ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- All Subjects: organic and mineral interactions
Hydrothermal reactions of organic compounds in the presence of minerals: a study of carboxylic acids
Description
Carboxylic acids are an abundant and reactive species present throughout our solar system. The reactions of carboxylic acids can shape the organic abundances within oil field brines, carbonaceous chondrites, and different ranks of coal.
I have performed hydrothermal experiments with model aromatic carboxylic acids in the presences of different oxide minerals to investigate the reactions available to carboxylic acids in the presence of mineral surfaces. By performing experiments containing one organic compound and one mineral surface, I can begin to unravel the different reactions that can occur in the presence of different minerals.
I performed experiments with phenylacetic acid (PAA), hydrocinnamic acid (HCA) and benzoic acid (BA) in the presence of spinel (MgAl2O4), magnetite (Fe3O4), hematite (Fe2O3), and corundum (Al2O3). The focus of this work was metal oxide minerals, with and without transition metal atoms, and with different crystal structures. I found that all four oxide minerals facilitated ketonic decarboxylation reactions of carboxylic acids to form ketone structures. The two minerals containing transition metals (magnetite and hematite) also opened a reaction path involving electrochemical oxidation of one carboxylic acid, PAA, to the shorter chain version of a second carboxylic acid, BA, in experiments starting with PAA. Fundamental studies like these can help to shape our knowledge of the breadth of organic reactions that are possible in geologic systems and the mechanisms of those reactions.
I have performed hydrothermal experiments with model aromatic carboxylic acids in the presences of different oxide minerals to investigate the reactions available to carboxylic acids in the presence of mineral surfaces. By performing experiments containing one organic compound and one mineral surface, I can begin to unravel the different reactions that can occur in the presence of different minerals.
I performed experiments with phenylacetic acid (PAA), hydrocinnamic acid (HCA) and benzoic acid (BA) in the presence of spinel (MgAl2O4), magnetite (Fe3O4), hematite (Fe2O3), and corundum (Al2O3). The focus of this work was metal oxide minerals, with and without transition metal atoms, and with different crystal structures. I found that all four oxide minerals facilitated ketonic decarboxylation reactions of carboxylic acids to form ketone structures. The two minerals containing transition metals (magnetite and hematite) also opened a reaction path involving electrochemical oxidation of one carboxylic acid, PAA, to the shorter chain version of a second carboxylic acid, BA, in experiments starting with PAA. Fundamental studies like these can help to shape our knowledge of the breadth of organic reactions that are possible in geologic systems and the mechanisms of those reactions.
ContributorsJohnson, Kristin Nicole (Author) / Shock, Everett (Thesis advisor) / Hartnett, Hilairy (Committee member) / Gould, Ian (Committee member) / Arizona State University (Publisher)
Created2017
Description
A clean and sustainable alternative to fossil fuels is solar energy. For efficient use of solar energy to be realized, artificial systems that can effectively capture and convert sunlight into a usable form of energy have to be developed. In natural photosynthesis, antenna chlorophylls and carotenoids capture sunlight and transfer the resulting excitation energy to the photosynthetic reaction center (PRC). Small reorganization energy, λ and well-balanced electronic coupling between donors and acceptors in the PRC favor formation of a highly efficient charge-separated (CS) state. By covalently linking electron/energy donors to acceptors, organic molecular dyads and triads that mimic natural photosynthesis were synthesized and studied. Peripherally linked free base phthalocyanine (Pc)-fullerene (C60) and a zinc (Zn) phthalocyanine-C60 dyads were synthesized. Photoexcitation of the Pc moiety resulted in singlet-singlet energy transfer to the attached C60, followed by electron transfer. The lifetime of the CS state was 94 ps. Linking C60 axially to silicon (Si) Pc, a lifetime of the CS state of 4.5 ns was realized. The exceptionally long-lived CS state of the SiPc-C60 dyad qualifies it for applications in solar energy conversion devices. A secondary electron donor was linked to the dyad to obtain a carotenoid (Car)-SiPc-C60 triad and ferrocene (Fc)-SiPc-C60 triad. Excitation of the SiPc moiety resulted in fast electron transfer from the Car or Fc secondary electron donors to the C60. The lifetime of the CS state was 17 ps and 1.2 ps in Car-SiPc-C60 and Fc-SiPc-C60, respectively. In Chapter 3, an efficient synthetic route that yielded regioselective oxidative porphyrin dimerization is presented. Using Cu2+ as the oxidant, meso-β doubly-connected fused porphyrin dimers were obtained in very high yields. Removal of the copper from the macrocycle affords a free base porphyrin dimer. This allows for exchange of metals and provides a route to a wider range of metallporphyrin dimers. In Chapter 4, the development of an efficient and an expedient route to bacteriopurpurin synthesis is discussed. Meso-10,20- diformylation of porphyrin was achieved and one-pot porphyrin diacrylate synthesis and cyclization to afford bacteriopurpurin was realized. The bacteriopurpurin had a reduction potential of - 0.85 V vs SCE and λmax, 845 nm.
ContributorsArero, Jaro (Author) / Gust, Devens (Thesis advisor) / Moore, Ana (Committee member) / Gould, Ian (Committee member) / Arizona State University (Publisher)
Created2014