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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.
51

A study of the interactions between ylidic phosphorus species and organic acids

Lamb, Sarah January 1998 (has links)
This thesis describes the synthesis and characterisation of phosphonium aryloxides, amides and phosphides. These compounds have been formed via the deprotonation of organic acids [of the type ROH, and R(_2)X, where X = NH, PH, R = aryl group] by basic phosphonium ylidic species [R(_3)PX, X = CH(_2,) C(Me)H, C(Ph)H, NH] in mixtures of hydrocarbon (toluene) and/or polar (acetonitrile, thf) solvents. All of these compounds contain both acidic CHs and 'naked' anions which promote extensive hydrogen bonding. Chapter 1 provides an outline of the fields of ylidic chemistry and hydrogen bonding. In Chapter 2, general experimental methods are described. Chapter 3 records all experimental results pertaining to this work. Here preparation of starting materials is documented, followed by an account of the synthesis and characterisation of twenty-three compounds. For all compounds melting point measurements, (^1)H NMR, (^31)P NMR, infrared spectra, and elemental analysis are recorded. Discussion of these results is documented in Chapters 4 to 7. Where possible, solid-state structures for compounds obtained by single crystal X-ray diffraction (nineteen structures) and single crystal neutron diffraction (two structures) are included. Chapter 4 discusses simple phosphonium aryloxide salts, while Chapter 5 is concerned with related phosphonium amides and phosphides. Chapter 6 deals with an extension of this work involving multifiinctional organic acids. Finally, Chapter 7 discusses unexpected results resulting from the work described in Chapter 6.
52

Hydrogen Bonding Interactions of Ferrocene-peptides: From Molecule to Large Scale Assemblies

Beheshti, Samaneh 10 December 2012 (has links)
The main goal of this thesis was to explore the role of H-bonding interactions in ferrocene peptide conjugates at the molecular and supramolecular level. With the help of detailed spectroscopic and crystallographic studies, the intermolecular association of a range of conjugates was studied and described here. It was shown that C-terminal modifications directed the supramolecular assembly. In the case of Fc[CO-Gly-Val-OH]2, the C-terminal carboxylate group directed intermolecular interactions, causing formation of a supramolecular architecture that was characterized by large solvent-filled hydrophobic channels. In the absence of this directional group, as was the case in Fc[CO-Leu-Val-OMe]2 extended β-sheets were formed. Hierarchical self-assembly of disubstituted ferrocene peptide conjugates possessing Gly-Val-Phe and Gly-Val-Phe-Phe peptide substituents gave rise to nano- and micro-sized assemblies. Spontaneous self-assembly of Fc-peptides through intra-and intermolecular hydrogen bonding interactions induced supramolecular building blocks, which further associated to fibers, large fibrous crystals, and twisted ropes. Next, intermolecular H-bonding interactions were studied using a surface-based approach. A fragment of the amyloid-beta (Aβ) peptide was bound to a gold surface through a C-terminal Cys. Various aspects of the peptide film were examined using different electrochemical and surface analytical techniques. The interaction of Congo red and of Lys-Leu-Val-Phe-Phe with the immobilized Aβ fragment was studied using electrochemical methods, showing responses that indicated intermolecular interactions. This surface approach was used to probe the interaction of a series of ferrocene peptides (Fc-CO-Leu-Val-Phe-Phe-OX and Fc-CO-Lys(Boc)-Leu-Val-Phe-Phe-OX with X=H and Me) with the surface-bound Aβ fragment. Biomolecular interactions between Fc-peptides and the Aβ-modified surface were studied by electrochemical methods. The current response of the Fc redox process was modulated by the interaction with the Aβ-modified surface.
53

Syntheses and hydrogen bonding properties of dipyrrinone analogs /

Salzameda, Nicholas Thomas. January 2006 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2006. / "December, 2006." Includes bibliographical references (leaves 120-123). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm.
54

Nuclear-magnetic-resonance studies of hydrogen bonding

Davis, Jefferson Clark, January 1959 (has links)
Thesis--University of California, Berkeley, 1959. / Includes bibliographical references (p. 74-76).
55

Synthesis and physical properties of dipyrrinone analogs of bilirubin

Datta, Suchitra. January 2008 (has links)
Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "December 2008." Includes bibliographical references (leaves 201-211). Online version available on the World Wide Web.
56

Aspects of the crystal chemistry of organic acid-amides

King, John January 1994 (has links)
No description available.
57

Double hydrogen bonding of 1, 8-biphenylenediol with various bases /

Hahn, Soonkap January 1985 (has links)
No description available.
58

Double hydrogen bonding of 1,8-biphenylenediol and its derivatives /

Ahn, Kyunghye January 1986 (has links)
No description available.
59

Ab initio vibrational analyses of complex molecular species

Chapman, Darren Mark January 1999 (has links)
No description available.
60

Theoretical studies and structural analysis of models of surface organometallic centres

Adnan, Rohana January 2000 (has links)
No description available.

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