Nanosecond nonlinear optical limiting properties of new trinuclear lanthanide phthalocyanines in solution and as thin films
- Sekhosana, Kutloano Edward, Amuhaya, Edith, Nyokong, Tebello
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7267 , http://hdl.handle.net/10962/d1020276
- Description: 2,4,6-Tris[3-thio-9,10,16,17,23,24-hexa(4-tertbutylphenoxy) phthalocyaninato ytterbium (III) chloride]-s-triazin (3) and its lutetium counterpart (4) were synthesized. The nonlinear optical behavior of 3 and 4 were characterized in solution and when embedded in polymer as thin films. Thin films of complexes 3 and 4 in poly(bisphenol A carbonate) showed improved nonlinear optical properties when compared to solution. Complex 3 showed a lower threshold for optical limiting intensity (Ilim) than complex 4, and for phthalocyanines in general. Ilim values were even lower in films compared to solutions. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.08.047
- Full Text: false
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7267 , http://hdl.handle.net/10962/d1020276
- Description: 2,4,6-Tris[3-thio-9,10,16,17,23,24-hexa(4-tertbutylphenoxy) phthalocyaninato ytterbium (III) chloride]-s-triazin (3) and its lutetium counterpart (4) were synthesized. The nonlinear optical behavior of 3 and 4 were characterized in solution and when embedded in polymer as thin films. Thin films of complexes 3 and 4 in poly(bisphenol A carbonate) showed improved nonlinear optical properties when compared to solution. Complex 3 showed a lower threshold for optical limiting intensity (Ilim) than complex 4, and for phthalocyanines in general. Ilim values were even lower in films compared to solutions. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.08.047
- Full Text: false
Optical nonlinearities and photophysicochemical behaviour of green and blue forms of lutetium bisphthalocyanines
- Sekhosana, Kutloano Edward, Amuhaya, Edith, Mack, John, Nyokong, Tebello
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7316 , http://hdl.handle.net/10962/d1020543
- Description: A rare earth sandwich-type phthalocyanine: bis-{2,3,9,10,16,17,23,24-octa(4-tert-butylphenoxy) phthalocyaninato} lutetium(III) has been synthesized. The photophysical and nonlinear optical behavior of both the “green” and “blue” forms ([LuIIIPc2] and [LuIIIPc2]−, respectively) of the complex have been investigated. High triplet state and singlet oxygen quantum yield values were obtained for the neutral blue form which contains no unpaired electrons. Relatively high third order susceptibility and hyperpolarizability values of the order of 10−10 and 10−28 esu were obtained for both the green and blue forms, respectively. A very low threshold intensity of 0.00051 J cm−2 was obtained for the blue form. Hence the complex shows promise for non-linear optical applications. , Original publication is available at http://dx.doi.org/10.1039/C4TC00505H
- Full Text:
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7316 , http://hdl.handle.net/10962/d1020543
- Description: A rare earth sandwich-type phthalocyanine: bis-{2,3,9,10,16,17,23,24-octa(4-tert-butylphenoxy) phthalocyaninato} lutetium(III) has been synthesized. The photophysical and nonlinear optical behavior of both the “green” and “blue” forms ([LuIIIPc2] and [LuIIIPc2]−, respectively) of the complex have been investigated. High triplet state and singlet oxygen quantum yield values were obtained for the neutral blue form which contains no unpaired electrons. Relatively high third order susceptibility and hyperpolarizability values of the order of 10−10 and 10−28 esu were obtained for both the green and blue forms, respectively. A very low threshold intensity of 0.00051 J cm−2 was obtained for the blue form. Hence the complex shows promise for non-linear optical applications. , Original publication is available at http://dx.doi.org/10.1039/C4TC00505H
- Full Text:
Photodynamic antimicrobial chemotherapy activity of (5,10,15,20-tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III)
- Managa, Muthumuni, Amuhaya, Edith, Nyokong, Tebello
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
- Authors: Managa, Muthumuni , Amuhaya, Edith , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7296 , http://hdl.handle.net/10962/d1020359
- Description: (5,10,15,20-Tetrakis(4-(4-carboxyphenycarbonoimidoyl)phenyl)porphyrinato) chloro gallium(III) (complex 1) was conjugated to platinum nanoparticles (PtNPs) (represented as 1-PtNPs). The resulting conjugate showed 18 nm red shift in the Soret band when compared to 1 alone. Complex 1 and 1-PtNPs showed promising photodynamic antimicrobial chemotherapy (PACT) activity against Staphylococcus aureus, Escherichia coli and Candida albicans in solution where the log reductions obtained were 4.92, 3.76, and 3.95, respectively for 1-PtNPs. The singlet oxygen quantum yields obtained were higher at 0.56 for 1-PtNPs in DMF while that of 1 was 0.52 in the same solvent. This resulted in improved PACT activity for 1-PtNPs compared to 1 alone. , Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.06.088
- Full Text: false
- Date Issued: 2015
Photophysical properties of zinc phthalocyanine–uridine single walled carbon nanotube – conjugates
- Ogbodu, Racheal O, Amuhaya, Edith, Mashazi, Philani N, Nyokong, Tebello
- Authors: Ogbodu, Racheal O , Amuhaya, Edith , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7274 , http://hdl.handle.net/10962/d1020289 , http://dx.doi.org/10.1016/j.saa.2015.04.040
- Description: Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.04.040
- Full Text: false
- Date Issued: 2015
- Authors: Ogbodu, Racheal O , Amuhaya, Edith , Mashazi, Philani N , Nyokong, Tebello
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:7274 , http://hdl.handle.net/10962/d1020289 , http://dx.doi.org/10.1016/j.saa.2015.04.040
- Description: Original publication is available at http://dx.doi.org/10.1016/j.saa.2015.04.040
- 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
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