Nonlinear optical response of tetra and mono substituted zinc phthalocyanine complexes
- Fashina, Adedayo, Nyokong, Tebello
- Authors: Fashina, Adedayo , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7281 , http://hdl.handle.net/10962/d1020318 , Original publication is available at http://dx.doi.org/10.1016/j.jlumin.2015.06.003
- Description: The nonlinear absorption properties of 6 mono-substituted and 3 symmetric zinc phthalocyanine complexes have been studied in dimethylsulfoxide (DMSO) using 10 ns pulses at 532 nm. The non linear absorption of the complexes has been studied using the Z-scan technique. The study showed that both the singlet and triplet excited states contribute to the non linear absorption behavior. The nonlinear third-order susceptibility and second-order hyperpolarizability values of the complexes are reported. It was observed that two of the symmetric phthalocyanine complexes (5-α substituted with aminophenoxy and 9-β substituted with carboxyphenoxy) showed better and promising optical nonlinearity when compared to the other complexes studied.
- Full Text: false
- Date Issued: 2015
- Authors: Fashina, Adedayo , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7281 , http://hdl.handle.net/10962/d1020318 , Original publication is available at http://dx.doi.org/10.1016/j.jlumin.2015.06.003
- Description: The nonlinear absorption properties of 6 mono-substituted and 3 symmetric zinc phthalocyanine complexes have been studied in dimethylsulfoxide (DMSO) using 10 ns pulses at 532 nm. The non linear absorption of the complexes has been studied using the Z-scan technique. The study showed that both the singlet and triplet excited states contribute to the non linear absorption behavior. The nonlinear third-order susceptibility and second-order hyperpolarizability values of the complexes are reported. It was observed that two of the symmetric phthalocyanine complexes (5-α substituted with aminophenoxy and 9-β substituted with carboxyphenoxy) showed better and promising optical nonlinearity when compared to the other complexes studied.
- Full Text: false
- Date Issued: 2015
Photophysical studies of newly derivatized mono substituted phthalocyanines grafted onto silica nanoparticles via click chemistry
- Fashina, Adedayo, Amuhaya, Edith, Nyokong, Tebello
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7272 , http://hdl.handle.net/10962/d1020287 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.12.070
- Description: This work reports on the synthesis, characterization and photophysical studies of newly derived phthalocyanine complexes and the phthalocyanine–silica nanoparticles conjugates. The derived phthalocyanine complexes have one terminal alkyne group. The derived phthalocyanine complexes showed improved photophysical properties (ФF, ФT, ΦΔ and τT) compared to the respective phthalocyanine complexes from which they were derived. The derived phthalocyanine complexes were conjugated to the surface of an azide functionalized silica nanoparticles via copper (1) catalyzed cyclo-addition reaction. All the conjugates showed lower triplet quantum yields ranging from 0.37 to 0.44 compared to the free phthalocyanine complexes. The triplet lifetimes ranged from 352 to 484 μs for the conjugates and from 341 to 366 μs for the free phthalocyanine complexes.
- Full Text: false
- Date Issued: 2015
- Authors: Fashina, Adedayo , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7272 , http://hdl.handle.net/10962/d1020287 , Original publication is available at http://dx.doi.org/10.1016/j.saa.2014.12.070
- Description: This work reports on the synthesis, characterization and photophysical studies of newly derived phthalocyanine complexes and the phthalocyanine–silica nanoparticles conjugates. The derived phthalocyanine complexes have one terminal alkyne group. The derived phthalocyanine complexes showed improved photophysical properties (ФF, ФT, ΦΔ and τT) compared to the respective phthalocyanine complexes from which they were derived. The derived phthalocyanine complexes were conjugated to the surface of an azide functionalized silica nanoparticles via copper (1) catalyzed cyclo-addition reaction. All the conjugates showed lower triplet quantum yields ranging from 0.37 to 0.44 compared to the free phthalocyanine complexes. The triplet lifetimes ranged from 352 to 484 μs for the conjugates and from 341 to 366 μs for the free phthalocyanine complexes.
- Full Text: false
- Date Issued: 2015
Physicochemical behavior of nanohybrids of mono and tetra substituted carboxyphenoxy phthalocyanine covalently linked to GSH–CdTe/CdS/ZnS quantum dots
- Oluwole, David O, Nyokong, Tebello
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7266 , http://hdl.handle.net/10962/d1020275 , http://dx.doi.org/10.1016/j.poly.2014.10.024
- Description: Zinc monocarboxyphenoxy and tetracarboxyphenoxy phthalocyanines were covalently linked with three different sizes of glutathione capped core/shell/shell {CdTe/CdS/ZnS(4.2), CdTe/CdS/ZnS(5.1) and CdTe/CdS/ZnS(6.7)}; a core shell {CdTe/CdS(3.1)} and core {CdTe(2.4)} quantum dots. The physicochemical behavior and Förster resonance energy transfer (FRET) processes of the nanohybrids were investigated. The highest FRET efficiency was observed with CdTe/CdS/ZnS(6.7) nanohybrids with 98% and the least efficiency was observed with CdTe(2.4) nanohybrids with 85%. The CdTe/CdS/ZnS(6.7) also showed the best physicochemical behavior. These good physicochemical properties make the synthesized nanohybrids viable photosensitizers. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.10.024
- Full Text: false
- Date Issued: 2015
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: text , Article
- Identifier: vital:7266 , http://hdl.handle.net/10962/d1020275 , http://dx.doi.org/10.1016/j.poly.2014.10.024
- Description: Zinc monocarboxyphenoxy and tetracarboxyphenoxy phthalocyanines were covalently linked with three different sizes of glutathione capped core/shell/shell {CdTe/CdS/ZnS(4.2), CdTe/CdS/ZnS(5.1) and CdTe/CdS/ZnS(6.7)}; a core shell {CdTe/CdS(3.1)} and core {CdTe(2.4)} quantum dots. The physicochemical behavior and Förster resonance energy transfer (FRET) processes of the nanohybrids were investigated. The highest FRET efficiency was observed with CdTe/CdS/ZnS(6.7) nanohybrids with 98% and the least efficiency was observed with CdTe(2.4) nanohybrids with 85%. The CdTe/CdS/ZnS(6.7) also showed the best physicochemical behavior. These good physicochemical properties make the synthesized nanohybrids viable photosensitizers. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.10.024
- Full Text: false
- Date Issued: 2015
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