Chemistry Commons^™

The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake

Theses and Dissertations

Incorporation of silicon in the ligand backbone would yield electron-rich metal complexes upon coordination to transition metal complexes. The coordination chemistry of semirigid benzyl phosphines bearing a single or multiple phosphorus atoms and varying number of Si−H moieties has gained interest in recent years. This dissertation focuses on synthesizing silyl and germyl transition metal complexes of groups 9 and 10. Chapter II presents the synthesis of a family of four coordinated 14-electron rhodium complexes. The newly synthesized complexes were characterized in solution by multinuclear NMR spectroscopy and in the solid-state by single-crystal X-ray diffraction. These d⁶ complexes possess sawhorse …

Photo-Reactivity Of Bifunctional Naphthalene Compounds Toward Dna, Qi Zhang

Theses and Dissertations

DNA interstrand cross-link (ICL) can covalently bind two DNA strands, preventing DNA strands separation, and therefore, blocking DNA transcription and replication, which are essential biological processes for cell division. Among different methods to induce DNA interstrand cross-linking, photoinduction is an important way to activate the cross-linking reactions due to its many characteristics, such as non-invasive, controllability, selectivity and biorthogonality. My research mainly focuses on developing novel binaphthalene compounds which can be activated by 350 nm UV light to produce DNA interstrand cross-linking via alkylation. We designed and synthesized a series of binaphthalene analogues with different substituents at the position-4’ on …

Polyaniline-Derivatives Based On Poly (Heterocyclic Diphenylamine) With Improved Electrochemical Stability And Processability, Mohammed Noifa Almtiri

Theses and Dissertations

Today, smart innovation has become an essential part of human life; thus, contemporary technologies are always looking for intelligent, responsive, and efficient materials to satisfy these demands. Consequently, synthetic "metals" or, more precisely, intrinsically conducting polymers (CPs) have begun to find a place as valuable and practical materials for a new generation of devices. Amongst all intrinsic conducting polymers, polyaniline (PANI) has attracted significant attention due to its outstanding air and moisture stability, simple preparation technique, and high electrical conductivity (chapter I).

Chapter II represents the synthesis of a new PANI derivative that contains a phenoxazine unit co-polymerized with p-phenylenediamine …

Inducible Dna Interstrand Cross-Linking Agents: Design, Synthesis, Mechanism, And Biomedical Applications, Muhammad Asad Uz Zaman

Theses and Dissertations

DNA is the carrier of genetic information, making its chemical reactivity and function extremelyimportant. DNA interstrand cross-links (ICL) leads to covalent bind of two strands, which prevents the separation of double helix. DNA ICLs are the sources of the cytotoxicity of antitumor and anticancer agents. This thesis focuses on investigating the reactivity of a varieties of aromatic compounds towards DNA. Some of these molecules can be activated by photo irradiation to induce DNA ICL formation via alkylation. Others undergo activation by H2O2 to release DNA cross-linking agents. We investigated the mechanism of function of these inducible DNA cross-linking agents as …

A Modular Synthesis Of Processable And Thermally Stable Semi-Fluorinated Aryl Ether Polymers Via Step-Growth Polymerization Of Fluoroalkenes, Ketki Eknath Shelar

Theses and Dissertations

Tailored fluoropolymers remain the leading choice for a wide variety of advanced high-performance applications, including electronic/optical and energy conversion, owing to their unique blend of complementary high-performance properties. Amorphous semi-fluorinated polymers exhibit improved solubility and melt processability when compared to traditional perfluoropolymers. A leading class of semi-fluorinated aryl ether polymers includes perfluorocyclobutyl (PFCB), perfluorocycloalkenyl (PFCA), and fluoroarylene vinylene ether (FAVE) polymers. Monomers containing aromatic trifluorovinyl ethers (TFVE) are used to synthesize PFCB polymers via radical-mediated [2+2] cyclodimerization. On the other hand, FAVE and PFCA polymers are polymerized via base-mediated nucleophilic addition/elimination of bisphenols with TFVE monomers and decafluorocyclohexene respectively. The …

Synthesis Of Conjugated Polymers From Xanthene And Alkenyl Flanked Diketopyrrolopyrrole Monomers For High-Performance Electronic Applications., Ranganath Wijesinghe Wahalathantrige Don

Theses and Dissertations

In traditional electronics, inorganic materials such as silicon and germanium are used as semiconductors due to their outstanding semiconducting properties. Unfortunately, inorganic materials are rigid due to their high crystalline nature, and processing these materials is complex and expensive. Furthermore, traditional semiconducting materials do not have favorable mechanical properties in applications such as wearable devices and large-area applications with complicated shapes. Conjugated conducting polymers (CCPs) are being explored as alternative materials to conventional semiconductors due to their mechanical properties and high conductivity. CCPs offer properties such as solution and low-temperature processability, flexibility, thermal and optical properties that traditional semiconductors could …

Synthesis And Characterization Of Sustainable And Biobased Copolymers From Lignocellulosic, Guery Saenz

Theses and Dissertations

Natural compounds have been the primary resource used to produce polymeric materials by humankind since the mid-1900s. Yet, progress in bio-based polymers from renewable feedstock has encountered some obstacles, mainly due to the low prices of petroleum-based monomers, compared to natural and sustainable materials. However, most commodity plastics are non-degradable materials, and solid plastic waste accumulation adversely affects the environment. As the world population is growing and demanding chemicals, energy, and plastics materials, polymer research is focusing on synthesizing bio-based and degradable polymers. Thus, biomass, a sustainable and inexpensive feedstock, is highly appropriate for designing alternative thermoplastics that are degradable …

The Activity Of Qh Ii 66 And It’S Analogs In Medulloblastoma, Melanoma And Non-Small Cell Lung Cancer Cell Lines., Taukir Ahmed

Theses and Dissertations

GABAARs (gamma-aminobutyric acid type A receptors) are transmembrane pentameric ligand-gated chloride ion channels that respond to GABA, the central nervous system's principal inhibitory neurotransmitter (CNS). The benzodiazepines (BZDs) bind between the GABAAR α+γ2-subunits at their extracellular interface. The binding of ligands to distinct subunits of GABAA receptors, notably the α1-6β2/3γ2 ion channels, can have a wide range of effects on brain activities. The sedative, ataxic, amnesic, anticonvulsant, and addictive actions of GABAARs' α1-subtype selective ion channels should be avoided, except for the anticonvulsant and anxiolytic effects, while creating ligands for this BZ allosteric modulatory site. Many studies have linked the …

Design And Synthesis Of Chiral And Achiral Benzodiazepines And Imidazodiazepines As Α–Subtype Selective Gabaar Positive Modulators To Treat Schistosomiasis, Epilepsy, Asthma And Some Mental Disorders, Md Yeunus Mian

Theses and Dissertations

Part I: Design, synthesis, and biological evaluation of non-sedating anti-schistosomal agents

Schistosomiasis is a parasitic flatworm infection with only one drug therapy currently on the market, praziquantel. An old lead identified by Roche, meclonazepam (US Patent 4031078A) displayed antiparasitic efficacy but was not pursued due to dose-limiting sedation in human clinical trials (S. Afr. Med J. 1979 Apr 14;55(16):617-8, PMID: 380021). However, given the superior spectrum of activity meclonazepam displays relative to praziquantel (which is unable to cure immature parasites within the host) and advances in the understanding of benzodiazepine SAR at human GABAARs, the study of this benzodiazepine was …

Part I: Synthesis Of Quinolones For Inhibition Of The Β-Barrel Assembly Machine In Gram Negative Bacteria; Part Ii: Synthesis Of Azo Dye Sensors For Detection Of Metal Ions In Aqueous Environments, Katryna Williams

Theses and Dissertations

Part I: Antibiotic resistance in Gram-negative bacteria is a growing cause of concern worldwide. Thousands of people die from antibiotic resistant bacteria every year. The β-Barrel Assembly Machine (BAM) in Gram-negative bacteria plays a role in antibiotic resistance as its porin, BamA, can regulate which molecules enter the cell, meaning it can prevent antibiotics from entering the bacterial cell. BamA exists in an open and closed form and is only selective in its closed form. BamA opens and closes through the H-bonding of two intramolecular β-strands. It is theorized that the creation of a β-sheet mimetic, based on work done …

Guest Host Chemistry Part I: The Synthesis Of Metal Selective Sensors Part Ii: The Synthesis Of Antibiotic Precursors And Intermediates, Trevor Moss Hagemann

Theses and Dissertations

Part 1: Metal Selective Sensors

The work herein describes the creation of a library of sensors for the detection of metal ions in aqueous systems. The solid support these dyes are attached to facilitates a continuous measurement of metal ion concentrations in aqueous systems. The sensors are based on an azo dye core structure wherein detection of metal ions is observed by the change in absorbance of the dye upon binding. These sensors are capable of detecting metal ions in the ppb range, specific dyes interacting with specific metal ions cause distinct spectral changes, providing substantial information. the aggregate response …

Asymmetric Cuh-Catalyzed Reductive Coupling Of Alleneamides With Carbonyl Electrophiles And The Mechanistic Investigation Into The Suzuki-Miyaura Cross-Couplings Of Electron-Deficient Systems, Samantha L. Gargaro

Theses and Dissertations

Most natural products and other biologically active small molecules contain multiple stereogenic heteroatoms throughout their carbon scaffold. As a result, methods to install these multi-heteroatom functionalities efficiently are highly desirable. Reductive coupling reactions have been studied extensively, and reductive allylation has been a key method for generating chiral secondary and tertiary allylic alcohols. This work focuses on utilizing naturally abundant and inexpensive Cu for the asymmetric reductive coupling of alleneamides with carbonyl electrophiles to access highly functionalized multi-heteroatom scaffolds that are difficult to produce via traditional methods. Described herein are methods for these asymmetric reductive coupling reactions. Chapter 1 describes …