proceeds spontaneously at room temperature. It is, however, very temperature dependent and effectively ceases at zero degrees Celsius. The reaction was monitored in situ using FT-IR. The active nitrating agent is formed from the partial electron donation by the NO2 to the Na+ cations present in the zeolite lattice. Under the reaction conditions, chlorobenzene is not readily mobile through the pore system; …


Progress Towards An Aza-Michael Addition To Ketones, Bowman Potter Jun 2011

Progress Towards An Aza-Michael Addition To Ketones, Bowman Potter

Honors Theses

The aza-Michael addition to unsaturated ketones under neutral to mildly basic condition is a difficult transformation due to the inherent unreactivity of ketones toward the addition of weak nucleophiles. This thesis reports on efforts to develop an environmentally friendly, stereoselective and low-cost organo-catalyzed aza-Michael reaction between unsaturated ketones and nitrogen nucleophiles, such as phthalimide, under neutral to mildly basic conditions using the most inexpensive chiral secondary amine catalyst, proline.1 Both proline and the organic base triethylamine were found to be catalytic in the testing platform of cyclohexen-2-one and phthalimide, and another testing platform of 4-hexen-3-one and phthalimide. Likewise, when screened …


Application Of Term-Rewriting Grammar In Chemical Reaction Prediction, Patra Volarath Apr 2008

Application Of Term-Rewriting Grammar In Chemical Reaction Prediction, Patra Volarath

Chemistry Dissertations

Synthesis planning is a critical process in chemical design. A number of computer programs have been developed to assist the chemists with this procedure. Most of the programs utilize combinations of computational approaches. These have been successfully applied to a number of the synthesis predictions. However, they require numerous rules to screen for potential targets, as well as to keep the system from reaching the combinatorial explosion. This results in the advanced algorithms becoming more complex and parameter-sensitive. This can be problematic, particularly in the cases in which a large number of the compounds are to be handled, because it …


Reactions Of Atomic Carbon With Acid Chlorides, Daniel B. Herrick Jan 2008

Reactions Of Atomic Carbon With Acid Chlorides, Daniel B. Herrick

Honors Theses

This thesis is the first report of reactions of atomic carbon with acid chlorides. Carbon is known to react with phosgene to afford dichlorocarbene. We report a similar reaction with carbon and acid chlorides, generating alkylchlorocarbenes. We examine both the nature of the carbene products generated through deoxygenation and the general reactivity of carbon with the acid chlorides. We report two ways in which carbon reacts with acid chlorides. First, as expected from prior work with phosgene, carbon deoxygenates the carbonyl group yielding alkylchlorcarbenes, which rearrange as expected. Second, carbon abstracts the chlorine, and generates the acyl radical, which, in …


Reactions Of Chlorine Atoms With Aromatic Compounds, Barbara O'Leary Oct 1998

Reactions Of Chlorine Atoms With Aromatic Compounds, Barbara O'Leary

Masters

This thesis presents the results of kinetic studies on the reactions of chlorine atoms with a series of aromatic compounds. (please see full text for complete abstract)


New Syntheses Of Diaryl Ethers, Tyrosinols, B-Hydroxytyrosinols, L,L-Isodityrosinol And L,L-Isodityrosine-Derived Agents Via The Diels-Alder Reaction, Xianqi Feng May 1992

New Syntheses Of Diaryl Ethers, Tyrosinols, B-Hydroxytyrosinols, L,L-Isodityrosinol And L,L-Isodityrosine-Derived Agents Via The Diels-Alder Reaction, Xianqi Feng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Syntheses of diaryl ethers were approached by use of a Diels-Alder reaction employing a new type of diene attached with an aryloxy group. Thus, 2-methyl-3-phenoxybutadiene (90b ), 2- methoxy-3-phenoxybutadiene (92b) and (4S)-3-(t- butyloxycarbony1)-2 ,2-dimethyl-4-( 4-(3-methoxy-1,3 -butadienyl-2- oxy )phenylmethyl]oxazolidine (93b) were synthesized in ~65% yields by methylenation of the carbonyl function in the corresponding 2- substituted acrylate aryl ester using Tebbe's reagent. The 1,3- bis[(trimethylsilyl)oxy ]-2-phenoxybutadiene (105) was made from 1-phenoxy-2-propanone (101) by a sequence of formylation and enolsilylation. Methyl propiolate (107) and dimethyl acetylenedicarboxylate (113) were heated at reflux with diene 9 0 b and 92b in toluene to provide …


The Reaction Of Dimethyl-And Di-N-Butylcopper Lithium With 3-Bromo-2-(2-Phenylacetamido) Acrylic Acid, Kim David Richards May 1975

The Reaction Of Dimethyl-And Di-N-Butylcopper Lithium With 3-Bromo-2-(2-Phenylacetamido) Acrylic Acid, Kim David Richards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reaction of dimethylcopper lithium and di-n-butylcopper lithium with 3-bromo-2-(2-phenylacetamido) acrylic acid, mp 174 - 175°, produced as major products 3-methyl-2-(2-phenylacetamido) acrylic acid and 3-n-butyl-2-(2-phenylacetamido) acrylic acid, respectively. The dimethylcopper lithium reaction was stereospecific for the E geometrical isomer, mp 198 - 199°, and produced 3-methyl-2-(2-phenylacetamido) acrylic acid and 2-(2-phenylacetamido) acrylic acid in a 3:1 molar ratio, respectively. The di-n-butylcopper lithium reaction produced as the main products 3-n-butyl-2-(2-phenylacetamido) acrylic acid and 2-(2- phenylacetamido) acrylic acid in a 7:1 molar ratio, respectively, with the 3-n-butylacrylic acid comprising 83% of the product. The reaction …


The Reaction Of Some Sodium Salts Of Fatty Acids And Benzoic Acid With Α-Bromobenzyl Cyanide, Richard W. Perkins May 1953

The Reaction Of Some Sodium Salts Of Fatty Acids And Benzoic Acid With Α-Bromobenzyl Cyanide, Richard W. Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fife (4) and O'Shaughnessy (12) have made a series of di-esters by allowing the sodium salts of various fatty acids to react with ethyl monochloracetate according to the following equation:

RCO2Na ≠ ClCH2CO2C2H5 ---------> RCO2CH2CO2C2H5 ≠ NaCl .

The mechanism of the reaction appears to be ionic and to involve the attack of an RCO2- ion on the carbon atom to which the chlorine atom is attached. As the RCO2- approaches this carbon atom the chlorine atom moves …