Characterization of nickel tetrahydroxy phthalocyanine complexes and the electrocatalytic oxidation of 4-chlorophenol
- Khene, Samson M, Lobb, Kevin A, Nyokong, Tebello
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
Theoretical and photodynamic therapy characteristics of heteroatom doped detonation nanodiamonds linked to asymmetrical phthalocyanine for eradication of breast cancer cells
- Matshitse, Refilwe, Tshiwawa, Tendamudzimu, Managa, Muthumuni, Nwaji, Njemuwa, Lobb, Kevin A, Nyokong, Tebello
- Authors: Matshitse, Refilwe , Tshiwawa, Tendamudzimu , Managa, Muthumuni , Nwaji, Njemuwa , Lobb, Kevin A , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186089 , vital:44462 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117465"
- Description: An amide mono substituted benzothiozole phthalocyanine: zinc(II) 3-(4-((3,17,23-tris(4-(benzo [d]thiazol-2-yl)phenoxy)-9-yl)oxy) phenyl)amide phthalocyanine (NH2BzPc) was covalently linked to undoped and heteroatom doped detonation nanodiamonds (DNDs): B@DNDs, P@DNDs, S@DNDs, N@DNDs, and SandN@DNDs There is a drastic decrease in highest occupied molecular orbital (HOMO) – lowest unoccupied molecular orbital (LUMO) energy gaps for nanoconjugates compared to DNDs alone. B@DNDs-NH2BzPc, SandN@DNDs-NH2BzPc, and P@DNDs-NH2BzPc showed superior photodynamic therapy (PDT) effects. DNDs-NH2BzPc also had a small HOMO-LUMO gap, but did not show improved PDT activity compared to the Pc alone, suggesting doping of DNDs is important. This study shows improved PDT effect on Michigan Cancer Foundation-7 breast cancer lines at 7.63%, 7.62% and 6.5% cell viability for P@DNDs-NH2BzPc, SandN@DNDs-NH2BzPc and B@DNDs-NH2BzPc, respectively.
- Full Text:
- Date Issued: 2020
- Authors: Matshitse, Refilwe , Tshiwawa, Tendamudzimu , Managa, Muthumuni , Nwaji, Njemuwa , Lobb, Kevin A , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186089 , vital:44462 , xlink:href="https://doi.org/10.1016/j.jlumin.2020.117465"
- Description: An amide mono substituted benzothiozole phthalocyanine: zinc(II) 3-(4-((3,17,23-tris(4-(benzo [d]thiazol-2-yl)phenoxy)-9-yl)oxy) phenyl)amide phthalocyanine (NH2BzPc) was covalently linked to undoped and heteroatom doped detonation nanodiamonds (DNDs): B@DNDs, P@DNDs, S@DNDs, N@DNDs, and SandN@DNDs There is a drastic decrease in highest occupied molecular orbital (HOMO) – lowest unoccupied molecular orbital (LUMO) energy gaps for nanoconjugates compared to DNDs alone. B@DNDs-NH2BzPc, SandN@DNDs-NH2BzPc, and P@DNDs-NH2BzPc showed superior photodynamic therapy (PDT) effects. DNDs-NH2BzPc also had a small HOMO-LUMO gap, but did not show improved PDT activity compared to the Pc alone, suggesting doping of DNDs is important. This study shows improved PDT effect on Michigan Cancer Foundation-7 breast cancer lines at 7.63%, 7.62% and 6.5% cell viability for P@DNDs-NH2BzPc, SandN@DNDs-NH2BzPc and B@DNDs-NH2BzPc, respectively.
- Full Text:
- Date Issued: 2020
Interaction between nickel hydroxy phthalocyanine derivatives with p-chlorophenol
- Khene, Samson, Lobb, Kevin A, Nyokong, Tebello
- Authors: Khene, Samson , Lobb, Kevin A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248461 , vital:51688 , xlink:href="https://doi.org/10.1016/j.electacta.2010.10.007"
- Description: In this work the interaction between peripherally (β) substituted nickel tetrahydroxyphthalocyanines (β-NiPc(OH)4 and β-Ni(O)Pc(OH)4) with p-chlorophenol is theoretically rationalised by performing calculations at B3LYP/6-31G(d) level. Density functional theory (DFT) and molecular orbital theory are used to calculate the condensed Fukui function for phthalocyanine derivatives and p-chlorophenol, in order to determine the reactive sites involved when p-chlorophenol is oxidized, and to compare theoretically predicted reactivity to experimentally determined electrocatalytic activity. Electrocatalytic activities of adsorbed NiPc derivatives: ads-α-NiPc(OH)8-OPGE (OPGE = ordinary poly graphite electrode), ads-α-NiPc(OH)4-OPGE and ads-β-NiPc(OH)4-OPGE are compared with those of the polymerized counterparts: poly-α-Ni(O)Pc(OH)8-OPGE, poly-α-NiPc(OH)4-OPGE and poly-β-NiPc(OH)4-OPGE, respectively.
- Full Text:
- Date Issued: 2010
- Authors: Khene, Samson , Lobb, Kevin A , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248461 , vital:51688 , xlink:href="https://doi.org/10.1016/j.electacta.2010.10.007"
- Description: In this work the interaction between peripherally (β) substituted nickel tetrahydroxyphthalocyanines (β-NiPc(OH)4 and β-Ni(O)Pc(OH)4) with p-chlorophenol is theoretically rationalised by performing calculations at B3LYP/6-31G(d) level. Density functional theory (DFT) and molecular orbital theory are used to calculate the condensed Fukui function for phthalocyanine derivatives and p-chlorophenol, in order to determine the reactive sites involved when p-chlorophenol is oxidized, and to compare theoretically predicted reactivity to experimentally determined electrocatalytic activity. Electrocatalytic activities of adsorbed NiPc derivatives: ads-α-NiPc(OH)8-OPGE (OPGE = ordinary poly graphite electrode), ads-α-NiPc(OH)4-OPGE and ads-β-NiPc(OH)4-OPGE are compared with those of the polymerized counterparts: poly-α-Ni(O)Pc(OH)8-OPGE, poly-α-NiPc(OH)4-OPGE and poly-β-NiPc(OH)4-OPGE, respectively.
- Full Text:
- Date Issued: 2010
Trends in the optical and redox properties of tetraphenyltetraphenanthroporphyrins
- Mack, John, Lobb, Kevin A, Nyokong, Tebello, Shen, Zhen, Kobayashi, Nagao
- Authors: Mack, John , Lobb, Kevin A , Nyokong, Tebello , Shen, Zhen , Kobayashi, Nagao
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245809 , vital:51407 , xlink:href="https://doi.org/10.1142/S1088424612500885"
- Description: The results of TD-DFT calculations for a series of tetraaryltetraphenanthroporphyrins containing para-substituents with differing electron donating and accepting properties are compared to the observed optical and redox properties and Michl's perimeter model is used as a conceptual framework for analyzing the results.
- Full Text:
- Date Issued: 2012
- Authors: Mack, John , Lobb, Kevin A , Nyokong, Tebello , Shen, Zhen , Kobayashi, Nagao
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245809 , vital:51407 , xlink:href="https://doi.org/10.1142/S1088424612500885"
- Description: The results of TD-DFT calculations for a series of tetraaryltetraphenanthroporphyrins containing para-substituents with differing electron donating and accepting properties are compared to the observed optical and redox properties and Michl's perimeter model is used as a conceptual framework for analyzing the results.
- Full Text:
- Date Issued: 2012
Introducing chemistry students to the “real world” of chemistry
- Brown, Michael E, Cosser, Ronald C, Davies-Coleman, Michael T, Kaye, Perry T, Klein, Rosalyn, Lamprecht, Emmanuel, Lobb, Kevin A, Nyokong, Tebello, Sewry, Joyce D, Tshentu, Zenixole R, Van der Zeyde, Tino, Watkins, Gareth M
- Authors: Brown, Michael E , Cosser, Ronald C , Davies-Coleman, Michael T , Kaye, Perry T , Klein, Rosalyn , Lamprecht, Emmanuel , Lobb, Kevin A , Nyokong, Tebello , Sewry, Joyce D , Tshentu, Zenixole R , Van der Zeyde, Tino , Watkins, Gareth M
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449360 , vital:74814 , xlink:href="https://doi.org/10.1021/ed8001539"
- Description: A majority of chemistry graduates seek employment in a rapidly changing chemical industry. Our attempts to provide the graduates with skills in entrepreneurship and the ability to understand and communicate with their chemical engineering colleagues, in addition to their fundamental knowledge of chemistry, are described. This is done at second-year level with practical projects in which student teams formulate and prepare relatively simple chemical products for marketing, followed a year later by a more advanced study of the feasibility of producing and marketing a fine chemical on a commercial scale.
- Full Text:
- Date Issued: 2010
- Authors: Brown, Michael E , Cosser, Ronald C , Davies-Coleman, Michael T , Kaye, Perry T , Klein, Rosalyn , Lamprecht, Emmanuel , Lobb, Kevin A , Nyokong, Tebello , Sewry, Joyce D , Tshentu, Zenixole R , Van der Zeyde, Tino , Watkins, Gareth M
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449360 , vital:74814 , xlink:href="https://doi.org/10.1021/ed8001539"
- Description: A majority of chemistry graduates seek employment in a rapidly changing chemical industry. Our attempts to provide the graduates with skills in entrepreneurship and the ability to understand and communicate with their chemical engineering colleagues, in addition to their fundamental knowledge of chemistry, are described. This is done at second-year level with practical projects in which student teams formulate and prepare relatively simple chemical products for marketing, followed a year later by a more advanced study of the feasibility of producing and marketing a fine chemical on a commercial scale.
- Full Text:
- Date Issued: 2010
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