Microwave synthesis and photophysics of new tetrasulfonated tin (II) macrocycles
- Khene, Samson, Ogunsipe, Abimbola, Antunes, Edith M, Nyokong, Tebello
- Authors: Khene, Samson , Ogunsipe, Abimbola , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281269 , vital:55708 , xlink:href="https://doi.org/10.1142/S108842460700014X"
- Description: This work reports on the microwave synthesis of tetrasulfonated tin phthalocyanine and tetrasulfonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (more than 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The α,β,γ-tetrabenzcorrole complex has lower triplet life times and yields, while the binding constant and quenching (of bovine serum albumin) constant are lower for α,β,γ-tetrabenzcorrole compared to tetrasulfonated tin phthalocyanine.
- Full Text:
- Date Issued: 2007
- Authors: Khene, Samson , Ogunsipe, Abimbola , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281269 , vital:55708 , xlink:href="https://doi.org/10.1142/S108842460700014X"
- Description: This work reports on the microwave synthesis of tetrasulfonated tin phthalocyanine and tetrasulfonated tin α,β,γ-tetrabenzcorrole. The latter was only formed at low ratios (more than 1:8) of 4-sulfophthalic acid to urea. Both complexes are aggregated in aqueous media, but can be partly or fully disaggregated by the addition of Triton X-100. The α,β,γ-tetrabenzcorrole complex has lower triplet life times and yields, while the binding constant and quenching (of bovine serum albumin) constant are lower for α,β,γ-tetrabenzcorrole compared to tetrasulfonated tin phthalocyanine.
- Full Text:
- Date Issued: 2007
Photocatalysis of 4-nitrophenol using zinc phthalocyanine complexes
- Marais, Eloïse A, Klein, Rosalyn, Antunes, Edith M, Nyokong, Tebello
- Authors: Marais, Eloïse A , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007
- Authors: Marais, Eloïse A , Klein, Rosalyn , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281286 , vital:55709 , xlink:href="https://doi.org/10.1016/j.molcata.2006.07.055"
- Description: Photodegradation of 4-nitrophenol (4-Np) in the presence of zinc tetrasulfophthalocyanine (ZnPcS4), zinc octacarboxyphthalocyanine (ZnPc(COOH)8) and a sulfonated ZnPc containing a mixture of differently sulfonated derivatives (ZnPcSmix), as photocatalysts is reported. ZnPcSmix is the most effective catalyst in terms of a high quantum yield for 4-Np degradation and the stability of the catalyst. However ZnPc(COOH)8 degrades readily during the catalysis, but it has a higher quantum yield (Φ4-Np) for 4-Np degradation than the rest of the complexes. The Φ4-Np values were closely related to the singlet oxygen quantum yields ΦΔ and hence aggregation. The rate constants for the reaction with 4-Np were kr = 0.67 × 106 mol−1 dm3 s−1 for ZnPcSmix and 2.8 × 108 mol−1 dm3 s−1 for ZnPc(COOH)8.
- Full Text:
- Date Issued: 2007
Synthesis and electrochemical properties of purple manganese (III) and red titanium (IV) phthalocyanine complexes octa-substituted at non-peripheral positions with pentylthio groups
- Mbambisa, Gcineka, Tau, Prudence, Antunes, Edith M, Nyokong, Tebello
- Authors: Mbambisa, Gcineka , Tau, Prudence , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271252 , vital:54525 , xlink:href="https://doi.org/10.1016/j.poly.2007.08.007"
- Description: The synthesis and electrochemical characterisation of octapentylthiophthalocyaninato manganese (III) acetate (4) and octapentylthiophthalocyaninato titanium (IV) oxide (5) complexes are reported. The complexes have an unusual purple (4) and red (5) colouration since the Q-band is shifted to the near infrared region with Q-band maxima at 893 nm and 808 nm in dichloromethane for 4 and 5, respectively. The structures of the complexes were confirmed by elemental analysis and interpretation of their spectroscopic data, including 2D NMR. The cyclic voltammetry (CV) of the Mn complex (4) showed four quasi reversible couples. The reduction processes are attributed to MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 and the oxidation processes to MnIVPc−2/MnIIIPc−2 and MnIVPc−1/MnIVPc−2. The processes were confirmed by spectroelectrochemistry. A well-defined spectrum of the rare MnIVPc−2 species is reported. The CV of the Ti complex (5) showed two well-resolved reduction processes due to TiIVPc−2/TiIIIPc−2 and TiIIIPc−2/TiIIPc−2. However, oxidation processes of the complex revealed adsorption behaviour and resulted in decomposition on electrolysis using spectroelectrochemistry.
- Full Text:
- Date Issued: 2007
- Authors: Mbambisa, Gcineka , Tau, Prudence , Antunes, Edith M , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271252 , vital:54525 , xlink:href="https://doi.org/10.1016/j.poly.2007.08.007"
- Description: The synthesis and electrochemical characterisation of octapentylthiophthalocyaninato manganese (III) acetate (4) and octapentylthiophthalocyaninato titanium (IV) oxide (5) complexes are reported. The complexes have an unusual purple (4) and red (5) colouration since the Q-band is shifted to the near infrared region with Q-band maxima at 893 nm and 808 nm in dichloromethane for 4 and 5, respectively. The structures of the complexes were confirmed by elemental analysis and interpretation of their spectroscopic data, including 2D NMR. The cyclic voltammetry (CV) of the Mn complex (4) showed four quasi reversible couples. The reduction processes are attributed to MnIIIPc−2/MnIIPc−2 and MnIIPc−2/MnIIPc−3 and the oxidation processes to MnIVPc−2/MnIIIPc−2 and MnIVPc−1/MnIVPc−2. The processes were confirmed by spectroelectrochemistry. A well-defined spectrum of the rare MnIVPc−2 species is reported. The CV of the Ti complex (5) showed two well-resolved reduction processes due to TiIVPc−2/TiIIIPc−2 and TiIIIPc−2/TiIIPc−2. However, oxidation processes of the complex revealed adsorption behaviour and resulted in decomposition on electrolysis using spectroelectrochemistry.
- Full Text:
- Date Issued: 2007
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