Physical Sciences and Mathematics Commons^™

Synthesis And Formation Mechanism Of Cuins2 Nanocrystals With A Tunable Phase, Chao Yu, Linlin Zhang, Long Tian, Dan Liu, Fanglin Chen, Cheng Wang

Faculty Publications

Chalcopyrite CuInS₂ (CIS) hierarchical structures composed of nanoflakes with a thickness of about 5 nm were synthesized by a facial solvothermal method. The thermodynamically metastable wurtzite phase CIS would be obtained by using InCl₃ instead of In(NO₃)₃ as In precursor. The effects of the In precursor and the volume of concentrated HCl aqueous solution on the phases and morphologies of CIS nanocrystals have been systematically investigated. Experimental results indicated that the obtained phases of CIS nanocrystals were predominantly determined by precursor-induced intermediate products. The photocatalytic properties of chalcopyrite and wurtzite CIS in visible-light-driven degradation of …

Oxocarbenium Ion And Alkene Metathesis Strategies For The Synthesis Of Complex Cyclohexanes, Clayton Errol Mattis

Dissertations, Theses, and Capstone Projects

Highly oxygenated cyclohexanes comprise the structures of a number of pharmacologically interesting molecules, including potently bioactive natural products and carbapyranosides. The latter, which are unnatural analogues of carbohydrates in which the ring oxygen of the parent sugar is replaced with a methylene group, have attracted interest as hydrolytically stable mimetics of their parent O-glycosides. This research reports the development of two general methodologies for the synthesis of highly oxygenated cyclohexanes: (1) Oxocarbenium Ion Cyclization (OCC) and (2) Ring Closing Metathasis (RCM).

Chapter one gives a review of the literature on the synthesis for highly oxygenated cyclohexanes.

Previous results from this …

Design, Synthesis, Characterization, And Evaluation Of Surface Modified Boronate Ester Covalent Organic Frameworks, Matthew W. Di Carmine

Theses and Dissertations

Covalent Organic Frameworks (COFs) were first reported in 2005 and are analogous to Metal Organic Frameworks (MOFs), with proposed applications in separation, storage and sequestration. Since COFs are comprised of lighter elements they are considered more advantageous for weight-sensitive applications. However, COFs are susceptible to degradation by weak nucleophiles such as water (i.e. hydrolysis). The Lavigne group has focused on developing structure-property relationships for COFs. It was previously demonstrated that the porosity of the COFs could be tailored by incorporating small alkyl chains on one monomer. Inclusion of these alkylated monomers into COF materials effectively increased the COF hydrophobicity resulting …

A Novel Dual Allosteric Activation Mechanism Of Escherichia Coli Adp-Glucose Pyrophosphorylase: The Role Of Pyruvate, Matías D. Asención Diez, Mabel C. Aleanzi, Alberto A. Iglesias, Miguel Ballicora

Chemistry: Faculty Publications and Other Works

Fructose-1,6-bisphosphate activates ADP-glucose pyrophosphorylase and the synthesis of glycogen in Escherichia coli. Here, we show that although pyruvate is a weak activator by itself, it synergically enhances the fructose-1,6-bisphosphate activation. They increase the enzyme affinity for each other, and the combination increases Vmax, substrate apparent affinity, and decreases AMP inhibition. Our results indicate that there are two distinct interacting allosteric sites for activation. Hence, pyruvate modulates E. coli glycogen metabolism by orchestrating a functional network of allosteric regulators. We postulate that this novel dual activator mechanism increases the evolvability of ADP-glucose pyrophosphorylase and its related metabolic control.

Metal-Organic Frameworks Based On Pyridyl-Tetrazole Ligands Containing Ester Or Carboxylate Pendant Arms, Ursula Sheridan, John Gallagher, Morten Bjerrum, Adrienne Fleming, Fintan Kelleher, John Mcginley

Articles

The coordination of pyridyl-tetrazole derivatives containing ester substituents, at either the N-1 or N-2 position of the tetrazole ring, with copper(II) chloride results in the formation of either 1:1 or 1:2 copper to ligand complexes, depending on the ligand. However, when the ester functionality is changed to a carboxylate group, the resulting complexation reactions yield metal-organic frameworks. The resulting structures vary dramatically in pore size, depending on both reaction solvents and position of carboxylate group on the tetrazole ring. Despite the presence of sodium cations in the reaction mixtures, no sodium incorporation was ever observed in any of the complexes. …

Synthesis And Resolution Of A Substituted Dioxolane From Glycerol, Susannah Dawn Cox

Undergraduate Honors Thesis Collection

Glycerol (Figure 1) is one of the major byproducts in the manufacturing of biofuels. As the interest in biodiesel grows, production of glycerol will also increase. Investigating glycerol's potential as a chemical feedstock could lead to the discovery of new uses for this byproduct created from biofuel production. By developing pathways to use glycerol as a starting material and as a solvent we will be able to synthesize other chemically relevant compounds.

Suzuki-Miyaura Reactions Are Used To Synthesize Z-Alkenes From Cyclic Boronic Half-Acids, Daniel Lee French

Undergraduate Honors Thesis Collection

Cis-Alkenes provide the basic structure and reactivity for a variety of compounds, from the common chemicals found in any organic laboratory to advanced drugs used to treat cancer or suppress the immune system (Littke & Fu, 2002). Synthetically, alkenes are also of use in that they serve as a site for further chemistry. Historically, Z-alkenes have been more difficult to synthesize than their E-counterparts (McNulty et al., 2010; Siau, Zhang, & Zhao, 2012). Furthermore, in many reactions, a mixture of E- and Z- conformations of the alkene is produced. Such differences may seem trivial upon first inspection, but because there …

(Η5‐Cyclopentadienyl)Tricarbonylmanganese(I) Complexes, Patrick N. Kirk, Michael P. Castellani

Chemistry Faculty Research

Since the initial preparation of (η⁵‐C₅H₅)Mn(CO)₃ by Fischer and Jira in 1954, many methods have been developed for the synthesis of this compound (often referred to as “cymantrene”) and its C₅ substituted derivatives. Interestingly, each of these preparations has at least one significant drawback from a preparative perspective (thallium reagents, high pressures, poor yields, or reactants that require significant preparative investment). Surprisingly missing from this collection of preparative methods is the direct reaction between commercially available Mn(CO)₅Br and NaC₅H₅. In 1988, however, Smart and coworkers found …

Size-Dependent Interactions Of Metal Nanoparticles With Fluorophores And Semiconductors, Liyana A. Wajira Ariyadasa

Dissertations

In recent years, nanoscale metallic particles have gained considerable interest due to their potential applications in advanced technology. Despite such interest, synthetic procedures that produce gram-scale, well-defined metallic nanoparticles with controlled size and shape, especially with diameters less than 5 nm remains a challenge. Our work has focused on developing synthetic procedures that produce well-defined platinum and palladium metal nanoparticles in the 1-5 nm size range. Thioether ligands were used as stabilizers and resulted in metal nanoparticles with controlled size. The nanoparticles were characterized using transmission electron microscopy (TEM), x-ray diffraction (XRD), selected area electron diffraction (SAED), x-ray photoelectron spectroscopy …

Facile Synthesis And Characterization Of A Thermally Stable Silica-Doped Alumina With Tunable Surface Area, Porosity, And Acidity, Maryam Khosravi Mardkhe

Theses and Dissertations

Mesoporous γ-Al2O3 is one of the most widely used catalyst supports for commercial catalytic applications. The performance of a catalyst strongly depends on the combination of textural, chemical and physical properties of the support. Pore size is essential since each catalytic system requires a unique pore size for optimal catalyst loading, diffusion and selectivity. In addition, high surface area and large pore volume usually result in higher catalyst loading, which increases the number of catalytic reaction sites and decreases reaction time. Therefore, determination of surface area and porosity of porous supports is critical for the successful design and optimization of …

Synthesis, Crystal Structure Refinement, And Electrical Conductivity Of Pb(8−X)Na2smx(Vo4)6o(X/2), Tatiana M. Savankova, Lev G. Akselrud, Lyudmyla I. Ardanova, Alexey V. Ignatov, Eugeni I. Get’Man, Roman E. Gladyshevskii, Stanislav N. Loboda

Biochemistry, Chemistry and Geology Department Publications

Solid solutions of Pb(8−x)Na2Smx(VO4)6O(x/2) were studied using X-ray diffraction analysis including Rietveld refinement and scanning electron microscopy and by measuring their electrical conductivity. Crystal structure of the solid solutions was refined and the solubility region 0 ≤ x ≤ 0.2 was determined for samarium substitution for lead under the scheme 2Pb2+ + ◻ → 2Sm3+ + O2-. The influence of degree of substitution on the electrical conductivity of solid solutions was established.

Synthesis And Characterization Of New (E)-N'-(Substituted Benzylidene)-2-(3-(2-Methyl)-4-Oxo-3,4-Dihydroquinazolin-2-Ylthio)Acetohydrazides, Aamer Saeed, Shams-Ul Mahmood, Ulrich Flörke

Turkish Journal of Chemistry

A small library of new azomethine derivatives of 3-aryl-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones was synthesized. The key intermediates 2-thioxo-quinazolinones (3a--e), obtained in 2 steps from the corresponding anilines, were treated with methyl chloroacetate to afford S-substituted esters (4a,d), which were then converted into corresponding acetohydrazides (5a,d). Further, acetohydrazide (5d) was converted to the azomethines derivatives (6a--k) by reacting with a number of suitably substituted benzaldehydes. FTIR, ^1H NMR, ^{13}C NMR, GC-MS, and elemental analyses were used to confirm the assigned structures of the synthesized compounds. Further, compounds 3a, 5, and 6j were also confirmed by X-ray diffraction data.

New Soluble Amidoamine Substituted Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Solution Properties, Senem Çolak, Sali̇h Zeki̇ Yildiz

Turkish Journal of Chemistry

The synthesis of tetraaminopropylamid substituted phthalocyanines was targeted to prepare enhanced soluble phthalocyanines in common solvents from hydrophobic to hydrophilic that bore nonionic groups on their periphery. Metal-free (H_2Pc) and metallophthalocyanines (Zn(II) (ZnPc), Cu(II) (CuPc) and Co(II) (CoPc)) were prepared and characterized by UV-Vis, FT-IR, and mass spectroscopies. The ^1H NMR spectra were recorded for the diamagnetic phthalocyanine species H_2Pc and ZnPc. The phthalocyanines showed sufficient solubility in common organic solvents such as dimethyl sulfoxide, tetrahydrofuran, and ethanol. However, methanol was not a good solvent for CuPc and H_2Pc. Solubility and aggregation studies of H_2Pc and ZnPc were performed in …

Using Structure-Based Organic Chemistry Online Tutorials With 2 Automated Correction For Student Practice And Review, Timothy O'Sullivan, Gráinne Hargaden

Articles

This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Technological University Dublin. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing students to develop essential problem-solving skills in organic chemistry. This online approach may be used for both formative and summative assessment. Students complete one problem set weekly or fortnightly, which consists of a number of questions of varying difficulty. A wide range of question types is possible; for example, prediction of reaction products, identification of reaction intermediates …

The Chemistry Concerned With The Sonochemical-Assisted Synthesis Of Ceo_2/Poly(Amic Acid) Nanocomposites, Shiva Yazdani, Mehdi Hatami, Seyed Mohammad Vahdat

Turkish Journal of Chemistry

A series of new poly(amic acid) (PAA) surface-modified cerium oxide (CeO_2) nanocomposites were prepared by sonochemical-assisted method. In the first step, treatment of the surface of CeO_2 nanoparticles with hexadecyltrimethoxysilane as a surface modifier was achieved. In the second step, the partially surface-treated nanoparticles were incorporated into PAA by different weight from 4% to 12%. PAA was synthesized by polycondensation reaction of benzophenone tetracarboxylic dianhydride and 3,5-diamino-N-(4-hydroxyphenyl) benzamide in N-methyl-2-pyrrolidone. The chemical structure of PAA was confirmed by ^1H NMR and FTIR spectroscopy. The polymer had an inherent viscosity of 0.38 dL/g. Three PAA/CeO_2 nanocomposite formulations were prepared from the …

Electrochemistry Of Fe(Iv) And Mn(Iv) Corroles Containing Meso-Dichlorophenyl Substituents And The Use Of These Compounds As Catalysts For The Electroreduction Of Dioxygen In Acid Media, Lina Ye, Zhongping Ou, Deying Meng, Mingzhu Yuan, Yuanyuan Fang, Karl M. Kadish

Turkish Journal of Chemistry

Two meso-dichlorophenyl substituted metallocorroles were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in dichloromethane, benzonitrile, and pyridine containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) as supporting electrolyte. The examined compounds are represented as (Cl_2Ph)_3CorFe^{IV}Cl and (Cl_2Ph)_3CorMn^{IV}Cl where (Cl_2Ph)_3Cor is the trianion of 5,10,15-tri(2,4-dichlorophenyl)corrole. Each metallocorrole was examined as to its catalytic activity for the electoreduction of dioxygen when coated on an edge-plane pyrolytic graphite electrode in 1.0 M HClO_4. Cyclic voltammetry combined with linear sweep voltammetry at a rotating disk electrode (RDE) and a rotating ring disk electrode (RRDE) was utilized to evaluate the catalytic activity for the …

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …