Open Access. Powered by Scholars. Published by Universities.®
- Publication Type
Articles 1 - 14 of 14
Full-Text Articles in Chemistry
Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov
Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov
Michigan Tech Publications
Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed …
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Browse all Theses and Dissertations
One goal of the Turnbull research group has been the synthesis of dihalogenated arylsydnones; i.e. sydnones with halogen substitution on the sydnone ring itself, as well as at the position on the aryl ring ortho to the sydnone. Further, it has been of interest to explore the reactivity of these compounds, once obtained. The present study examined the synthesis of 4-iodo-3-(2-iodoaryl)-, or “diiodo”, and 4-bromo-3-(2-bromoaryl)-, or “dibromo”, sydnones and the reactions of these compounds with Na2SO3 (sodium sulfite) and NaBH4 (sodium borohydride) to create a better understanding of the reactivity of diiodo and dibromo arylsydnones in general. Additionally, the reactivity …
Synthesis And Reactivity Of Sydnone Derived 1,3,4-Oxadiazol-2(3h)-Ones, Jonathan Michael Tumey
Synthesis And Reactivity Of Sydnone Derived 1,3,4-Oxadiazol-2(3h)-Ones, Jonathan Michael Tumey
Browse all Theses and Dissertations
5-(Bromomethyl)- and 5-(trichloromethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-ones were synthesized from bromocarbonyl hydrazine intermediate salts and acid halides to provide further evidence for our proposed mechanism for the formation of oxadiazolone ring systems from sydnones. 5-(Bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was a compound of interest due to its SN2 possibilities and three potential sites of diversification. The procedure to synthesize 5-(bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was developed originally by Madaram in the Turnbull lab, but was further optimized in the present work by altering the time, temperature and stoichiometric equivalents of the acid halide to provide high purity and excellent yields of the product. While this compound of interest had been isolated and …
Toward The Synthesis Of Functionalized Poly (Ether Ether Ketone): Monitoring The Meta-Fluorine Displacement In 3,5,4’-Trifluorobenzophenone, Giovanni Covarrubias
Toward The Synthesis Of Functionalized Poly (Ether Ether Ketone): Monitoring The Meta-Fluorine Displacement In 3,5,4’-Trifluorobenzophenone, Giovanni Covarrubias
Browse all Theses and Dissertations
The synthesis of functionalized, linear poly (ether ether ketone), tailored to be semi-crystalline and soluble in a variety of organic-solvents was explored. Nucleophilic aromatic substitution was a chemical reaction method used to condense 3,5,4’-trifluorobenzophenone (TFK) with four different phenols at its para-positioned carbon-fluorine site: 4-methoxyphenol, 3-aminophenol, 4-bromophenol, and m-cresol. Further poly-condensation of functionalized TFK occurred at the meta-positioned carbon-fluorine sites with 4,4’-Bis[4-hydroxyphenoxy] benzophenone (Big A2) and 4,4’-difluorobenzophenone at molar equivalents of 1 to 0.5, respectively. The reaction afforded products that became insoluble in solvents needed for nuclear magnetic resonance spectroscopic (e.g. DMSO-d6) analysis. The lack of desirable compounds compelled the …
Computational And Experimental Investigations Concerning Rare Gas And Dpal Lasers And A Relaxation Kinetics Investigation Of The Br2 + 2no = 2brno Equilibrium, Joel R. Schmitz
Browse all Theses and Dissertations
This research contains four different research projects, the first an educational project introducing hydrogen bromide and deuterium bromide (HBr/DBr) and carbon monoxide (CO) as viable options for infrared vibration-rotation spectroscopy at 0.125 cm-1 or 0.5 cm-1 resolution in the teaching laboratory. The second project involved determining the spectral shifts of lanthanide fibers for diode-pumped alkali laser (DPAL) applications. Spectral shifts of lanthanides were determined using UV-VIS-NIR absorbance spectroscopy and laser-induced fluorescence (LIF). The third project entailed computing Ar* atomic energy levels and the potential energy curves of Ar*+He laser systems arising from 3p54s1 and 3p …
The Synthesis Of 3,5-Difluorobenzophenone Derivatives And Their Corresponding Peek Copolymers, Rachael Stuck
The Synthesis Of 3,5-Difluorobenzophenone Derivatives And Their Corresponding Peek Copolymers, Rachael Stuck
Browse all Theses and Dissertations
Poly(aryl ether ketone)s (PAEK) are high performance thermoplastics, which are chemically robust, semi-crystalline, and stable at high temperatures. Of the family of PAEKs, poly(ether ether ketone) (PEEK) is a well-known semi-crystalline thermoplastic widely used for electronics, energy, industrial, and medical applications due to its resistance to solvents, radiation, heat, and other environmental factors. The traditional PEEK is prepared from 4,4’-difluorobenzophenone (2) and disodium hydroquinone. However, a challenge is processability, since due to its highly crystalline nature, PEEK possesses very limited solubility. An approach to solve these issues is to pre-functionalize PEEK polymers synthesized by nucleophilic aromatic substitution from 3,5-difluorobenzophenone (1) …
The Synthesis And Characterization Of Double And Triple Tethered Indeno[2.1-C]Fluorendiones, Daniel K. Greene
The Synthesis And Characterization Of Double And Triple Tethered Indeno[2.1-C]Fluorendiones, Daniel K. Greene
Browse all Theses and Dissertations
A series of terephthalate esters was synthesized via a Diels-Alder reaction between 2,5-dicarboethoxy-3,4-diphenylcyclopentadienone and various alkynes in order to study reaction conditions necessary to synthesize poly(indeno[2,1-c]fluorene-5,8-dione)s. Diethyl 2,3-diphenyl-5-butylterephthalate, 1,4-bis(3,4-diphenyl-2,5-di(ethoxycarbonyl) phenyl)butane and N,N,N-tris(3,4-diphenyl-2,5-di(ethoxycarbonyl)phenylmethyl)amine were synthesized and characterized by IR, 1H NMR, 13C NMR, 13C NMR DEPT135 spectroscopies as well as elemental composition. Hydrolysis conditions of the terephthalates using potassium hydroxide were also investigated. It was found that large stoichiometric equivalents of base coupled with reaction times over twenty-four hours afforded only partially hydrolyzed products. The synthesis of 6-butylindeno[2,1-c]fluoren-5,8-dione was successfully carried out by the sulfuric acid catalyzed, intramolecular, Friedel-Crafts cyclization of …
Chemical Applications In Techniques Of Emerging Significance: Nanoparticle Transformation In Mitochondria And Relative Tautomer Populations In Cellular Automata, Gregory Arland Bowers
Chemical Applications In Techniques Of Emerging Significance: Nanoparticle Transformation In Mitochondria And Relative Tautomer Populations In Cellular Automata, Gregory Arland Bowers
Browse all Theses and Dissertations
Two techniques of emerging importance were used to study different biochemical phenomena: the fate of silver nanoparticles in Vero 76 African green monkey kidney cell mitochondria, and the effect of pH on tautomer ratios using cellular automata. In the first area of research Vero 76 Africa green monkey kidney cells were incubated with silver nanoparticles (AgNP) and ionic silver (Ag+). After 24 hours the cell mitochondria were harvested, then processed with CPE-TFF and ICP-OES. The initial AgNP incubation formed 52.9% ± 15.5% AgNP and 29.9% ± 4.0% Ag+, while the ionic silver incubation formed 9.5% ± 0.9% AgNP and 60.6% …
Hydrothermal Atomic Force Microscopy Investigation Of Barite Growth: The Role Of Spectator Ions In Elementary Step Edge Growth Kinetics And Hillock Morphology, Sarah A. Jindra
Browse all Theses and Dissertations
To better understand the role of spectator ions in barite growth, the kinetics of step edge growth on barite (001) surfaces were studied under various salt solutions. Hydrothermal Atomic Force Microscopy (HAFM) was used to investigate the effect of background electrolytes (NaCl, NaBr and NaNO3) as a function of saturation index and ionic strength (I) on barite growth sourced at dislocations at 108 oC. Results show that hillock morphology is affected by I, as well as type of anion, where the prevalence of steps aligned on the [010] direction is highest under Cl- …
Synthesis Of Alkyl Substituted Phenylated Poly(Ether Ether Ketone Ketone)S, Matthew Cerone
Synthesis Of Alkyl Substituted Phenylated Poly(Ether Ether Ketone Ketone)S, Matthew Cerone
Browse all Theses and Dissertations
A phenylated bis(fluorobenzoyl) monomer, 5-hexyl-2,3-diphenyl-1,4-bis(fluorobenzoyl)benzene, was synthesized via a four-step process. The first three compounds synthesized were diethyl 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxylate, 5-hexyl-1,4-bis(hydroxymethyl)-2,3-diphenylbenzene and 5-hexyl-2,3-diphenyl-1,4-benzenedicarboxaldehyde. The final step involved the reaction of the Grignard formed from p-bromofluorobenzene with the dialdehyde to yield a diol intermediate which was oxidized to the bis(fluorobenzoyl) monomer by use of a Jones oxidation. The monomer was polymerized by nucleophilic aromatic substitution (NAS) with bisphenol-A, resorcinol, and hydroquinone in N-methyl-pyrrolidone (NMP) to yield novel, phenylated PEEKKs. The number-average molecular weights (Mn) for the polymers were found to be 35,700 g/mol, 34,800 g/mol and 28,000 g/mol, respectively and the weight-average …
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Synthesis Of 4-Iodo-3-(2-Iodoaryl) And 4-Bromo-3-(2-Bromoaryl) Sydnones And Their Reactions With Sodium Sulfite, Sodium Borohydride, And Iodine Monochloride, Kyle Jacob Liddy
Browse all Theses and Dissertations
One goal of the Turnbull research group has been the synthesis of dihalogenated arylsydnones; i.e. sydnones with halogen substitution on the sydnone ring itself, as well as at the position on the aryl ring ortho to the sydnone. Further, it has been of interest to explore the reactivity of these compounds, once obtained. The present study examined the synthesis of 4-iodo-3-(2-iodoaryl)-, or "diiodo", and 4-bromo-3-(2-bromoaryl)-, or "dibromo", sydnones and the reactions of these compounds with Na2SO3 (sodium sulfite) and NaBH4 (sodium borohydride) to create a better understanding of the reactivity of diiodo and dibromo arylsydnones in general. Additionally, the reactivity …
Incorporation Of Indeno[2,1-C]Fluorenes Into Polymers Via Nucleophilic Aromatic Substitution, Nathaniel Brackett
Incorporation Of Indeno[2,1-C]Fluorenes Into Polymers Via Nucleophilic Aromatic Substitution, Nathaniel Brackett
Browse all Theses and Dissertations
A difluoro indeno[2,1-c]fluorene monomer was synthesized by a four-step process. The first compound synthesized by a two-step process was 2,5- bis(ethoxycarbonyl)-3,4-di(4-fluorophenyl)cyclopentadienone. The next two compounds synthesized were diethyl 2,3-bis(fluorophenyl)-5-hexylterephthalate and 2,3- bis(fluorophenyl)-5-hexylterephthalic acid. The final step involved an intramolecular Friedel-Crafts acylation of the terephthalic acid derivative to form 3,10-difluoro-5,8- dioxo-5,8-dihydro-6-hexylindeno[2,1-c]fluorene. The difluoro monomer was reacted in a series of nucleophilic aromatic substitution (NAS) polymerization reactions with bisphenol-A in N-methyl-pyrrolidone (NMP) in an attempt to form novel poly(ether ether ketone ketone)s containing the indeno[2,1-c]fluorene structure. Analysis of the product by NMR and TLC showed the reaction was unsuccessful and the difluoro …
Hydrothermal Atomic Force Microscopy Investigation Of Barite Growth: The Role Of Spectator Ions In Elementary Step Edge Growth Kinetics And Hillock Morphology, Sarah A. Jindra
Browse all Theses and Dissertations
To better understand the role of spectator ions in barite growth, the kinetics of step edge growth on barite (001) surfaces were studied under various salt solutions. Hydrothermal Atomic Force Microscopy (HAFM) was used to investigate the effect of background electrolytes (NaCl, NaBr and NaNO3) as a function of saturation index and ionic strength (I) on barite growth sourced at dislocations at 108 oC. Results show that hillock morphology is affected by I, as well as type of anion, where the prevalence of steps aligned on the [010] direction is highest under Cl- There is a modest increase in kinetic …
Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Amira Moayad Alsenbel
Investigating Potential Pollutant Sources Causing Lack Of Biodiversity In Lytle Creek And Indian Run, Amira Moayad Alsenbel
Browse all Theses and Dissertations
Limited macroinvertebrate biodiversity in Lytle Creek that runs through downtown Wilmington, Ohio has been documented over decades with the lowest in Lytle Creek at Sugar Grove Cemetery. Lytle Creek, a tributary of the Little Miami River, is a conduit for storm water and wastewater from an airport, downtown storm water with input from local businesses, and a wastewater treatment plant. This study was conducted to see if heavy metal pollution in the sediment, water quality, and Escherichia coli (E. coli) could be contributing factors in reduced macroinvertebrate populations. Eight sites were chosen for sediment sampling to measure trace metals. Mercury …