In this study, a series of carboxylic acid functionalised pyrrole derivatives and ferrocene- and
ruthenocene-containing dipyrromethanes were synthesised. Porphyrin complexes bearing a
mono-carboxylic acid functional group in the β-position as well as ferrocene or ruthenocene in
the -5-, or -5,10-, or -5,15- meso positions have been prepared from these pyrrole derivatives.
A series of metal-free tetraphenylporphyrins containing nitro, amino or carboxylic acid
functional groups on the para position of one of the phenyl rings were synthesised from pyrrole
and a substituted benzaldehyde. In addition, a series of metal-free porphyrins containing an
electron-withdrawing CF3 group in the ortho, meta or para positions of a phenyl group in one or
two of the four meso porphyrin position as well as three or two electron-donating ferrocenyl or
ruthenocenyl group in the other meso porphyrin positions were synthesised though a modified
statistical condensation procedure of a substituted dipyrromethane and an appropriately
functionalised benzaldehyde. Copper and nickel were also inserted into the cavities of these
porphyrins. Techniques to synthesise water-soluble polymers bearing a porphyrin side chain
were also developed. All complexes were fully characterised inter alia with 1H NMR, IR and
UV/vis spectroscopic methods and by electrochemical studies.
The new porphyrins described in this study may enhance cancer therapy by synergistic effects
between the chemotherapeutically active metallocene groups and the photodynamically active
porphyrin macrocycle. The availability of water-soluble porphyrins via the water-soluble ADF quantum chemical computations were performed on peripherally and non-peripherally
substituted phthalocyanines to optimise gas phase structures and to generate theoretically
predicted UV/vis spectra. The result indicated that DFT calculations could be utilised to design a
phthalocyanine that possesses Q-band λmax values in its electronic spectra that is red-shifted
enough to render the phthalocyanine appropriate for application in photodynamic therapy of
cancer.
polymeric drug delivery systems synthesised in this study may enhance clinical administration of
these new antineoplastic drugs to patients.
Electrochemical studies revealed that all ferrocene-containing porphyrins exhibited chemically
and electrochemically reversible one-electron transfer steps for the Fc/Fc+ couple. Because of the
use of [NBu4][B(C6F5)4] as supporting electrolyte, an electrochemical reversible Rc/Rc+ couple
could be identified, rather than the usual irreversible Cp2RuII/Cp2RuIV couple. The metallocenefree
porphyrins exhibited two one-electron oxidation waves as well as two one-electron
reduction waves. The metallocene-containing porphyrins exhibited only one one-electron
oxidation wave; the second went-off scale in the potential window that CH2Cl2 as solvent allows.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-05242013-154532 |
| Date | 24 May 2013 |
| Creators | Shago, Rebotsamang Florence |
| Contributors | Prof JC Swarts |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-05242013-154532/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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