Font Size: a A A

Part I: Toward hydrophilic and non-aggregated phthalocyanines. Part II: Assembling tetrapyrrole derivatives by axial coordination and covalent linkage

Posted on:2005-04-30Degree:Ph.DType:Thesis
University:Chinese University of Hong Kong (People's Republic of China)Candidate:Choi, Tsang Ming MichaelFull Text:PDF
GTID:2451390008994358Subject:Chemistry
Abstract/Summary:
This thesis reports our investigation on several classes of specially designed phthalocyanines. Part 1 of the thesis describes several approaches to generate water-soluble phthalocyanines, including the use of hydrophilic oligo(ethylene glycol) substituents, surfactants, and the host-guest complexation with beta-cyclodextrin. Part 2 of the thesis reports the assembling of mixed tetrapyrrole derivatives through axial coordination or covalent linkage.; Chapter 1 presents an overview of the chemistry and properties of phthalocyanines, focusing on the hydrophilic analogues. Examples of water-soluble phthalocyanines with different substituents are described, including their synthesis and photophysical properties.; Chapter 2 describes the synthesis of a series of zinc(II) phthalocyanines containing four or eight dendritic substituents with terminal oligo(ethylene glycol) chains. The synthesis involves transesterification as the key step. The spectroscopic properties of these hydrophilic phthalocyanines, and the effects of surfactants and metal ions on their aggregation properties are also discussed.; Chapter 3 reports the preparation of several silicon(IV) phthalocyanines with adamantyl substitutent(s) at the axial position(s). The complexation of these compounds with beta-cyclodextrin has been examined by UV-Vis spectroscopy. For the unsymmetrical analogue with a N,N-dimethylaminoethoxy substitutent, it forms a 1:1 complex with beta-cyclodextrin with an association constant of 4.5 x 104 M-1.; Chapter 4 reviews mixed tetrapyrrolic systems containing porphyrins and phthalocyanines, including their synthesis and photophysical properties.; Self-assembly of bis(pyridinolato)phthalocyaninatosilicon(IV) and a series of zinc(II) tetrapyrrole derivatives by axial coordination is described in chapter 5. The coordination has been studied by 1H NMR, UV Vis, and fluorescence spectroscopy. The molecular structure of the first porphyrin-phthalocyanine hybrid other than sandwich-type complexes has also been determined. It has been found that 1:1 or 1:2 complexes are formed depending on the tetrapyrrole derivatives.; Chapter 6 discusses the preparation, spectroscopic, and electrochemical properties of several porphyrin-phthalocyanine trimeric systems linked by covalent bondings. The systems exhibit a highly efficient energy and/or electron transfer processes, leading to a rapid quenching of the fluorescence emission.; At the end of this thesis, selected 1H NMR spectra and crystallographic data are given as an Appendix.
Keywords/Search Tags:Phthalocyanines, Tetrapyrrole derivatives, Part, Axial coordination, Thesis, Hydrophilic, Covalent, Several
Related items