Open Access. Powered by Scholars. Published by Universities.®

Chemistry Commons

Open Access. Powered by Scholars. Published by Universities.®

22,398 Full-Text Articles 32,798 Authors 3,813,508 Downloads 256 Institutions

All Articles in Chemistry

Faceted Search

22,398 full-text articles. Page 7 of 579.

Cation-Π Interactions Of Selected Alkali Metal Ions With Two Benzene Rings Connected Through Linear Chains, Nouf Alshamrani 2018 Clark Atlanta University

Cation-Π Interactions Of Selected Alkali Metal Ions With Two Benzene Rings Connected Through Linear Chains, Nouf Alshamrani

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

Quantum chemical calculations at M06-2X/6-311+G(2d,2p) level were employed to examine the structures, dissociation energies and vibrational spectra of complexes formed by Li+, Na+ and K+ with diphenylmethane, 1,2-diphenylethane, 1,3-diphenylpropane, [2.2]paracyclophane and [3.3]paracyclophane molecules. The effect of heteroatom substitution in the connecting chains of 1,3-diphenylpropane and [3.3]paracyclophane molecules on the binding affinity of cations with ligands was also included in this study. The complexes of [3.3] paracyclophane based molecules seem to have weak cation-pi interactions with metal ions Na+ and K+ when they were placed between two ...


Synthetic Approaches Towards Novel Isoform Selective Pi3k Inhibitors And Their Biological Activities Against Prostate Cancer Cells, Idris Wazeerud-Din 2018 Atlanta University Center

Synthetic Approaches Towards Novel Isoform Selective Pi3k Inhibitors And Their Biological Activities Against Prostate Cancer Cells, Idris Wazeerud-Din

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

The development of novel imidazopyridines, which includes both tetrahydroimidazo[1,5-a]pyridine (rIMP) and imidazo[1,5-a]pyridine (IMP) was investigated using conventional and microwave induced procedures that afforded compounds at high yield of 88-96%. rIMP was synthesized using a two-step procedure that involved the microwave synthesis of IMP, then the reduction of the pyridine moiety of the fused imidazopyridine rings using 10% Pd/C and hydrazine monohydrate. The microwave synthesis of imidazopyridines involved the one pot reaction of 2-benzoylpyridine, substituted benzaldehyde and ammonium formate in acetic acid under open vessel microwave conditions, which resulted in products within 40 minutes ...


Enhanced Acidity Of Acetic And Pyruvic Acids On The Surface Of Water, Alexis J. Eugene, Elizabeth A. Pillar, Agustín J. Colussi, Marcelo I. Guzman 2018 University of Kentucky

Enhanced Acidity Of Acetic And Pyruvic Acids On The Surface Of Water, Alexis J. Eugene, Elizabeth A. Pillar, Agustín J. Colussi, Marcelo I. Guzman

Chemistry Faculty Publications

Understanding the acid–base behavior of carboxylic acids on aqueous interfaces is a fundamental issue in nature. Surface processes involving carboxylic acids such as acetic and pyruvic acids play roles in (1) the transport of nutrients through cell membranes, (2) the cycling of metabolites relevant to the origin of life, and (3) the photooxidative processing of biogenic and anthropogenic emissions in aerosols and atmospheric waters. Here, we report that 50% of gaseous acetic acid and pyruvic acid molecules transfer a proton to the surface of water at pH 2.8 and 1.8 units lower than their respective acidity constants ...


Infra-Red Microwave Spectra, Overtones, Degeneracy And Thermal Populations All In One Diagram, Carl W. David 2018 University of Connecticut

Infra-Red Microwave Spectra, Overtones, Degeneracy And Thermal Populations All In One Diagram, Carl W. David

Chemistry Education Materials

An old drawing, which had an error in it, is re-presented (corrected) for understanding the relationships in diatomic vibrational-rotational interactions at the introductory level.


Light Absorption By Polar And Non-Polar Aerosol Compounds From Laboratory Biomass Combustion, Deep Sengupta, Vera Samburova, Chiranjiva Bhattarai, Elena Kirillova, Lynn Mazzoleni, Michealene Iaukea-Lum, Adam Watts, Audrey Khlystov 2018 Desert Research Institute

Light Absorption By Polar And Non-Polar Aerosol Compounds From Laboratory Biomass Combustion, Deep Sengupta, Vera Samburova, Chiranjiva Bhattarai, Elena Kirillova, Lynn Mazzoleni, Michealene Iaukea-Lum, Adam Watts, Audrey Khlystov

Department of Chemistry Publications

Fresh and atmospherically aged biomass-burning (BB) aerosol mass is mostly comprised of strongly light-absorbing black carbon (BC) and of organic carbon (OC) with its light-absorbing fraction – brown carbon (BrC). There is a lack of data on the physical and chemical properties of atmospheric BB aerosols, leading to high uncertainties in estimates of the BB impact on air quality and climate, especially for BrC. The polarity of chemical compounds influences their fate in the atmosphere including wet/dry deposition and chemical and physical processing. So far, most of the attention has been given to the water-soluble (polar) fraction of BrC, while ...


Design, Synthesis, And Oxidation Reactivity Of Palladacyclic Complexes Containing N-Donor Ligands, Ava Behnia 2018 The University of Western Ontario

Design, Synthesis, And Oxidation Reactivity Of Palladacyclic Complexes Containing N-Donor Ligands, Ava Behnia

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and reactivity of complexes containing the cycloneophyl-Pd(II) group, PdCH2CMe2C6H4, in combination with N-donor ligands. These compounds contain both alkyl- and arylpalladium bonds and the selectivity of bond cleavage in reactions with oxidants and protic reagents is studied, often involving oxidative addition and reductive elimination reaction sequences.

The diimine ligand in [Pd(CH2CMe2C6H4)(MesN=CH-CH=NMes)] does not support formation of stable palladium(IV) complexes, but reactions with Br2 or I2 lead to reductive elimination by C-C bond ...


Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li 2018 Purdue University

Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated ...


Electronic Effect Of Platinum Alloy Catalysts On Olefin Hydrogenation Kinetics, Colin Reedy, Jeff Miller, Stephen Purdy 2018 Creighton University

Electronic Effect Of Platinum Alloy Catalysts On Olefin Hydrogenation Kinetics, Colin Reedy, Jeff Miller, Stephen Purdy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Dehydrogenation of alkanes is the first step in transforming light hydrocarbons into liquid fuels and chemicals. This process has traditionally used platinum alloys as catalysts. Alloys are used industrially because they have a greater selectivity than monometallic platinum. Alloying platinum with an inactive promoter modifies the crystalline structure of the surface (geometric effect), and the 5d electrons in platinum responsible for chemistry (electronic effect); both have been suggested to be primarily responsible for dehydrogenation selectivity in platinum alloys. Alloy catalysts have been synthesized using early 3d transition metal promoters with the same Pt3M crystal structure. X-Ray Absorption Spectroscopy ...


Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei 2018 Purdue University

Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential ...


Ultrafast Laser Filament-Induced Fluorescence Spectroscopy Of Uranyl Fluoride, P. J. Skrodzki, M. Burger, L. A. Finney, F. Poineau, S. M. Balasekaran, J. Nees, K. R. Czerwinski, I. Jovanovic 2018 University of Michigan

Ultrafast Laser Filament-Induced Fluorescence Spectroscopy Of Uranyl Fluoride, P. J. Skrodzki, M. Burger, L. A. Finney, F. Poineau, S. M. Balasekaran, J. Nees, K. R. Czerwinski, I. Jovanovic

Chemistry and Biochemistry Faculty Publications

Uranyl fluoride (UO2F2) is a compound which forms in the reaction between water and uranium hexafluoride, a uranium containing gas widely used for uranium enrichment. Uranyl fluoride exhibits negligible natural background in atmosphere; as a result, its observation implies the presence and active operation of nearby enrichment facilities and could be used as a tracer for treaty verification technologies. Additionally, detection of UO2F2 has a potential application in guiding remediation efforts around enrichment facilities. Laser-induced fluorescence (LIF) has been proposed in the past as a viable technique for the detection and tracking of UO2F2. We demonstrate that ultrafast laser filamentation ...


Synthesis, Characterization, And Crystal Structure Of The (Η5-C5ph5)Cr(Co)3 Radical, Ray J. Hoobler, Marc A. Hutton, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger, Thomas C. Richards, William E. Geiger 2018 Marshall University

Synthesis, Characterization, And Crystal Structure Of The (Η5-C5ph5)Cr(Co)3 Radical, Ray J. Hoobler, Marc A. Hutton, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger, Thomas C. Richards, William E. Geiger

Michael P. Castellani

The reaction between Cr(CO)6 and Na(C5Ph5 ) in refluxing diglyme yields [Na(diglyme)3/2][(C5Ph5)Cr(CO)3], 1. Metathesis of 1 with [Ph3P=N=PPh3 ]Cl in CH2Cl2 yields [Ph3P=N=PPh3][(C5Ph5)Cr(CO)3], 2. Oxidation of 1 by AgBF4 in cold THF under an argon atmosphere produces (C5Ph5)Cr(CO)3, 3. Complexes 2 and 3 form a redox pair connected by a quasireversible one-electron process, E0 = -0.69 V vs ...


Synthesis And X-Ray Crystal Structure Of [(C5ph5)Crcl(Μ-Cl)2tl]2: An Example Of The Rare M-X-Tli Linkage (X = Halide), K. Brian Davis, T. David Harris, Michael Castellani, James A. Golen, Arnold L. Rheingold 2018 Marshall University

Synthesis And X-Ray Crystal Structure Of [(C5ph5)Crcl(Μ-Cl)2tl]2: An Example Of The Rare M-X-Tli Linkage (X = Halide), K. Brian Davis, T. David Harris, Michael Castellani, James A. Golen, Arnold L. Rheingold

Michael P. Castellani

Reaction of solid TlCl with [(C5Ph5)CrCl(m-Cl)]2 in CH2Cl2 solvent yields the monomeric complex (C5Ph5)CrCl(m-Cl)2Tl in 80% isolated yield. The C5H5 and C5Me5 analogues do not react with TlCl suggesting a steric basis for the reaction of the C5Ph5 material. An X-ray crystal structure of [(C5Ph5)CrCl(m-Cl)2Tl]2•2CH2Cl2 was obtained.


Substitution Reactions Of (C5ph5)Cr(Co)3: Structural, Electrochemical, And Spectroscopic Characterization Of (C5ph5)Cr(Co)2l, L = Pme3, Pme2ph, P(Ome)3, D. John Hammack, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger 2018 Marshall University

Substitution Reactions Of (C5ph5)Cr(Co)3: Structural, Electrochemical, And Spectroscopic Characterization Of (C5ph5)Cr(Co)2l, L = Pme3, Pme2ph, P(Ome)3, D. John Hammack, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger

Michael P. Castellani

The radical complex (C5Ph5)Cr(CO)3 reacts with small, neutral, monodentate Lewis bases (PMe3, PMe2Ph, P(OMe)3) in THF at −78 °C (PMe2Ph reacts at ambient temperature) to yield the monomeric substitution products (C5Ph5)Cr(CO)2L·THF as thermally stable solids. Electrochemical and spectroscopic data are provided. An X-ray crystal structure of the hemisolvate (C5Ph5)Cr(CO)2PMe3·0.5THF was obtained. Frozen-solution ESR spectra of (C5Ph5)Cr(CO)2L in toluene are comparable to those ...


Immobilization Of Gold Nanoparticles On Nitrided Carbon Fiber Ultramicroelectrodes By Direct Reduction, George Affadu-Danful 2018 East Tennessee State University

Immobilization Of Gold Nanoparticles On Nitrided Carbon Fiber Ultramicroelectrodes By Direct Reduction, George Affadu-Danful

Electronic Theses and Dissertations

Due to enhanced properties such as large surface area-to-volume ratio, metal nanoparticles are often employed as catalysts for various applications. However, most studies involving nanoparticle catalysts have been conducted on collections of particles rather than single nanoparticles. Results obtained for ensemble systems can be difficult to interpret due to variations in particle loading and interparticle distance, which are often challenging to control and characterize. In this study, two immobilization strategies for incorporating gold nanoparticles (AuNPs) on carbon fiber ultramicroelectrodes (UMEs) were compared with the goal of extending these techniques to nanoelectrodes for studies of single AuNPs. Both layer-by-layer deposition of ...


Comparing Laser Assisted Pulling And Chemical Vapor Deposition Methods In The Fabrication Of Carbon Ultramicro- And Nanoelectrodes, Theophilus Neequaye 2018 East Tennessee State University

Comparing Laser Assisted Pulling And Chemical Vapor Deposition Methods In The Fabrication Of Carbon Ultramicro- And Nanoelectrodes, Theophilus Neequaye

Electronic Theses and Dissertations

Ultramicroelectrodes (UMEs) (limiting dimensions <~25 μm) and nanoelectrodes (<~100 nm) exhibit enhanced electrochemical properties compared to macroscopic electrodes. Their small sizes and enhanced properties make them well-suited for various interesting and important applications such as measuring redox-active species in nonaqueous solvents, studying intermediates of fast electrochemical reactions, and investigating electrochemical and electrocatalytic properties of single nanoparticles. While UMEs are commercially available, nanoelectrode fabrication is still largely confined to research labs. Various methods for constructing nanoelectrodes have been reported and continue to be developed, but most require considerable expertise, and comparisons between different fabrication processes are lacking. In this work, a comparison of laser-assisted pulling and chemical vapor deposition (CVD) methods of electrode fabrication is made with the aim of optimizing production of carbon nanoelectrodes for single nanoparticle electrochemical measurements. By examining effects of pulling parameters, post-pulling treatments, and CVD processing, electrodes as small as ~50 nm were successfully produced.


Safe Use Of Hydrogen Peroxide In The Organic Lab, Patrick Dussault 2018 University of Nebraska-Lincoln

Safe Use Of Hydrogen Peroxide In The Organic Lab, Patrick Dussault

Organic Peroxides: Safety Issues

The article describes good practices for use of hydrogen peroxide (H2O2) in an organic lab setting. Major headings include:

Leading references; Toxicity; Physical properties; Chemical properties; Stability and incompatibilities; Confinement/pressure; and, References to accidents involving H2O2.


Alkene Ozonolysis In The Academic Lab, Patrick Dussault 2018 University of Nebraska-Lincoln

Alkene Ozonolysis In The Academic Lab, Patrick Dussault

Organic Peroxides: Safety Issues

The following information is offered as a guide based upon our experience with application of ozone for organic oxidations and hydroperoxide synthesis. Please send suggestions, requests, or corrections to pdussault1@unl.edu.

Introduction and leading references

Overview of ozonolysis: Mechanism, Substrate reactivity, Typical reaction conditions, Reaction monitoring, Reaction work-ups

Safety Issues

Acknowledgements:

------------

The following provides a brief introduction to the application of ozonolysis within academic labs. Ozonolysis remains among the most frequently used of methods for oxidative cleavage of alkenes. While best known as a means by which to introduce aldehydes and ketones, ozonolysis can also be used to generate ...


Synthesis And Characterization Of Zinc(Ii) Dipyrrin Photosensitizers, Norah Alqahtani 2018 East Tennessee State University

Synthesis And Characterization Of Zinc(Ii) Dipyrrin Photosensitizers, Norah Alqahtani

Electronic Theses and Dissertations

Photocatalytic carbon dioxide reduction transforms CO2 to useful chemicals and fuels, reducing CO2 emissions and making fossil fuels more renewable. Due to a lack of earthabundant sensitizers, we want to design new earth-abundant sensitizers to go with the many known carbon dioxide reduction catalysts. Zn(II) dipyrrin complexes strongly absorb visible light, but their excited state properties have not been widely studied. To investigate their photophysical properties, two Zn dipyrrin complexes, with and without heavy atoms, were synthesized and characterized by NMR and mass spectrometry. The photophysical properties of the two complexes were measured in polar and non-polar solvents, particularly ...


Hydrocarbon Reaction Experiment [Chemistry], Kevin Mark 2018 CUNY La Guardia Community College

Hydrocarbon Reaction Experiment [Chemistry], Kevin Mark

Open Educational Resources

The Foundations of Chemistry SCC 110 course is required for LaGuardia’s Health Sciences students interested in the Nursing, Dietetic Technician and Veterinary Technician programs. This course has been designated for the Inquiry and Problem Solving competency as well the Digital Communication ability. SCC 110 students will use SCC 110 lecture material and information in the SCC 110 lab manual to perform an electrophilic addition. Students will be able to correlate the organic theory concepts with the experiment by making physical observations (e.g., color changes) when carrying out the lab procedures. The student findings will be synthesized and expressed ...


Hydrolysis Of Cellulose And Biomass Using Blue Molybdenum, Farouk Awudu 2018 East Tennessee State University

Hydrolysis Of Cellulose And Biomass Using Blue Molybdenum, Farouk Awudu

Electronic Theses and Dissertations

Hydrolysis of cellulosic biomass is an important and ongoing subject of research due to generating precursors for biofuel synthesis. This work involves hydrolysis of microcrystalline cellulose and Arundo donax to glucose. Methods for acid hydrolysis include the use of sulfuric acid, phosphomolybdic acid, blue molybdenum using low concentrations at 40-100 °C. For comparison purposes, enzymatic hydrolysis was also carried out using cellulase. Products were quantified by measuring total organic carbon and reducible sugars using dinitrosalicylic acid. Use of phosphomolybdic acid, blue molybdenum and sulfuric acid even at 6.0 M did not increase the amount of glucose compared to using ...


Digital Commons powered by bepress