Lipophilic M(α,α′-OC5H11)8phthalocyanines (M = H2 and Ni(II)): synthesis, electronic structure, and their utility for highly efficient carbonyl reductions
- Jiang, Yu, Li, Minzhi, Liang, Xu, Mack, John, Wildervanck, Martijn, Nyokong, Tebello, Qin, Mingfeng, Zhu, Weihua
- Authors: Jiang, Yu , Li, Minzhi , Liang, Xu , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Qin, Mingfeng , Zhu, Weihua
- Date: 2015-10-07
- Subjects: Dalton Transactions (2015), 44, 18237-18246, doi:10.1039/c5dt03256c
- Language: English
- Type: Article
- Identifier: vital:7282 , http://hdl.handle.net/10962/d1020322
- Description: A lipophilic and electron-rich phthalocyanine (α,α′-n-OC5H11)8-H2Pc and its nickel(II) complex (α,α′-n-OC5H11)8-Ni(II)Pc have been synthesized and characterized. Detailed analyses of the electronic structure were carried out by spectroscopy, electrochemistry, spectroelectrochemistry, and TD-DFT calculations. A series of experiments demonstrate that the (α,α′-n-OC5H11)8-Ni(II)Pc complex can be used as a catalyst for highly efficient carbonyl reductions. , Original publication is available at http://dx.doi.org/10.1039/C5DT03256C
- Full Text:
- Authors: Jiang, Yu , Li, Minzhi , Liang, Xu , Mack, John , Wildervanck, Martijn , Nyokong, Tebello , Qin, Mingfeng , Zhu, Weihua
- Date: 2015-10-07
- Subjects: Dalton Transactions (2015), 44, 18237-18246, doi:10.1039/c5dt03256c
- Language: English
- Type: Article
- Identifier: vital:7282 , http://hdl.handle.net/10962/d1020322
- Description: A lipophilic and electron-rich phthalocyanine (α,α′-n-OC5H11)8-H2Pc and its nickel(II) complex (α,α′-n-OC5H11)8-Ni(II)Pc have been synthesized and characterized. Detailed analyses of the electronic structure were carried out by spectroscopy, electrochemistry, spectroelectrochemistry, and TD-DFT calculations. A series of experiments demonstrate that the (α,α′-n-OC5H11)8-Ni(II)Pc complex can be used as a catalyst for highly efficient carbonyl reductions. , Original publication is available at http://dx.doi.org/10.1039/C5DT03256C
- Full Text:
Life orientation sexuality education in South Africa: gendered norms, justice and transformation
- Shefer, Tamara, Macleod, Catriona I
- Authors: Shefer, Tamara , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6310 , http://hdl.handle.net/10962/d1018868
- Description: [From introduction] Research on sexual practices among young South Africans has proliferated in light of the national imperatives to challenge the spread of HIV/AIDS, gender-based violence and unwanted early pregnancies. It has been widely acknowledged that, in order to respond to these social problems, we need to understand the enmeshment of gender, class, age and other forms of social inequality, and how these are played out in ‘normal’ heterosexual relationships. Life Orientation (LO) sexuality education programmes have been viewed as key locations for incorporating education to challenge negative assumptions in respect of HIV/AIDS, gender-based violence and unwanted pregnancy and to promote safer, equitable and non-violent sexual practices. There is a paucity of work that interrogates the LO sexuality education programme in terms of gender norms, gender justice and gender transformation. In the handful of studies conducted on school-based sexuality education in South Africa, researchers have foregrounded a number of challenges, including the dominance of a guiding metaphor of danger and disease in the sexuality education component of LO manuals (Macleod, 2009); educators using a transmission mode of teaching to the exclusion of participation and experiential modes of learning (Rooth, 2005); educators understanding sexuality education as chiefly addressing the provision of information concerning, and prevention of, HIV/AIDS (Francis, 2011); teachers’ preference for abstinence-only education taught by means of a series of moral injunctions (Francis, 2011); and the avoidance of discussions of sexual diversity, and the endorsement of compulsory heterosexuality when same-sex relationships are mentioned (Francis, 2012). Recent research has also highlighted the variation in how teachers approach sexuality education. Francis and DePalma (2014) indicate that, while teachers may promote abstinence as the only appropriate choice for young people, they also recognise the value of teaching relationships and safe sex (aspects associated with comprehensive sexuality education). In their study, Helleve et al. (2009) report that Grades 8 and 9 LO teachers felt confident in teaching HIV and sexuality. This special issue of Perspectives in Education builds on this research by drawing together several papers that examine how LO or Life Skills sexuality programmes challenge and/or reproduce normative constructions of gender and gendered power relations. All the papers use qualitative research to locate these programmes within the complex contexts of their enactment, drawing attention to the multiple possibilities and limitations of such programmes. In the next section, we summarise the key problematics addressed in each of the papers. What curiosities drove the studies conducted by these researchers interested in gender dynamics in schools and LO or Life Skills sexuality education? Why are these curiosities important? We then highlight the key findings that emerged from these curiosities and the nuanced data collected. Finally, and most importantly in terms of the aims of this special issue, we address the ways in which a critical gender lens that facilitates gender transformation and gender justice could possibly be incorporated into LO or Life Skills sexuality programmes.
- Full Text:
- Date Issued: 2015
- Authors: Shefer, Tamara , Macleod, Catriona I
- Date: 2015
- Language: English
- Type: Article
- Identifier: vital:6310 , http://hdl.handle.net/10962/d1018868
- Description: [From introduction] Research on sexual practices among young South Africans has proliferated in light of the national imperatives to challenge the spread of HIV/AIDS, gender-based violence and unwanted early pregnancies. It has been widely acknowledged that, in order to respond to these social problems, we need to understand the enmeshment of gender, class, age and other forms of social inequality, and how these are played out in ‘normal’ heterosexual relationships. Life Orientation (LO) sexuality education programmes have been viewed as key locations for incorporating education to challenge negative assumptions in respect of HIV/AIDS, gender-based violence and unwanted pregnancy and to promote safer, equitable and non-violent sexual practices. There is a paucity of work that interrogates the LO sexuality education programme in terms of gender norms, gender justice and gender transformation. In the handful of studies conducted on school-based sexuality education in South Africa, researchers have foregrounded a number of challenges, including the dominance of a guiding metaphor of danger and disease in the sexuality education component of LO manuals (Macleod, 2009); educators using a transmission mode of teaching to the exclusion of participation and experiential modes of learning (Rooth, 2005); educators understanding sexuality education as chiefly addressing the provision of information concerning, and prevention of, HIV/AIDS (Francis, 2011); teachers’ preference for abstinence-only education taught by means of a series of moral injunctions (Francis, 2011); and the avoidance of discussions of sexual diversity, and the endorsement of compulsory heterosexuality when same-sex relationships are mentioned (Francis, 2012). Recent research has also highlighted the variation in how teachers approach sexuality education. Francis and DePalma (2014) indicate that, while teachers may promote abstinence as the only appropriate choice for young people, they also recognise the value of teaching relationships and safe sex (aspects associated with comprehensive sexuality education). In their study, Helleve et al. (2009) report that Grades 8 and 9 LO teachers felt confident in teaching HIV and sexuality. This special issue of Perspectives in Education builds on this research by drawing together several papers that examine how LO or Life Skills sexuality programmes challenge and/or reproduce normative constructions of gender and gendered power relations. All the papers use qualitative research to locate these programmes within the complex contexts of their enactment, drawing attention to the multiple possibilities and limitations of such programmes. In the next section, we summarise the key problematics addressed in each of the papers. What curiosities drove the studies conducted by these researchers interested in gender dynamics in schools and LO or Life Skills sexuality education? Why are these curiosities important? We then highlight the key findings that emerged from these curiosities and the nuanced data collected. Finally, and most importantly in terms of the aims of this special issue, we address the ways in which a critical gender lens that facilitates gender transformation and gender justice could possibly be incorporated into LO or Life Skills sexuality programmes.
- Full Text:
- Date Issued: 2015
A phenomenological case study of a lecturer's understanding of himself as an assessor
- Authors: Grant, Rose
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6087 , http://hdl.handle.net/10962/d1008582
- Description: Based on the findings of research conducted as part of a doctoral study aimed at obtaining an understanding of what it means to be an assessor in higher education, this paper outlines the experience of an individual lecturer at a South African university and describes the meaning he makes of his practice as an assessor within the context of a changing understanding of the nature and purpose of higher education. Making a case for personal agency and innovation as critical qualities in the assessment endeavour, the researcher suggests that, in contrast to a view of education increasingly focused on standardization, accountability and outcomes, student assessment is essentially a human encounter in which the humanity and emotions of both lecturer and student need to be acknowledged.
- Full Text:
- Date Issued: 2008
- Authors: Grant, Rose
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6087 , http://hdl.handle.net/10962/d1008582
- Description: Based on the findings of research conducted as part of a doctoral study aimed at obtaining an understanding of what it means to be an assessor in higher education, this paper outlines the experience of an individual lecturer at a South African university and describes the meaning he makes of his practice as an assessor within the context of a changing understanding of the nature and purpose of higher education. Making a case for personal agency and innovation as critical qualities in the assessment endeavour, the researcher suggests that, in contrast to a view of education increasingly focused on standardization, accountability and outcomes, student assessment is essentially a human encounter in which the humanity and emotions of both lecturer and student need to be acknowledged.
- Full Text:
- Date Issued: 2008
The assessment and treatment of post-abortion syndrome : a systematic case study from Southern Africa
- Boulind, Melissa, Edwards, David J A
- Authors: Boulind, Melissa , Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6270 , http://hdl.handle.net/10962/d1008270
- Description: This article reports a clinical case study of "Grace", a black Zimbabwean woman with post-abortion syndrome (PAS), a form of post-traumatic stress disorder precipitated by aborting an unwanted pregnancy. She was treated by a middle class white South African trainee Clinical Psychologist. The case narrative documents the assessment and the course of treatment which was guided by ongoing case formulation based on current evidence-based models. Factors that made her vulnerable to developing PTSD included active suppression of the memory of the event and lack of social support. An understanding of these factors was used to guide an effective intervention. In spite of the differences in culture and background between client and therapist, there was considerable commonality in their experience as young women and students who each had to balance personal and occupational priorities. The narrative also highlights the commonalities of Grace's experiences with those reported in the literature on post-abortion syndrome, which is mostly from the U. S. A. and Europe.
- Full Text:
- Date Issued: 2008
- Authors: Boulind, Melissa , Edwards, David J A
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6270 , http://hdl.handle.net/10962/d1008270
- Description: This article reports a clinical case study of "Grace", a black Zimbabwean woman with post-abortion syndrome (PAS), a form of post-traumatic stress disorder precipitated by aborting an unwanted pregnancy. She was treated by a middle class white South African trainee Clinical Psychologist. The case narrative documents the assessment and the course of treatment which was guided by ongoing case formulation based on current evidence-based models. Factors that made her vulnerable to developing PTSD included active suppression of the memory of the event and lack of social support. An understanding of these factors was used to guide an effective intervention. In spite of the differences in culture and background between client and therapist, there was considerable commonality in their experience as young women and students who each had to balance personal and occupational priorities. The narrative also highlights the commonalities of Grace's experiences with those reported in the literature on post-abortion syndrome, which is mostly from the U. S. A. and Europe.
- Full Text:
- Date Issued: 2008
Effects of differently shaped silver nanoparticles on the photophysics of pyridylsulfanyl-substituted phthalocyanines
- D’Souza, Sarah, Mashazi, Philani N, Britton, Jonathan, Nyokong, Tebello
- Authors: D’Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7290 , http://hdl.handle.net/10962/d1020353
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.06.038
- Full Text: false
- Authors: D’Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7290 , http://hdl.handle.net/10962/d1020353
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2015.06.038
- Full Text: false
Electrocatalytic behahiour of cobalt tetraamino-phthalocyanine in the presence of a composite of reduced graphene nanosheets and of multi-walled carbon nanotubes
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7309 , http://hdl.handle.net/10962/d1020386
- Description: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10−8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2014.05.093
- Full Text: false
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7309 , http://hdl.handle.net/10962/d1020386
- Description: A composite of multi-walled carbon nanotubes (MWCNT) with reduced graphene nanosheets (rGNS-2) was developed in order to minimize the restacking of the latter. The composite was used to modify a glassy carbon electrode (GCE). GCE was further modified with cobalt tetraamino phthalocyanine (CoTAPc). The modified electrode is represented as rGNS-2-MWCNT-CoTAPc-GCE. X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electrochemical microscopy and Raman spectroscopy were used to explore into surface functionalities, morphology and topography of the nanocomposite. The rGNS-2-MWCNT-CoTAPc-GCE had a low limit of detection of 3.32 × 10−8 M towards the detection of paraguat as a test analyte. A mechanism for paraquat detection using an rGNS-2-MWCNT-CoTAPc-GCE is also proposed in this work. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2014.05.093
- Full Text: false
Optical properties and electronic structures of axially-ligated group 9 porphyrins
- Wang, Bei-Bei, Zuo, Huiping, Mack, John, Majumdar, Poulomi, Nyokong, Tebello, Chan, Kin Shing, Shen, Zhen
- Authors: Wang, Bei-Bei , Zuo, Huiping , Mack, John , Majumdar, Poulomi , Nyokong, Tebello , Chan, Kin Shing , Shen, Zhen
- Language: English
- Type: Article
- Identifier: vital:7295 , http://hdl.handle.net/10962/d1020358
- Description: A series of group 9 metal tetra-(p-tolyl)-porphyrin (M(ttp), M = Co(II), Rh(III), Ir(III)) complexes with axial phenyl substituents have been synthesized and characterized. An aryl bromide cleavage reaction of transition metal complexes was used to prepare the complexes from Co(ttp), Rh(ttp)Cl and Ir(ttp)COCl, respectively. Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations have been used to study trends in the optical spectra and electronic structures. The effect of introducing different para-substituents on the phenyl substituents was examined. During fluorescence emission studies, phosphorescence was observed for the Ir(III) complexes in the near infrared (NIR) region. , Original publication is available at http://dx.doi.org/10.1142/S108842461550073X
- Full Text: false
- Authors: Wang, Bei-Bei , Zuo, Huiping , Mack, John , Majumdar, Poulomi , Nyokong, Tebello , Chan, Kin Shing , Shen, Zhen
- Language: English
- Type: Article
- Identifier: vital:7295 , http://hdl.handle.net/10962/d1020358
- Description: A series of group 9 metal tetra-(p-tolyl)-porphyrin (M(ttp), M = Co(II), Rh(III), Ir(III)) complexes with axial phenyl substituents have been synthesized and characterized. An aryl bromide cleavage reaction of transition metal complexes was used to prepare the complexes from Co(ttp), Rh(ttp)Cl and Ir(ttp)COCl, respectively. Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations have been used to study trends in the optical spectra and electronic structures. The effect of introducing different para-substituents on the phenyl substituents was examined. During fluorescence emission studies, phosphorescence was observed for the Ir(III) complexes in the near infrared (NIR) region. , Original publication is available at http://dx.doi.org/10.1142/S108842461550073X
- Full Text: false
Photophysichochemical behavior of carbazole derivatized zinc phthalocyanine in the presence of ZnO microparticles and when embedded in electrospun fibers
- Khoza, Phindile, Antunes, Edith M, Nyokong, Tebello
- Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7303 , http://hdl.handle.net/10962/d1020380
- Description: The synthesis of a zinc phthalocyanine complex tetrasubstituted with carbazole functionality at the peripheral position (complex 4) is reported. The singlet oxygen quantum yield of the complex was found to be 0.83 in dimethylformamide (DMF). The complex was subsequently conjugated to zinc oxide microparticles (ZnOMPs), the conjugation (formation of the amide bond) was confirmed by IR spectroscopy. The presence of ZnOMPs was found to reduce the singlet oxygen produced (ΦΔ = 0.63) in DMF. Polystyrene electrospun fibers of complex 4 alone and its conjugate to ZnOMPs were found to be thermally stable. The singlet oxygen quantum yield of the modified electrospun fibers was determined in aqueous media with ADMA as a singlet oxygen quencher and were 0.25 and 0.20 for complex 4 and 4-ZnOMPs embedded in fibers, respectively. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2013.12.019
- Full Text: false
- Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7303 , http://hdl.handle.net/10962/d1020380
- Description: The synthesis of a zinc phthalocyanine complex tetrasubstituted with carbazole functionality at the peripheral position (complex 4) is reported. The singlet oxygen quantum yield of the complex was found to be 0.83 in dimethylformamide (DMF). The complex was subsequently conjugated to zinc oxide microparticles (ZnOMPs), the conjugation (formation of the amide bond) was confirmed by IR spectroscopy. The presence of ZnOMPs was found to reduce the singlet oxygen produced (ΦΔ = 0.63) in DMF. Polystyrene electrospun fibers of complex 4 alone and its conjugate to ZnOMPs were found to be thermally stable. The singlet oxygen quantum yield of the modified electrospun fibers was determined in aqueous media with ADMA as a singlet oxygen quencher and were 0.25 and 0.20 for complex 4 and 4-ZnOMPs embedded in fibers, respectively. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2013.12.019
- Full Text: false
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