Spectroscopic studies of substrates used for solid-phase synthesis and combinatorial chemistry : fundamentals and applications
Spectroscopic studies of substrates used for solid-phase synthesis and combinatorial chemistry : fundamentals and applications
Combinatorial Chemistry has become an extremely efficient method of producing chemical compounds in the last twenty years, but the resin beads that are used in this method of solid phase chemistry are little understood. The work presented in this thesis is concerned with using scanning confbcal Raman spectroscopy to investigate the properties of the polymer beads and the distribution and properties of cyanobenzoic acid once loaded onto the support. The beads act as a lens, the AFM results show that the surface is smooth above 0.1 jim. It was found that the cyanobenzamide tag is approximately evenly distributed in the bead. The tag is distributed in all areas where there is polymer. Mapping the whole area of a dry bead showed that areas of higher concentration of tag were found in very small-localised areas. Swollen beads showed a very even distribution of tag. The tag was found to have a slightly non-linear relationship between loading and peak intensity. This was attributed to the change in environment as the molecules came closer together and the intermolecular interactions between them. These interactions produced a shift to higher wavenumbers with higher loading of the nitrile stretch. The intensity of the Raman peak as a function of distance down through the bead (z-direction) is seen to be symmetric about the bead centre for the swollen beads but a distinct asymmetry is observed for dry beads.. This is due to the re & action of light at the air/bead interface leading to the bead acting as a lens. A discrepancy is observed in the size of the dry bead in the z-direction and x-y plane this is equal to the ratio of refractive indices of air and polystyrene.
University of Southampton
Rose, Abigail
7e1f0e36-2ad5-4e29-b9b9-756484f1f8c6
2000
Rose, Abigail
7e1f0e36-2ad5-4e29-b9b9-756484f1f8c6
Rose, Abigail
(2000)
Spectroscopic studies of substrates used for solid-phase synthesis and combinatorial chemistry : fundamentals and applications.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Combinatorial Chemistry has become an extremely efficient method of producing chemical compounds in the last twenty years, but the resin beads that are used in this method of solid phase chemistry are little understood. The work presented in this thesis is concerned with using scanning confbcal Raman spectroscopy to investigate the properties of the polymer beads and the distribution and properties of cyanobenzoic acid once loaded onto the support. The beads act as a lens, the AFM results show that the surface is smooth above 0.1 jim. It was found that the cyanobenzamide tag is approximately evenly distributed in the bead. The tag is distributed in all areas where there is polymer. Mapping the whole area of a dry bead showed that areas of higher concentration of tag were found in very small-localised areas. Swollen beads showed a very even distribution of tag. The tag was found to have a slightly non-linear relationship between loading and peak intensity. This was attributed to the change in environment as the molecules came closer together and the intermolecular interactions between them. These interactions produced a shift to higher wavenumbers with higher loading of the nitrile stretch. The intensity of the Raman peak as a function of distance down through the bead (z-direction) is seen to be symmetric about the bead centre for the swollen beads but a distinct asymmetry is observed for dry beads.. This is due to the re & action of light at the air/bead interface leading to the bead acting as a lens. A discrepancy is observed in the size of the dry bead in the z-direction and x-y plane this is equal to the ratio of refractive indices of air and polystyrene.
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Published date: 2000
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Local EPrints ID: 464292
URI: http://eprints.soton.ac.uk/id/eprint/464292
PURE UUID: 046de6e9-e9ca-4321-be8f-a2fe99c75214
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Date deposited: 04 Jul 2022 21:58
Last modified: 16 Mar 2024 19:23
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Author:
Abigail Rose
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