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Synthetic studies of functional zinc phthalocyanines and boron dipyrromethenes. / CUHK electronic theses & dissertations collection

1H and 13C{1H} NMR spectra of all the new compounds and crystallographic data are given in the Appendix. / Chapter 1 presents an overview of phthalocyanines including their general synthesis, properties, and applications. Special attention has been placed on the unsymmetrical analogues, and those which are efficient photosensitizers in photodynamic therapy. A brief account on BODIPYs as another versatile class of functional dyes is also given. / Chapter 2 describes the synthesis, spectroscopic characterization, photophysical properties, and in vitro photodynamic activities of three novel amphiphilic zinc(II) phthalocyanines substituted with one or two 3,4,5-tris(3,6,9-trioxadecoxy)benzoxy group(s). These compounds exhibit significantly higher photodynamic activities toward HepG2 and HT29 cell lines. The alpha-substituted analogue is particularly potent with IC50 values as low as 0.02 microM. The higher photodynamic activity of this compound can be attributed to its lower aggregation tendency in the culture media as shown by absorption spectroscopy and higher cellular uptake as suggested by the stronger intracellular fluorescence, resulting in a higher efficiency to generate reactive oxygen species inside the cells. / Chapter 4 focuses on a related series of 1,4-disubstituted zinc(II) phthalocyanines. These compounds possess two oligoethylene glycol methyl ether chains with various length at the 1,4-di-alpha-positions. The effects of the chain length on their aggregation, photophysical properties, cellular uptake, and in vitro photodynamic activities have been explored. / Chapter 5 presents the synthesis, characterization, and photophysical properties of another series of zinc(II) phthalocyanines conjugated with one, two or four isopropylidene protected glucofuranose unit(s) through a tetraethylene glycol linker. With these hydrophilic substituents, these macrocycles are highly soluble in common organic solvents and biological media. Their in vitro photodynamic activities toward HT29 and HepG2 cells have also been evaluated. Compared with the tetra-glucosylated phthalocyanines, which are almost nonphotocytotoxic, the mono- and di-glucosylated analogues exhibit a higher photodynamic activity. The di-alpha-substituted analogue is particularly potent with IC50 values as low as 0.03 microM. / Chapter 6 reports the synthesis, characterization, and photophysical properties of two novel conjugates of subphthalocyanine substituted axially with a BODIPY or distyryl-BODIPY moiety. Both systems absorb over a broad range in the visible region. They also exhibit a highly efficient photo-induced energy transfer process either from the excited BODIPY to the subphthalocyanine core or from the excited subphthalocyanine to the distyryl-BODIPY unit. The energy transfer quantum yields are close to unity for both of these conjugates. / Chapter 7 describes the preparation and photophysical properties of another two BODIPY and monostyryl-BODIPY conjugates which are linked to a silicon(IV) phthalocyanine core. These conjugates serve as excellent artificial photosynthetic models for the study of energy and electron transfer processes. Depending on the axial substituents, these conjugates exhibit predominantly a photo-induced energy or electron transfer process in toluene. / The related studies of a series of novel di-alpha-substituted zinc(II) phthalocyanines having two biocompatible triethylene glycol methyl ether chains or glycerol moieties are described in Chapter 3. Compared with the unsubstituted analogue, these compounds have a red-shifted Q band, and exhibit a relatively weaker fluorescence emission and higher efficiency to generate singlet oxygen. As a result, these compounds are promising candidates for photodynamic therapy. In vitro studies on HepG2 and HT29 cells have shown that they are highly photocytotoxic with IC50 values as low as 0.06 microM. / This thesis describes my synthetic studies on several series of functional zinc(II) phthalocyanines and boron dipyrromethenes (BODIPYs). Their applications as efficient photosensitizers in photodynamic therapy and light harvesting systems have also been explored. / Liu, Jianyong. / Adviser: Dennis Keepui Ng. / Source: Dissertation Abstracts International, Volume: 71-01, Section: B, page: 0326. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / 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 Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_344378
Date January 2009
ContributorsLiu, Jianyong., Chinese University of Hong Kong Graduate School. Division of Chemistry.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, theses
Formatelectronic resource, microform, microfiche, 1 online resource (xxiv, 273 leaves : ill.)
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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