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.

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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.

The nuclear magnetic resonance spectra of a number of organosilieon compounds are examined. The 7.95 Mcs. silicon-29 spectra are obtained for these compounds and the chemical shifts are considered in detail. It is proposed that the trends observed are the result of a competition between two opposing effects; a paramagnetic shift influenced by changes in the effective nuclear charge on silicon and a diamagnetic shift influenced by (p→d)π bonding. The concept of the competitive shift mechanism rationalizes the chemical shifts observed for series of the type MexSiX₄₋x (where: X = 0Me,0Et, 0Ac, Cl, F and C₆H₅) but does not explain the shifts of silicon hydrides. This concept also rationalizes the trends observed in ¹¹⁹Sn chemical shifts but, logically, does not apply to ¹³C chemical shifts where the d-orbital contribution must vanish. None of the observed coupling constants correlate with the ²⁹Si chemical shifts. Available theories are found to be inadequate to describe the coupling constants in these molecules. A new long range coupling is observed between the methyl groups on silicon attached to oxygen and chlorine with J[subscript]HCSiCH of about 0.35 c.p.s. / Science, Faculty of / Chemistry, Department of / Graduate

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