Physical Sciences and Mathematics Commons^™

Synthesis And Characterization Of Rhenium 2,2′-Pyridylnaphthyridine Metal Complexes, Benjamin F. Solomon

Honors Theses

Rhenium (Re) is a group 7 heavy 5d transition metal in the same family as manganese (Mn) and technetium (Tc). Re-carbonyl complexes are known to be catalysts for many different kinds of reactions from C-C bond formation to reduction reactions like CO₂ reduction (CO₂RR)^1,2. With this in mind, we have prepared a set of six Re-carbonyl complexes of 2,2′-pyridyl-1,6-naphthyridine (1,6- pynap) and 2,2′-pyridyl-1,8-naphthyridine (1,8-pynap), a redox non-innocent ligand containing a bpy moiety as well as an additional aryl nitrogen binding location at which another metal-ligand bond could form. We have synthesized these complexes as precursors …

Synthesis And Study Of Unsymmetrical Bidentate Bis(Phosphino)Pyrrole Ligands And Their Transition Metal Complexes, Julia F. Vidlak

Honors Theses

Our laboratory has reported the synthesis and characterization of a broad library of unsymmetrical bidentate bis(phosphino)pyrrole (BPP) ancillary ligands for use in nickel-catalyzed cross-coupling reactions. The electronic and steric properties of nickel complexes bearing these ligands are examined, and our data support the hypothesis that these ligands produce nickel complexes with electron-deficient metal centers. The syntheses of (BPP)Ni(o-tolyl)Cl precatalysts for utilization in nickel-catalyzed Buchwald-Hartwig Amination are described, and preliminary reactivity studies reveal that (BPP)Ni(o-tolyl)Cl precatalysts are effective in promoting C–N cross-coupling reactions. Finally, we report steric measurements and electronic properties obtained from computed (BPP)NiCl2 and (BPP)Ni(CO)2 complexes, respectively. Additional reactivity …

Stereochemical Control In Suzuki Cross Coupling Reactions Of Acyclic (Z)-Beta-Haloacroleins, William Carrick

Honors Theses

Beta-chloroenals are readily accessible substances and are efficient precursors for a variety of heterocyclic compounds. Suzuki type cross-coupling reactions of such compounds with arylboronic acids yield ��,��-diarylacroleins with control of stereochemistry. The oxidation of these enals to the corresponding acids and subsequent oxidative lactonization leads to formation of the respective coumarins. The chemistry involved in these transformations with special attention to stereochemistry of the Suzuki coupling reaction will be discussed. A full NMR analysis involving 1H, 13C, COSY, NOESY, HSQC, and HMBC was performed to unambiguously confirm the structure and show that the reaction proceeds with retention of stereochemistry.

Adhering Homogeneous Molecular Electrocatalysts Entrapped In Micelles To Electrode Surfaces, Emily Kuhlmann

Honors Theses

Heterogeneous catalysts are important to industrial use; however, mechanistic studies are difficult because they lack the easy tunability of homogeneous catalysts. One solution could be to immobilize homogeneous catalysts using micelles while maintaining catalytic properties and activities.

Aldol Condensations And Nitrile Aldol Reactions Mediated By Trimethylsilyl Trifluoromethanesulfonate, Samuel R. Bottum

Honors Theses

In the presence of excess trimethylsilyl trifluoromethanesulfonate (TMSOTf), ketones and esters undergo aldol addition and dehydration to yield chalcones and cinnamates. This one-pot reaction proceeds through in situ enol silane formation, avoiding the need to pre-form and purify the nucleophile in the Mukaiyama aldol reaction. The stoichiometry of the TMSOTf controls whether the reaction proceeds with simple addition or addition-dehydration. When (trimethylsilyl) acetonitrile is stirred with an aldehyde and TMSOTf, nitrile aldol addition is observed.

Nanoparticles As Alternative Ceramic Glaze Colorants, Nathan Dinh

Honors Theses

Metallic nanoparticles, including gold and silver, have been used in wide-ranging applications due to their versatile characteristics. These include catalysis, biosensing, imaging, cancer treatments, and art. Due to the phenomenon called surface plasmon resonance, metallic particles change optical properties when sized in the nanoscale based on their composition, shape, diameters, or aspect ratios. In study, these robust nanoparticle systems are applied as an alternative to traditional bulk metal colorants in ceramic glazes.

In this study, the research goals are two-fold: to understand firing mechanism on the gold nanoparticle size and to develop these processes for wider use by regular artisans. …

Synthesis, Characterization, And Reactivity Of Palladium Proazaphosphatrane Complexes, Adrian D. Matthews

Honors Theses

Palladium-catalyzed cross-coupling reactions provide an efficient pathway to a wide variety of otherwise inaccessible compounds. In this study, the synthesis and reactivity of novel palladium proazaphosphatrane complexes that are believed to be intermediates in C–N cross-coupling reactions are described. Both the fundamental reactivity of these complexes and elementary steps involved in a catalytic process are demonstrated. The catalytic viability of palladium proazaphosphatrane complexes is shown through stoichiometric and catalytic cross-coupling reactions. Our findings support the long-standing hypothesis that proazaphosphatranes are conformationally flexible ligands that stabilize a number of catalytic intermediates.

Design Of New Ruthenium Complexes For Photoactivated Chemotherapy, Lindsey Paul

Honors Theses

Photoactivated chemotherapy (PACT) offers a targeted approach to cancer treatment through selective drug activation. Substitutionally labile ruthenium-based prodrugs undergo ligand-loss when irradiated, producing an unbound ligand and a Ru-aqua complex. We report the synthesis and cytotoxicity of several new ruthenium-centered complexes and their irradiation products for use in PACT. A series of complexes were synthesized in order to study the effects of structural differences on cell viability. Cell viability was tested on T47D human breast cancer cells in the presence of compound to determine cytotoxicity and dose-response. While neither the Rucomplexes nor their ligands demonstrated cytotoxicity, their Ru-aqua dissociation complexes …

Structural Investigations Using Theoretical Approaches : A Study Of Metal Halides, Borylenes, Phenalenyl Complexes And Σ-Hole Interactions, Supreeth Prasad

Honors Theses

The anomalous bending in the group 2 binary dihalides and the absence of this behavior in group 12 systems is well established. Their structuralpreferences contradict simple bonding models, yet they have received little to no attention in the literature. In this work, for the first time, the gas phase structuralpreferences of the groups 2 and 12 mixed (ternary) dihalides MXY (M=Be, Mg, Ca, Sr, Ba, Ra, Zn, Cd and Hg,and X, Y=F, Cl, Br, I, At) are investigated at high levels of theory. I extend a previously established softness criterion for bending to the mixed systems and I find that …

Investigating Medicinally Important Portein-Protein And Protein-Ligand Interactions : A Computational Approach, Cooper Ashley Taylor

Honors Theses

Molecular dynamics (MD) simulations and computational chemistry allow for an atomistic understanding of protein-protein and protein-ligand binding motifs. Through the use of MD, medicinally relevant complexes can be examined in detail unattainable by experimental methods. Within this work, systems pertinent to both Alzheimer’s Disease and HIV-1 are probed and thoroughly sampled to help elucidate potential therapeutic pathways. We used molecular dynamics and free energy estimations to gauge the affinity for the binary and ternary complexes of KLC1, APP and JIP1, three proteins all believed to be involved in the propagation of Alzheimer’s Disease. Two areas of thought exist suggesting that …

Synthetic Flexibility Of A Bromopyrrole Ester Intermediate : Toward Novel Biologically Active Compounds, Scott Cameron Yeudall

Honors Theses

Compounds containing the pyrrole ring as a core structural motif continue to show significant biological activity, and both natural product derivatives and novel chemical scaffolds show potential for use as pharmaceuticals in treating a variety of cancers, infections, and inflammation. Given the widespread and important applications of compounds containing this motif, novel, rapid, and selective methods for the synthesis of multifunctional pyrroles is of some importance. Previous work in our group has utilized palladium-mediated Suzuki cross-coupling as a powerful tool for functionalizing activated bromopyrrole esters, generating structural analogues of bioactive natural products. We have also used a similar approach to …

Structure-Function Relationships Affecting The Sensing Mechanism Of Monolayer-Protected Cluster Doped Xerogel Amperometric Glucose Biosensors, Luke T. Dipasquale

Honors Theses

The research conducted in the Leopold Bioanalytical and Nanomaterials Analytical Chemistry Lab prior to the summer of 2013 focused on the synthesis of a functional biosensor equipped with a nanoparticle network embedded in a xerogel film for the detection of glucose. Xerogel-based films featuring embedded glucose oxidase enzyme and doped with alkanethiolate-protected gold NPs, known as monolayer protected clusters (MPCs), exhibit significantly enhanced performance compared to analogous systems without NPs including higher sensitivity, faster response time, and extended linear/dynamic ranges.

The following presented research is a systematic study of the structure-function relationships critical to understanding the sensing mechanism of the …

The Application Of Formyl Group Activation Of Brompyrrole Esters To A Formal Synthesis Of Lycogarubin C, Jon Patteson

Honors Theses

Lycogarubln C is a member of an interesting family of marine natural products, which contains two indole groups appended to a pyrrole scaffold at the 3 and 4 positions. Such compounds are proposed to be biosynthetically related to the important antitumor agent, Staurosporine. Recent work in our lab involving the use of Suzuki cross-coupling reactions of an ortho activated bromoformylpyrrole ester has provided key intermediates for the synthesis of pyrrole natural products and pyrolle-based analogues.

A Computational Investigation Of Halogen Bonding With Halomethanes And Their Group 14 Analogues, William Kretz

Honors Theses

It is known that halogen bonding is supported by so-called sigma holes on halides that interact with bases, but what are the limits of that interaction? How does the interaction depend on the group to which the halogen atom is bonded? To answer these questions, complexes of the form MH3X---Y (where M=C, Si, Ge, Sn, Pb; X= F, Cl, Br, I and Y are Lewis bases) were optimized and their energetics and relative stability were assessed. The Lewis bases range from NH3 to the more complicated pentafluroropyridine (F-py). Calculations were performed entirely at the MP2(full) level of theory, including frequency …

The Effects Of Coal Mining On Health In Appalachia : Global Context And Social Justice Implications, Adrienne Schmidt

Honors Theses

The purpose of this report is to investigate the environmental and health effects of coal mining in the Appalachian region of the United States in the context of global natural resource extraction, explore existing regulation for the reduction of negative environmental health effects of mining in Appalachia, and explore the social justice implications of current mining practices. The research for this report was limited to literature published in English. It was found that there are widespread negative health effects of mining in Appalachia due to environmental toxins, a toxic social environment of limited economic opportunity, and occupational health hazards. The …

One-Pot Reactions Of Ethyl Propiolate, Ana Maria Neferu

Honors Theses

Through an efficient one-pot reaction sequence, ethyl propiolate can be transformed into a complex, usefully functionalized bicyclic product. Thioconjugate addition yielding Z-selective enoates has been developed for both aromatic thiols (trialkylamine-catalyzed) and aliphatic thiols (KOt-Bu-catalyzed). The oxidation of the thioenoates thus generated is followed by Li-catalyzed oxidation to sulfones using mCPBA, and Li-catalyzed Diels–Alder addition of cyclopentadiene. These subsequent steps are performed in situ, without any purification of intermediates. The yields obtained using the described synthesis are acceptable for a one-pot three-step sequence. Preliminary conjugate addition results with alcohols and amines as nucleophiles are also presented.

Synthesis Of Indole Containing Pyrimidines, Kara Finzel

Honors Theses

No abstract provided.

Studies On Vinamidinium Salt Amine Exchange Reactions, Borohydride Reductions, And Subsequent Transformations, Xian Jia

Honors Theses

This research would not have been possible without the extraordinary guidance of Dr. John Gupton who I like to think of as the brains behind the operation. In addition, Dr. Nakul Telang, a postdoctoral fellow in Dr. Gupton’s research lab, has provided great support, assistance and humor throughout my undergraduate research career. The other student members of the lab that I would like to recognize for their support and contribution to this project are Ben Giglio, James Eaton, Peter Barelli, Mona Hovaizi, Kayleigh Hall, Scott Welden, Kara Finzel. We also thank the National Institutes of Health (grant no. R15‐CA67236) for …

Optical Properties Of Multilayer-Polyelectrolyte Films With Incorporated Gold Nanomaterials (Solid Nanoparticles And Hollow Nanoshells), Robert Watson Day

Honors Theses

The growth of various multilayer‐polymer multilayer‐nanoparticle films was successfully achieved. Multilayer‐polymer multilayer‐nanoparticle films with 1, 3, and 5 polymer layers between nanoparticle layers exhibit significantly different optical properties due to the differences in magnitude of particle plasmon coupling. These film systems were also successfully extended to hollow gold nanoshells, which have significantly enhanced optical properties in comparison to solid gold nanoparticles of similar sizes. A proposal for utilizing this increased sensitivity of the gold nanoshells to explore the ‘microenvironments’ for optimizing potential sensing applications is also presented.

Molecular Modeling Of Para-Benzyne And A Series Of Push-Pull [14]-Pyridoannulenes, Evan B. Wang

Honors Theses

Molecular modeling is vital for gaining insight into experimental results and discovering molecular properties not yet characterized by experiment. Depending on the type of molecule under investigation, certain methods will yield more accurate and revealing answers. In the first project, a state-averaged, multireference complete active space (CAS) approach was used for the determination of the vertical excitation energies of valence and Rydberg states of para-benzyne. Orbitals were generated with a 10- and 32-state averaged multiconfigurational self consistent field (MCSCF) approach. Electron correlation was included using multireference configuration interaction with singles and doubles (MR-CISD), including Pople correction for size extensivity (MR-CISD+Q), …

Polyelectrolyte-Linked, Multi-Layer Film Assemblies Of Aqueous Nanoparticles And Nanoshells, Anne Galyean

Honors Theses

Multi-layer films of nanoparticles and nanoshells featuring various polymeric linkage molecules have been assembled and their optical properties characterized. The growth dynamics, including molecular weight effects, and stability of the various nanoparticle film constructions, using both single polymer as well as combinations of alternating charge polyelectrolytes as linking mechanisms, are presented. The polymeric linkers studied include poly-L-lysine, poly-L-arginine, poly(allylamine hydrochloride), and polyamidoamine dendrimers. Significantly air stable films were achieved with the use of multi-layered polymeric bridges between the nanoparticles and nanoshells. Optical sensitivity normally observed with these nanomaterials in solution was observed for their corresponding film geometries, with the nanoshell …