Redox reactions of an Mo (V) tetrasulfophthalocyanine
- Ferraudi, Guillermo, Nyokong, Tebello, Feliz, Mario, Perkovic, Marc, Rillema, D Paul
- Authors: Ferraudi, Guillermo , Nyokong, Tebello , Feliz, Mario , Perkovic, Marc , Rillema, D Paul
- Date: 1994
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295530 , vital:57351 , xlink:href="https://doi.org/10.1016/0020-1693(93)03664-V"
- Description: The preparation of an Mo(V) tetrasulfophthalocyanine and some of its thermal and photochemical reactions have been investigated in this work. Electrochemical processes have been followed by means of the UVVis spectral changes and compared with those observed in flash photolysis. Mo(IV) and Mo(V)-ligand-radical species are common intermediates of the electrochemical and photochemical reactions. In 254 nm irradiations of the Mo(V) tetrasulfophthalocyanine in aqueous solutions of 2-propanol, the macrocycle can be photohydrogenated and the product of the photolysis can be reoxidized with O2 back to the parent complex.
- Full Text:
- Date Issued: 1994
- Authors: Ferraudi, Guillermo , Nyokong, Tebello , Feliz, Mario , Perkovic, Marc , Rillema, D Paul
- Date: 1994
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295530 , vital:57351 , xlink:href="https://doi.org/10.1016/0020-1693(93)03664-V"
- Description: The preparation of an Mo(V) tetrasulfophthalocyanine and some of its thermal and photochemical reactions have been investigated in this work. Electrochemical processes have been followed by means of the UVVis spectral changes and compared with those observed in flash photolysis. Mo(IV) and Mo(V)-ligand-radical species are common intermediates of the electrochemical and photochemical reactions. In 254 nm irradiations of the Mo(V) tetrasulfophthalocyanine in aqueous solutions of 2-propanol, the macrocycle can be photohydrogenated and the product of the photolysis can be reoxidized with O2 back to the parent complex.
- Full Text:
- Date Issued: 1994
Interaction of cyanide with iron (II) phthalocyanine
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295497 , vital:57347 , xlink:href="https://doi.org/10.1039/DT9930003601"
- Description: The kinetics and equilibria for the reaction between cyanide and iron (II) phthalocyanine [Fe(pc)](H2pc = phthalocyanine) in dimethyl sulfoxide (dmso) were studied at 25 °C. The complex [Fe(pc)(CN)2]2– is formed in two consecutive pseudo-first-order processes with k2f= 17.5 ± 0.8 dm3 mol–1 s–1 and k3f= 0.20 ± 0.05 dm3 mol–1 s–1, where k2f and k3f are the rate constants for the binding of the first and second cyanide ligands, respectively. The equilbrium constants were fund to be K2= 3.0 × 103 dm3 mol–1 and K3= 5.7 × 102 dm3 mol–1, for the formation of [Fe(pc)(CN)(dmso)]– and [Fe(pc)(CN)2]2–, respectively.
- Full Text:
- Date Issued: 1993
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295497 , vital:57347 , xlink:href="https://doi.org/10.1039/DT9930003601"
- Description: The kinetics and equilibria for the reaction between cyanide and iron (II) phthalocyanine [Fe(pc)](H2pc = phthalocyanine) in dimethyl sulfoxide (dmso) were studied at 25 °C. The complex [Fe(pc)(CN)2]2– is formed in two consecutive pseudo-first-order processes with k2f= 17.5 ± 0.8 dm3 mol–1 s–1 and k3f= 0.20 ± 0.05 dm3 mol–1 s–1, where k2f and k3f are the rate constants for the binding of the first and second cyanide ligands, respectively. The equilbrium constants were fund to be K2= 3.0 × 103 dm3 mol–1 and K3= 5.7 × 102 dm3 mol–1, for the formation of [Fe(pc)(CN)(dmso)]– and [Fe(pc)(CN)2]2–, respectively.
- Full Text:
- Date Issued: 1993
Kinetics of the reaction of cyanide with ruthenium phthalocyanine complexes
- Nyokong, Tebello, Guthrie-Strachan, Jeffry
- Authors: Nyokong, Tebello , Guthrie-Strachan, Jeffry
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295509 , vital:57348 , xlink:href="https://doi.org/10.1016/S0020-1693(00)85128-2"
- Description: Kinetic studies of the reaction of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc in DMF are reported. In the presence of a large excess of cyanide, the (CN)2RuPc complex is formed by pseudo first order kinetics. The reaction is first order in both cyanide and phthalocyanine, with specific rate constants of 5.2×10−2 and 7.2×10−2 M−1 s−1 for reactions of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc, respectively. The rate constants correspond to the coordination of the second cyanide ligand to the ruthenium phthalocyanine species.
- Full Text:
- Date Issued: 1993
- Authors: Nyokong, Tebello , Guthrie-Strachan, Jeffry
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295509 , vital:57348 , xlink:href="https://doi.org/10.1016/S0020-1693(00)85128-2"
- Description: Kinetic studies of the reaction of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc in DMF are reported. In the presence of a large excess of cyanide, the (CN)2RuPc complex is formed by pseudo first order kinetics. The reaction is first order in both cyanide and phthalocyanine, with specific rate constants of 5.2×10−2 and 7.2×10−2 M−1 s−1 for reactions of cyanide with (CO)(DMF)RuPc and (DMSO)2RuPc, respectively. The rate constants correspond to the coordination of the second cyanide ligand to the ruthenium phthalocyanine species.
- Full Text:
- Date Issued: 1993
The nature of the oxidation products of dicyanoruthenium phthalocyanine in aqueous and non-aqueous solvents
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295543 , vital:57352 , xlink:href="https://doi.org/10.1016/S0277-5387(00)81741-6"
- Description: The cyclic voltammetry of [(CN)2RuIIPc]2− in acetonitrile or dichloromethane shows two oxidation couples at E12 = 0.31 and 0.85 V (vs S.C.E.) in CH2Cl2 and E12 = 0.45 and 1.15 V (vs S.C.E.) in acetonitrile. The spectroelectrochemistry of [(CN)2RuIIPc]2− in these solvents showed that oxidations occur at the phthalocyanine ligand. K2[(CN)2RuIIPc] dissolves in water at pHs greater than 5. The cyclic voltammetry of this complex showed oxidation couples at 0.32 and 0.29 V (vs S.C.E.) for aqueous solutions containing sodium sulphate (0.1M) and for buffered solutions (pH = 9), respectively. Both cyclic voltammetry and controlled potential coulometry gave evidence of electrocrystallization of the oxidation product. Chemical oxidations of [(CN)2RuIIPc]2− in water also showed phthalocyanine ligand oxidation.
- Full Text:
- Date Issued: 1993
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295543 , vital:57352 , xlink:href="https://doi.org/10.1016/S0277-5387(00)81741-6"
- Description: The cyclic voltammetry of [(CN)2RuIIPc]2− in acetonitrile or dichloromethane shows two oxidation couples at E12 = 0.31 and 0.85 V (vs S.C.E.) in CH2Cl2 and E12 = 0.45 and 1.15 V (vs S.C.E.) in acetonitrile. The spectroelectrochemistry of [(CN)2RuIIPc]2− in these solvents showed that oxidations occur at the phthalocyanine ligand. K2[(CN)2RuIIPc] dissolves in water at pHs greater than 5. The cyclic voltammetry of this complex showed oxidation couples at 0.32 and 0.29 V (vs S.C.E.) for aqueous solutions containing sodium sulphate (0.1M) and for buffered solutions (pH = 9), respectively. Both cyclic voltammetry and controlled potential coulometry gave evidence of electrocrystallization of the oxidation product. Chemical oxidations of [(CN)2RuIIPc]2− in water also showed phthalocyanine ligand oxidation.
- Full Text:
- Date Issued: 1993
Chemistry Department: we are chemicals all over
- Authors: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7173 , http://hdl.handle.net/10962/d1006080
- Description: National University of Lesotho publication: The Light in the Night article by Tebello Nyokong on the Chemistry Department
- Full Text:
- Authors: Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7173 , http://hdl.handle.net/10962/d1006080
- Description: National University of Lesotho publication: The Light in the Night article by Tebello Nyokong on the Chemistry Department
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Group photo's of Staff and Student Collaborators
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7231 , http://hdl.handle.net/10962/d1006061
- Description: Group photo's of Staff and Student collaborators at Rhodes University
- Full Text:
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7231 , http://hdl.handle.net/10962/d1006061
- Description: Group photo's of Staff and Student collaborators at Rhodes University
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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
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- 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
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Optical nonlinearities in non-peripherally substituted pyridyloxy phthalocyanines: a combined effect of symmetry, ring-strain and demetallation
- Sanusi, Kayode, Antunes, Edith M, Nyokong, Tebello
- Authors: Sanusi, Kayode , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7301 , http://hdl.handle.net/10962/d1020375
- Description: The optical nonlinearities of six non-peripherally-substituted pyridyloxy phthalocyanines have been studied at 532 nm using a nanosecond Z-scan technique in a dimethyl sulphoxide solution. Ring-strain effects and the absence of a metal center were found to greatly reduce the inherent high nonlinearities expected of some of these phthalocyanine complexes. Of the six molecules investigated, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyaninato lead(II) 3, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyanine 5, and 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyanine 6 were found to exhibit negligible nonlinear optical behavior, due to either the absence of asymmetry or central metal and/or the presence of a ring-strain effect. A two-photon absorption process was found to be the major contributor to the observed reverse saturable absorption (RSA) in 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyaninato lead(II) 4, 1(4)-mono-(2-pyridyloxy)phthalocyaninato lead(II) 7, and 1(4)-mono-(4-pyridyloxy)phthalocyaninato lead(II) 8, with large two-photon absorption cross-section, high hyperpolarizability and high third-order susceptibility values in the range of 4.53 × 10−43–5.33 × 10−42 cm4 s per photon, 1.61 × 10−28–1.89 × 10−27 esu and 9.73 × 10−12–7.05 × 10−11 esu respectively. , Original publication is available at http://dx.doi.org/10.1039/C3DT52462K , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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- Authors: Sanusi, Kayode , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7301 , http://hdl.handle.net/10962/d1020375
- Description: The optical nonlinearities of six non-peripherally-substituted pyridyloxy phthalocyanines have been studied at 532 nm using a nanosecond Z-scan technique in a dimethyl sulphoxide solution. Ring-strain effects and the absence of a metal center were found to greatly reduce the inherent high nonlinearities expected of some of these phthalocyanine complexes. Of the six molecules investigated, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyaninato lead(II) 3, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyanine 5, and 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyanine 6 were found to exhibit negligible nonlinear optical behavior, due to either the absence of asymmetry or central metal and/or the presence of a ring-strain effect. A two-photon absorption process was found to be the major contributor to the observed reverse saturable absorption (RSA) in 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyaninato lead(II) 4, 1(4)-mono-(2-pyridyloxy)phthalocyaninato lead(II) 7, and 1(4)-mono-(4-pyridyloxy)phthalocyaninato lead(II) 8, with large two-photon absorption cross-section, high hyperpolarizability and high third-order susceptibility values in the range of 4.53 × 10−43–5.33 × 10−42 cm4 s per photon, 1.61 × 10−28–1.89 × 10−27 esu and 9.73 × 10−12–7.05 × 10−11 esu respectively. , Original publication is available at http://dx.doi.org/10.1039/C3DT52462K , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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Photo's taken in chemistry and pharmacy laboratoriums at Rhodes University where Professor Tebello Nyokong worked with her students
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7230 , http://hdl.handle.net/10962/d1006053
- Description: Photo's taken in chemistry and pharmacy laboratoriums at Rhodes University where Professor Tebello Nyokong worked with her students.
- Full Text:
- Authors: Nyokong, Tebello
- Language: English
- Type: still image
- Identifier: vital:7230 , http://hdl.handle.net/10962/d1006053
- Description: Photo's taken in chemistry and pharmacy laboratoriums at Rhodes University where Professor Tebello Nyokong worked with her students.
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Photoinactivation of Candida albicans and Escherichia coli using aluminium phthalocyanine on gold nanoparticles
- Mthethwa, Thandekile, Nyokong, Tebello
- Authors: Mthethwa, Thandekile , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7298 , http://hdl.handle.net/10962/d1020364
- Description: The conjugates of aluminium phthalocyanine (complex 1) with gold nanorods (complex 1–AuNRs) and bipyramids (complex 1–AuBPs) showed improved singlet oxygen quantum yields of 0.23 and 0.24, respectively, compared to that of complex 1 alone at 0.12. Complex 1 and its conjugates were used for the photoinactivation of fungi (C. albicans) and bacteria cells (E. coli). The Q band absorbances were the same for the Pc alone and when conjugated to AuNPs. The efficiency of these conjugates was evaluated by measuring the log reduction of the microorganisms (C. albicans and E. coli) after irradiation with visible light in the presence of photosensitizers. Aluminium phthalocyanine alone showed log 1.78 and log 2.51 reductions for C. albicans and E. coli respectively. However, the conjugates showed higher photosensitization with log 2.08 and log 3.34 for C. albicans and E. coli, respectively using 1–AuBPs. For complex 1–AuNRs log 2.53 and log 3.71 were achieved for C. albicans and E. coli respectively. The statistical analysis of the results showed that the enhanced photoinactivation observed in both microorganisms was irrespective of the shape of the nanoparticles conjugated. Photoinactivation of C. albicans was less than that of E. coli even though a higher concentration of complex 1 or its conjugates was used in C. albicans. , Original publication is available at http://dx.doi.org/10.1039/C4PP00315B , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iTextSharp 5.5.1 �2000-2014 iText Group NV (AGPL-version); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
- Full Text:
- Authors: Mthethwa, Thandekile , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7298 , http://hdl.handle.net/10962/d1020364
- Description: The conjugates of aluminium phthalocyanine (complex 1) with gold nanorods (complex 1–AuNRs) and bipyramids (complex 1–AuBPs) showed improved singlet oxygen quantum yields of 0.23 and 0.24, respectively, compared to that of complex 1 alone at 0.12. Complex 1 and its conjugates were used for the photoinactivation of fungi (C. albicans) and bacteria cells (E. coli). The Q band absorbances were the same for the Pc alone and when conjugated to AuNPs. The efficiency of these conjugates was evaluated by measuring the log reduction of the microorganisms (C. albicans and E. coli) after irradiation with visible light in the presence of photosensitizers. Aluminium phthalocyanine alone showed log 1.78 and log 2.51 reductions for C. albicans and E. coli respectively. However, the conjugates showed higher photosensitization with log 2.08 and log 3.34 for C. albicans and E. coli, respectively using 1–AuBPs. For complex 1–AuNRs log 2.53 and log 3.71 were achieved for C. albicans and E. coli respectively. The statistical analysis of the results showed that the enhanced photoinactivation observed in both microorganisms was irrespective of the shape of the nanoparticles conjugated. Photoinactivation of C. albicans was less than that of E. coli even though a higher concentration of complex 1 or its conjugates was used in C. albicans. , Original publication is available at http://dx.doi.org/10.1039/C4PP00315B , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iTextSharp 5.5.1 �2000-2014 iText Group NV (AGPL-version); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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Photophysical and photochemical properties of a novel thiol terminated low symmetry zinc phthalocyanine complex and its gold nanoparticles conjugate
- Mthethwa, Thandekile P., Tuncel, Sinem, Durmuş, Mahmut, Nyokong, Tebello
- Authors: Mthethwa, Thandekile P. , Tuncel, Sinem , Durmuş, Mahmut , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7329 , http://hdl.handle.net/10962/d1020590
- Description: A novel thiol functionalized zinc phthalocyanine complex (ZnPcSH) is reported in this work. This complex was conjugated to gold nanoparticles. The photophysical and photochemical properties of the complex and the conjugate were investigated. Upon conjugation a blue shift was observed from the UV-Vis spectra. The conjugate showed a decrease in the fluorescence quantum yield and lifetime. An increase in the triplet quantum yield and lifetime was observed for ZnPcSH following conjugation to gold nanoparticles. Both ZnPcSH and its conjugate with gold nanoparticles showed high singlet oxygen quantum yields with the conjugate being higher than the Pc alone. , Original publication is available at http://dx.doi.org/10.1039/C3DT32698E
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- Authors: Mthethwa, Thandekile P. , Tuncel, Sinem , Durmuş, Mahmut , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7329 , http://hdl.handle.net/10962/d1020590
- Description: A novel thiol functionalized zinc phthalocyanine complex (ZnPcSH) is reported in this work. This complex was conjugated to gold nanoparticles. The photophysical and photochemical properties of the complex and the conjugate were investigated. Upon conjugation a blue shift was observed from the UV-Vis spectra. The conjugate showed a decrease in the fluorescence quantum yield and lifetime. An increase in the triplet quantum yield and lifetime was observed for ZnPcSH following conjugation to gold nanoparticles. Both ZnPcSH and its conjugate with gold nanoparticles showed high singlet oxygen quantum yields with the conjugate being higher than the Pc alone. , Original publication is available at http://dx.doi.org/10.1039/C3DT32698E
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Photophysical properties of a new water soluble tetra thiamine substituted zinc phthalocyanine conjugated to gold nanorods of different aspect ratios
- Mthethwa, Thandekile, Antunes, Edith M, Nyokong, Tebello
- Authors: Mthethwa, Thandekile , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7302 , http://hdl.handle.net/10962/d1020379
- Description: A water soluble zinc phthalocyanine substituted with thiamine is reported in this work. The aggregation of this compound in aqueous solutions causes quenching of the fluorescence quantum yields. Gold nanospheres and nanorods were linked to the phthalocyanine. X-ray photoelectron spectroscopy showed that both the amine and the sulphur groups on the thiamine substituent of the zinc phthalocyanine were involved in the linking to gold nanoparticles. The Pc showed an increase in the fluorescence quantum yields in the presence of the nanoparticles. The singlet oxygen quantum yield increased when the Pc was conjugated to the nanoparticles and even higher for larger aspect ratio gold nanorods. , Original publication is available at http://dx.doi.org/10.1039/C4DT00197D , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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- Authors: Mthethwa, Thandekile , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7302 , http://hdl.handle.net/10962/d1020379
- Description: A water soluble zinc phthalocyanine substituted with thiamine is reported in this work. The aggregation of this compound in aqueous solutions causes quenching of the fluorescence quantum yields. Gold nanospheres and nanorods were linked to the phthalocyanine. X-ray photoelectron spectroscopy showed that both the amine and the sulphur groups on the thiamine substituent of the zinc phthalocyanine were involved in the linking to gold nanoparticles. The Pc showed an increase in the fluorescence quantum yields in the presence of the nanoparticles. The singlet oxygen quantum yield increased when the Pc was conjugated to the nanoparticles and even higher for larger aspect ratio gold nanorods. , Original publication is available at http://dx.doi.org/10.1039/C4DT00197D , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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Physicochemical properties of a zinc phthalocyanine – pyrene conjugate adsorbed onto single walled carbon nanotubes
- Ogbodu, Racheal O, Antunes, Edith M, Nyokong, Tebello
- Authors: Ogbodu, Racheal O , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7328 , http://hdl.handle.net/10962/d1020589
- Description: A conjugate between zinc monoamino phthalocyanine (ZnMAPc) and pyrene (Py) represented as ZnMAPc–Py (complex 3) was synthesized and characterized by various spectroscopic techniques and by elemental analysis. This manuscript also reports on the photochemical and photophysical properties of 3. This new compound exhibited higher triplet, fluorescence and singlet oxygen quantum yields in comparison to the phthalocyanine alone, hence showing the advantages of attaching pyrene to the Pc without breaking the conjugation. We also observed a decrease in photophysical parameters upon adsorbing the ZnMAPc–Py complex onto single walled carbon nanotubes (SWCNT). However, ZnMAPc–Py still generated some singlet oxygen when adsorbed onto SWCNT. , Original publication is available at http://dx.doi.org/10.1039/C3DT50335F
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- Authors: Ogbodu, Racheal O , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7328 , http://hdl.handle.net/10962/d1020589
- Description: A conjugate between zinc monoamino phthalocyanine (ZnMAPc) and pyrene (Py) represented as ZnMAPc–Py (complex 3) was synthesized and characterized by various spectroscopic techniques and by elemental analysis. This manuscript also reports on the photochemical and photophysical properties of 3. This new compound exhibited higher triplet, fluorescence and singlet oxygen quantum yields in comparison to the phthalocyanine alone, hence showing the advantages of attaching pyrene to the Pc without breaking the conjugation. We also observed a decrease in photophysical parameters upon adsorbing the ZnMAPc–Py complex onto single walled carbon nanotubes (SWCNT). However, ZnMAPc–Py still generated some singlet oxygen when adsorbed onto SWCNT. , Original publication is available at http://dx.doi.org/10.1039/C3DT50335F
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Synthesis, characterization and photophysical properties of an acenaphthalene fused-ring-expanded NIR absorbing aza-BODIPY dye
- Majumdar, Poulomi, Mack, John, Nyokong, Tebello
- Authors: Majumdar, Poulomi , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7283 , http://hdl.handle.net/10962/d1020328
- Description: The synthesis and characterization of an NIR absorbing acenaphthalene fused-ring-expanded aza-BODIPY dye are reported. In contrast with its naphtho-fused analogue, a stable complex is obtained when the corresponding phthalonitrile is used as the precursor. A comparison is made with the photophysical properties of 3,5-diphenyl-aza-dibenzoBODIPY. , Original publication is available at http://dx.doi.org/10.1039/C5RA14916A , Arbortext Advanced Print Publisher 9.1.510/W Unicode , Acrobat Distiller 8.1.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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- Authors: Majumdar, Poulomi , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7283 , http://hdl.handle.net/10962/d1020328
- Description: The synthesis and characterization of an NIR absorbing acenaphthalene fused-ring-expanded aza-BODIPY dye are reported. In contrast with its naphtho-fused analogue, a stable complex is obtained when the corresponding phthalonitrile is used as the precursor. A comparison is made with the photophysical properties of 3,5-diphenyl-aza-dibenzoBODIPY. , Original publication is available at http://dx.doi.org/10.1039/C5RA14916A , Arbortext Advanced Print Publisher 9.1.510/W Unicode , Acrobat Distiller 8.1.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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