Synthesis and photophysical properties of BODIPY-decorated graphene quantum dot–phthalocyanine conjugates
- Nwahara, Nnamdi, Nkhahle, Reitumetse, Ngoy, Bokolombe P, Mack, John, Nyokong, Tebello
- Authors: Nwahara, Nnamdi , Nkhahle, Reitumetse , Ngoy, Bokolombe P , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233409 , vital:50088 , xlink:href="https://doi.org/10.1039/C8NJ00758F"
- Description: This work reports on the synthesis and characterisation of novel supramolecular hybrids containing BODIPY-decorated graphene quantum dots (BODIPY@GQDs) and zinc phthalocyanine. Graphene quantum dots (GQDs) were functionalized with L-glutathione (GSH) in order to assist coupling to the BODIPY dye. {2,9(10)16(17)23(24)-Tetrakis-[3-(diethylamino)phenoxy]phthalocyaninato}zinc(II) (1) was immobilized via π–π stacking interaction on the BODIPY-decorated GQDs and pristine GQDs to form the supramolecular hybrids 1-BODIPY@GQDs and 1-GQDs, respectively. The photophysical and photochemical properties of these conjugates were investigated. Energy transfer occurred from the (i) GQDs to BODIPY, (ii) GQDs to 1, and (iii) BODIPY@GQDs to 1via fluorescence resonance energy transfer (FRET). The highest FRET efficiency was observed for the BODIPY@GQDs (0.93). The introduction of the BODIPY core to the GQD structure resulted in higher triplet, and singlet oxygen quantum yields for the resultant Pc/GQD hybrid (1-BODIPY@GQDs). The zeta potential values obtained imply a high colloidal stability for the supramolecular hybrids. The results suggest that such hybrids may be applied in fields such as photodynamic therapy (PDT), where a high singlet oxygen quantum yield is desired.
- Full Text:
- Date Issued: 2018
- Authors: Nwahara, Nnamdi , Nkhahle, Reitumetse , Ngoy, Bokolombe P , Mack, John , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/233409 , vital:50088 , xlink:href="https://doi.org/10.1039/C8NJ00758F"
- Description: This work reports on the synthesis and characterisation of novel supramolecular hybrids containing BODIPY-decorated graphene quantum dots (BODIPY@GQDs) and zinc phthalocyanine. Graphene quantum dots (GQDs) were functionalized with L-glutathione (GSH) in order to assist coupling to the BODIPY dye. {2,9(10)16(17)23(24)-Tetrakis-[3-(diethylamino)phenoxy]phthalocyaninato}zinc(II) (1) was immobilized via π–π stacking interaction on the BODIPY-decorated GQDs and pristine GQDs to form the supramolecular hybrids 1-BODIPY@GQDs and 1-GQDs, respectively. The photophysical and photochemical properties of these conjugates were investigated. Energy transfer occurred from the (i) GQDs to BODIPY, (ii) GQDs to 1, and (iii) BODIPY@GQDs to 1via fluorescence resonance energy transfer (FRET). The highest FRET efficiency was observed for the BODIPY@GQDs (0.93). The introduction of the BODIPY core to the GQD structure resulted in higher triplet, and singlet oxygen quantum yields for the resultant Pc/GQD hybrid (1-BODIPY@GQDs). The zeta potential values obtained imply a high colloidal stability for the supramolecular hybrids. The results suggest that such hybrids may be applied in fields such as photodynamic therapy (PDT), where a high singlet oxygen quantum yield is desired.
- Full Text:
- Date Issued: 2018
The Primary Demonstration of Exciton Coupling Effects on Optical Limiting Properties of Blue Double-Decker Lanthanide Phthalocyanine Salts
- Sekhosana, Kutloano E, Nkhahle, Reitumetse, Nyokong, Tebello
- Authors: Sekhosana, Kutloano E , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234614 , vital:50213 , xlink:href="https://doi.org/10.1002/slct.201800597"
- Description: In this manuscript, novel green and blue sandwich-type rare-earth phthalocyanines (LnPc2) are presented. This parent green LnPc2 complex is named bis-{2(3),9(10),16(17),23(24)-tetra(4-tert-buylphenoxy) phthalocyaninato} neodymium (III) (2) and modified into blue LnPc2 complexes (3), (4) and (5) based on hexadecyltrimethylammonium ion, mononeodymium(III) diacetate and monodysprosium(III) diacetate as counter ions, respectively. These stable blue lanthanide Pc salts are highly soluble in many organic and inorganic solvents. All complexes 2, 3, 4 and 5 were studied for optical limiting for the first time using Z-scan at nanosecond regime in the visible absorption spectral wavelength (532 nm). Our studies reveal the advantage of exciton coupling in blue sandwich-type rare-earth phthalocyanines over the π-radicals (characterized by blue valence at 485 nm) in the green counterpart which are in resonance with the 532 nm wavelength for optical limiting application. Large singlet ground state to excited state absorption cross section ratios were found, particularly for complex 5 in comparison to that of complex 2.
- Full Text:
- Date Issued: 2018
- Authors: Sekhosana, Kutloano E , Nkhahle, Reitumetse , Nyokong, Tebello
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/234614 , vital:50213 , xlink:href="https://doi.org/10.1002/slct.201800597"
- Description: In this manuscript, novel green and blue sandwich-type rare-earth phthalocyanines (LnPc2) are presented. This parent green LnPc2 complex is named bis-{2(3),9(10),16(17),23(24)-tetra(4-tert-buylphenoxy) phthalocyaninato} neodymium (III) (2) and modified into blue LnPc2 complexes (3), (4) and (5) based on hexadecyltrimethylammonium ion, mononeodymium(III) diacetate and monodysprosium(III) diacetate as counter ions, respectively. These stable blue lanthanide Pc salts are highly soluble in many organic and inorganic solvents. All complexes 2, 3, 4 and 5 were studied for optical limiting for the first time using Z-scan at nanosecond regime in the visible absorption spectral wavelength (532 nm). Our studies reveal the advantage of exciton coupling in blue sandwich-type rare-earth phthalocyanines over the π-radicals (characterized by blue valence at 485 nm) in the green counterpart which are in resonance with the 532 nm wavelength for optical limiting application. Large singlet ground state to excited state absorption cross section ratios were found, particularly for complex 5 in comparison to that of complex 2.
- Full Text:
- Date Issued: 2018
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