Chemistry Commons^™

Ab Initio Investigation Of Hydrogen Bonding And Network Structure In A Supercooled Model Of Water, Lei Liang, Paul Rulis, Lizhi Ouyang, Wai-Yim Ching

Mathematical Sciences Faculty Research

The hydrogen bond (HB) and network structure in a large periodic model of 340 water molecules are investigated by ab initio methods. This model has a density of 1.00 g/cc, very small distortions of O–H bond length and H–O–H bond angle, and the peak positions in the radial distribution functions in close agreement with experiment. The 340 molecules can be classified into four groups according to the number of HBs quantitatively determined by the bond-order values. The percentages of water molecules with two, three, four, and five HBs are, respectively, 3.2%, 10.3%, 85%, and 1.5%, with an average HB number …

Methods And Compositions For Treating Neurological Disorders, Tae H. Ji, Inhae Ji

Chemistry Faculty Patents

This disclosure relates to methods and compositions useful for the treatment of senile dementia. More particularly the disclosure relates to methods and compositions for the treatment of senile dementia related to diabetes.

Electrochemical Studies Of Quinone On Clay-Modified Platinum Electrodes, Thomas Edward Nelson

Theses (2 year embargo)

No abstract provided.

Instrumentation Analysis For Large Molecules: A Theoretical Study And Simulations, Yi She

Student Theses and Dissertations

Instrumentation analysis such as mass spectrometry allows one to analyze size up to 100kD safely. Difficulty arises from kinetic energies carried by larger-size molecules. Currently our group is developing a high pressure device, and the plan requires a theory (mathematics and physics) to back it up and highly accurate simulations for visualization and interpretation of the theoretical results. Such simulation is computationally (time-wise) difficult because of immense number of collisions. In our first trial of larger-molecule simulation, we incorporate a concept of drag with slip correction factor, relaxation time, and fluid viscosity into a statistical trajectory model currently common used. …

Spectroscopic And Computational Insight Into Weak Noncovalent Interactions In Crystalline Pyrimidine, Ashley M. Wright, Lynn V. Joe, Austin A. Howard, Gregory S. Tschumper, Nathan I. Hammer

Chemistry Faculty Research & Creative Works

Effects of weak C-H⋯N interactions on the vibrational spectrum of crystalline pyrimidine are studied using Raman spectroscopy and electronic structure computations. When pyrimidine transitions from the liquid to solid state, peaks in the Raman spectrum exhibit non-uniform shifts. Calculations performed on a cluster of nine pyrimidine molecules (one pyrimidine molecule embedded in a field of its eight nearest neighbors in the crystalline geometry) predict that modes involving the movement of hydrogen atoms are associated with the observed shifts. Assignments of fundamentals and combination bands in both the liquid and solid states are also revised in the complicated C-H stretching region. …

Ligand Fluorination To Optimize Preferential Oxidation Of Carbon Monoxide By Water-Soluble Rhodium Porphyrins, Justin C. Biffinger, Shriharsha Uppaluri, Haoran Sun, Stephen G. Dimagno

Stephen DiMagno Papers

Catalytic, low temperature preferential oxidation (PROX) of carbon monoxide by aqueous [5,10,15,20-tetrakis- (4-sulfonatophenyl)-2,3,7,8,12,13,17,18-octafluoroporphyrinato]- rhodium(III) tetrasodium salt, (1[Rh(III)]) and [5,10,15, 20-tetrakis(3-sulfonato-2,6-difluorophenyl)-2,3,7,8,12,13, 17,18-octafluoroporphyrinato]rhodium(III) tetrasodium salt, (2[Rh(III)]) is reported. The PROX reaction occurs at ambient temperature in buffered (4 ≤ pH ≤ 13) aqueous solutions. Fluorination on the porphyrin periphery is shown to increase the CO PROX reaction rate, shift the metal centered redox potentials, and acidify ligated water molecules. Most importantly, β-fluorination increases the acidity of the rhodium hydride complex (pK_a = 2.2 ± 0.2 for 2[Rh-D]); the dramatically increased acidity of the Rh(III) hydride complex precludes proton reduction …

A P38Α-Selective Chemosensor For Use In Unfractionated Cell Lysates, Cliff I. Stains, Elvedin Luković, Barbara Imperiali

Cliff Stains Publications

Recent efforts have identified the p38α Ser/Thr kinase as a potential target for the treatment of inflammatory diseases as well as non-small cell lung carcinoma. Despite the significance of p38α, no direct activity probe compatible with cell lysate analysis exists. Instead, proxies for kinase activation, such as phosphospecific antibodies, which do not distinguish between p38 isoforms, are often used. Our laboratory has recently developed a sulfonamido-oxine (Sox) fluorophore that undergoes a significant increase in fluorescence in response to phosphorylation at a proximal residue, allowing for real-time activity measurements. Herein we report the rational design of a p38α-selective chemosensor using this …

Synthesis Of High Magnetization Feco Alloys Prepared By A Modified Polyol Process, Zachary J. Huba, Kyler J. Carroll, Everett E. Carpenter

Chemistry Publications

High magnetization, soft ferromagnetic FeCo alloy nanoparticles were synthesized at various Fe to Co ratios using a modified polyol process. Transmission electron microscopy images revealed that Fe-rich particles had a cubic shape with a mean particle size of 100 nm, while Co-rich particles had a spherical shape. A maximum saturation magnetization of 212 emu/g was recorded for both Fe₆₀Co₄₀ and Fe₇₅Co₂₅ particles. X-ray diffraction scans at room temperatureof synthesized particles were characteristic of body-centered-cubic single-phase FeCo. Variabletemperature x-ray diffraction scans under N₂ gas revealed an order–disorder transition at 600 °C and a transition …

Spin Transition In Gd3n@C-80, Detected By Low-Temperature On-Chip Squid Technique, L. Chen, E. E. Carpenter, C. S. Hellberg, H. C. Dorn, M. Schultz, W/ Wernsdorfer, I. Chiorescu

Chemistry Publications

We present a magnetic study of the Gd₃N@C₈₀ molecule, consisting of a Gd-trimer via a nitrogen atom, encapsulated in a C₈₀ cage. This molecular system can be an efficient contrast agent for magnetic resonance imaging (MRI) applications. We used a low-temperature technique able to detect small magnetic signals by placing the sample in the vicinity of an on-chip SQUID. The technique implemented at the National High Magnetic Field Laboratory has the particularity of being able to operate in high magnetic fields of up to 7 T. The Gd₃N@C₈₀shows a paramagnetic behavior and …

Research-Based Resources To Teach Chemistry : Chem Demos, Guided Inquiry Labs, Professional Development & Teaching Strategies., Anil Banerjee

Faculty Bibliography

No abstract provided.

Seasonal Spatial And Temporal Distribution Of Daytime Inhalation-Level Particulate Matter In Washington, Dc, Samuel Abegaz

Faculty Bibliography

The spatial and temporal variations of inhalation-level airborne particulate matter in four Wards of Washington, DC were characterized during two six-week observation periods in the summer and fall of 2003. The average aerosol mass densities during the summer (19.3 μg m −3) were roughly double the average values observed during the fall (10.0 μg m−3). In general, a concentration gradient is observed from north to south across the District of Columbia with the gradient becoming more pronounced in the summer time. The fine aerosol size fractions centered at 0.15 and 0.30 microns dominated the mass distributions during both observation periods …

Henrietta Lacks And The Miraculous Hela Cells, Debriana Giboney

Natural Sciences Student Research Presentations

No abstract provided.

The Immortal Life Of Henrietta Lacks, Ashea Ryans

Natural Sciences Student Research Presentations

No abstract provided.

Henrietta Lacks And Hela, Abby Miles

Natural Sciences Student Research Presentations

No abstract provided.

Semen Quality And Chemical Oxidative Stress; Quantification And Remediation, Saleem Ali Bani-Hani

ETD Archive

The necessary multi-step process to prepare human semen for assisted reproduction (AR) such as in vitro fertilization (IVF) is known to induce oxidative stress in human spermatozoa and subsequent damage to the integrity of their cell components and, thus, to their function. Literature reports have viewed this as a potential link with the high frequency of birth defects among the IVF babies. In this work, we studied the effect of incubation and centrifugation on human sperm quality using established AR protocols. We found that in vitro incubation and centrifugation (20 min at 220g) of sperm generally degrade sperm quality in …

Quantitative And Qualitative Mass Spectrometric Analysis Of Anticancer Agents, Drugs Of Abuse And Enzyme-Inhibitor Complexes, Keri M. Smith

ETD Archive

Mass spectrometry is a valuable tool in the analysis of many types of compounds. From small molecules to large proteins, mass spectrometry can help to interrogate samples and give insights to the origins of disease as well as calculate an exact concentration. Bioanalytical method development is an integral component in the measurement of such compounds. To facilitate proper analytical investigation, the process of method development, analysis, and interpretation must be understood. This work describes the basis and procedure for bioanalytical method development and its detailed application to preclinical studies of the antineoplastic agent hexamethylene bisacetamide and measurement ofillicit drugs of …

Novel Thermal Analytical Techniques To Characterize Drugs And Drug Delivery, Lakshmi Swetha Kaza

ETD Archive

This thesis encompasses three significant projects. The study includes the characterization and evaluation of the properties of a commercial contraceptive transdermal patch, Ortho Evra® by Dielectric Analysis and Differential Scanning Calorimetry (DSC). This study helps in monitoring the mobility of the drug and transport properties by Isothermal and Scanning Dielectric Analysis as a function of temperature and frequency. The drugs in this product are norelgestromin and ethinyl estradiol. DSC was used to detect any crystalline character of the drugs by their fusion properties. Having no melting endotherm and detecting a glass transition temperature suggested that the drugs in the patches …

Utilization Of Dna/Dendron Conjugates For Dna Monolayers On Gold: A Comparative Study, Erik Steven Vint

Theses, Dissertations and Capstones

The uses of single-stranded DNA probes tethered to solid supports have gained interest in recent years due to the increasing number of applications these systems present. However, the traditional methods used to fabricate these monolayers are flawed. The synthesis and purification of multithiol headgroups for improvement upon ssDNA surface attachment for the fabrication of self-assembled monolayers on gold surfaces is described. Generation 4 polyamidoamine dendrons were conjugated to ssDNA oligomers in a one-to-one ratio and functionalized to provide multiple thiol groups for possible surface attachment. Modification of the dendrimer’s amine terminated periphery groups to thiols was confirmed using 1 H …

Development Of A Novel Gc/Ms Method For The Detection Of Nicotinamide And Activity Of Adp-Ribosylating Toxins, Lindsay R. Lermo, Thomas O. Munson, Michael H. Godsey

CUP Undergraduate Research

ADP-ribosylating toxin enzymes break NADH (Figure1) and transfer the ADP-ribosyl group to a residue on a target protein, permanently inactivating or denaturing the protein. This activity is typically detected with a radioassay, which is expensive and requires radioactive materials.

ADP-ribosylation corresponds with the release of nicotinamide. It is possible to detect nicotinamide with a Gas Chromatograph/Mass Spectrometer (GC/MS) (Jacobson, Dame, Pyrek & Jacobson, 1995). The purpose of this study is to measure ADP-ribosylation activity using GC/MS by detecting the liberated nicotinamide. By derivatizing the nicotinamide, the detection limit was lowered to 0.5ng/μl. Control measurements of ADP-ribosylation activity by a cholera …

Progress Toward Removal Of The Purification Tag In A Putative Toxin Protein Via Site-Specific Mutagenesis And Proteolytic Cleavage, Joanna L. Fridlund, Bethany G. Taylor, Michael H. Godsey

CUP Undergraduate Research

Putative toxin protein BC_2332, isolated from Bacillus cereus, which is a relative of Bacillus anthracis, shows similarity in the active site to ADP-ribosylating proteins present in cholera and diphtheria. Preliminary attempts to measure the activity of the putative toxin were unsuccessful leading to the hypothesis that the purification tag is hindering the activity. This hypothesis is supported by crystal structure analysis showing the putative active site occupied by the purification tag. Our objective was to remove the purification tag, via two different methods, in order to relieve potential inhibition. Both methods have faced obstacles and the work is continuing.

A New Noncovalent Force: Comparison Of P∙∙∙N Interaction With Hydrogen And Halogen Bonds, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

When PH(3) is paired with NH(3), the two molecules are oriented such that the P and N atoms face one another directly, without the intermediacy of a H atom. Quantum calculations indicate that this attraction is due in part to the transfer of electron density from the lone pair of the N atom to the σ(∗) antibond of a P-H covalent bond. Unlike a H-bond, the pertinent hydrogen is oriented about 180° away from, instead of toward, the N, and the N lone pair overlaps with the lobe of the P-H σ(∗) orbital that is closest to the P. In …

Introductory Chemistry, David W. Ball

Textbooks

This is the textbook for CHEM 105 at Liberty University.

David W. Ball of Cleveland State University brings his new survey of general chemistry text, Introductory Chemistry, to the market with a fresh theme that will be sure to hold student interest: "Chemistry is Everywhere." Introductory Chemistry is intended for a one-semester introductory or preparatory chemistry course. Throughout the chapters, David presents two features that reinforce the theme of the textbook, that chemistry is everywhere.

Effect Of Intraligand Π-Delocalization On The Photophysical Properties Of Two New Ru(Ii) Complexes, Dean H. Johnston

Chemistry Faculty Scholarship

Two new Ru(II) complexes, [Ru(bpy)2(1-COO-iqu)]+ (2; bpy = 2,2_-bipyridine, 1-COO-iqu− = isoquinoline- 1-carboxylate) and [Ru(bpy)2(3-COO-iqu)]+ (3; 3-COO-iqu− = isoquinoline-3-carboxylate), were prepared and their crystal structures solved. The ground and excited state properties of 2 and 3 were characterized and compared to those of [Ru(bpy)3]2+ (1). The presence of the oxygen atom in the Ru(II) coordination sphere makes 2 and 3 easier to oxidize than 1. The Ru→bpy MLCT absorption and emission of 2 and 3 are red-shifted relative to that of 1 in CH2Cl2, and the E00 energies were estimated to be 1.89 eV and 1.95 eV from the low …

Enantiocontrolled Solid-State Photodimerizations Via A Chiral Sulfonamidecinnamic Acid, Kraig A. Wheeler, Joshua D. Wiseman, Rebecca C. Grive

Faculty Research and Creative Activity

The supramolecular patterns of three polymorphs of a chiral sulfonamidecinnamic acid reveal components effectively organized into predetermined hydrogen-bonded dimers with favorable <3.8A ° olefin spacing for enantioselective single-crystal-to-single-crystal [2 + 2] photodimerization reactions.

2-[(Naphthalen-1-Yl­Methyl­­Idene)Amino]-5-Methyl­Phenol, Ralph Isovitsch, Gabriella Orona, Vanessa Molinar, Frank R. Fronczek

Chemistry

No abstract provided.

Modifiable Hyperbranched Polyester Drug Delivery Systems, Dorothy Ogden

Browse all Theses and Dissertations

This work encompassed synthesis and characterization of biocompatible hyperbranched polyester drug delivery systems prepared with fumaric acid, glycerol and polyethylene glycol. The polymers were manufactured in the melt utilizing A2 + CB2 polymerization. The ratio of A2:CB2 was modified and excess B was added to end-cap the polymers to avoid cross-linking. Fumaric acid was selected as the A2 monomer because the double bond provided a site for polymer backbone modification or covalent attachment of active pharmaceutical ingredients. Acetaminophen and Ondansetron Hydrochloride were added to evaluate feasibility of using the polyesters as drug delivery systems. The weight average molecular weight of …

Unexpected Origins Of The Enhanced Pairing Affinity Of 2 '-Fluoro-Modified Rna, Pradeep Pallan, Emily M. Greene, Paul A. Jicman, Rajendra K. Pandey, Muthiah Manoharan, Eriks Rozners, Egli Martin

Chemistry Faculty Scholarship

Various chemical modifications are currently being evaluated for improving the efficacy of short interfering RNA (siRNA) duplexes as antisense agents for gene silencing in vivo. Among the 2'-ribose modifications assessed to date, 2'deoxy-2'-fluoro-RNA (2'-F-RNA) has unique properties for RNA interference (RNAi) applications. Thus, 2'-F-modified nucleotides are well tolerated in the guide (antisense) and passenger (sense) siRNA strands and the corresponding duplexes lack immunostimulatory effects, enhance nuclease resistance and display improved efficacy in vitro and in vivo compared with unmodified siRNAs. To identify potential origins of the distinct behaviors of RNA and 2'-F-RNA we carried out thermodynamic and X-ray crystallographic analyses …

An Evaluation Study Of The Effectiveness Of Using A Reaction-Based Process For Hydrazine Waste Remediation, Cristina M. Oropeza

Electronic Theses and Dissertations

Hydrazine (HZ) and monomethylhydrazine (MMH) are used extensively as hypergolic propellants at Kennedy Space Center. These highly reactive fuels are considered highly toxic, and potentially carcinogenic. Consequently, the transport, handling, and disposal of hydrazines is strictly regulated to protect personnel and the environment. Currently, KSC generates large volumes of hydrazine-laden wastewater for disposal. This waste is contained and shipped on public highways for subsequent disposal by incineration presenting a potentially catastrophic threat to the environment and the general public in the event of an accidental release. Other existing remediation methods include oxidative and reductive pathways as well as biodegradation in …

Synthesis And Characterisation Of Macrocycles Containing Both Tetrazole And Pyridine Functionalities, Adrienne Fleming, Jackie Gaire, Fintan Kelleher, John Mcginley, Vickie Mckee

Articles

The syntheses of tetra-tetrazole macrocycles containing at least one 2,6-bis(tetrazole)pyridine unit, linked by a variety of n-alkyl (n = 3, 5, 7 or 9 carbon atoms) chain lengths, are described. There has been no previous incorporation of the pyridine moiety into a tetra-tetrazolophane macrocycle. The crystal structure of one such tetra-tetrazole macrocycle has also been structurally characterised and revealed a bowl-shaped conformation.

Dications Of 3-Phenyl-Indenylidene Dibenzo[ A.D ]Cycloheptene: The Role Of Charge In The Antiaromaticity Of Cationic Systems, Nancy S. Mills, Francine E. Cheng, Joseph M. Baylan, Cornelia Tirla, Jennifer L. Hartmann, Kiran C. Patel, Bart J. Dahl, Sean P. Mcclintock

Chemistry Faculty Research

Dications of 9-(3-phenyl-1H-inden-1-ylidene)-5H-dibenzo[a,d]cycloheptene, 52+, were prepared by oxidation with SbF5 in SO2ClF, and their magnetic behavior was compared to dications of 9-(3-phenyl-1H-inden-1-ylidene)-9H-fluorene, 22+. The good correlation between the experimental 1H NMR shifts for the dications that were oxidized cleanly and the chemical shifts calculated by the GAIO method supported the use of the nucleus independent chemical shifts, NICS, to evaluate the antiaromaticity of the indenyl systems of 22+/52+ and their unsubstituted parent compounds, 62+ and 72+, as well as the antiaromaticity of the fluorenyl system of 22+/72+ …