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2015

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Chemistry Faculty Publications

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Articles 1 - 30 of 75

Full-Text Articles in Physical Sciences and Mathematics

Optical-Optical Double Resonance, Laser Induced Fluorescence, And Revision Of The Signs Of The Spin-Spin Constants Of The Boron Carbide (Bc) Free Radical, Fumie X. Sunahori, Ramya Nagarajan, Dennis J. Clouthier Dec 2015

Optical-Optical Double Resonance, Laser Induced Fluorescence, And Revision Of The Signs Of The Spin-Spin Constants Of The Boron Carbide (Bc) Free Radical, Fumie X. Sunahori, Ramya Nagarajan, Dennis J. Clouthier

Chemistry Faculty Publications

The cold boroncarbide free radical (BC X  4Σ−) has been produced in a pulsed discharge free jet expansion using a precursor mixture of trimethylborane in high pressure argon. High resolution laser induced fluorescencespectra have been obtained for the B  4Σ−–X  4Σ− and E  4Π–X  4Σ− band systems of both 11BC and 10BC. An optical-optical double resonance (OODR) scheme was implemented to study the finer details of both band systems. This involved pumping a single rotational level of the B state with one laser and then …

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Crystal Structure Of (E)-13-(Pyrimidin-5-Yl)Parthenolide, Shobanbabu Bommagani, Narsimha Reddy Penthala, Sean Parkin, Peter A. Crooks Dec 2015

Crystal Structure Of (E)-13-(Pyrimidin-5-Yl)Parthenolide, Shobanbabu Bommagani, Narsimha Reddy Penthala, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compound, C19H22N2O3, {systematic name (1aR,4E,7aS,8E,10aS,10bR)-1a,5-dimethyl-8-[(pyrimidin-5-yl)­methylid­ene]-2,3,6,7,7a,8,10a,10b-octa­hydro­oxireno[2′,3′:9,10]cyclo­deca­[1,2-b]furan-9(1aH)-one} was obtained from the reaction of parthenolide [systematic name (1aR,7aS,10aS,10bR,E)-1a,5-dimethyl-8-methyl­ene-2,3,6,7,7a,8,10a,10b-octa­hydro­oxireno[2′,3′:9,10]cyclodeca­[1,2-b]furan-9(1aH)-one] with 5-bromo­pyrimidine under Heck reaction conditions, and was identified as an E isomer. The mol­ecule possesses ten-, five- (lactone) and three-membered (epoxide) rings with a pyrimidine group as a substituent. The ten-membered ring displays an approximate chair–chair conformation, while the lactone ring shows a flattened …

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Benz[C,D]Indolium-Containing Monomethine Cyanine Dyes: Synthesis And Photophysical Properties, Eduardo Soriano, Cory Holder, Andrew R. Levitz, Maged Henary Dec 2015

Benz[C,D]Indolium-Containing Monomethine Cyanine Dyes: Synthesis And Photophysical Properties, Eduardo Soriano, Cory Holder, Andrew R. Levitz, Maged Henary

Chemistry Faculty Publications

Asymmetric monomethine cyanines have been extensively used as probes for nucleic acids among other biological systems. Herein we report the synthesis of seven monomethine cyanine dyes that have been successfully prepared with various heterocyclic moieties such as quinoline, benzoxazole, benzothiazole, dimethyl indole, and benz[e]indole adjoining benz[c,d]indol-1-ium, which was found to directly influence their optical and energy profiles. In this study the optical properties vs. structural changes were investigated using nuclear magnetic resonance and computational approaches. The twisted conformation unique to monomethine cyanines was exploited in DNA binding studies where the newly designed sensor displayed an increase in fluorescence when bound …

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Solution-Printed Organic Semiconductor Blends Exhibiting Transport Properties On Par With Single Crystals, Muhammad R. Niazi, Ruipeng Li, Er Qiang Li, Ahmad R. Kirmani, Maged Abdelsamie, Qingxiao Wang, Wenyang Pan, Marcia M. Payne, John E. Anthony, Detlef-M. Smilgies, Sigurdur T. Thoroddsen, Emmanuel P. Giannelis, Aram Amassian Nov 2015

Solution-Printed Organic Semiconductor Blends Exhibiting Transport Properties On Par With Single Crystals, Muhammad R. Niazi, Ruipeng Li, Er Qiang Li, Ahmad R. Kirmani, Maged Abdelsamie, Qingxiao Wang, Wenyang Pan, Marcia M. Payne, John E. Anthony, Detlef-M. Smilgies, Sigurdur T. Thoroddsen, Emmanuel P. Giannelis, Aram Amassian

Chemistry Faculty Publications

Solution-printed organic semiconductors have emerged in recent years as promising contenders for roll-to-roll manufacturing of electronic and optoelectronic circuits. The stringent performance requirements for organic thin-film transistors (OTFTs) in terms of carrier mobility, switching speed, turn-on voltage and uniformity over large areas require performance currently achieved by organic single-crystal devices, but these suffer from scale-up challenges. Here we present a new method based on blade coating of a blend of conjugated small molecules and amorphous insulating polymers to produce OTFTs with consistently excellent performance characteristics (carrier mobility as high as 6.7 cm2V−1s−1, low threshold …

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The Nicotine Metabolite, Cotinine, Alters The Assembly And Trafficking Of A Subset Of Nicotinic Acetylcholine Receptors, Ashley M. Fox, Faruk H. Moonschi, Christopher I. Richards Oct 2015

The Nicotine Metabolite, Cotinine, Alters The Assembly And Trafficking Of A Subset Of Nicotinic Acetylcholine Receptors, Ashley M. Fox, Faruk H. Moonschi, Christopher I. Richards

Chemistry Faculty Publications

Exposure to nicotine alters the trafficking and assembly of nicotinic receptors (nAChRs), leading to their up-regulation on the plasma membrane. Although the mechanism is not fully understood, nicotine-induced up-regulation is believed to contribute to nicotine addiction. The effect of cotinine, the primary metabolite of nicotine, on nAChR trafficking and assembly has not been extensively investigated. We utilize a pH-sensitive variant of GFP, super ecliptic pHluorin, to differentiate between intracellular nAChRs and those expressed on the plasma membrane to quantify changes resulting from cotinine and nicotine exposure. Similar to nicotine, exposure to cotinine increases the number of α4β2 receptors on the …

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Comparison Of The Crystal Structures Of 4,4′-Bis­­[3-(4-Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Bi­Phenyl And 4,4′-Bis­­[3-(2,2,6,6-Tetra­Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Biphen­Yl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks Oct 2015

Comparison Of The Crystal Structures Of 4,4′-Bis­­[3-(4-Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Bi­Phenyl And 4,4′-Bis­­[3-(2,2,6,6-Tetra­Methyl­Piperidin-1-Yl)Prop-1-Yn-1-Yl]-1,1′-Biphen­Yl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

As part of a comprehensive program to discover α9α10 nicotinic acetyl­choline receptor antagonists, the title compounds C30H36N2, (I), and C36H48N2, (II), were synthesized by coupling 4,4′-bis­(3-bromo­prop-1-yn-1-yl)-1,1′-biphenyl with 4-methyl­piperidine and 2,2,6,6-tetra­methyl­piperidine, respectively, in aceto­nitrile at room temperature. In compound (I), the biphenyl system has a twisted conformation with a dihedral angle of 26.57 (6)° between the two phenyl rings of the biphenyl moiety, while in compound (II), the biphenyl moiety sits on a crystallographic inversion centre so the two phenyl rings are exactly coplanar. The terminal piperidine rings in …

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Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks Oct 2015

Comparison Crystal Structure Conformations Of Two Structurally Related Biphenyl Analogues: 4,4'-Bis[3-(Pyrrolidin-1-Yl)Prop-1-Yn-1-Yl]-1,1'-Biphenyl And 4,4'-Bis{3-[(S)-2-Methylpyrrolidin-1-Yl]Prop-1-Yn-1-Yl}-1,1'-Biphenyl, Anqi Wan, Narsimha Reddy Penthala, E. Kim Fifer, Sean Parkin, Peter A. Crooks

Chemistry Faculty Publications

The title compounds, C26H28N2, (I), and C28H32N2, (II), were designed based on the structure of the potent 910 nicotinic acetyl­choline receptor antagonist ZZ161C {1,1'-[[1,1'-biphen­yl]-4,4'-diylbis(prop-2-yne-3,1-di­yl)]bis­(3,4-di­methyl­pyridin-1-ium) bromide}. In order to improve the druglikeness properties of ZZ161C for potential oral administration, the title compounds (I) and (II) were prepared by coupling 4,4'-bis­(3-bromo­prop-1-yn-1-yl)-1,1'-biphenyl with pyrrol­idine, (I), and (S)-2-methyl­pyrrolidine, (II), respectively, in aceto­nitrile at room temperature. The asymmetric unit of (I) contains two half mol­ecules that each sit on sites of crystallographic inversion. As a result, the biphenyl ring systems in …

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Multi-Dimensional Glycan Microarrays With Glyco-Macroligands, Satya Nandana Narla, Huan Nie, Yu Li, Xue-Long Sun Oct 2015

Multi-Dimensional Glycan Microarrays With Glyco-Macroligands, Satya Nandana Narla, Huan Nie, Yu Li, Xue-Long Sun

Chemistry Faculty Publications

Glycan microarray has become a powerful high-throughput tool for examining binding interactions of carbohydrates with the carbohydrate binding biomolecules like proteins, enzymes, antibodies etc. It has shown great potential for biomedical research and applications, such as antibody detection and profiling, vaccine development, biomarker discovery, and drug screening. Most glycan microarrays were made with monovalent glycans immobilized directly onto the array surface via either covalent or non-covalent bond, which afford a multivalent glycans in two dimensional (2D) displaying. A variety of glyco-macroligands have been developed to mimic multivalent carbohydrate-protein interactions for studying carbohydrate-protein interactions and biomedical research and applications. Recently, a …

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Stochastic Optical Reconstruction Microscopy Imaging Of Microtubule Arrays In Intact Arabidopsis Thaliana Seedling Roots, Bin Dong, Xiaochen Yang, Shaobin Zhu, Diane C. Bassham, Ning Fang Oct 2015

Stochastic Optical Reconstruction Microscopy Imaging Of Microtubule Arrays In Intact Arabidopsis Thaliana Seedling Roots, Bin Dong, Xiaochen Yang, Shaobin Zhu, Diane C. Bassham, Ning Fang

Chemistry Faculty Publications

Super-resolution fluorescence microscopy has generated tremendous success in revealing detailed subcellular structures in animal cells. However, its application to plant cell biology remains extremely limited due to numerous technical challenges, including the generally high fluorescence background of plant cells and the presence of the cell wall. In the current study, stochastic optical reconstruction microscopy (STORM) imaging of intact Arabidopsis thaliana seedling roots with a spatial resolution of 20–40 nm was demonstrated. Using the super-resolution images, the spatial organization of cortical microtubules in different parts of a whole Arabidopsis root tip was analyzed quantitatively, and the results show the dramatic differences …

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Electron Transfer During Metal-Assisted And Stain Etching Of Silicon, Kurt W. Kolasinski Oct 2015

Electron Transfer During Metal-Assisted And Stain Etching Of Silicon, Kurt W. Kolasinski

Chemistry Faculty Publications

The etching of silicon in fluoride solutions is limited by the kinetics of charge transfer not thermodynamics. This characteristic is what gives fluoride etching its great versatility in making different types of nanostructures as the result of self-limiting chemistry. This review approaches the kinetics of electron transfer from silicon and metal coated silicon to a solution phase species from a fundamental point of view in order to establish a better understanding of the mechanisms of nanostructure formation during metal assisted and stain etching of silicon. Band bending calculations demonstrate that diffusion of holes away from low work function metals such …

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Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman Sep 2015

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10–6 occurs for …

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Effects Of Interferons And Double-Stranded Rna On Human Prostate Cancer Cell Apoptosis, Haiyan Tan, Chun Zeng, Junbo Xie, Norah J. Alghamdi, Ya Song, Hongbing Zhang, Aimin Zhou, Di Jin Sep 2015

Effects Of Interferons And Double-Stranded Rna On Human Prostate Cancer Cell Apoptosis, Haiyan Tan, Chun Zeng, Junbo Xie, Norah J. Alghamdi, Ya Song, Hongbing Zhang, Aimin Zhou, Di Jin

Chemistry Faculty Publications

Prostate cancer is the second most commonly diagnosed cancer among men in the United States. Prostate cancer therapy is severely hampered by lack of response and development of resistance to conventional chemotherapeutic drugs in patients. Therefore, the development and discovery of new drugs have become an urgent clinical need. Interferons (IFNs), a family of pleiotropic cytokines, exert antitumor activities due to their anti-proliferative, immunomodulatory and proapoptotic functions. Here, we report that pretreatment of prostate cancer PC-3 cells with IFNs sensitized these cells to double-stranded RNAs (dsRNAs)-induced apoptosis. The enhancement effect of IFN treatment was dependent on IFN subtypes, in particular, …

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Localization Length Scales Of Triplet Excitons In Singlet Fission Materials, Sam L. Bayliss, Karl J. Thorley, John E. Anthony, Hélène Bouchiat, Neil C. Greenham, Alexei D. Chepelianskii Sep 2015

Localization Length Scales Of Triplet Excitons In Singlet Fission Materials, Sam L. Bayliss, Karl J. Thorley, John E. Anthony, Hélène Bouchiat, Neil C. Greenham, Alexei D. Chepelianskii

Chemistry Faculty Publications

We measure the dielectric confinement length scales of triplet excitons in organic semiconductors by jointly measuring their microwave-domain electric and magnetic susceptibilities. We apply this technique to characterize triplet excitons in two singlet fission materials with distinct solid-state packing and correlate the extracted localization length scales with the role of the excitonic environment. By using the magnetic susceptibility simultaneously determined through our experiments, we compare the independently extracted dielectric and spin-spin localization length scales, highlighting the role of local anisotropy on the properties of excitonic triplet states.

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Far From 'Easy' Spectroscopy With The 8Π And Griffin Spectrometers At Triumf-Isac, Steven W. Yates, P. E. Garrett, A. J. Radich, J. M. Allmond, C. Andreoiu, G. C. Ball, P. C. Bender, L. Bianco, V. Bildstein, H. Bidaman, R. Braid Sep 2015

Far From 'Easy' Spectroscopy With The 8Π And Griffin Spectrometers At Triumf-Isac, Steven W. Yates, P. E. Garrett, A. J. Radich, J. M. Allmond, C. Andreoiu, G. C. Ball, P. C. Bender, L. Bianco, V. Bildstein, H. Bidaman, R. Braid

Chemistry Faculty Publications

The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world's most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of 124Cs to study the nuclear structure of 124Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0+ …

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Identifying The Tautomeric Form Of A Deoxyguanosine-Estrogen Quinone Intermediate, Douglas E. Stack Sep 2015

Identifying The Tautomeric Form Of A Deoxyguanosine-Estrogen Quinone Intermediate, Douglas E. Stack

Chemistry Faculty Publications

Mechanistic insights into the reaction of an estrogen o-quinone with deoxyguanosine has been further investigated using high level density functional calculations in addition to the use of 4-hyroxycatecholestrone (4-OHE1) regioselectivity labeled with deuterium at the C1-position. Calculations using the M06-2X functional with large basis sets indicate the tautomeric form of an estrogen-DNA adduct present when glycosidic bonds cleavage occurs is comprised of an aromatic A ring structure. This tautomeric form was further verified by use of deuterium labelling of the catechol precursor use to form the estrogen o-quinone. Regioselective deuterium labelling at the C1-position of the estrogen A ring allows …

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Quantitative Analysis Of The Density Of Trap States At The Semiconductor-Dielectric Interface In Organic Field-Effect Transistors, Peter J. Diemer, Zachary A. Lamport, Yaochuan Mei, Jeremy W. Ward, Katelyn P. Goetz, Wei Li, Marcia M. Payne, Martin Guthold, John E. Anthony, Oana D. Jurchescu Sep 2015

Quantitative Analysis Of The Density Of Trap States At The Semiconductor-Dielectric Interface In Organic Field-Effect Transistors, Peter J. Diemer, Zachary A. Lamport, Yaochuan Mei, Jeremy W. Ward, Katelyn P. Goetz, Wei Li, Marcia M. Payne, Martin Guthold, John E. Anthony, Oana D. Jurchescu

Chemistry Faculty Publications

The electrical properties of organic field-effect transistors are governed by the quality of the constituting layers, and the resulting interfaces. We compare the properties of the same organic semiconductor film, 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene, with bottom SiO2 dielectric and top Cytop dielectric and find a 10× increase in charge carrier mobility, from 0.17 ± 0.19 cm2 V−1 s−1 to 1.5 ± 0.70 cm2 V−1 s−1, when the polymer dielectric is used. This results from a significant reduction of the trap density of states in the semiconductor band-gap, and a decrease in the …

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Enzyme Localization, Crowding, And Buffers Collectively Modulate Diffusion-Influenced Signal Transduction: Insights From Continuum Diffusion Modeling, Peter M. Kekenes-Huskey, Changsun Eun, J. A. Mccammon Sep 2015

Enzyme Localization, Crowding, And Buffers Collectively Modulate Diffusion-Influenced Signal Transduction: Insights From Continuum Diffusion Modeling, Peter M. Kekenes-Huskey, Changsun Eun, J. A. Mccammon

Chemistry Faculty Publications

Biochemical reaction networks consisting of coupled enzymes connect substrate signaling events with biological function. Substrates involved in these reactions can be strongly influenced by diffusion “barriers” arising from impenetrable cellular structures and macromolecules, as well as interactions with biomolecules, especially within crowded environments. For diffusion-influenced reactions, the spatial organization of diffusion barriers arising from intracellular structures, non-specific crowders, and specific-binders (buffers) strongly controls the temporal and spatial reaction kinetics. In this study, we use two prototypical biochemical reactions, a Goodwin oscillator, and a reaction with a periodic source/sink term to examine how a diffusion barrier that partitions substrates controls reaction …

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Boron-Rich Benzene And Pyrene Derivatives For The Detection Of Thermal Neutrons, Henok A. Yemam, Adam Mahl, Unsal Koldemir, Tyler Remedes, Sean Parkin, Uwe Greife, Alan Sellinger Sep 2015

Boron-Rich Benzene And Pyrene Derivatives For The Detection Of Thermal Neutrons, Henok A. Yemam, Adam Mahl, Unsal Koldemir, Tyler Remedes, Sean Parkin, Uwe Greife, Alan Sellinger

Chemistry Faculty Publications

A synthetic methodology is developed to generate boron rich aromatic small molecules based on benzene and pyrene moieties for the detection of thermal neutrons. The prepared aromatic compounds have a relatively high boron content up to 7.4 wt%, which is important for application in neutron detection as 10B (20% of natural abundance boron) has a large neutron induced reaction cross-section. This is demonstrated by preparing blends of the synthesized molecules with fluorescent dopants in poly(vinyltoluene) matrices resulting in comparable scintillation light output and neutron capture as state-of-the art commercial scintillators, but with the advantage of much lower cost. The …

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Determination Of Triapine, A Ribonucleotide Reductase Inhibitor, In Human Plasma By Liquid Chromatography Tandem Mass Spectrometry, Ye Feng, Charles A. Kunos, Yan Xu Sep 2015

Determination Of Triapine, A Ribonucleotide Reductase Inhibitor, In Human Plasma By Liquid Chromatography Tandem Mass Spectrometry, Ye Feng, Charles A. Kunos, Yan Xu

Chemistry Faculty Publications

Triapine is an inhibitor of ribonucleotide reductase (RNR). Studies have shown that triapine significantly decreases the activity of RNR and enhanced the radiation-mediated cytotoxicity in cervical and colon cancer. In this work, we have developed and validated a selective and sensitive LC-MS/MS method for the determination of triapine in human plasma. In this method, 2-[(3-fluoro-2-pyridinyl)methylene] hydrazinecarbothioamide (NSC 266749) was used as the internal standard (IS); plasma samples were prepared by deproteinization with acetonitrile; tripaine and the IS were separated on a Waters Xbridge Shield RP18 column (3.5 µm; 2.1 × 50 mm) using a mobile phase containing 25.0% methanol and …

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Globally Profiling Sialylation Status Of Macrophages Upon Statin Treatment, Dan Wang, Huan Nie, Evgeny Ozhegov, Lin Wang, Aimin Zhou, Yu Li, Xue Long Sun Sep 2015

Globally Profiling Sialylation Status Of Macrophages Upon Statin Treatment, Dan Wang, Huan Nie, Evgeny Ozhegov, Lin Wang, Aimin Zhou, Yu Li, Xue Long Sun

Chemistry Faculty Publications

Sialic acids (SAs) are widely expressed on immune cells and their levels and linkages named as sialylation status vary upon cellular environment changes related to both physiological and pathological processes. In this study, we performed a global profiling of the sialylation status of macrophages and their release of SAs in the cell culture medium by using flow cytometry, confocal microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). Both flow cytometry and confocal microscopy results showed that cell surface α-2,3-linked SAs were predominant in the normal culture condition and changed slightly upon treatment with atorvastatin for 24 h, whereas α-2,6-linked SAs …

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O-Glcnacylation Of G6pd Promotes The Pentose Phosphate Pathway And Tumor Growth, Xiongjian Rao, Xiaotao Duan, Weimin Mao, Xuexia Li, Zhonghua Li, Qian Li, Zhiguo Zheng, Haimiao Xu, Min Chen, Peng George Wang, Yingjie Wang, Binghui Shen, Wen Yi Sep 2015

O-Glcnacylation Of G6pd Promotes The Pentose Phosphate Pathway And Tumor Growth, Xiongjian Rao, Xiaotao Duan, Weimin Mao, Xuexia Li, Zhonghua Li, Qian Li, Zhiguo Zheng, Haimiao Xu, Min Chen, Peng George Wang, Yingjie Wang, Binghui Shen, Wen Yi

Chemistry Faculty Publications

The pentose phosphate pathway (PPP) plays a critical role in macromolecule biosynthesis and maintaining cellular redox homoeostasis in rapidly proliferating cells. Upregulation of the PPP has been shown in several types of cancer. However, how the PPP is regulated to confer a selective growth advantage on cancer cells is not well understood. Here we show that glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the PPP, is dynamically modified with an O-linked b-N-acetylglucosamine sugar in response to hypoxia. Glycosylation activates G6PD activity and increases glucose flux through the PPP, thereby providing precursors for nucleotide and lipid biosynthesis, and reducing equivalents for …

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Hydrogen Sulfide Prodrugs—A Review, Yueqin Zheng, Xingyue Ji, Kaili Ji, Binghe Wang Sep 2015

Hydrogen Sulfide Prodrugs—A Review, Yueqin Zheng, Xingyue Ji, Kaili Ji, Binghe Wang

Chemistry Faculty Publications

Abstract Hydrogen sulfide (H2S) is recognized as one of three gasotransmitters together with nitric oxide (NO) and carbon monoxide (CO). As a signaling molecule, H2S plays an important role in physiology and shows great potential in pharmaceutical applications. Along this line, there is a need for the development of H2S prodrugs for various reasons. In this review, we summarize different H2S

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Homo–Lumo Energy Gap Control In Platinum(Ii) Biphenyl Complexes Containing 2,2′-Bipyridine Ligands, D. Paul Rillema, Stanislav R. Stoyanov, Arvin Cruz Ph.D., Huy Nguyen, Curtis Moore, Wei Huang, Khamis Siam, Ali Jehan, Venugopal Komreddy Aug 2015

Homo–Lumo Energy Gap Control In Platinum(Ii) Biphenyl Complexes Containing 2,2′-Bipyridine Ligands, D. Paul Rillema, Stanislav R. Stoyanov, Arvin Cruz Ph.D., Huy Nguyen, Curtis Moore, Wei Huang, Khamis Siam, Ali Jehan, Venugopal Komreddy

Chemistry Faculty Publications

A series of platinum(II) biphenyl 2,2’-bipyridine complexes containing electron-donating and electron-withdrawing moieties on the 4 and 4’ positions of the bipyridine ligand exhibit emission from excited states in the 600 nm region of the spectrum upon excitation in the metal-to-ligand charge transfer transition located near 450 nm. These complexes are distorted from planarity based on both single crystal structure determinations and density functional theory (DFT) calculations of isolated molecules in acetonitrile. The DFT also reveals the geometry of the lowest-lying triplet state (LLTS) of each complex that is important for emission behavior. The LLTS are assigned based on the electron …

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Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd Aug 2015

Electrochemical Characterization Of Self-Assembled Monolayers On Gold Substrates Derived From Thermal Decomposition Of Monolayer-Protected Cluster Films, Michael C. Leopold, Tran T. Doan, Melissa J. Mullaney, Andrew F. Loftus, Christopher M. Kidd

Chemistry Faculty Publications

Networked films of monolayer-protected clusters (MPCs), alkanethiolate-stabilized gold nanoparticles, can be thermally decomposed to form stable gold on glass substrates that are subsequently modified with self-assembled monolayers (SAMs) for use as modified electrodes. Electrochemical assessment of these SAM-modified gold substrates, including double-layer capacitance measurements, linear sweep desorption of the alkanethiolates, and diffusional redox probing, all show that SAMs formed on gold supports formed from thermolysis of MPC films possess substantially higher defect density compared to SAMs formed on traditional evaporated gold. The density of defects in the SAMs on thermolyzed gold is directly related to the strategies used to assemble …

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Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert Aug 2015

Synthesis And Flammability Testing Of Epoxy Functionalized Phosphorous-Based Flame Retardants, Vladimir Benin, Xuemei Cui, Alexander Morgan, Karl Seiwert

Chemistry Faculty Publications

Several potential new phosphorus-containing flame retardant molecules were evaluated for heat release reduction potential by incorporation of the molecules into a polyurethane, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The heat release reduction potential of these substances was evaluated using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods to qualitatively evaluate their potential reactivity into the polyurethane prior to heat release testing. The functionality of the flame retardants was epoxide based that would potentially react with the diol during polyurethane synthesis. Flammability testing …

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Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng Jul 2015

Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng

Chemistry Faculty Publications

The formation of secondary organic aerosol (SOA) from the oxidation of β-pinene via nitrate radicals is investigated in the Georgia Tech Environmental Chamber (GTEC) facility. Aerosol yields are determined for experiments performed under both dry (relative humidity (RH) < 2 %) and humid (RH = 50 % and RH = 70 %) conditions. To probe the effects of peroxy radical (RO2) fate on aerosol formation, "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are performed. Gas-phase organic nitrate species (with molecular weights of 215, 229, 231, and 245 amu, which likely correspond to molecular formulas of C10H17NO4, C10H15NO5, C10H17NO …

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Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin Jul 2015

Crystal Structure Of Orthorhombic {Bis-[(Pyridin-2-Yl)Methyl](3,5,5,5-Tetrachloropentyl)Amine-Κ3N,N',N''}Chloridocopper(Ii) Perchlorate, Katherine A. Bussey, Annie R. Cavalier, Jennifer R. Connell, Margaret E. Mraz, Kayode D. Oshin, Tomislav Pintauer, Danielle L. Gray, Sean Parkin

Chemistry Faculty Publications

In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitro­gen atoms from the bis­[(pyridin-2-yl)meth­yl](3,5,5,5-tetra­chloro­pent­yl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bis­[(pyridin-2-yl)meth­yl](3,5,5,5-tetra­chloro­pent­yl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cu⋯Cl inter­actions between symmetry-related mol­ecules create a dimerization with a chloride occupying the apical …

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Low-Voltage Polymer/Small-Molecule Blend Organic Thin-Film Transistors And Circuits Fabricated Via Spray Deposition, Simon Hunter, Jeremy W. Ward, Marcia M. Payne, John E. Anthony, Oana D. Jurchescu, Thomas D. Anthopoulos Jun 2015

Low-Voltage Polymer/Small-Molecule Blend Organic Thin-Film Transistors And Circuits Fabricated Via Spray Deposition, Simon Hunter, Jeremy W. Ward, Marcia M. Payne, John E. Anthony, Oana D. Jurchescu, Thomas D. Anthopoulos

Chemistry Faculty Publications

Organic thin-film electronics have long been considered an enticing candidate in achieving high-throughput manufacturing of low-power ubiquitous electronics. However, to achieve this goal, more work is required to reduce operating voltages and develop suitable mass-manufacture techniques. Here, we demonstrate low-voltage spray-cast organic thin-film transistors based on a semiconductor blend of 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene and poly(triarylamine). Both semiconductor and dielectric films are deposited via successive spray deposition in ambient conditions (air with 40%–60% relative humidity) without any special precautions. Despite the simplicity of the deposition method, p-channel transistors with hole mobilities of >1 cm2/Vs are realized at −4 …

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The Neutron Time-Of-Flight Cross Section Program At The University Of Kentucky - Adventures In Analysis Ii, J. R. Vanhoy, S. F. Hicks, B. C. Combs, B. P. Crider, A. J. French, E. A. Garza, S. L. Henderson, T. J. Howard, S. H. Liu, S. Nigam, R. L. Pecha, E. E. Peters, Francisco M. Prados-Estévez, Marcus T. Mcellistrem, B. J. Rice, T. J. Ross, Z. C. Santonil, L. C. Sidwell, J. L. Steves, Steven W. Yates May 2015

The Neutron Time-Of-Flight Cross Section Program At The University Of Kentucky - Adventures In Analysis Ii, J. R. Vanhoy, S. F. Hicks, B. C. Combs, B. P. Crider, A. J. French, E. A. Garza, S. L. Henderson, T. J. Howard, S. H. Liu, S. Nigam, R. L. Pecha, E. E. Peters, Francisco M. Prados-Estévez, Marcus T. Mcellistrem, B. J. Rice, T. J. Ross, Z. C. Santonil, L. C. Sidwell, J. L. Steves, Steven W. Yates

Chemistry Faculty Publications

Elastic and inelastic neutron differential cross sections are measured at the University of Kentucky Accelerator Laboratory (www.pa.uky.edu/accelerator/) at incident energies in the fast neutron region. The laboratorys facilities and instrumentation will be described and our measurement and analysis procedures outlined. Many corrections are required for neutron scattering experiments and the analysis utilizes information from many other cross section data sets and model calculations. Exploring and understanding the limitations of the foundational information and procedures are important for controlling the accuracy of the cross section results. We are examining the limitations in neutron detection efficiency, the normalization of (n,n′ …

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“No-Spin” States And Low-Lying Structures In 130Xe And 136Xe, T. J. Ross, E. E. Peters, Anagha Chakraborty, B. P. Crider, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. R. Vanhoy, Steven W. Yates May 2015

“No-Spin” States And Low-Lying Structures In 130Xe And 136Xe, T. J. Ross, E. E. Peters, Anagha Chakraborty, B. P. Crider, Ajay Kumar, S. H. Liu, Marcus T. Mcellistrem, Francisco M. Prados-Estévez, J. R. Vanhoy, Steven W. Yates

Chemistry Faculty Publications

Inelastic neutron scattering on solid 130XeF2 and 136XeF2 targets was utilized to populate excited levels in 130Xe and 136Xe. When calculating nuclear matrix elements vital to the understanding of double-beta decay, it is important to have a clear understanding of the low-lying level structure of both the parent and daughter nucleus. Of particular relevance to double-beta decay searches are the assignments of 0+ states. We show here that in the case of 130Xe there are several discrepancies in the adopted level structure. We found that one previous 0+ candidate level (1590 …

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