Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Ionic liquid (3)
- Aldol reaction (2)
- Antibacteria (2)
- Keratin (2)
- Nanodiscs (2)
-
- Resonance Raman (2)
- 2-b]thiophene (1)
- Alkylation (1)
- Allosteric properties (1)
- Androgen Synthesis (1)
- Asymmetric catalysis (1)
- BTEX (1)
- Biocompatible (1)
- Biomimetic (1)
- Branch (1)
- C60 (1)
- CO2 Reduction (1)
- CYP17A1 (1)
- CYP2B4 (1)
- CYP3A4 (1)
- Caboxamide (1)
- Cation radicals (1)
- Cellulose (1)
- Cyclic voltammetry (1)
- Cyclocarbonylation (1)
- Cytochrome P450 (1)
- Cytochrome b5 (1)
- Diene ligands (1)
- Dienyl-iron cations (1)
- Dissociation (1)
- Publication
- Publication Type
Articles 1 - 30 of 41
Full-Text Articles in Physical Sciences and Mathematics
The Effect Of Mo Doping On The Charge Separation Dynamics And Photocurrent Performance Of Bivo4 Photoanodes, Brian Pattengale, Jier Huang
The Effect Of Mo Doping On The Charge Separation Dynamics And Photocurrent Performance Of Bivo4 Photoanodes, Brian Pattengale, Jier Huang
Chemistry Faculty Research and Publications
Doping with electron-rich elements in BiVO4 photoanodes has been demonstrated as a desirable approach for improving their carrier mobility and charge separation efficiency. However, the effect of doping and dopant concentration on the carrier dynamics and photoelectrochemical performance remains unclear. In this work, we examined the effects of Mo doping on the charge separation dynamics and photocurrent performance in BiVO4photoanodes. We show that the photocurrent of BiVO4 photoanodes increases with increasing concentration of the Mo dopant, which can be attributed to both the improved carrier mobility resulting from increased electron density and charge separation efficiency due …
Dihedral-Angle-Controlled Crossover From Static Hole Delocalization To Dynamic Hopping In Biaryl Cation Radicals, Marat R. Talipov, Tushar S. Navale, Mohammad M. Hossain, Ruchi Shukla, Maxim V. Ivanov, Rajendra Rathore
Dihedral-Angle-Controlled Crossover From Static Hole Delocalization To Dynamic Hopping In Biaryl Cation Radicals, Marat R. Talipov, Tushar S. Navale, Mohammad M. Hossain, Ruchi Shukla, Maxim V. Ivanov, Rajendra Rathore
Chemistry Faculty Research and Publications
In cases of coherent charge-transfer mechanism in biaryl compounds the rates follow a squared cosine trend with varying dihedral angle. Herein we demonstrate using a series of biaryl cation radicals with varying dihedral angles that the hole stabilization shows two different regimes where the mechanism of the hole stabilization switches over from (static) delocalization over both aryl rings to (dynamic) hopping. The experimental data and DFT calculations of biaryls with different dihedral angles unequivocally support that a crossover from delocalization to hopping occurs at a unique dihedral angle where the electronic coupling (Hab) is one half of …
Synthesis, X-Ray Structures, Electronic Properties, And O2/No Reactivities Of Thiol Dioxygenase Active-Site Models, Anne A. Fischer, Nuru Stracey, Sergey V. Lindeman, Thomas C. Brunold, Adam T. Fiedler
Synthesis, X-Ray Structures, Electronic Properties, And O2/No Reactivities Of Thiol Dioxygenase Active-Site Models, Anne A. Fischer, Nuru Stracey, Sergey V. Lindeman, Thomas C. Brunold, Adam T. Fiedler
Chemistry Faculty Research and Publications
Mononuclear non-heme iron complexes that serve as structural and functional mimics of the thiol dioxygenases (TDOs), cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO), have been prepared and characterized with crystallographic, spectroscopic, kinetic, and computational methods. The high-spin Fe(II) complexes feature the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP) ligand that replicates the three histidine (3His) triad of the TDO active sites. Further coordination with bidentate l-cysteine ethyl ester (CysOEt) or cysteamine (CysAm) anions yielded five-coordinate (5C) complexes that resemble the substrate-bound forms of CDO and ADO, respectively. Detailed electronic-structure descriptions of the [Fe(Ph2TIP)(LS,N)]BPh4 complexes, where L …
Critical Role Of The Secondary Binding Pocket In Modulating The Enzymatic Activity Of Dusp5 Toward Phosphorylated Erks, Marat R. Talipov, Jaladhi Nayak, Michael Lepley, Robert D. Bongard, Daniel Sem, Ramani Ramchandran, Rajendra Rathore
Critical Role Of The Secondary Binding Pocket In Modulating The Enzymatic Activity Of Dusp5 Toward Phosphorylated Erks, Marat R. Talipov, Jaladhi Nayak, Michael Lepley, Robert D. Bongard, Daniel Sem, Ramani Ramchandran, Rajendra Rathore
Chemistry Faculty Research and Publications
DUSP5 is an inducible nuclear dual-specificity phosphatase that specifically interacts with and deactivates extracellular signal-regulated kinases ERK1 and ERK2, which are responsible for cell proliferation, differentiation, and survival. The phosphatase domain (PD) of DUSP5 has unique structural features absent from other nuclear DUSPs, such as the presence of a secondary anion-binding site in the proximity of the reaction center and a glutamic acid E264 positioned next to the catalytic cysteine C263, as well as a remote intramolecular disulfide linkage. The overall 400 ns molecular dynamics simulations indicate that the secondary binding site of DUSP5 PD acts as an allosteric regulator …
Conformational States Of Cytochrome P450 Oxidoreductase Evaluated By Förster Resonance Energy Transfer Using Ultrafast Transient Absorption Spectroscopy, Elizaveta A. Kovrigina, Brian Pattengale, Chuanwu Xia, Azamat R. Galiakhmetov, Jier Huang, Jung Ja Kim, Evgueni Kovrigin
Conformational States Of Cytochrome P450 Oxidoreductase Evaluated By Förster Resonance Energy Transfer Using Ultrafast Transient Absorption Spectroscopy, Elizaveta A. Kovrigina, Brian Pattengale, Chuanwu Xia, Azamat R. Galiakhmetov, Jier Huang, Jung Ja Kim, Evgueni Kovrigin
Chemistry Faculty Research and Publications
NADPH-cytochrome P450 oxidoreductase (CYPOR) was shown to undergo large conformational rearrangements in its functional cycle. Using a new Förster resonance energy transfer (FRET) approach based on femtosecond transient absorption spectroscopy (TA), we determined the donor–acceptor distance distribution in the reduced and oxidized states of CYPOR. The unmatched time resolution of TA allowed the quantitative assessment of the donor–acceptor FRET, indicating that CYPOR assumes a closed conformation in both reduced and oxidized states in the absence of the redox partner. The described ultrafast TA measurements of FRET with readily available red–infrared fluorescent labels open new opportunities for structural studies in chromophore-rich …
Synthesis, Structure And Antimicrobial Property Of Green Composites From Cellulose, Wool, Hair And Chicken Feather, Chieu D. Tran, Franja Prosenc, Mladen Franko, Gerald Benzi
Synthesis, Structure And Antimicrobial Property Of Green Composites From Cellulose, Wool, Hair And Chicken Feather, Chieu D. Tran, Franja Prosenc, Mladen Franko, Gerald Benzi
Chemistry Faculty Research and Publications
Novel composites between cellulose (CEL) and keratin (KER) from three different sources (wool, hair and chicken feather) were successfully synthesized in a simple one-step process in which butylmethylimidazolium chloride (BMIm+Cl−), an ionic liquid, was used as the sole solvent. The method is green and recyclable because [BMIm+Cl−] used was recovered for reuse. Spectroscopy (FTIR, XRD) and imaging (SEM) results confirm that CEL and KER remain chemically intact and homogeneously distributed in the composites. KER retains some of its secondary structure in the composites. Interestingly, the minor differences in the structure of KER …
An Investigation Of The Requirements For Excimer Formation And Charge Stabilization In Model Pi-Stacked Assemblies, Brandon Uhler
An Investigation Of The Requirements For Excimer Formation And Charge Stabilization In Model Pi-Stacked Assemblies, Brandon Uhler
Dissertations (1934 -)
Formation of -stacked excimers plays an important role in many systems, ranging from biological phenomena and polymer formation and function to photovoltaic devices and organic molecular electronics. In these systems, the geometrical reorganization of the ground state upon photoexcitation is still a subject of debate. In this work, we compare the dynamics of excimer formation and hole (charge) stabilization in fluorene and fluorene-based model systems. We use a variety of gas-phase methods to examine the spectroscopy and dynamics of these systems, including Two-Color Resonant Two-Photon Ionization (2CR2PI), Hole-Burning (HB), Laser Induced Fluorescence (LIF), and Dispersed Fluorescence (DF). In order to …
Evidence That Cytochrome B5 Acts As A Redox Donor In Cyp17a1 Mediated Androgen Synthesis, Ruchia Duggal, Yilin Liu, Michael C. Gregory, Ilia G. Denisov, James R. Kincaid, Stephen G. Sligar
Evidence That Cytochrome B5 Acts As A Redox Donor In Cyp17a1 Mediated Androgen Synthesis, Ruchia Duggal, Yilin Liu, Michael C. Gregory, Ilia G. Denisov, James R. Kincaid, Stephen G. Sligar
Chemistry Faculty Research and Publications
Cytochrome P450 17A1 (CYP17A1) is an important drug target for castration resistant prostate cancer. It is a bi-functional enzyme, catalyzing production of glucocorticoid precursors by hydroxylation of pregnene-nucleus, and androgen biosynthesis by a second C--C lyase step, at the expense of glucocorticoid production. Cytochrome b5(cyt b5) is known to be a key regulator of the androgen synthesis reaction in vivo, by a mechanism that is not well understood. Two hypotheses have been proposed for the mechanism by which cyt b5 increases androgen biosynthesis. Cyt b5 could act as an allosteric effector, binding to …
First Experimental Evidence For The Diverse Requirements Of Excimer Vs Hole Stabilization In Π-Stacked Assemblies, Neil Reilly, Maxim Vadimovich Ivanov, Brandon Uhler, Marat R. Talipov, Rajendra Rathore, Scott Reid
First Experimental Evidence For The Diverse Requirements Of Excimer Vs Hole Stabilization In Π-Stacked Assemblies, Neil Reilly, Maxim Vadimovich Ivanov, Brandon Uhler, Marat R. Talipov, Rajendra Rathore, Scott Reid
Chemistry Faculty Research and Publications
Exciton formation and charge separation and transport are key dynamical events in a variety of functional polymeric materials and biological systems, including DNA. Beyond the necessary cofacial approach of a pair of aromatic molecules at van der Waals contact, the extent of overlap and necessary geometrical reorganization for optimal stabilization of an excimer vs dimer cation radical remain unresolved. Here, we compare experimentally the dynamics of excimer formation (via emission) and charge stabilization (via threshold ionization) of a novel covalently linked, cofacially stacked fluorene dimer (F2) with the unlinked van der Waals dimer of fluorene, that is, (F)2. …
Two's Company, Three's A Crowd: Exciton Localization In Cofacially Arrayed Polyfluorenes, Marat R. Talipov, Maxim Vadimovich Ivanov, Scott Reid, Rajendra Rathore
Two's Company, Three's A Crowd: Exciton Localization In Cofacially Arrayed Polyfluorenes, Marat R. Talipov, Maxim Vadimovich Ivanov, Scott Reid, Rajendra Rathore
Chemistry Faculty Research and Publications
Understanding the mechanisms of long-range energy transfer through polychromophoric assemblies is critically important in photovoltaics and biochemical systems. Using a set of cofacially arrayed polyfluorenes (Fn), we investigate the mechanism of (singlet) exciton delocalization in π-stacked polychromophoric assemblies. Calculations reveal that effective stabilization of an excimeric state requires an ideal sandwich-like arrangement; yet surprisingly, emission spectroscopy indicates that exciton delocalization is limited to only two fluorene units for all n. Herein, we show that delocalization is determined by the interplay between the energetic gain from delocalization, which quickly saturates beyond two units in larger Fn, …
Analysis Of Heme Iron Coordination In Dgcr8: The Heme-Binding Component Of The Microprocessor Complex, Hazel M. Girvan, Justin M. Bradley, Myles R. Cheesman, James R. Kincaid, Yilin Liu, Kazimierz Czarnecki, Karl Fisher, David Leys, Stephen E. J. Rigby, Andrew W. Munro
Analysis Of Heme Iron Coordination In Dgcr8: The Heme-Binding Component Of The Microprocessor Complex, Hazel M. Girvan, Justin M. Bradley, Myles R. Cheesman, James R. Kincaid, Yilin Liu, Kazimierz Czarnecki, Karl Fisher, David Leys, Stephen E. J. Rigby, Andrew W. Munro
Chemistry Faculty Research and Publications
DGCR8 is the RNA-binding partner of the nuclease Drosha. Their complex (the “Microprocessor”) is essential for processing of long, primary microRNAs (pri-miRNAs) in the nucleus. Binding of heme to DGCR8 is essential for pri-miRNA processing. On the basis of the split Soret ultraviolet–visible (UV–vis) spectrum of ferric DGCR8, bis-thiolate sulfur (cysteinate, Cys–) heme iron coordination of DGCR8 heme iron was proposed. We have characterized DGCR8 heme ligation using the Δ276 DGCR8 variant and combined electron paramagnetic resonance (EPR), magnetic circular dichroism (MCD), electron nuclear double resonance, resonance Raman, and electronic absorption spectroscopy. These studies indicate DGCR8 bis-Cys heme …
Efficient Method For Calculations Of Ro-Vibrational States In Triatomic Molecules Near Dissociation Threshold: Application To Ozone, Alexander Teplukhin, Dmitri Babikov
Efficient Method For Calculations Of Ro-Vibrational States In Triatomic Molecules Near Dissociation Threshold: Application To Ozone, Alexander Teplukhin, Dmitri Babikov
Chemistry Faculty Research and Publications
A method for calculations of rotational-vibrational states of triatomic molecules up to dissociation threshold (and scattering resonances above it) is devised, that combines hyper-spherical coordinates, sequential diagonalization-truncation procedure, optimized grid DVR, and complex absorbing potential. Efficiency and accuracy of the method and new code are tested by computing the spectrum of ozone up to dissociation threshold, using two different potential energy surfaces. In both cases good agreement with results of previous studies is obtained for the lower energy states localized in the deep (∼10 000 cm−1) covalent well. Upper part of the bound state spectrum, within 600 cm−1 below dissociation …
Multifunctional Heterocyclic Scaffolds For Hybrid Lewis Acid/Lewis Base Catalysis Of Carbon–Carbon Bond Formation, Dennis Wiedenhoeft, Adam R. Benoit, Yibiao Wu, Jacob D. Porter, Elisia Meyle, Teresa H.W. Yeung, Raechel Huff, Sergey Lindeman, Chris Dockendorff
Multifunctional Heterocyclic Scaffolds For Hybrid Lewis Acid/Lewis Base Catalysis Of Carbon–Carbon Bond Formation, Dennis Wiedenhoeft, Adam R. Benoit, Yibiao Wu, Jacob D. Porter, Elisia Meyle, Teresa H.W. Yeung, Raechel Huff, Sergey Lindeman, Chris Dockendorff
Chemistry Faculty Research and Publications
No abstract provided.
Resonance Raman Studies Of Oxygenated Forms Of Myoglobin And Cyp2b4 And Their Mutants, Ying Wang
Resonance Raman Studies Of Oxygenated Forms Of Myoglobin And Cyp2b4 And Their Mutants, Ying Wang
Dissertations (1934 -)
Important oxidative heme enzymes use hydrogen peroxide or activate molecular oxygen to generate highly reactive peroxo-, hydroperoxo- and feryl intermediates resulting from heterolytic O-O bond cleavage. Members of the cytochrome P450 superfamily catalyze difficult chemical transformations, including hydroxylations and C-C bond cleavage reactions. In mammals, these enzymes function to reliably produce important steroids with the required high degree of structural precision. On the other hand, certain other mammalian P450s serve a different role, efficiently metabolizing xenobiotics, including pharmaceuticals and environmental pollutants. Though so important, the precise mechanisms involved in such transformations are incompletely understood, because of difficulties in structurally characterizing …
Probing The Effects Of Nano-Domains On The Redox Products In Molecular Solvents-Rtils Mixtures, Abderrahman Atifi
Probing The Effects Of Nano-Domains On The Redox Products In Molecular Solvents-Rtils Mixtures, Abderrahman Atifi
Dissertations (1934 -)
Room temperature ionic liquids (RTIL) have been very attractive as replacements for molecular solvents (MS) in many areas in chemistry. The use of the RTIL in mixture with MS as reaction media will reduce the cost and viscosity of RTILs. The formation of RTIL nano-domains (nano-structures) in the mixture may lead to partitioning of solutes between the MS and the RTIL phase, where the properties and reactivity would be more like those in pure ionic liquids. In the present work, analytical approaches have been employed to probe the presence and effects of RTIL nano-domains on redox processes in the mixture. …
Supramolecular Assembly Of Metal-Organic Tubes Constructed From The Ditopic Heteroscorpionate Ligand (4-Nh2C6H4)Chpz2 (Pz = Pyrazol-1-Yl) And Silver(I), James R. Gardinier, Jeewantha S. Hewage, Justin Hoffman, Sergey V. Lindeman, Natalia B. Shustova
Supramolecular Assembly Of Metal-Organic Tubes Constructed From The Ditopic Heteroscorpionate Ligand (4-Nh2C6H4)Chpz2 (Pz = Pyrazol-1-Yl) And Silver(I), James R. Gardinier, Jeewantha S. Hewage, Justin Hoffman, Sergey V. Lindeman, Natalia B. Shustova
Chemistry Faculty Research and Publications
The possibility of constructing tubular metal-organic structures with aid of weak hydrogen-bonding interactions between suitably designed metallacycles was explored. For this purpose, the new heteroditopic ligand (4-NH2C6H4)CHpz2 (L1) was prepared in good (75 %) yield by a one-pot procedure starting from commercial 4-acetamidobenzaldehyde. The equimolar reactions between L1 and various silver(I) salts gave the intended 1:1 complexes in which the metallacycles were assembled into tubes. However, the exact nature of the assemblies (including their solvate compositions) varied depending on anion, solvent, and concentration of the original crystallization solution. For the trifluoromethanesulfonate anion, a …
Mononuclear Iron-(Hydro/Semi)Quinonate Complexes Featuring Neutral And Charged Scorpionates: Synthetic Models Of Intermediates In The Hydroquinone Dioxygenase Mechanism, Amanda E. Baum, Sergey V. Lindeman, Adam T. Fiedler
Mononuclear Iron-(Hydro/Semi)Quinonate Complexes Featuring Neutral And Charged Scorpionates: Synthetic Models Of Intermediates In The Hydroquinone Dioxygenase Mechanism, Amanda E. Baum, Sergey V. Lindeman, Adam T. Fiedler
Chemistry Faculty Research and Publications
Neutral and anionic scorpionate ligands have been employed to generate active-site models of hydroquinone dioxygenases (HQDOs). While the nonheme Fe center in nearly all HQDOs is coordinated to one Asp (or Glu) and two His residues, 1,2-gentisate dioxygenase (GDO) is unique in featuring a three His triad instead. A synthetic GDO model was therefore prepared with the neutral tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP) ligand. The gentisate substrate was mimicked with the bidentate ligand 2-(1-methylbenzimidazol-2-yl)hydroquinonate (BIHQ). X-ray diffraction analysis of the resulting complex, [Fe(Ph2TIP)(BIHQ)]OTf (1a), revealed a distorted square-pyramidal geometry. Structural and electrochemical data collected for 1a were compared to …
The Use Of Isomeric Testosterone Dimers To Explore Allosteric Effects In Substrate Binding To Cytochrome P450 Cyp3a4, Ilia G. Denisov, Piotr J. Mak, Yelena V. Grinkova, Dominic Bastien, Gervais Bérubé, Stephen G. Sligar, James R. Kincaid
The Use Of Isomeric Testosterone Dimers To Explore Allosteric Effects In Substrate Binding To Cytochrome P450 Cyp3a4, Ilia G. Denisov, Piotr J. Mak, Yelena V. Grinkova, Dominic Bastien, Gervais Bérubé, Stephen G. Sligar, James R. Kincaid
Chemistry Faculty Research and Publications
Abstract: Cytochrome P450 CYP3A4 is the main drug-metabolizing enzyme in the human liver, being responsible for oxidation of 50% of all pharmaceuticals metabolized by human P450 enzymes. Possessing a large substrate binding pocket, it can simultaneously bind several substrate molecules and often exhibits a complex pattern of drug–drug interactions. In order to better understand structural and functional aspects of binding of multiple substrate molecules to CYP3A4 we used resonance Raman and UV–VIS spectroscopy to document the effects of binding of synthetic testosterone dimers of different configurations, cis-TST2 and trans-TST2. We directly demonstrate that the binding …
Development Of New Ligand Scaffolds For The Preparation Of Heterobimetallic Complexes, Alexander Richard Treleven
Development Of New Ligand Scaffolds For The Preparation Of Heterobimetallic Complexes, Alexander Richard Treleven
Master's Theses (2009 -)
There is currently much interest in the development of methods to harness sustainable, CO2 neutral, non-fossil fuel based energy sources due to diminishing worldwide supply of fossil fuels and concerns over historically high levels of CO2 in the atmosphere, which may have a devastating impact on the world’s climate. One such avenue is through the conversion of atmospheric CO2 into useful, high-energy density, organic fuel sources. Photosynthesis is the biological process by which plants convert sunlight, water, and CO2 into the reduced organic materials that we extract from the earth and burn (completing the cycle back to CO2) to release …
Photochemical Electrocyclic Ring Closure And Elimination Reactions Of N-(Oxothioxanthenyl)Naphthothiophene Carboxamides, Himali Devika Jayasekara
Photochemical Electrocyclic Ring Closure And Elimination Reactions Of N-(Oxothioxanthenyl)Naphthothiophene Carboxamides, Himali Devika Jayasekara
Dissertations (1934 -)
Photochemical cleavage reactions have found a widespread used in biological applications that require the photorelease of biologically active molecules such as proteins, peptides, neurotransmitters, and nucleotide phosphates. This research focuses on the design of photoremovable protecting groups which can be utilized to release these biomolecules by photolysis. These biomolecules are attached to the photoremovable protecting group at the sites of functional groups that are present within these substrates. Such functional groups are carboxylates, phosphates, thiolates, or phenolates, which upon exposure to light, are released as anions of varying basicities. The photochemical reaction involved is an electrocyclic ring closure between aromatic …
Novel Numerical Models Of Electrostatic Interactions And Their Application To S-Nitrosothiol Simulations, Maxim Vadimovich Ivanov
Novel Numerical Models Of Electrostatic Interactions And Their Application To S-Nitrosothiol Simulations, Maxim Vadimovich Ivanov
Dissertations (1934 -)
Atom-centered point charge model of the molecular electrostatics remains a major workhorse in the atomistic biomolecular simulations. However, this approximation fails to reproduce anisotropic features of the molecular electrostatic potential (MEP), and the existing methods of the charge derivation are often associated with the numerical instabilities. This work provides an in-depth analysis of these limitations and offers a novel approach to describe electrostatic interactions that paves the way toward efficient next-generation force fields. By analyzing the charge fitting problem from first principles, as an example of the mathematical inverse problem, we show that the numerical instabilities of the charge-fitting problem …
Synthesis And Characterization Of Biologically Relevant Fe(Ii) Complexes Containing Redox-Active (Hydro)Quinone Ligands, Amanda Elizabeth Baum
Synthesis And Characterization Of Biologically Relevant Fe(Ii) Complexes Containing Redox-Active (Hydro)Quinone Ligands, Amanda Elizabeth Baum
Dissertations (1934 -)
Redox-active p-(hydro)quinones work in concert with transition-metal centers to facilitate electron transfers in numerous biological contexts. While p-(hydro)quinones are known to interact with both heme and nonheme iron cofactors, the nonheme systems are particularly relevant to photosynthetic and bioremediation processes. In photosynthesis, two p-quinones facilitate an electron transfer away from the photoexcited P680 cofactor via a non-heme Fe(II) center. Based on EPR results, this interaction results in formation of transient Fe(II)/p-semiquinone (pSQ) species. In addition, a superoxo-iron(II)-pSQ species has been proposed as an intermediate of the oxidative cleavage mechanism of hydroquinone dioxygenases (HQDOs), which play a central role in the …
Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C-C And C-O Bond Activation Reactions, Junghwa Kim
Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C-C And C-O Bond Activation Reactions, Junghwa Kim
Dissertations (1934 -)
Etherification of alcohols is one of the most fundamental transformations in organic synthesis. Williamson ether synthesis is the most well-known synthetic method of unsymmetrical ether synthesis which is still being used in both industrial and academic laboratories. We have developed a novel catalytic etherification reaction using two different alcohols by using a well-defined cationic ruthenium catalyst. The reaction scope as well as the mechanistic study of the reaction are described.Hydroacylation is considered to be a powerful synthetic transformation for producing functionalized ketones from relatively simple olefin substrates. Despite remarkable progress in intra and intermolecular hydroacylations, the substrate scope of the …
Investigation Of The Use Of A Plasticizer-Polymer Sensor Coating With Improved Long-Term Stability In The Liquid Phase, Laura Jeanne Alderson
Investigation Of The Use Of A Plasticizer-Polymer Sensor Coating With Improved Long-Term Stability In The Liquid Phase, Laura Jeanne Alderson
Master's Theses (2009 -)
Benzene is one of the volatile organic compounds present in crude oil and gasoline. Leakage from underground storage tanks or hazardous waste sites can introduce benzene contamination into nearby groundwater. Benzene is a known carcinogen and its exposure is limited by the Environmental Protection Agency to 5 parts per billion (ppb) in drinking water. Early, accurate detection of the presence of benzene contamination in groundwater supplies is extremely important. Shear horizontal surface acoustic wave (SH-SAW) devices with a chemically sensitive coating can be used for the detection of volatile organic compounds in liquid, such as BTEX (benzene, toluene, ethylbenzene and …
Fluorescence Of Supported Phospholipid Bilayers Recorded In A Conventional Horizontal-Beam Spectrofluorometer, Elizaveta A. Kovrigina, Evgeni L. Kovrigin
Fluorescence Of Supported Phospholipid Bilayers Recorded In A Conventional Horizontal-Beam Spectrofluorometer, Elizaveta A. Kovrigina, Evgeni L. Kovrigin
Chemistry Faculty Research and Publications
Supported phospholipid bilayers are a convenient model of cellular membranes in studies of membrane biophysics and protein-lipid interactions. Traditionally, supported lipid bilayers are formed on a flat surface of a glass slide to be observed through fluorescence microscopes. This paper describes a method to enable fluorescence detection from the supported lipid bilayers using standard horizontal-beam spectrofluorometers instead of the microscopes. In the proposed approach, the supported lipid bilayers are formed on the inner optical surfaces of the standard fluorescence microcell. To enable observation of the bilayer absorbed on the cell wall, the microcell is placed in a standard fluorometer cell …
Influence Of Rtil Nanodomains On The Voltammetry And Spectroelectrochemistry Of Fullerene C60 In Benzonitrile/Room Temperature Ionic Liquids Mixtures, Abderrahman Atifi, Michael D. Ryan
Influence Of Rtil Nanodomains On The Voltammetry And Spectroelectrochemistry Of Fullerene C60 In Benzonitrile/Room Temperature Ionic Liquids Mixtures, Abderrahman Atifi, Michael D. Ryan
Chemistry Faculty Research and Publications
The cyclic voltammetry of fullerene C60 was examined in mixed benzonitrile/RTIL solvents in order to probe the effect of nanodomains in the mixed RTIL/benzonitrile solutions and their effect upon the voltammetry. In probing the interactions of the fullerides (up to C603−) with RTILs, BMIm+ (1-butyl-3-methylimidazolium, mostly planar) and tetraalkylammonium (more spherical/flexible) salts were used. In order to investigate these shifts in more detail, the ΔE12° (=E°1–E°2) and ΔE23° (=E°2–E°3) values, which were independent of the reference potential, were used. At higher concentrations of …
Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations With Phosphonate Stabilized Nucleophiles: Application To The Synthesis Of Oxygenated Metabolites Of Carvone, Do W. Lee, Charles Felix Manful, Jayapal Reddy Gone, Yuzhi Ma, William Donaldson
Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations With Phosphonate Stabilized Nucleophiles: Application To The Synthesis Of Oxygenated Metabolites Of Carvone, Do W. Lee, Charles Felix Manful, Jayapal Reddy Gone, Yuzhi Ma, William Donaldson
Chemistry Faculty Research and Publications
The addition of phosphonate stabilized carbon nucleophiles to acyclic (pentadienyl)iron(1+) cations proceeds predominantly at an internal carbon to afford (pentenediyl)iron complexes. Those complexes bearing an electron withdrawing group at the σ-bound carbon (i.e., 13/14) are stable and isolable, while complexes which do not contain an electron withdrawing group at the σ-bound carbon undergo CO insertion, reductive elimination and conjugation of the double bond to afford cyclohexenone products (21/22). Deprotonation of the phosphonate 13/14 or 21 and reaction with paraformaldehyde affords the olefinated products. This methodology was utilized to prepare oxygenated carvone metabolites (±)-25 and (±)-26.
Recent Advances In Development And Applications Of The Mixed Quantum/Classical Theory For Inelastic Scattering, Dmitri Babikov, Alexander Semenov
Recent Advances In Development And Applications Of The Mixed Quantum/Classical Theory For Inelastic Scattering, Dmitri Babikov, Alexander Semenov
Chemistry Faculty Research and Publications
A mixed quantum/classical approach to inelastic scattering (MQCT) is developed in which the relative motion of two collision partners is treated classically, and the rotational and vibrational motion of each molecule is treated quantum mechanically. The cases of molecule + atom and molecule + molecule are considered including diatomics, symmetric-top rotors, and asymmetric-top rotor molecules. Phase information is taken into consideration, permitting calculations of elastic and inelastic, total and differential cross sections for excitation and quenching. The method is numerically efficient and intrinsically parallel. The scaling law of MQCT is favorable, which enables calculations at high collision energies and for …
One-Pot Synthesis Of Biocompatible Silver Nanoparticle Composites From Cellulose And Keratin: Characterization And Antimicrobial Activity, Chieu D. Tran, Franja Prosenc, Mladen Franko, Gerald Benzi
One-Pot Synthesis Of Biocompatible Silver Nanoparticle Composites From Cellulose And Keratin: Characterization And Antimicrobial Activity, Chieu D. Tran, Franja Prosenc, Mladen Franko, Gerald Benzi
Chemistry Faculty Research and Publications
A novel, simple method was developed to synthesize biocompatible composites containing 50% cellulose (CEL) and 50% keratin (KER) and silver in the form of either ionic (Ag+) or Ag0 nanoparticles (Ag+NPs or Ag0NPs). In this method, butylmethylimmidazolium chloride ([BMIm+Cl–]), a simple ionic liquid, was used as the sole solvent and silver chloride was added to the [BMIm+Cl–] solution of [CEL+KER] during the dissolution process. The silver in the composites can be maintained as ionic silver (Ag+) or completely converted to metallic silver (Ag …
Accessing Spin-Crossover Behaviour In Iron(Ii) Complexes Of N-Confused Scorpionate Ligands, James R. Gardinier, Alexander Richard Treleven, Kristin J. Meise, Sergey Lindeman
Accessing Spin-Crossover Behaviour In Iron(Ii) Complexes Of N-Confused Scorpionate Ligands, James R. Gardinier, Alexander Richard Treleven, Kristin J. Meise, Sergey Lindeman
Chemistry Faculty Research and Publications
The first examples of a class of N-confused tris(pyrazolyl)methane ‘scorpionate’ ligands have been prepared. The magnetic properties of their iron(II) tetrafluoroborate complexes are dictated by changing one substituent per ligand rather than three as is typical for normal scorpionate ligands.