Chemistry Commons^™

Synthesis, Reactivity, And Nmr Trends Of Early Transition Metal Compounds, Tabitha Marie Cook

Doctoral Dissertations

This dissertation focuses of three different subjects. The first is the synthesis and characterization of heptacoordinate amidinate compounds. Heptacoordinate compounds are not common, but their structures have been studied. Group 4 amidinate compounds have been used as precursors in the CVD/ ALD processes. Ancillary ligands, such as amidinates, have been used to reduce air-sensitivity of complexes. Reactions of these complexes with water have been used to make metal oxide thin films.

In the first study, the complexes Zr[MeC(NⁱPr)₂]₃Cl [zirconium trisamidinate chloride], Hf[MeC(NⁱPr)₂]₃Cl [hafnium trisamidinate chloride], Zr[MeC(NⁱPr) …

Modeling The 3-Dimensional Structure Of D(Cgcgaattcgcg) And Its 8-Oxo-Da5 Adduct With 1h Nmr Noesy Refinements, Christopher Miles Reynolds

MSU Graduate Theses

Since the characterization of the oligomer d(CGCGAATTCGCG) has been published by Dickerson et al., computational studies have been carried out to produce an accurate 3D model. These models are important for visualizing how certain DNA repair enzymes, such as the glycosylases, recognize sites of damage by signatures of local 3D distortion. Using 1H NOESY-generated internuclear distances to replicate the model of this oligomer and a derivative with an 8-oxo-dA5 lesion, we propose characteristics of helical distortion that DNA glycosylases might use for identifying this form of damage. In addition, this method of comparison can be used to study the repair …

Rapid Screening And Quantification Of Synthetic Cannabinoids In Dart-Ms And Nmr Spectroscopy, Michael A. Marino Ed.D., Robert B. Cody, A. John Dane, Ling Huang

Faculty Works: Biology, Chemistry, and Environmental Studies

The usage of herbal incenses intentionally doped with synthetic cannabinoids has caused an increase in medical incidents and has triggered legislation to ban these products throughout the world. Law enforcement agencies are experiencing sample backlogs due to the variety of the products and the addition of new and still-legal compounds. In our study, proton Nuclear Magnetic Resonance spectroscopy (NMR) was employed to promptly identify the synthetic cannabinoids after their rapid, direct detection on the herbs and in the powders by Direct Analysis in Real Time-Mass Spectrometry (DART-MS). Compared to conventional lengthy pre-NMR sample clean-up and purification, a simple sample preparation …

Interaction Of Spliceosomal U2 Snrnp Protein P14 With Its Branch Site Rna Target, William Perea Vargas

Dissertations, Theses, and Capstone Projects

Newly transcribed precursor messenger RNA (pre-mRNA) molecules contain coding sequences (exons) interspersed with non-coding intervening sequences (introns). These introns must be removed in order to generate a continuous coding sequence prior to translation of the message into protein. The mechanism through which these introns are removed is known as pre-mRNA splicing, a two-step reaction catalyzed be a large macromolecular machine, the spliceosome, located in the nucleus of eukaryotic cells. The spliceosome is a protein-directed ribozyme composed of small nuclear RNAs (snRNA) and hundreds of proteins that assemble in a very dynamic process. One of these snRNAs, the U2 snRNA, is …

Evaluating The Role That A Putative Fxiii Binding Site Plays In The Reactivity Of Three Glutamines Within The Coagulation Substrate Fibrinogen Aα (233-425)., Chad A. Stephens

College of Arts & Sciences Senior Honors Theses

Formation of a stable thrombus in vivo depends on the interaction between fibrinogen and the transglutaminase factor XIII (FXIII). Characteristics of blood plasma, such as concentration of Ca2+, are well known to regulate the activation and subsequent reactivity of FXIII. Despite this knowledge, the role fibrin(ogen) plays in modulating FXIII activation and reactivity is not entirely delineated. Currently, the coagulation substrate fibrinogen Aα is proposed to contain a binding site for the active factor XIII with fibrinogen Aα E396 serving a major role. A series of mass spectrometry and NMR spectroscopy studies was conducted to assess whether putative interactions between …

Biodegradable Copolymers Made With Magnesium Complexes, Reile M. Slattery, Joseph M. Fritsch

Seaver College Research And Scholarly Achievement Symposium

In this study, a bis-ligated magnesium complex was used to initiate the ring opening copolymerization of L-lactide (L-LA) and ϵ-caprolatone (ϵCL) and the isolated polymeric materials were characterized with NMR spectroscopy. First, the simultaneous feeding of both monomers resulted in the synthesis of homopolymer poly-lactic acid (PLA). Polymerization experiments with sequential addition of L-LA and ϵCL yielded surprising results. The ring opening polymerization of ϵCL yielded poly-caprolactone (PCL) which with the addition of L-LA yielded a di-block copolymer of PCL and PLA. The presence of the two homopolymer blocks in the copolymer was identified with ¹³C NMR where …

Optimizing Protocols For Carbohydrate Nmr Chemical Shift Computations, Michael Trent Kemp

USF Tampa Graduate Theses and Dissertations

The spectroscopic analysis of cellulose is experimentally challenging while computationally accessible with recent developments in NMR code. However, prior to using density functional theory to calculate the NMR chemical shifts of cellulose, smaller, sugar-like molecule systems need to be benchmarked against experimental values. The quantum mechanical / molecular mechanical (QM/MM) calculations presented herein utilize six test systems: ethanol, pyridine, pyrrolidine, pyrrole, myo-inositol and scyllo-inositol in conjunction with the reference tetramethylsilane used to scale the calculated isotropic shielding tensors to relative chemical shifts. The effect of solvent on calculated NMR chemical shifts has also been investigated with regard to quantity of …

Rapid Identification Of Synthetic Cannabinoids In Herbal Incenses With Dart-Ms And Nmr, Michael A. Marino Ed.D., Robert Cody, Brandy Voyer, Mercurio Veltri, Ling Huang, A. John Dane

Faculty Works: Biology, Chemistry, and Environmental Studies

The usage of herbal incenses containing synthetic cannabinoids has caused an increase in medical incidents and triggered legislations to ban these products throughout the world. Law enforcement agencies are experiencing sample backlogs due to the variety of the products and the addition of new and still-legal compounds. In our study, proton nuclear magnetic resonance (NMR) spectroscopy was employed to promptly screen the synthetic cannabinoids after their rapid, direct detection on the herbs and in the powders by direct analysis in real time mass spectrometry (DART-MS). A simple sample preparation protocol was employed on 50 mg of herbal sample matrices for …

Fundamental Studies Of Humic Acid's Influence On Pollutant Toxicity To Aquatic Organisms, Rachel Dawn Deese

LSU Doctoral Dissertations

The main purpose of the research presented in this dissertation was to further understand the intricate and convoluted interactions between natural organic material, biological entities, and pollutants. This was achieved by utilizing humic acids (HAs) from differing sources, chemically modified humic acid, two biological entities (model biomembranes and Artemia Franciscana), and three types of pollutants (cations, surfactants, and carbon nanotubes). Fluorescence spectroscopy and model biomembranes were used to measure the change in HA’s ability to interact with the biomembranes in the presence of cations. Three differently sourced HAs, chemical modified HAs, and a range of cations were studied to elucidate …

Investigating The Structure Of The Papain-Inhibitor Complex Using Spr And Nmr, Margaret Sara Thomasson

LSU Doctoral Dissertations

Cysteine proteases (CPs) are enzymes with a nucleophilic thiol in their active sites. Inhibitors of cysteine proteases (ICPs) occur naturally in bacterial pathogens and some protozoa. In parasites, ICPs are often virulence factors, contributing to the formation and survival of amastigotes within host cells. These amastigotes have higher CP activity, therefore making both ICPs and CPs potential drug targets. Despite great genetic variability, ICPs contain highly conserved structural features, including a series of defined loops that play a significant role in binding CPs. Papain, a CP from Carica papaya, complexes with ICP from Leishmania mexicana. Although the individual 3-D structures …

Detailed Source-Specific Molecular Composition Of Ambient Aerosol Organic Matter Using Ultrahigh Resolution Mass Spectrometry And H Nmr, Amanda S. Willoughby, Andrew S. Wozniak, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Organic aerosols (OA) are universally regarded as an important component of the atmosphere that have far-ranging impacts on climate forcing and human health. Many of these impacts are related to OA molecular characteristics. Despite the acknowledged importance, current uncertainties related to the source apportionment of molecular properties and environmental impacts make it difficult to confidently predict the net impacts of OA. Here we evaluate the specific molecular compounds as well as bulk structural properties of total suspended particulates in ambient OA collected from key emission sources (marine, biomass burning, and urban) using ultrahigh resolution mass spectrometry (UHR-MS) and proton nuclear …