Representations of the subject ‘woman’ and the politics of abortion: an analysis of South African newspaper articles from 1978 to 2005
- Macleod, Catriona I, Feltham-King, Tracey
- Authors: Macleod, Catriona I , Feltham-King, Tracey
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446286 , vital:74487 , xlink:href="https://doi.org/10.1080/13691058.2012.685760"
- Description: A key element in cultural and gender power relations surrounding abortion is how women who undergo an abortion are represented in public talk. We analyse how women were named and positioned, and the attendant constructions of abortion, in South African newspaper articles on abortion from 1978 to 2005, a period during which there were radical political and legislative shifts. The name ‘woman’ was the most frequently used (70% of articles) followed by ‘girl/teenager/child’ (25%), ‘mother’ (25%), ‘patient’ (11%) and ‘minor’ (6%). The subject positionings enabled by these names were dynamic and complex and were interwoven with the localised, historical politics of abortion. The ‘innocent mother’ and the bifurcated ‘patient’ (woman/foetus) positionings were invoked in earlier epochs to promote abortion under medical conditions. The ‘dangerous mother’ and woman as ‘patient’ positionings were used more frequently under liberal abortion legislation to oppose and to advocate for abortion, respectively. The positioning of the ‘girl/teenager/child’ as dependent and vulnerable was used in contradictory ways, both to oppose abortion and to argue for a liberalisation of restrictive legislation, depending on the attendant construction of abortion. The neutral naming of ‘woman’ was, at times, linked to the liberal imaginary of ‘choice’.
- Full Text:
- Authors: Macleod, Catriona I , Feltham-King, Tracey
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446286 , vital:74487 , xlink:href="https://doi.org/10.1080/13691058.2012.685760"
- Description: A key element in cultural and gender power relations surrounding abortion is how women who undergo an abortion are represented in public talk. We analyse how women were named and positioned, and the attendant constructions of abortion, in South African newspaper articles on abortion from 1978 to 2005, a period during which there were radical political and legislative shifts. The name ‘woman’ was the most frequently used (70% of articles) followed by ‘girl/teenager/child’ (25%), ‘mother’ (25%), ‘patient’ (11%) and ‘minor’ (6%). The subject positionings enabled by these names were dynamic and complex and were interwoven with the localised, historical politics of abortion. The ‘innocent mother’ and the bifurcated ‘patient’ (woman/foetus) positionings were invoked in earlier epochs to promote abortion under medical conditions. The ‘dangerous mother’ and woman as ‘patient’ positionings were used more frequently under liberal abortion legislation to oppose and to advocate for abortion, respectively. The positioning of the ‘girl/teenager/child’ as dependent and vulnerable was used in contradictory ways, both to oppose abortion and to argue for a liberalisation of restrictive legislation, depending on the attendant construction of abortion. The neutral naming of ‘woman’ was, at times, linked to the liberal imaginary of ‘choice’.
- Full Text:
Research Testbed Networks: Practical Tools for Service Delivery?
- Wertlen, Ronald R, Siebörger, Ingrid, Tsietsi, Mosiuoa, Shibeshi, Zelalem S, Terzoli, Alfredo
- Authors: Wertlen, Ronald R , Siebörger, Ingrid , Tsietsi, Mosiuoa , Shibeshi, Zelalem S , Terzoli, Alfredo
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429204 , vital:72567 , https://doi.org/10.1002/j.1681-4835.2012.tb00351.x
- Description: The Telkom Centre of Excellence (CoE) at Rhodes University, housed in the Computer Science department was opened in 1997. The CoE's focus on Distributed multimedia service platforms soon showed that the technology being researched could be applied in the disadvantaged peri‐urban communities. The CoE has thus concentrated its research on building a testbed network that delivers real services to real users. In 2007, the testbed was extended to include a marginalised rural area in the Siyakhula Living Lab. The greatest factor in the sustainability of the CoE testbed network has been maintaining usefulness to all the stakeholders over the last 12 years. Industrial funding, University outreach goals and research goals could all be harmonised, while sustaining the delivery of high quality informatics services in the community. This paper presents a brief case study of the communications network testbed and how it was applied to the Development Informatics space. It analyses the roles played by stakeholders in either assisting and sustaining or obstructing the service delivery. It makes key recommendations on best practices for research networks that can also bring informatics to disadvantaged communities. It shows how testbeds for the research of new technologies can be designed so as to allow Development Informatics work to take place on such networks.
- Full Text:
- Authors: Wertlen, Ronald R , Siebörger, Ingrid , Tsietsi, Mosiuoa , Shibeshi, Zelalem S , Terzoli, Alfredo
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429204 , vital:72567 , https://doi.org/10.1002/j.1681-4835.2012.tb00351.x
- Description: The Telkom Centre of Excellence (CoE) at Rhodes University, housed in the Computer Science department was opened in 1997. The CoE's focus on Distributed multimedia service platforms soon showed that the technology being researched could be applied in the disadvantaged peri‐urban communities. The CoE has thus concentrated its research on building a testbed network that delivers real services to real users. In 2007, the testbed was extended to include a marginalised rural area in the Siyakhula Living Lab. The greatest factor in the sustainability of the CoE testbed network has been maintaining usefulness to all the stakeholders over the last 12 years. Industrial funding, University outreach goals and research goals could all be harmonised, while sustaining the delivery of high quality informatics services in the community. This paper presents a brief case study of the communications network testbed and how it was applied to the Development Informatics space. It analyses the roles played by stakeholders in either assisting and sustaining or obstructing the service delivery. It makes key recommendations on best practices for research networks that can also bring informatics to disadvantaged communities. It shows how testbeds for the research of new technologies can be designed so as to allow Development Informatics work to take place on such networks.
- Full Text:
Reverse saturation absorption spectra and optical limiting properties of chlorinated tetrasubstituted phthalocyanines containing different metals
- Tuhl, Ahmad, Manaa, Hacene, Makhseed, Saad, Al-Awadi, Nouria, Matthew, Jacob, Ibrahim, Hamada Mohamed, Nyokong, Tebello, Behbehani, Haider
- Authors: Tuhl, Ahmad , Manaa, Hacene , Makhseed, Saad , Al-Awadi, Nouria , Matthew, Jacob , Ibrahim, Hamada Mohamed , Nyokong, Tebello , Behbehani, Haider
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243498 , vital:51158 , xlink:href="https://doi.org/10.1016/j.optmat.2012.05.018"
- Description: A highly non-aggregated series of peripherally tetra(2,6-diisopropylphenoxy) substituted phthalocyanines (Pcs) containing different metals (Al, Ga, In and Zn) were prepared and their nonlinear optical properties (NLO), including the optical limiting behavior were investigated. This study explores the effect of the implanted metals along with the peripheral chlorine atoms on the NLO of the prepared complexes, thereby improving their optical limiting performance. The best wavelength at which the Pc complex exhibits the strongest nonlinear effect was determined over the low absorption window region (420–590 nm) comprised between the Q and B bands using a nanosecond pulsed laser with the aid of a Z-scan technique. The excited state absorption cross sections (σeff) have been found to be wavelength dependent with common double peaks at 505 nm and around 485 nm and the highest value was calculated for Pc1–In (1.1 × 10−16 cm2). The figure of merit spectra show different spectral structure when compared to the excited state absorption spectra and the largest figure of merit value was found to be around 107 for Pc1–In derivative. In full agreement with reverse saturation results, the optical limiting measurements, carried out at 485 nm and 532 nm for each derivative, show very low optical limiting thresholds at the former wavelength. In the continuous wave excitation regime, the Z-scan measurements, which were carried out at 632.8 and 532 nm, showed strong refractive and absorptive nonlinear effects.
- Full Text:
- Authors: Tuhl, Ahmad , Manaa, Hacene , Makhseed, Saad , Al-Awadi, Nouria , Matthew, Jacob , Ibrahim, Hamada Mohamed , Nyokong, Tebello , Behbehani, Haider
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243498 , vital:51158 , xlink:href="https://doi.org/10.1016/j.optmat.2012.05.018"
- Description: A highly non-aggregated series of peripherally tetra(2,6-diisopropylphenoxy) substituted phthalocyanines (Pcs) containing different metals (Al, Ga, In and Zn) were prepared and their nonlinear optical properties (NLO), including the optical limiting behavior were investigated. This study explores the effect of the implanted metals along with the peripheral chlorine atoms on the NLO of the prepared complexes, thereby improving their optical limiting performance. The best wavelength at which the Pc complex exhibits the strongest nonlinear effect was determined over the low absorption window region (420–590 nm) comprised between the Q and B bands using a nanosecond pulsed laser with the aid of a Z-scan technique. The excited state absorption cross sections (σeff) have been found to be wavelength dependent with common double peaks at 505 nm and around 485 nm and the highest value was calculated for Pc1–In (1.1 × 10−16 cm2). The figure of merit spectra show different spectral structure when compared to the excited state absorption spectra and the largest figure of merit value was found to be around 107 for Pc1–In derivative. In full agreement with reverse saturation results, the optical limiting measurements, carried out at 485 nm and 532 nm for each derivative, show very low optical limiting thresholds at the former wavelength. In the continuous wave excitation regime, the Z-scan measurements, which were carried out at 632.8 and 532 nm, showed strong refractive and absorptive nonlinear effects.
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Richard T. Carson: Contingent valuation: a comprehensive bibliography and history
- Authors: Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71504 , vital:29859 , https://link.springer.com/content/pdf/10.1007/s10824-012-9165-7.pdf
- Description: For those of us who have been involved in willingness to pay studies for some time, Contingent Valuation: A comprehensive bibliography and history by Richard Carson is a fascinating read, tracking the early development of the method and debates around it from an insider’s perspective. As someone who has not only been involved in contingent valuation research over many years, but who has also been instrumental in shaping it, Richard Carson is the ideal author of this carefully crafted book.
- Full Text:
- Authors: Snowball, Jeanette D
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71504 , vital:29859 , https://link.springer.com/content/pdf/10.1007/s10824-012-9165-7.pdf
- Description: For those of us who have been involved in willingness to pay studies for some time, Contingent Valuation: A comprehensive bibliography and history by Richard Carson is a fascinating read, tracking the early development of the method and debates around it from an insider’s perspective. As someone who has not only been involved in contingent valuation research over many years, but who has also been instrumental in shaping it, Richard Carson is the ideal author of this carefully crafted book.
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Schottky barrier diode parameters of Ag/MgPc/p-Si structure
- Canlıca, Mevlüde, Coskun, Mustafa, Altındal, Ahmet, Nyokong, Tebello
- Authors: Canlıca, Mevlüde , Coskun, Mustafa , Altındal, Ahmet , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245820 , vital:51408 , xlink:href="https://doi.org/10.1142/S1088424612500824"
- Description: An Ag/Pc/p-Si Schottky barrier (SB) diode was fabricated. The current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G-V) measurements were carried out to determine the characteristic parameters such as barrier height, ideality factor and series resistance of the SB diode. The non-linear behavior of ln (I) vs. ln (V) and ln (I/V) vs. V1/2 plots indicated that the thermoionic emission theory can be applied to evaluate junction parameters for the investigated SB diode rather than space-charge limited conduction (SCLC) mechanism and bulk-limited Poole–Frenkel emission. The bulk doping concentration NB and fixed oxide charges Nf was determined from the measured high frequency C-V curve and was found to be 9.5 × 1014 cm-3 and 2.3 × 1013 cm-2, respectively. The values of barrier height obtained from Norde's function were compared with those from the forward bias current-voltage characteristic, and it was seen that there was a good agreement between barrier heights from both methods.
- Full Text:
- Authors: Canlıca, Mevlüde , Coskun, Mustafa , Altındal, Ahmet , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245820 , vital:51408 , xlink:href="https://doi.org/10.1142/S1088424612500824"
- Description: An Ag/Pc/p-Si Schottky barrier (SB) diode was fabricated. The current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G-V) measurements were carried out to determine the characteristic parameters such as barrier height, ideality factor and series resistance of the SB diode. The non-linear behavior of ln (I) vs. ln (V) and ln (I/V) vs. V1/2 plots indicated that the thermoionic emission theory can be applied to evaluate junction parameters for the investigated SB diode rather than space-charge limited conduction (SCLC) mechanism and bulk-limited Poole–Frenkel emission. The bulk doping concentration NB and fixed oxide charges Nf was determined from the measured high frequency C-V curve and was found to be 9.5 × 1014 cm-3 and 2.3 × 1013 cm-2, respectively. The values of barrier height obtained from Norde's function were compared with those from the forward bias current-voltage characteristic, and it was seen that there was a good agreement between barrier heights from both methods.
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Seasonal distribution, breeding season and wing moult in the Splendid Glossy Starling Lamprotornis splendidus
- Authors: Craig, Adrian J F K
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449535 , vital:74828 , https://doi.org/10.2989/00306525.2012.655429
- Description: Seasonal migration by Splendid Glossy Starlings has been confirmed only for Kenya and Zambia. Populations in almost all other countries have been categorised as ‘resident’ by some observers, but ‘nomadic’ is a more accurate description of their status. The breeding season is accurately known for few localities. Estimates for the duration of wing moult ranged from 70–130 d based on small samples. Regional divergences in the timing of wing moult remain open to three possible interpretations: (1) differences between years in the timing of wing moult; (2) differences between sex and/or age classes; and (3) population movements, so that birds from different regions may successively occupy the same areas. The available data are inadequate to resolve these questions.
- Full Text:
- Authors: Craig, Adrian J F K
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449535 , vital:74828 , https://doi.org/10.2989/00306525.2012.655429
- Description: Seasonal migration by Splendid Glossy Starlings has been confirmed only for Kenya and Zambia. Populations in almost all other countries have been categorised as ‘resident’ by some observers, but ‘nomadic’ is a more accurate description of their status. The breeding season is accurately known for few localities. Estimates for the duration of wing moult ranged from 70–130 d based on small samples. Regional divergences in the timing of wing moult remain open to three possible interpretations: (1) differences between years in the timing of wing moult; (2) differences between sex and/or age classes; and (3) population movements, so that birds from different regions may successively occupy the same areas. The available data are inadequate to resolve these questions.
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Service discovery using open sound control
- Eales, Andrew, Foss, Richard
- Authors: Eales, Andrew , Foss, Richard
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426890 , vital:72398 , https://www.aes.org/e-lib/online/browse.cfm?elib=16432
- Description: The Open Sound Control (OSC) control protocol does not have service discovery capabilities. The approach to adding service discovery to OSC proposed in this paper uses the OSC address space to represent services within the context of a logical device model. This model allows services to be represented in a context-sensitive manner by relating parameters representing services to the logical organization of a device. Implementation of service discovery is done using standard OSC messages and requires that the OSC address space be designed to support these messages. This paper illustrates how these enhancements to OSC allow a device to advertise its services. Controller applications can then explore the device’s address space to discover services and retrieve the services required by the application. The Open Sound Control (OSC) control protocol does not have service discovery capabilities. The approach to adding service discovery to OSC proposed in this paper uses the OSC address space to represent services within the context of a logical device model. This model allows services to be represented in a context-sensitive manner by relating parameters representing services to the logical organization of a device. Implementation of service discovery is done using standard OSC messages and requires that the OSC address space be designed to support these messages. This paper illustrates how these enhancements to OSC allow a device to advertise its services. Controller applications can then explore the device’s address space to discover services and retrieve the services required by the application.
- Full Text:
- Authors: Eales, Andrew , Foss, Richard
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/426890 , vital:72398 , https://www.aes.org/e-lib/online/browse.cfm?elib=16432
- Description: The Open Sound Control (OSC) control protocol does not have service discovery capabilities. The approach to adding service discovery to OSC proposed in this paper uses the OSC address space to represent services within the context of a logical device model. This model allows services to be represented in a context-sensitive manner by relating parameters representing services to the logical organization of a device. Implementation of service discovery is done using standard OSC messages and requires that the OSC address space be designed to support these messages. This paper illustrates how these enhancements to OSC allow a device to advertise its services. Controller applications can then explore the device’s address space to discover services and retrieve the services required by the application. The Open Sound Control (OSC) control protocol does not have service discovery capabilities. The approach to adding service discovery to OSC proposed in this paper uses the OSC address space to represent services within the context of a logical device model. This model allows services to be represented in a context-sensitive manner by relating parameters representing services to the logical organization of a device. Implementation of service discovery is done using standard OSC messages and requires that the OSC address space be designed to support these messages. This paper illustrates how these enhancements to OSC allow a device to advertise its services. Controller applications can then explore the device’s address space to discover services and retrieve the services required by the application.
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Single walled carbon nanotubes functionalized with nickel phthalocyanines
- Khene, Samson, Nyokong, Tebello
- Authors: Khene, Samson , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245843 , vital:51410 , xlink:href="https://doi.org/10.1142/S1088424611004439"
- Description: In this work we report on electrochemical behavior of nickel phthalocyanine derivatives tetrasubstituted peripherally and non-peripherally with hydroxy and used to modify single walled carbon nanotubes. Nickel phthalocyanine complex octasubstituted at the peripheral positions with hydroxy groups was also used to modify single walled carbon nanotubes. Nickel phthalocyanine complex tetrasubstituted with amino groups at peripheral position was covalently and non-covalently linked to single walled carbon nanotubes. All the conjugates of nickel phthalocyanine derivatives with single walled carbon nanotubes were used for the electro oxidation of 4-chlorophenol. The nickel phthalocyanine octabsubstituted with hydroxy groups at the non-peripheral positions gave the best current response and the best resistance against electrode fouling for the oxidation of 4-chlorophenol.
- Full Text:
- Authors: Khene, Samson , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245843 , vital:51410 , xlink:href="https://doi.org/10.1142/S1088424611004439"
- Description: In this work we report on electrochemical behavior of nickel phthalocyanine derivatives tetrasubstituted peripherally and non-peripherally with hydroxy and used to modify single walled carbon nanotubes. Nickel phthalocyanine complex octasubstituted at the peripheral positions with hydroxy groups was also used to modify single walled carbon nanotubes. Nickel phthalocyanine complex tetrasubstituted with amino groups at peripheral position was covalently and non-covalently linked to single walled carbon nanotubes. All the conjugates of nickel phthalocyanine derivatives with single walled carbon nanotubes were used for the electro oxidation of 4-chlorophenol. The nickel phthalocyanine octabsubstituted with hydroxy groups at the non-peripheral positions gave the best current response and the best resistance against electrode fouling for the oxidation of 4-chlorophenol.
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Social recruiting: a next generation social engineering attack
- Schoeman, A H B, Irwin, Barry V W
- Authors: Schoeman, A H B , Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428600 , vital:72523 , https://www.jstor.org/stable/26486876
- Description: Social engineering attacks initially experienced success due to the lack of understanding of the attack vector and resultant lack of remedial actions. Due to an increase in media coverage corporate bodies have begun to defend their interests from this vector. This has resulted in a new generation of social engineering attacks that have adapted to the industry response. These new forms of attack take into account the increased likelihood that they will be detected; rendering traditional defences against social engineering attacks moot. This paper highlights these attacks and will explain why traditional defences fail to address them as well as suggest new methods of incident response.
- Full Text:
- Authors: Schoeman, A H B , Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428600 , vital:72523 , https://www.jstor.org/stable/26486876
- Description: Social engineering attacks initially experienced success due to the lack of understanding of the attack vector and resultant lack of remedial actions. Due to an increase in media coverage corporate bodies have begun to defend their interests from this vector. This has resulted in a new generation of social engineering attacks that have adapted to the industry response. These new forms of attack take into account the increased likelihood that they will be detected; rendering traditional defences against social engineering attacks moot. This paper highlights these attacks and will explain why traditional defences fail to address them as well as suggest new methods of incident response.
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Spectral, photophysical and photochemical properties of tetra-and octaglycosylated zinc phthalocyanines
- Iqbal, Zafar, Masilela, Nkosiphile, Nyokong, Tebello, Lyubimtsev, Alexey, Hanack, Michael, Ziegler, Thomas
- Authors: Iqbal, Zafar , Masilela, Nkosiphile , Nyokong, Tebello , Lyubimtsev, Alexey , Hanack, Michael , Ziegler, Thomas
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244428 , vital:51256 , xlink:href="https://doi.org/10.1039/c2pp05348a"
- Description: Photophysical and photochemical properties of a series of tetra- and octaglycosylated zinc phthalocyanines (ZnPcs) substituted with glucose and galactose moieties have been reported. Spectral properties of these phthalocyanines are compared in DMSO. Absorption spectra of the non-peripherally tetra-substituted ZnPcs 2 showed a significant red shift in their Q-band maxima as compared to the peripherally substituted analog 1. All the complexes gave high triplet quantum yields ranging from 0.68 to 0.88, whereas triplet lifetimes were in the range of 100–430 µs in argon-saturated solutions. The octagalactosylated ZnPc 3b showed the highest triplet quantum yield and singlet oxygen quantum yield of 0.88 and 0.69, respectively. The fluorescence quantum yields and lifetimes of all the compounds under investigation were within the range of zinc phthalocyanine complexes.
- Full Text:
- Authors: Iqbal, Zafar , Masilela, Nkosiphile , Nyokong, Tebello , Lyubimtsev, Alexey , Hanack, Michael , Ziegler, Thomas
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244428 , vital:51256 , xlink:href="https://doi.org/10.1039/c2pp05348a"
- Description: Photophysical and photochemical properties of a series of tetra- and octaglycosylated zinc phthalocyanines (ZnPcs) substituted with glucose and galactose moieties have been reported. Spectral properties of these phthalocyanines are compared in DMSO. Absorption spectra of the non-peripherally tetra-substituted ZnPcs 2 showed a significant red shift in their Q-band maxima as compared to the peripherally substituted analog 1. All the complexes gave high triplet quantum yields ranging from 0.68 to 0.88, whereas triplet lifetimes were in the range of 100–430 µs in argon-saturated solutions. The octagalactosylated ZnPc 3b showed the highest triplet quantum yield and singlet oxygen quantum yield of 0.88 and 0.69, respectively. The fluorescence quantum yields and lifetimes of all the compounds under investigation were within the range of zinc phthalocyanine complexes.
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Spectroscopic and physicochemical behavior of magnesium phthalocyanine derivatives mono-substituted with a carboxylic acid group
- Nombona, Nolwazi, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244450 , vital:51258 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.12.051"
- Description: This work reports on the synthesis of novel unsymmetrically substituted magnesium phthalocyanine complexes containing one carboxyl group. The physicochemical behavior of these complexes were compared with those of their unmetallated and zinc counterparts. The MgPcs showed interesting absorption spectra with [8,15,22-Tris-(naphtho)-4,5-(3-carboxy-1,2-dioxyphenyl)phthalocyaninato]magnesium (II) showing a large split in the Q band whereas [8,15,22-Tris-(naphtho)-2-(carboxy) phthalocyaninato]magnesium(II) presented only a small splitting. The magnesium phthalocyanine derivatives displayed higher fluorescence quantum yields compared to unmetallated and zinc phthalocyanine counterparts. The latter gave admirable triplet and singlet oxygen quantum yields. These molecules can distinctly be employed in the field of photodynamic therapy in combination with fluorescence imaging.
- Full Text:
- Authors: Nombona, Nolwazi , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244450 , vital:51258 , xlink:href="https://doi.org/10.1016/j.molstruc.2011.12.051"
- Description: This work reports on the synthesis of novel unsymmetrically substituted magnesium phthalocyanine complexes containing one carboxyl group. The physicochemical behavior of these complexes were compared with those of their unmetallated and zinc counterparts. The MgPcs showed interesting absorption spectra with [8,15,22-Tris-(naphtho)-4,5-(3-carboxy-1,2-dioxyphenyl)phthalocyaninato]magnesium (II) showing a large split in the Q band whereas [8,15,22-Tris-(naphtho)-2-(carboxy) phthalocyaninato]magnesium(II) presented only a small splitting. The magnesium phthalocyanine derivatives displayed higher fluorescence quantum yields compared to unmetallated and zinc phthalocyanine counterparts. The latter gave admirable triplet and singlet oxygen quantum yields. These molecules can distinctly be employed in the field of photodynamic therapy in combination with fluorescence imaging.
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STAT3 interacts directly with Hsp90:
- Prinsloo, Earl, Kramer, Adam H, Edkins, Adrienne L, Blatch, Gregory L
- Authors: Prinsloo, Earl , Kramer, Adam H , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165142 , vital:41212 , DOI: 10.1002/iub.607
- Description: Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin‐6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes.
- Full Text:
- Authors: Prinsloo, Earl , Kramer, Adam H , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165142 , vital:41212 , DOI: 10.1002/iub.607
- Description: Heat shock protein 90 (Hsp90) functionally modulates signal transduction. The signal transducer and activator of transcription 3 (STAT3) mediates interleukin‐6 family cytokine signaling. Aberrant activation and mutation of STAT3 is associated with oncogenesis and immune disorders, respectively. Hsp90 and STAT3 have previously been shown to colocalize and coimmunoprecipitate in common complexes.
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Students’ navigation of the uncharted territories of academic writing
- Bharuthram, Sharita, McKenna, Sioux
- Authors: Bharuthram, Sharita , McKenna, Sioux
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187373 , vital:44626 , xlink:href="https://doi.org/10.1080/18146627.2012.742651"
- Description: Many students enter tertiary education unfamiliar with the ‘norms and conventions’ of their disciplines. Research into academic literacies has shown that in order to succeed in their studies, students are expected to conform to these norms and conventions, which are often unrecognized or seen as ‘common sense’ by lecturers. Students have to develop their own ‘map’ of their programme’s expectations in order to make sense of the seemingly mysterious practices they are expected to take on. This study, undertaken at a University of Technology in South Africa, details students’ perceptions of their writing difficulties and their attempts to navigate their way through various writing tasks. The findings reveal that students experience a range of difficulties and that the students often feel unsupported in their travails with academic writing.
- Full Text:
- Authors: Bharuthram, Sharita , McKenna, Sioux
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187373 , vital:44626 , xlink:href="https://doi.org/10.1080/18146627.2012.742651"
- Description: Many students enter tertiary education unfamiliar with the ‘norms and conventions’ of their disciplines. Research into academic literacies has shown that in order to succeed in their studies, students are expected to conform to these norms and conventions, which are often unrecognized or seen as ‘common sense’ by lecturers. Students have to develop their own ‘map’ of their programme’s expectations in order to make sense of the seemingly mysterious practices they are expected to take on. This study, undertaken at a University of Technology in South Africa, details students’ perceptions of their writing difficulties and their attempts to navigate their way through various writing tasks. The findings reveal that students experience a range of difficulties and that the students often feel unsupported in their travails with academic writing.
- Full Text:
Substantive second-level reasoning and experiential learning in legal ethics
- Authors: Kruuse, Helen
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68983 , vital:29345 , https://hdl.handle.net/10520/EJC127082
- Description: Publisher version , This article takes a critical look at law teaching in South Africa and seeks to consider how the application of experiential learning theory may assist law students in gaining a deeper understanding of the law in general, and the complexities of real life practice in particular. While clinical legal education is often seen as the locus of experiential learning in law, the author proposes that well-structured simulations in class can achieve similar goals. The article comprises a description of the nature of experiential learning and a further description of the application of the principles of experiential learning in a particular simulation exercise in a Legal Ethics course (using the US case of Wash St Phys Ins Exch v Fisons Corp 858 P2d 1054 (Wash 1993) as a basis). The author posits that the so-called experiential learning "cycle" or "process" enables a process of learning which draws out the students' beliefs and ideas about a topic so that it can be examined, tested and integrated with new, more refined ideas. This notion is then in keeping with the expectation that students who emerge from higher education institutions have developed meta-cognitive skills. Essentially then, it is hoped that, by using the methods proposed in this article, students can then manage their own development and learning throughout life.
- Full Text: false
- Authors: Kruuse, Helen
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68983 , vital:29345 , https://hdl.handle.net/10520/EJC127082
- Description: Publisher version , This article takes a critical look at law teaching in South Africa and seeks to consider how the application of experiential learning theory may assist law students in gaining a deeper understanding of the law in general, and the complexities of real life practice in particular. While clinical legal education is often seen as the locus of experiential learning in law, the author proposes that well-structured simulations in class can achieve similar goals. The article comprises a description of the nature of experiential learning and a further description of the application of the principles of experiential learning in a particular simulation exercise in a Legal Ethics course (using the US case of Wash St Phys Ins Exch v Fisons Corp 858 P2d 1054 (Wash 1993) as a basis). The author posits that the so-called experiential learning "cycle" or "process" enables a process of learning which draws out the students' beliefs and ideas about a topic so that it can be examined, tested and integrated with new, more refined ideas. This notion is then in keeping with the expectation that students who emerge from higher education institutions have developed meta-cognitive skills. Essentially then, it is hoped that, by using the methods proposed in this article, students can then manage their own development and learning throughout life.
- Full Text: false
Syntheses, protonation constants and antimicrobial activity of 2-substituted N-alkylimidazole derivatives
- Kleyi, Phumelele, Walmsley, Ryan S, Gundhla, Isaac Z, Walmsley, Tara A, Jauka, Tembisa I, Dames, Joanna F, Walker, Roderick B, Torto, Nelson, Tshentu, Zenixole R
- Authors: Kleyi, Phumelele , Walmsley, Ryan S , Gundhla, Isaac Z , Walmsley, Tara A , Jauka, Tembisa I , Dames, Joanna F , Walker, Roderick B , Torto, Nelson , Tshentu, Zenixole R
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184066 , vital:44165 , xlink:href="https://www.ajol.info/index.php/sajc/article/view/123858"
- Description: A series of N-alkylimidazole-2-carboxylic acid, N-alkylimidazole-2-carboxaldehyde and N-alkylimidazole-2-methanol derivatives [alkyl = benzyl, methyl, ethyl, propyl, butyl, heptyl, octyl and decyl] have been synthesized and the protonation constants determined. The antimicrobial properties of the compounds were tested against Gram-negative (Escherichi coli), Gram-positive (Staphylococcus aureus and Bacillus subtilis subsp. spizizenii) bacterial strains and yeast (C. albicans). Both the disk diffusion and broth microdilution methods for testing the antimicrobial activity showed that N-alkylation of imidazole with longer alkyl chains and the substitution with low pKa group at 2-position resulted in enhanced antimicrobial activity. Particularly, the N-alkylimidazole-2-carboxylic acids exhibited the best antimicrobial activity due to the low pKa of the carboxylic acid moiety. Generally, all the N-alkylimidazole derivatives were most active against the Gram-positive bacteria [S. aureus (MIC = 5–160 µg mL–1) and B. subtilis subsp. spizizenii (5–20 µg mL–1)], with the latter more susceptible. All the compounds showed poor antimicrobial activity against both Gram-negative (E. coli, MIC = 0.15 to >2500 µg mL–1) bacteria and all the compounds were inactive against the yeast (Candida albicans).
- Full Text:
- Authors: Kleyi, Phumelele , Walmsley, Ryan S , Gundhla, Isaac Z , Walmsley, Tara A , Jauka, Tembisa I , Dames, Joanna F , Walker, Roderick B , Torto, Nelson , Tshentu, Zenixole R
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184066 , vital:44165 , xlink:href="https://www.ajol.info/index.php/sajc/article/view/123858"
- Description: A series of N-alkylimidazole-2-carboxylic acid, N-alkylimidazole-2-carboxaldehyde and N-alkylimidazole-2-methanol derivatives [alkyl = benzyl, methyl, ethyl, propyl, butyl, heptyl, octyl and decyl] have been synthesized and the protonation constants determined. The antimicrobial properties of the compounds were tested against Gram-negative (Escherichi coli), Gram-positive (Staphylococcus aureus and Bacillus subtilis subsp. spizizenii) bacterial strains and yeast (C. albicans). Both the disk diffusion and broth microdilution methods for testing the antimicrobial activity showed that N-alkylation of imidazole with longer alkyl chains and the substitution with low pKa group at 2-position resulted in enhanced antimicrobial activity. Particularly, the N-alkylimidazole-2-carboxylic acids exhibited the best antimicrobial activity due to the low pKa of the carboxylic acid moiety. Generally, all the N-alkylimidazole derivatives were most active against the Gram-positive bacteria [S. aureus (MIC = 5–160 µg mL–1) and B. subtilis subsp. spizizenii (5–20 µg mL–1)], with the latter more susceptible. All the compounds showed poor antimicrobial activity against both Gram-negative (E. coli, MIC = 0.15 to >2500 µg mL–1) bacteria and all the compounds were inactive against the yeast (Candida albicans).
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Synthesis and photophysical behavior of a novel zinc phthalocyanine containing a single carboxylic acid and three phenylthio substituents
- Forteath, Shaun, Antunes, Edith M, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243207 , vital:51127 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.03.050"
- Description: Zinc 2, (3)-tri-(phenylthio)-2, (3)-carboxy phthalocyanine (ZnPc(COOH)(SPh)3), zinc 2, (3)-tetra-(phenylthio) phthalocyanine (ZnPc(SPh)4) and 2, (3)-tetra-(phenylthio) phthalocyanine (H2Pc(SPh)4) were synthesized and their photophysical behavior were compared with those of a number of zinc phthalocyanine (ZnPc) derivatives. ZnPc(COOH)(SPh)3 and ZnPc(SPh)4 had similar fluorescence (ΦF=0.14) and triplet state (ΦT=0.65) quantum yields in dimethylsulfoxide, hence showing no effects of the replacement of one of the phenylthio groups with a carboxylic acid group. ZnPc(COOH)(SPh)3 displayed a slightly shorter triplet lifetime (τT=331 μs) than ZnPc (τT=350 μs) in DMSO, but within the range of ZnPc derivatives. The triplet lifetime for ZnPc(COOH)(SPh)3 is much longer than for the symmetrical derivative (ZnPc(SPh)4) with τT=149 μs in DMSO.
- Full Text:
- Authors: Forteath, Shaun , Antunes, Edith M , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243207 , vital:51127 , xlink:href="https://doi.org/10.1016/j.jlumin.2012.03.050"
- Description: Zinc 2, (3)-tri-(phenylthio)-2, (3)-carboxy phthalocyanine (ZnPc(COOH)(SPh)3), zinc 2, (3)-tetra-(phenylthio) phthalocyanine (ZnPc(SPh)4) and 2, (3)-tetra-(phenylthio) phthalocyanine (H2Pc(SPh)4) were synthesized and their photophysical behavior were compared with those of a number of zinc phthalocyanine (ZnPc) derivatives. ZnPc(COOH)(SPh)3 and ZnPc(SPh)4 had similar fluorescence (ΦF=0.14) and triplet state (ΦT=0.65) quantum yields in dimethylsulfoxide, hence showing no effects of the replacement of one of the phenylthio groups with a carboxylic acid group. ZnPc(COOH)(SPh)3 displayed a slightly shorter triplet lifetime (τT=331 μs) than ZnPc (τT=350 μs) in DMSO, but within the range of ZnPc derivatives. The triplet lifetime for ZnPc(COOH)(SPh)3 is much longer than for the symmetrical derivative (ZnPc(SPh)4) with τT=149 μs in DMSO.
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Synthesis and photophysical properties of covalent conjugates of aqua platinum (II) and octacarboxy-substituted zinc phthalocyanine
- Bulgakov, Roman A, Kuznetsova, Nina A, Dolotova, Olga V, Solovieva, Ludmila I, Mack, John, Chidawanyika, Wadzanai J U, Kaliya, Oleg L, Nyokong, Tebello
- Authors: Bulgakov, Roman A , Kuznetsova, Nina A , Dolotova, Olga V , Solovieva, Ludmila I , Mack, John , Chidawanyika, Wadzanai J U , Kaliya, Oleg L , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242726 , vital:51073 , xlink:href="https://doi.org/10.1142/S1088424612501209"
- Description: New covalent conjugates of aqua platinum(II) and octacarboxy-substituted zinc phthalocyanine, bearing one, two, three and four aqua platinum moieties on the periphery of the Pc ligand have been synthesized and characterized. The effect of the stepwise introduction of the aqua platinums on the photophysical and photochemical properties of these compounds has been investigated in dimethylsulfoxide solution. It has been found that aqua platinum moieties have only a limited effect on the dynamics of the singlet and triplet excited states, on the ability to sensitize singlet oxygen formation and on the photostability. Each conjugate has a high singlet oxygen quantum yield (ΦΔ 0.51–0.62) and thus retains potential for use as a dual action anticancer drugs by acting as a sensitizer for PDT in addition to the likely chemotherapeutic effects of the Pt(II) complexes.
- Full Text:
- Authors: Bulgakov, Roman A , Kuznetsova, Nina A , Dolotova, Olga V , Solovieva, Ludmila I , Mack, John , Chidawanyika, Wadzanai J U , Kaliya, Oleg L , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242726 , vital:51073 , xlink:href="https://doi.org/10.1142/S1088424612501209"
- Description: New covalent conjugates of aqua platinum(II) and octacarboxy-substituted zinc phthalocyanine, bearing one, two, three and four aqua platinum moieties on the periphery of the Pc ligand have been synthesized and characterized. The effect of the stepwise introduction of the aqua platinums on the photophysical and photochemical properties of these compounds has been investigated in dimethylsulfoxide solution. It has been found that aqua platinum moieties have only a limited effect on the dynamics of the singlet and triplet excited states, on the ability to sensitize singlet oxygen formation and on the photostability. Each conjugate has a high singlet oxygen quantum yield (ΦΔ 0.51–0.62) and thus retains potential for use as a dual action anticancer drugs by acting as a sensitizer for PDT in addition to the likely chemotherapeutic effects of the Pt(II) complexes.
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Synthesis and photophysical properties of peripherally and non-peripherally mercaptopyridine substituted metal free, Mg (II) and Al (III) phthalocyanines
- Arslanoğlu, Yasin, Idowu, Mopelela, Nyokong, Tebello
- Authors: Arslanoğlu, Yasin , Idowu, Mopelela , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243248 , vital:51131 , xlink:href="https://doi.org/10.1016/j.saa.2012.04.004"
- Description: The syntheses and photophysical properties of metallophthalocyanines containing Mg2+ and Al3+ as central metal ions and their unmetallated derivative (complexes 3–8) tetra- substituted at the non-peripheral (α) and peripheral (β) positions with 2-mercaptopyridine are reported. The trends in triplet and fluorescence quantum yields are described for these compounds. The complexes exhibited relatively high triplet quantum yields (ΦT) ranging from 0.33 to 0.54 and fluorescence quantum yields (ΦF) ranging from 0.02 to 0.29. Triplet state lifetimes of the complexes were long ranging from 120 to 460 μs, indicating a potential use of these complexes as photosensitizers.
- Full Text:
- Authors: Arslanoğlu, Yasin , Idowu, Mopelela , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243248 , vital:51131 , xlink:href="https://doi.org/10.1016/j.saa.2012.04.004"
- Description: The syntheses and photophysical properties of metallophthalocyanines containing Mg2+ and Al3+ as central metal ions and their unmetallated derivative (complexes 3–8) tetra- substituted at the non-peripheral (α) and peripheral (β) positions with 2-mercaptopyridine are reported. The trends in triplet and fluorescence quantum yields are described for these compounds. The complexes exhibited relatively high triplet quantum yields (ΦT) ranging from 0.33 to 0.54 and fluorescence quantum yields (ΦF) ranging from 0.02 to 0.29. Triplet state lifetimes of the complexes were long ranging from 120 to 460 μs, indicating a potential use of these complexes as photosensitizers.
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Synthesis and photophysicochemical properties of novel zinc phthalocyanines mono substituted with carboxyl containing functional groups
- Rapulenyane, Nomasonto, Antunes, Edith M, Masilela, Nkosiphile, Nyokong, Tebello
- Authors: Rapulenyane, Nomasonto , Antunes, Edith M , Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242389 , vital:51037 , xlink:href="https://doi.org/10.1016/j.jphotochem.2012.09.007"
- Description: This work reports on the synthesis and the physicochemical properties of novel unsymmetrically substituted zinc phthalocyanines (complexes 8, 10 and 11) and their symmetrically substituted counterparts (complexes 9, 12 and 13). The new complexes and their counterparts were successfully structurally characterized by IR, NMR, mass spectral and elemental analyses. Low fluorescence quantum yields (0.032) and lifetimes (0.91 ns) were obtained for the symmetrical ZnOTPc (complex 9) compared to the higher fluorescence quantum yields (0.15, 0.13, 0.10, 0.09 and 0.29) and lifetimes (4.4, 1.69, 1.69, 2.16 and 3.23 ns) obtained for ZnMPCPc (8), ZnTDTPc (12), ZnMCapPc (10), ZnMCafPc (11) and ZnTCPPc (13), respectively. All the complexes showed the ability to produce singlet oxygen with the highest triplet quantum yields obtained for 8 and 10 (0.80 and 0.65 respectively). High triplet lifetimes (109–286 μs) were obtained for all complexes. Complex 8 showed the longest triplet and fluorescence lifetimes as well the largest triplet state and singlet oxygen quantum yields.
- Full Text:
- Authors: Rapulenyane, Nomasonto , Antunes, Edith M , Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242389 , vital:51037 , xlink:href="https://doi.org/10.1016/j.jphotochem.2012.09.007"
- Description: This work reports on the synthesis and the physicochemical properties of novel unsymmetrically substituted zinc phthalocyanines (complexes 8, 10 and 11) and their symmetrically substituted counterparts (complexes 9, 12 and 13). The new complexes and their counterparts were successfully structurally characterized by IR, NMR, mass spectral and elemental analyses. Low fluorescence quantum yields (0.032) and lifetimes (0.91 ns) were obtained for the symmetrical ZnOTPc (complex 9) compared to the higher fluorescence quantum yields (0.15, 0.13, 0.10, 0.09 and 0.29) and lifetimes (4.4, 1.69, 1.69, 2.16 and 3.23 ns) obtained for ZnMPCPc (8), ZnTDTPc (12), ZnMCapPc (10), ZnMCafPc (11) and ZnTCPPc (13), respectively. All the complexes showed the ability to produce singlet oxygen with the highest triplet quantum yields obtained for 8 and 10 (0.80 and 0.65 respectively). High triplet lifetimes (109–286 μs) were obtained for all complexes. Complex 8 showed the longest triplet and fluorescence lifetimes as well the largest triplet state and singlet oxygen quantum yields.
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Synthesis and physicochemical behavior of new low symmetry Ge, Ti and Sn phthalocyanines
- Masilela, Nkosiphile, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242421 , vital:51040 , xlink:href="https://doi.org/10.1016/j.synthmet.2012.07.028"
- Description: The synthesis and photophysicochemical properties of new low symmetrically Ge, Sn and Ti phthalocyanines substituted with one carboxy containing group are reported. Broading and splitting in the absorption spectra were observed for some of the complexes in particular for both the titanium Pcs due to loss of symmetry. Higher fluorescence quantum yields and lifetimes were obtained for the Pcs substituted with three benzyloxy (5–7) compared to their corresponding counterparts substituted with six 2-diethylaminoethylthiol groups (9–11). The germanium Pc complexes gave the highest triplet and singlet oxygen quantum yields compared to all the other complexes studied in DMF. All the complexes showed reasonable ability to generate singlet oxygen with quantum yields ranging from 0.54 to 0.69.
- Full Text:
- Authors: Masilela, Nkosiphile , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242421 , vital:51040 , xlink:href="https://doi.org/10.1016/j.synthmet.2012.07.028"
- Description: The synthesis and photophysicochemical properties of new low symmetrically Ge, Sn and Ti phthalocyanines substituted with one carboxy containing group are reported. Broading and splitting in the absorption spectra were observed for some of the complexes in particular for both the titanium Pcs due to loss of symmetry. Higher fluorescence quantum yields and lifetimes were obtained for the Pcs substituted with three benzyloxy (5–7) compared to their corresponding counterparts substituted with six 2-diethylaminoethylthiol groups (9–11). The germanium Pc complexes gave the highest triplet and singlet oxygen quantum yields compared to all the other complexes studied in DMF. All the complexes showed reasonable ability to generate singlet oxygen with quantum yields ranging from 0.54 to 0.69.
- Full Text: