Synthesis and investigation of the chemosensing properties of novel fluorescent triazolyl coumarin-based polymers
- Ngororabanga, Jean Marie Vianney
- Authors: Ngororabanga, Jean Marie Vianney
- Date: 2017
- Subjects: Fluorescent polymers Chemical detectors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20110 , vital:29120
- Description: Environmental pollution by ionic species has become one of the greatest challenges to the sustainable development of communities. Increasing amounts of these ionic species in the environment is associated with several detrimental effects to human health and ecological systems. Proper detection and monitoring of these ionic species is essential. Considering the diversity of the ions and the fact that the available sensors are limited, it is clear that there is need for a rapid and low-cost method for recognition and monitoring of these ions. Fluorescence based methods are ranked among the most powerful transduction systems to signal chemical recognition events. Fluorescent polymers containing triazolyl coumarin units in the polymer backbone or as pendant groups were therefore designed and investigated as potential sensors for these ions. Three methods were used to incorporate triazolyl coumarin units into the polymers. The first method involved polymerization of the vinyl monomer containing the triazolyl coumarin unit. The second method involved AA-BB step-grow click polymerization of diazide and dialkyne-functionalized monomers. The third method involved post-polymerization functionalization of an azide-functionalized polymer with an alkyne functionalized coumarin derivative. In each method, formation of the triazole ring was achieved using a Cu(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC) reaction. The photophysical properties of the polymers and their starting monomers were investigated and compared. Polymers with triazolyl coumarin units in the backbone or as pendant groups were found to have higher absorption and emission intensities than their corresponding monomers while polymers resulting from functionalization of azide-functionalized polymer were found to exhibit improved photophysical properties compared to the starting azide-functionalized polymer. The chemosensing potential of the polymers was investigated through absorption and emission. The polymers were found to be selective towards different metal ions (Fe3+, Hg2+ and Al3+) and anions (-OH and F-). The mechanisms of interaction between the polymers and ions were investigated by comparing the absorption and emission spectra of the polymers to those of their monomers in the presence of an ion of interest. In some cases the mechanism of interaction was supported by 1H NMR and FT-IR.
- Full Text:
- Date Issued: 2017
- Authors: Ngororabanga, Jean Marie Vianney
- Date: 2017
- Subjects: Fluorescent polymers Chemical detectors
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10948/20110 , vital:29120
- Description: Environmental pollution by ionic species has become one of the greatest challenges to the sustainable development of communities. Increasing amounts of these ionic species in the environment is associated with several detrimental effects to human health and ecological systems. Proper detection and monitoring of these ionic species is essential. Considering the diversity of the ions and the fact that the available sensors are limited, it is clear that there is need for a rapid and low-cost method for recognition and monitoring of these ions. Fluorescence based methods are ranked among the most powerful transduction systems to signal chemical recognition events. Fluorescent polymers containing triazolyl coumarin units in the polymer backbone or as pendant groups were therefore designed and investigated as potential sensors for these ions. Three methods were used to incorporate triazolyl coumarin units into the polymers. The first method involved polymerization of the vinyl monomer containing the triazolyl coumarin unit. The second method involved AA-BB step-grow click polymerization of diazide and dialkyne-functionalized monomers. The third method involved post-polymerization functionalization of an azide-functionalized polymer with an alkyne functionalized coumarin derivative. In each method, formation of the triazole ring was achieved using a Cu(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC) reaction. The photophysical properties of the polymers and their starting monomers were investigated and compared. Polymers with triazolyl coumarin units in the backbone or as pendant groups were found to have higher absorption and emission intensities than their corresponding monomers while polymers resulting from functionalization of azide-functionalized polymer were found to exhibit improved photophysical properties compared to the starting azide-functionalized polymer. The chemosensing potential of the polymers was investigated through absorption and emission. The polymers were found to be selective towards different metal ions (Fe3+, Hg2+ and Al3+) and anions (-OH and F-). The mechanisms of interaction between the polymers and ions were investigated by comparing the absorption and emission spectra of the polymers to those of their monomers in the presence of an ion of interest. In some cases the mechanism of interaction was supported by 1H NMR and FT-IR.
- Full Text:
- Date Issued: 2017
Synthesis of fluorescent polymers with pendant triazole-quinoline groups via raft polymerization
- Ngororabanga, Jean Marie Vianney
- Authors: Ngororabanga, Jean Marie Vianney
- Date: 2014
- Subjects: Fluorescent polymers , Polymerization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10440 , http://hdl.handle.net/10948/d1020798
- Description: In this study, fluorescent polymers with pendant quinoline groups were synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) from a fluorescent quinoline-based vinyl monomer, synthesized in multiple steps from p-nitroaniline and crotonaldehyde. The structures of the synthesized vinyl monomer and polymers were confirmed by NMR and FT-IR spectroscopy, X-ray studies and modeling stdies. The photophysical properties of the synthesized quinoline compounds and resulting polymers were investigated. In order to evaluate the binding potential of our quinoline-based polymer in the presence of transition metal ions, preliminary studies on a complexation of quinoline-based polymers with Zn, Cd, Hg, Fe, and Ni were carried out. The investigation of fluorescence properties of the complexes showed fluorescence quenching for Fe(II), and fluorescence enhancement for the remaining ions [Zn(II), Cd(II), Hg(II), and Ni(II)].
- Full Text:
- Date Issued: 2014
- Authors: Ngororabanga, Jean Marie Vianney
- Date: 2014
- Subjects: Fluorescent polymers , Polymerization
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10440 , http://hdl.handle.net/10948/d1020798
- Description: In this study, fluorescent polymers with pendant quinoline groups were synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) from a fluorescent quinoline-based vinyl monomer, synthesized in multiple steps from p-nitroaniline and crotonaldehyde. The structures of the synthesized vinyl monomer and polymers were confirmed by NMR and FT-IR spectroscopy, X-ray studies and modeling stdies. The photophysical properties of the synthesized quinoline compounds and resulting polymers were investigated. In order to evaluate the binding potential of our quinoline-based polymer in the presence of transition metal ions, preliminary studies on a complexation of quinoline-based polymers with Zn, Cd, Hg, Fe, and Ni were carried out. The investigation of fluorescence properties of the complexes showed fluorescence quenching for Fe(II), and fluorescence enhancement for the remaining ions [Zn(II), Cd(II), Hg(II), and Ni(II)].
- Full Text:
- Date Issued: 2014
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