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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The electrogenerated chemiluminescence of unique organic chromophores

Sartin, Matthew McCullough, 1982- 29 August 2008 (has links)
Electrogenerated chemiluminescence (ECL) studies were performed on several interesting compounds. A series of silole-based (silacyclopentadiene) chromophores was examined to understand the effects of their structure on the electrochemistry and spectroscopy of these compounds. A case was observed in which high steric hindrance improved ECL by inhibiting internal conversion and protecting radicals from secondary reactions. Another case was observed in which steric effects induced a rotation in the silole substituents, increasing secondary reactions and lowering quantum efficiency ([Phi subscript PL]). Spiro-FPA, which consists of two DPA centers, exhibits excimer formation despite high steric hindrance, due to its ability to form di-ions, which have a greater electrostatic attraction to one another than mono-ions. The compound (dppy)BTPA is a highly solvatochromic, boron-containing chromophore that was examined in a variety of solvents. Of note is the emission in pure acetonitrile, which is prominent in the ECL spectrum, but barely visible in the photoluminescence. Finally, B⁸ amide, a compound based on the laser dye, BODIPY, was examined. It exhibited unusual ECL characteristics. These include a strong, long-wavelength emission and transients that are clearly visible for 20 min or more, but display dramatically varying light intensities with each pulse. Evidence for the contribution of a film formed with the oxidation product is presented. Additionally, ECL simulations are performed using a general physics software package to better understand some of the observed phenomena.
2

The electrogenerated chemiluminescence of unique organic chromophores

Sartin, Matthew McCullough. January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
3

Steric hindrance in the ketonic splitting of substituted acetoacetic ester

Abshier, George Stanley, January 1933 (has links) (PDF)
Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1933. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed June 14, 2010) Includes bibliographical references (p. 68-62) and index (p. 63-64).
4

Synthesis and characterization of electrically conducting poly(undecyl bithiophene)s

Narayan, Sujatha January 1999 (has links)
No description available.
5

The Effects of Carrier Ligands on Cisplatin Binding to Cysteine and Methionine

Smith, Adam C.R 01 April 2017 (has links)
We have reacted several derivatives of the anticancer drug cisplatin with N-acetyl-Lcysteine (N-AcCys) and N-acetyl-L-methionine (N-AcMet), which are two of the primary amino acid targets of platinum. NMR spectroscopy was used to monitor the reactions and determine the effect the different ligands would have on the platinum reactivity. Several of the platinum compounds were tested at pH of 4 and 7, and with platinum:amino acid ratios of 1:1, 2:1 and 1:2. Competition reactions between cysteine and methionine were done to confirm which would react with the platinum compound first. [Pt(dien)(NO3)]+ reacts faster with methionine than with cysteine at both pH 4 and 7 at a 1:1:1 ratio. [Pt(N,N,N',N',N"-pentamethyldiethylenetriamine)(NO3)]+ reacts with methionine faster at pH 4 but with cysteine faster at pH 7. This is most likely due to the thiol in the cysteine starting to deprotonate around pH 7. [Pt(Me4en)(NO3)2] (Me4en = N,N,N',N'-tetramethylethylenediamine) forms several products with N-AcCys at both pH 4 and 7, with the amounts of the products varying depending on the ratio of platinum and Cys. Mass spectrometry indicated one product as {[Pt(Me4en)(H2O)]2(N-AcCys)}2+, with two platinum compounds coordinated to a single cysteine. Lastly Pt[(en)(NO3)2] when reacting with N-AcCys at a ratio of 1:1 will coordinate with 2 different Cys molecules. With an excess of Pt the complex prefers to bind to only 1 Cys.
6

Dynamics of hard and soft colloids in confined geometries and on structured surfaces

Yarlagadda, Sri Charan 21 September 2015 (has links)
We investigated the depletion interactions of colloids and hindrance behavior of hard and soft colloidal particles near neighboring walls. We first used numerical modeling to compute depletion interaction strengths for simple geometries which eventually guided our experiments to make interactions highly selective. The model helped us in identifying the important parameters to finetune these interactions and shed light on geometric design rules to optimize desirable shape-selective interactions on a variety of complex geometries. We further reported experimental studies that highlight the differences in the dynamics of hard and soft colloids under confinement using video microscopy and particle tracking. It was found that both soft sphere systems that we investigated (swollen polymer particles, core/shell microgels) behave differently from hard sphere systems under all degrees of confinement that were measured. Our findings suggest that soft sphere systems have lesser hindrance compared to hard sphere counterparts and the hindrance varies as a function of softness. In order to understand the soft sphere confinement dynamics more clearly, implications for future research are discussed.
7

Stereoelectronic effects in homolytic reactions / by Christopher John Easton

Easton, Christopher J., 1955- January 1980 (has links)
iv, 191 leaves : ill. (some in end pocket) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1980
8

Stereoelectronic effects in homolytic reactions /

Easton, Christopher J., January 1980 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Dept. of Organic Chemistry, 1980.
9

Axial ligand binding equilibria as probes of the effective steric bulk of substituted tetraarylporphyrins

Thomas, Michael Craig. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references and index.
10

Computational study of the C-CI bond length

Reznickova, Anna. January 2010 (has links)
Honors Project--Smith College, Northampton, Mass., 2010.

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