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A novel series of silicon(IV) phthalocyanines substituted axially with one or two 1,3-bis(dimethylamino)-2-propoxy group(s) are described in Chapter 3. These compounds are essentially non-aggregated in common organic solvents and show a weak fluorescence emission, while their methylated derivatives are also non-aggregated even in aqueous media and exhibit a strong fluorescence emission. The photocytotoxicities of these compounds against HepG2 and J774 cells have also been investigated. These new phthalocyanines, in particular the unsymmetrical and amphiphilic analogues, are highly potent with IC50 values down to 20 nM. The cellular uptake and subcellular localisation of these compounds have also been studied by fluorescence microscopy. The unsymmetric phthalocyanine SiPc[OC3H5(NMe2 )2](OMe) has a high and selective affinity to the mitochondria of HepG2 cells. / Chapter 1 presents an overview of photodynamic therapy, including its historical development, current clinical status, and photophysical and biological mechanisms. Some representative photosensitisers are also reviewed. / Chapter 2 describes two silicon(IV) phthalocyanines containing poly(ethylene glycol) chains at the axial positions, including their synthesis, spectroscopic characteristics and photophysical properties. Their complexation with bovine serum albumin and in vitro photodynamic activities towards HepG2 human hepatocarcinoma cells and J774 mouse macrophage are also reported. / Chapter 4 discusses the photodynamic effects of a series of silicon(IV) phthalocyanines with different axial substituents against HT29 and T84 human colon adenocarcinoma cells, with the long-term goal of developing efficient photosensitising agents for colorectal cancer. While these compounds are not cytotoxic in the absence of light, they exhibit high photocytotoxicities with IC50 values as low as 17 nM. / Chapter 5 reports the synthesis and characterisation of a series of halogenated silicon(IV) phthalocyanines substituted axially with poly(ethylene glycol), 1,3-bis(dimethylamino)-2-propoxy or isopropylidene-protected galactose groups, with the goal of enhancing the photosensitising properties by heavy atom effect. (Abstract shortened by UMI.) / This thesis describes the synthesis, spectroscopic characterisation, and photo-physical and biological properties of a series of novel silicon(IV) phthalocyanines which are potentially useful as second-generation photosensitisers for photodynamic therapy. / Lo Pui-chi. / "September 2005." / Adviser: Dennis K. P. Ng. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3813. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Although the use of silicon-based reagents has undergone rapid development during the last twenty years, the application of organosilicon chemistry to asymmetric synthesis has been somewhat slower to develop. The many problems associated with the use of 'Si-centred' chiral organosilicon compounds has led to the application of 'C-centred' chiral organosilicon compounds. This work has been aimed at the synthesis and application of cyclic silicon species. Routes towards the synthesis of medium-sized rings have been investigated as a potential application of enantiomerically pure silacycles. This work has led to the discovery of an unusual tandem cycloaddition-bond fragmentation reaction of 3-(dienylacyloxy)cycloalk-2- en-l-ones, which affords a-tetralone as the principal product. Most work has been directed at the synthesis of asymmetric silacycles. Two routes have been explored. Firstly, the double asymmetric hydrosilylation of dienes, catalysts based on many transition metals were used but little evidence of hydrosilylation was observed. The second route is that of the double asymmetric hydroboration of divinylsilanes. Asymmetric stoichiometric hydroboration led to products of moderate to high enantiomeric excess, whilst rhodium-catalysed hydroboration led to high yields of the achiral syn isomer. The diastereoselectivity has been found to vary according to the length of the tether between two phosphine ligands, with maximum diastereoselectivity being observed for butanodiphosphines. NMR studies have investigated the possibility that this is related to the stability of a divinylsilane-diphosphine rhodium complex. Finally, the formation of a variety of silacycles has been attempted. Boron- redistribution of the product of hydroboration with (-)-diisopinocampheylborane has been shown to occur with retention of stereochemistry and subsequent carbonylation led to the formation of asymmetric silacyclohexanones. Oxidation of the hydroboration product led to the formation of a silyldiol species. Reactions of this silyldiol have provided the basis for encouraging preliminary attempts at the formation of other heterosilacycles.

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Thesis (M.A.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 19.

Thesis (Ph.D.) -- McMaster University, 2001. / Includes bibliographical references. Also available via World Wide Web.