https://search.dev.ndltd.org/etd/massey/oai:mro.massey.ac.nz:10179/2100
type: CreativeWork
name: Porphyrins for surface modification : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University, Palmerston North, New Zealand
description: The controlled synthesis of a variety of benzoic acid porphyrins ranging from monomers to arrays for the modification of TiO2 and GaAs semiconductors, and sulfur functionalised porphyrin monomers for attachment to GaAs and Au surfaces was achieved. A semi-quantitative study of the photosensitisation of TiO2 by the porphyrin acids was carried out. The syntheses of β-styryl linked porphyrin benzoic acids and some meso-substituted benzoic acid porphyrins was successfully carried out employing Wittig chemistry and classical porphyrin-forming condensation reactions with appropriate formyl methyl esters. Hydrolysis of the resulting porphyrin esters provided a facile and reliable acid synthesis, particularly where multi-step reactions were necessary. It was also demonstrated that acid functionality on porphyrins could be generated from aldehydes via esters, even though direct oxidation of the aldehydes to acids could not be achieved. The syntheses of "dipole" and "collinear" diporphyrins were achieved, providing two different porphyrin light harvesting arrays for evaluation on semiconductor surfaces. As a result of the synthesis of a new linear diporphyrin Building Block C, an alternative pathway to the controlled syntheses of mixed-metal and mixed-porphyrin arrays was achieved. This provided an alternative strategy for the controlled placement of three different metals into three different porphyrins of a linear triporphyrin, pentaporphyrin and a larger star-shaped nonaporphyrin. The exploitation of the stepwise controlled synthesis of the triporphyrin systems was expanded to include mixed-porphyrin systems synthesised with a unique tetraester porphyrin phosphonium salt. This phosphonium salt afforded mixed-diporphyrin and mixed-triporphyrin arrays, which were hydrolysed to give "sticky" mixed-diporphyrin and triporphyrin acid arrays. An alternative milder and higher yielding stepwise Wittig method was developed for the synthesis of a star shaped TXP pentaporphyrin. This …
abstract: The controlled synthesis of a variety of benzoic acid porphyrins ranging from monomers to arrays for the modification of TiO2 and GaAs semiconductors, and sulfur functionalised porphyrin monomers for attachment to GaAs and Au surfaces was achieved. A semi-quantitative study of the photosensitisation of TiO2 by the porphyrin acids was carried out. The syntheses of β-styryl linked porphyrin benzoic acids and some meso-substituted benzoic acid porphyrins was successfully carried out employing Wittig chemistry and classical porphyrin-forming condensation reactions with appropriate formyl methyl esters. Hydrolysis of the resulting porphyrin esters provided a facile and reliable acid synthesis, particularly where multi-step reactions were necessary. It was also demonstrated that acid functionality on porphyrins could be generated from aldehydes via esters, even though direct oxidation of the aldehydes to acids could not be achieved. The syntheses of "dipole" and "collinear" diporphyrins were achieved, providing two different porphyrin light harvesting arrays for evaluation on semiconductor surfaces. As a result of the synthesis of a new linear diporphyrin Building Block C, an alternative pathway to the controlled syntheses of mixed-metal and mixed-porphyrin arrays was achieved. This provided an alternative strategy for the controlled placement of three different metals into three different porphyrins of a linear triporphyrin, pentaporphyrin and a larger star-shaped nonaporphyrin. The exploitation of the stepwise controlled synthesis of the triporphyrin systems was expanded to include mixed-porphyrin systems synthesised with a unique tetraester porphyrin phosphonium salt. This phosphonium salt afforded mixed-diporphyrin and mixed-triporphyrin arrays, which were hydrolysed to give "sticky" mixed-diporphyrin and triporphyrin acid arrays. An alternative milder and higher yielding stepwise Wittig method was developed for the synthesis of a star shaped TXP pentaporphyrin. This …
author: Campbell, Wayne Mason
keywords: Porphyrin synthesis, Porphyrin acids, Solar cells, Organic compounds
date published: 2001
date modified: 2026-07-27T20:18:16Z
provider: Massey University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Massey University