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Photo-Isomerizable Complementary Hydrogen Bond Arrays, Jeffrey S. Pleizier

Electronic Thesis and Dissertation Repository

The use of light as an external stimulus provides a non-invasive technique to induce large changes in physical and chemical properties of a substrate. The incorporation of a photochromic subunit into supramolecular polymeric systems therefore adds a potential "smart" quality for polymer manipulation. The azo moiety (-N=N-) is one of the most popular photochromic units as the trans to cis isomerization results in a large degree of spatial rearrangement. This present thesis exploits the azo group by its incorporation into complementary hydrogen bonded complexes. Hydrogen bonding acceptor groups attached to the periphery of the central azo photoswitch provided strong complexation …

Synthesis And Characterization Of Alkynyl-Substituted Boron Formazanate Dyes, Alex Van Belois

Electronic Thesis and Dissertation Repository

This thesis outlines the synthesis and characterization of the first alkynyl-substituted boron formazanate complexes and explores the electronic and structural changes that occur in these systems as a result of chemical modification at the boron centre. An alkynyl-substituted complex appended with a redox-active handle is also described, and the chemical reduction and oxidation of this system is explored. Finally, a model reaction is examined as a proof of concept toward the post-synthetic modification of these boron formazanate systems through copper(I)-assisted alkyne-azide cycloaddition chemistry. Exploiting chemistry at the boron centre opens up new possibilities toward incorporating function onto the boron formazanate …

The Development Of Metal Complexes As Components Of Fluorescent And Nuclear Imaging Probes, William Turnbull

Electronic Thesis and Dissertation Repository

The advent of molecular imaging as a discipline has drastically improved our ability to understand the biochemical and cellular events that drive life, death and disease. This thesis will document the discovery of new metal chelators for Re/^99mTc, new methods of incorporating these metals into peptide structures, as well as new fluorescent compounds. These novel methods and compounds may be used in the development of molecular imaging probes for single photon emission computed tomography (SPECT) and optical imaging techniques, with applications for differentiating cancerous tissue from benign and healthy.

Chapter 2 discusses the development of a dual modality …

Effects Of High Pressure On Photochemical Reactivity Of Organic Molecular Materials Probed By Vibrational Spectroscopy, Jiwen Guan

Electronic Thesis and Dissertation Repository

Chemical transformations of molecular materials induced by high pressure and light radiation exhibit novel and intriguing aspects that have attracted much attention in recent years. Particularly, under the two stimuli, entire transformations of molecular species can be realized in condensed phases without employing additional chemical constraints, e.g., the need of solvents, catalysts or radical initiators. This new synthetic approach in chemistry therefore satisfies increasing need for production methods with reduced environmental impacts. Motivated by these promises, my Ph. D thesis focuses on this state-of-the-art branch of high-pressure photochemistry. Specifically, high pressure is employed to create the necessary reaction conditions to …

Synthesis Of 2-Thiouracil And 2-Thiothymine Peptide Nucleic Acid Monomers Compatible With Fmoc-Based Oligomerization, Timothy Martin-Chan

Electronic Thesis and Dissertation Repository

Pseudo-complementary nucleobases are modified nucleobases which exhibit normal base pairing with unmodified complementary nucleobases; however, will not undergo stable base pairing with other pseudo-complementary nucleobases. The pseudo-complementary nature of these bases is of interest for the synthesis of pseudo-complementary peptide nucleic acid (pcPNA) oligomers, which are capable of binding targets in double-stranded DNA through a double duplex strand invasion. Until recently, pcPNAs were synthesized via Boc-based oligomerization chemistry which is currently less popular than the Fmoc-based strategy.

This research describes the development of a Fmoc protected thiouracil PNA monomer with an acid labile protecting group for use in standard SPPS. …

Total Synthesis Of (±)-Isodihydrokoumine, (±)-(19z)-Taberpsychine, And (±)-Isodihydroukoumine N4 Oxide, Jeff Kerkovius

Electronic Thesis and Dissertation Repository

We report the total synthesis of the natural products (±)-isodihydrokoumine, and (±)-(19Z)-taberpsychine in 11 steps each, and (±)-isodihydrokoumine N₄-oxide in 12 steps from commercially available starting materials. The key reactions include an intramolecular [3+2] nitrone cycloaddition, and Lewis acid mediated cyclizations of a common intermediate to provide the core structures of either (19Z)-taberpsychine or isodihydrokoumine. Both failed and successful routes will be discussed.

Glycopolymer Functionalization Of Polymersomes, Josh Jadischke

Electronic Thesis and Dissertation Repository

Carbohydrates are important to cellular communication, recognition, and pathogenesis, making them a useful synthetic target for application in therapeutics and diagnosis. Synthetic carbohydrate presenting scaffolds can replicate or interrupt the binding interactions that occur in nature. Due to the weak nature of the monosaccharide-protein bond, most carbohydrate presenting scaffolds display saccharides in a multivalent manner to improve binding. Recently there has been an effort to combine carbohydrate containing scaffolds with polymersomes (vesicles composed of polymers), due to the structural resemblance of polymersome membranes to biological membranes. This thesis describes the progress towards functionalizing polymersomes with linear glycopolymers as a potential …