Synthesis of fluorescent polymers with coumarin backbones by "click" polymerization
- Authors: Okerio, Jaspher Mosomi
- Date: 2013
- Subjects: Polymerization , Fluorescent polymers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10431 , http://hdl.handle.net/10948/d1020132
- Description: Click chemistry is one of the growing areas of research which is applied in the design and synthesis of a wide range of polymeric architectures. This investigation focuses on the synthesis of fluorescent coumarin based polymers by “click” A-B step growth polymerization process and evaluation of their photophysical properties. Non-fluorescent azide-alkyne functionalized coumarin-based monomers were synthesized in multiple steps from 2,4-dihydroxybenzaldehyde in reasonable yields. Polymers with coumarin backbone were synthesized from azide-alkyne functionalized coumarin monomers via the Cu(I) catalyzed 1,3-dipolar cycloaddition reaction between azides and alkynes, a typical click reaction, to form polymers whose repeating units are connected by a 1,2,3-triazole ring. The structures of the synthesized polymers were confirmed by NMR and FT-IR spectroscopy. Finally, the photophysical properties of the synthesized monomers and polymers were evaluated in DMF. All coumarin based monomers showed reduced fluorescent properties due to the quenching effect from the azido group. Although all polymers absorbed at maximum wavelength of 340 nm, a characteristic for coumarin chromophore, the homo-polymers emitted at a shorter wavelength of 413 nm as compared to the co-polymers which emitted at 421 nm.
- Full Text:
- Date Issued: 2013
- Authors: Okerio, Jaspher Mosomi
- Date: 2013
- Subjects: Polymerization , Fluorescent polymers
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10431 , http://hdl.handle.net/10948/d1020132
- Description: Click chemistry is one of the growing areas of research which is applied in the design and synthesis of a wide range of polymeric architectures. This investigation focuses on the synthesis of fluorescent coumarin based polymers by “click” A-B step growth polymerization process and evaluation of their photophysical properties. Non-fluorescent azide-alkyne functionalized coumarin-based monomers were synthesized in multiple steps from 2,4-dihydroxybenzaldehyde in reasonable yields. Polymers with coumarin backbone were synthesized from azide-alkyne functionalized coumarin monomers via the Cu(I) catalyzed 1,3-dipolar cycloaddition reaction between azides and alkynes, a typical click reaction, to form polymers whose repeating units are connected by a 1,2,3-triazole ring. The structures of the synthesized polymers were confirmed by NMR and FT-IR spectroscopy. Finally, the photophysical properties of the synthesized monomers and polymers were evaluated in DMF. All coumarin based monomers showed reduced fluorescent properties due to the quenching effect from the azido group. Although all polymers absorbed at maximum wavelength of 340 nm, a characteristic for coumarin chromophore, the homo-polymers emitted at a shorter wavelength of 413 nm as compared to the co-polymers which emitted at 421 nm.
- Full Text:
- Date Issued: 2013
Synthesis of fluorescent polymers with pendant triazole-substituted coumarin side-chains via a combination of click chemistry and raft-mediated polymerization
- Authors: Wali, Nwabisa Whitney
- Date: 2013
- Subjects: Fluorescent polymers , Polymerization , Macromolecules -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10432 , http://hdl.handle.net/10948/d1020142
- Description: This research project focuses on the synthesis of fluorescent polymers with pendant triazole-substituted coumarin side chain units. Copper(I)-catalyzed Huisgen’s 1,3-dipolar cycloaddition of alkynes with azides to form a 1,2,3-triazole ring, a typical example of “click” reaction, has been utilized for the synthesis of a novel vinyl monomer, 2-oxo-3-(4- vinyl-1H-1,2,3-triazol-1-yl)-2H-chromen-7-yl acetate 62. The monomer and its precursors were synthesised and characterized using 1D- and 2D-NMR and FT-IR. Coumarin-containing triazole polymers were synthesised using free radical polymerization. Reversible Addition-Fragmentation Chain Transfer (RAFT)-mediated polymerization was used to synthesise well defined coumarin-containing triazole polymers with moderate PDI values. The polymers were characterised using 1H-NMR and FT-IR. Modelling of the monomer precursor 61 and the monomer 62 at DFT level of approximation provided useful insights into possible conformations adopted by the monomer precursor 61 and the monomer 62. The photophysical properties of the novel monomer and the synthesised polymers were investigated in a polar solvent.
- Full Text:
- Date Issued: 2013
- Authors: Wali, Nwabisa Whitney
- Date: 2013
- Subjects: Fluorescent polymers , Polymerization , Macromolecules -- Synthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10432 , http://hdl.handle.net/10948/d1020142
- Description: This research project focuses on the synthesis of fluorescent polymers with pendant triazole-substituted coumarin side chain units. Copper(I)-catalyzed Huisgen’s 1,3-dipolar cycloaddition of alkynes with azides to form a 1,2,3-triazole ring, a typical example of “click” reaction, has been utilized for the synthesis of a novel vinyl monomer, 2-oxo-3-(4- vinyl-1H-1,2,3-triazol-1-yl)-2H-chromen-7-yl acetate 62. The monomer and its precursors were synthesised and characterized using 1D- and 2D-NMR and FT-IR. Coumarin-containing triazole polymers were synthesised using free radical polymerization. Reversible Addition-Fragmentation Chain Transfer (RAFT)-mediated polymerization was used to synthesise well defined coumarin-containing triazole polymers with moderate PDI values. The polymers were characterised using 1H-NMR and FT-IR. Modelling of the monomer precursor 61 and the monomer 62 at DFT level of approximation provided useful insights into possible conformations adopted by the monomer precursor 61 and the monomer 62. The photophysical properties of the novel monomer and the synthesised polymers were investigated in a polar solvent.
- Full Text:
- Date Issued: 2013
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