• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 2
  • 1
  • Tagged with
  • 22
  • 22
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
11

The kinetics and mechanisms of substitutions in octahedral cobalt and chromium complexes.

Hui, Kwan-yu. January 1969 (has links)
Thesis--Ph. D., University of Hong Kong. / Includes The Sn mechanism in inorganic reactions. Pt. I. Hydroxide-ion substitution in halogenopentamminecobalt (III) complexes, by the author and others reprinted from Journal of the Chemical Society, May, 1965. Typewritten.
12

An investigation of anion binding by acyclic metal-centred receptors

Graydon, Andrew R. January 1995 (has links)
This thesis reflects two main aims. Firstly, the synthesis and characterisation of a number of potential anion receptors was undertaken and their anion binding properties were assessed. In so doing, a second aim was fulfilled, namely a comparison of the various methods of detecting the bound anion, and quantifying the binding strength. Four techniques appear in this thesis; <sup>1</sup>H nuclear magnetic resonance, UV-visible spectroscopy, electrochemistry and luminescent emission. Quantitative titrations were performed and, where possible, stability constants estimated. Chapter One provides an introduction to some of the themes of molecular recognition and provides a brief overview of the literature associated with anion recognition. A Prologue describes the design of the receptors studied; they all incorporate a metal centre and appended amide groups which provide sources of hydrogen bonding. The molecules are mostly cationic and a combination of positive charge and hydrogen bonding constitutes the binding interaction. Chapter Two is concerned with receptors based on cobalticinium, [Cp<sub>2</sub>Co]<sup> +</sup> . A number of receptors are presented and are found to bind anions with stability constants typically in the range of 500-1000 dm<sup>3</sup>mol<sup>-1</sup> . Receptors involving more than one cobalticinium centre are found to bind much more strongly and, furthermore, variations in functional groups appended close to the proposed coordination site impart selectivity; dihydrogen phosphate is bound more strongly than chloride. It is also found that different techniques give different stability constants and comment is made on this phenomenon. Chapter Three examines the role of positive charge in anion binding and describes the synthesis and coordination properties of several neutral receptors. These molecules retain hydrogen bonding sites, and it is found that this is sufficient to bind anions, but the strength of the interaction is greatly reduced. Chapter Four introduces another system, based on RuL(bpy)<sub>2</sub><sup>2+</sup> , where L is a 4,4'-amide disubstituted bpy. The strength of binding is an order of magnitude greater than the cobalticinium systems as detected by several methods including emission studies, which are very sensitive. Comparison with a neutral, rhenium-based receptor is made. A dihydrogen phosphate-selective luminescent sensor is also presented. The Epilogue identifies areas for future research. Specialised introductions and summaries are found at the beginning and end of each chapter.
13

Pyridylacetylenes and their cobalt clusters; novel naphthalimide monomers and polymers

Dana, Bogden Hariton, n/a January 2005 (has links)
A series of 2,6- and 3,5-ethynylpyridyl compounds and their cobalt clusters have been prepared and analysed in Chapter 2, in order to study through-space and through-bond interactions between the ethynyl arms. Bidentate N- donor ligands, such as bipyridine and o-phenanthroline with alkyne functionality have been used extensively as building blocks for a wide range of molecular materials, but monodentate ethynylpyridyls have received less attention. The results showed that while there is no orbital restriction on a RC[triple bond]C-n-[pi]�cc-C[triple bond]CR through-bond interaction in 2,6-ethynylpyridyls, no significant interaction exists. Nevertheless, there are intramolecular interactions as manifested in the distortions which occur in the solid state structure of the compounds and the lability of the diphenylphosphine methane (dppm) moieties in the oxidised Co₂(CO)₄dppm species. Polymerisation by Sonogashira coupling between dibromo pyridines or diiodo ferrocene and ethynyl pyridines resulted in only oligomeric fractions that could be separated. The thesis also reports the synthesis and characterization of some novel naphthalimide monomers with acrylic and allyl headgroups. The naphthalimide moiety is substituted in the 4-position with various functionalities. This is presented in detail in Chapter 3 of the thesis. The monomers� structure is the following: [illustration omitted] wherein: A may be a polymerizable group (methacrylate or allyl), which includes a spacer entity (aliphatic or aromatic); B is selected from an ethenyl or ethynyl linked organometallic group, a halogen and/or an amine (i.e. bromo, ethynylferrocene, ethenylferrocene, trimethylsilylethynyl, nitro, piperidine and ethenylpiperidine). The acrylic monomers were synthesized by coupling 4-bromo-1,8-naphthalic anhydride with an amino alcohol to give an imide, which then was coupled with methacryloyl chloride to provide the methacrylate. Functionalization in the 4-position of the naphthalimide moieties was achieved by Sonogashira and Heck coupling reactions with for example ethynylferrocene, trimethylsilyl acetylene, vinylferrocene. For the allyl monomers synthesis, a reaction between allyl amine and 4-Bromo-naphthalic anhydride provided 4-bromo-naphthalimido allyl, which was then functionalized by further Sonogashira and Heck coupling reactions. The monomers were polymerised and copolymerised with other widely used comonomers, such as methyl methacrylate, methyl acrylate, styrene, vinyl carbazole and acrylonitrile. The polymerisation processes and the full analyses of the (co)polymers are described in Chapter 4. Free radical polymerisation, FRP, initiated by azo bisisobutyronitrile, AIBN at elevated temperature was the main technique employed for making the (co)polymers. Atom Transfer Radical Polymerisation, ATRP was conducted for some monomers although the results were inconclusive (the yields were low, under 50%, but the molecular weight distributions were quite narrow, PDI�s <1.7). Heck coupling polymerisation was performed for the bromo- substituted methacrylic and allyl monomers and supplied colorful, well-defined polymeric materials, with low polymerisation degrees. All polymers were analyzed by HPLC, NMR, UV-VIS, IR, electrochemistry and fluorescence. The (co)polymers made by FRP had various molecular masses (Mn = 3000- 90.000), whereas the polydispersities were PDI = 1.4- 4.6. Most of the (co)polymers were fluorescent and had good thermal and electrochemical properties. Potential applications of the polymers have been suggested and relevant literature background in the field is provided in both Chapters 1 and 4. The monomers/ polymers are stable compounds (no special storage conditions required) and can act as good candidates for potential applications in light emitting devices, as resins/ binders for coating materials, in the dyes and pigment industry and also for manufacturing of conducting polymers and/or composite materials.
14

Ligand exchange and substitution on five-coordinate complexes of copper (II), nickel (II) and cobalt (II) /

Doddridge, Bruce Germein. January 1986 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1986. / Includes bibliographical references.
15

The synthesis and configuration of some polydentate amino acid complexes of cobalt(III) : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at the University of Canterbury /

Wilson-Coutts, Sarah Mary. January 1900 (has links)
Thesis (M. Sc.)--University of Canterbury, 2009. / Typescript (photocopy). "June 2009." Includes bibliographical references. Also available via the World Wide Web.
16

Synthesis, structure, and catalytic activity of cobalt nitrosyl complexes

Farnia, Seyd Morteza Famil January 1981 (has links)
No description available.
17

Ligand exchange and substitution on five-coordinate complexes of copper (II), nickel (II) and cobalt (II) / by Bruce Germein Dodridge

Doddridge, Bruce Germein January 1986 (has links)
Includes bibliographies / vi, 208 leaves : ill ; 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 Physical and Inorganic Chemistry, 1986
18

The structure and fluxionality of tetrahedral cobalt-based organometallic clusters.

Sutin, Karen Ann. McGlinchey, M. J. Unknown Date (has links)
Thesis (Ph. D.)--McMaster University (Canada), 1990. / Source: Dissertation Abstracts International, Volume: 62-13, Section: A, page: 0000.
19

Cationic Diels-Alder dienophiles stablized by cobalt-complexed alkynes

Dorset, Rachel Ruth. January 2010 (has links)
Honors Project--Smith College, Northampton, Mass., 2010. / Includes bibliographical references.
20

Organometallics in the stabilization of dyed fibres : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at the University of Canterbury /

Ayling, Neroli. January 1900 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). "March 2008." Includes bibliographical references (leaves 217-225). Also available via the World Wide Web.

Page generated in 0.0442 seconds