Nonlinear optical behaviour of indium-phthalocyanine tethered to magnetite or silica nanoparticles
- Sanusi, Kayode, Stone, Justin M., Nyokong, Tebello
- Authors: Sanusi, Kayode , Stone, Justin M. , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7259 , http://hdl.handle.net/10962/d1020268
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone. , Original publication is available at http://dx.doi.org/10.1039/C4NJ01619J
- Full Text: false
- Authors: Sanusi, Kayode , Stone, Justin M. , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7259 , http://hdl.handle.net/10962/d1020268
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone. , Original publication is available at http://dx.doi.org/10.1039/C4NJ01619J
- Full Text: false
Nonlinear optical behaviour of indium-phthalocyanine tethered to magnetite or silica nanoparticles.pdf
- Identifier: http://hdl.handle.net/10962/189933 , vital:44948
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone.
- Full Text:
- Identifier: http://hdl.handle.net/10962/189933 , vital:44948
- Description: Nonlinear absorption and optical limiting properties of indium phthalocyanine (complex 1) tethered to magnetite (SiMNP-1) or silica (SiNP-1) nanoparticles have been investigated using 10 ns pulses at 532 nm laser excitation. The optical limiting behaviours of the nanocomposites and the bare phthalocyanine are compared. Investigation of the triplet state dynamics revealed highly efficient triplet state absorption in the SiMNP-1 dyad. A large nonlinear absorption (βeff) that increased with decrease in the peak input fluence was observed for SiMNP-1. The SiNP-1 composite showed a slight increase in βeff with decreasing peak input fluence. The nonlinear optical data obtained for the SiNP-1 are within the same range of those of the indium phthalocyanine alone. The nanosecond nonlinear absorption and the optical limiting of the nanocomposites are shown to be dominated by a strong excited state absorption from a two-photon pumped state. Nonlinear scattering effects and strong excited state absorption from a two-photon pumped state account for the enhanced optical limiting behaviour of SiMNP-1 relative to the phthalocyanine alone.
- Full Text:
Novel, soluble, FluXoro functional substituted zinc phthalocyanines; synthesis, characterization and photophysicochemical properties
- Erdoğmuş, Ali, Nyokong, Tebello
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false
- Authors: Erdoğmuş, Ali , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7235 , http://hdl.handle.net/10962/d1019686
- Description: Three novel phthalonitriles and the respective, peripheral tetrakis zinc phthalocyanines were synthesized and characterized using elemental analysis, IR, 1H NMR, mass spectra and electronic spectroscopy. The phthalocyanines displayed good solubility in organic solvents such as CHCl3, DCM, DMSO, DMF, THF and toluene. The presence of a long chain fluorine substitituent was found to result in reduced aggregation. The singlet oxygen, photodegradation, fluorescence quantum yield, triplet quantum yield and triplet life time of the complexes in toluene were determined. The effect of fluoro-functional groups on the photophysical and photochemical parameters of the zinc(II) phthalocyanines are also reported. Fluorescence quantum yields for the complexes ranged from 0.021 to 0.041 , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2010.01.001
- Full Text: false
Novobiocin–ferrocene conjugates possessing anticancer and antiplasmodial activity independent of HSP90 inhibition.
- Mbaba, Mziyanda, de la Mare, Jo-Anne, Sterrenberg, Jason N, Kajewole, Deborah, Maharaj, Shantal, Edkins, Adrienne L, Isaacs, Michelle, Hoppe, Heinrich C, Khanye, Setshaba D
- Authors: Mbaba, Mziyanda , de la Mare, Jo-Anne , Sterrenberg, Jason N , Kajewole, Deborah , Maharaj, Shantal , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122858 , vital:35359 , https://doi.org/10.1007/s00775-018-1634-9
- Description: A series of tailored novobiocin–ferrocene conjugates was prepared in moderate yields and investigated for in vitro anticancer and antiplasmodial activity against the MDA-MB-231 breast cancer line and Plasmodium falciparum 3D7 strain, respectively. While the target compounds displayed moderate anticancer activity against the breast cancer cell line with IC50 values in the mid-micromolar range, compounds 10a–c displayed promising antiplasmodial activity as low as 0.889 µM. Furthermore, the most promising compounds were tested for inhibitory effects against a postulated target, heat shock protein 90 (Hsp90).
- Full Text:
- Authors: Mbaba, Mziyanda , de la Mare, Jo-Anne , Sterrenberg, Jason N , Kajewole, Deborah , Maharaj, Shantal , Edkins, Adrienne L , Isaacs, Michelle , Hoppe, Heinrich C , Khanye, Setshaba D
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/122858 , vital:35359 , https://doi.org/10.1007/s00775-018-1634-9
- Description: A series of tailored novobiocin–ferrocene conjugates was prepared in moderate yields and investigated for in vitro anticancer and antiplasmodial activity against the MDA-MB-231 breast cancer line and Plasmodium falciparum 3D7 strain, respectively. While the target compounds displayed moderate anticancer activity against the breast cancer cell line with IC50 values in the mid-micromolar range, compounds 10a–c displayed promising antiplasmodial activity as low as 0.889 µM. Furthermore, the most promising compounds were tested for inhibitory effects against a postulated target, heat shock protein 90 (Hsp90).
- Full Text:
NRF Lifetime Achievement Award 2013
- Authors: Nyokong, Tebello
- Identifier: vital:7221 , http://hdl.handle.net/10962/d1005898
- Description: The NRF Lifetime Achiever award honours a deserving South African who is considered to have made outstanding or extraordinary contributions of an international standard and impact, to the development of science in and for South Africa over an extended period of time.
- Full Text: false
- Authors: Nyokong, Tebello
- Identifier: vital:7221 , http://hdl.handle.net/10962/d1005898
- Description: The NRF Lifetime Achiever award honours a deserving South African who is considered to have made outstanding or extraordinary contributions of an international standard and impact, to the development of science in and for South Africa over an extended period of time.
- Full Text: false
NUMSA Report - Motor industry negotiations
- NUMSA
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/113106 , vital:33707
- Description: Today the bosses can see that workers are standing up for their rights. Their organisations are growing. 230 000 metal workers are united in NUMSA and more than 1 million workers are united in COSATU. The united power of workers have forced the bosses to accept changes to the vicious LRA. The united voice of the oppressed and exploited people have forced the bosses government to unban our organisations. And so the workers voice demanding control over their own lives is growing stronger day by day. The bosses can see that the workers have a plan. That workers are marching along a road which will lead them to victory and freedom. But the bosses too come with their own plan. And the bosses plan is aimed at protecting and increasing their profits and priviledges. The bosses plan is trying to force the workers to walk along the road of deregulation and increased profits for the bosses. This plan is seeking to divide workers and so to break their strength. The bosses plan aims to undermine centralised bargaining. They are scared to face the united power of motor workers. So they try to shift bargaining to plant and company level.
- Full Text:
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/113106 , vital:33707
- Description: Today the bosses can see that workers are standing up for their rights. Their organisations are growing. 230 000 metal workers are united in NUMSA and more than 1 million workers are united in COSATU. The united power of workers have forced the bosses to accept changes to the vicious LRA. The united voice of the oppressed and exploited people have forced the bosses government to unban our organisations. And so the workers voice demanding control over their own lives is growing stronger day by day. The bosses can see that the workers have a plan. That workers are marching along a road which will lead them to victory and freedom. But the bosses too come with their own plan. And the bosses plan is aimed at protecting and increasing their profits and priviledges. The bosses plan is trying to force the workers to walk along the road of deregulation and increased profits for the bosses. This plan is seeking to divide workers and so to break their strength. The bosses plan aims to undermine centralised bargaining. They are scared to face the united power of motor workers. So they try to shift bargaining to plant and company level.
- Full Text:
NUMSA workers build co-operatives
- NUMSA
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/114271 , vital:33961
- Description: There are two main co-operative activities that are supported by NUMSA. The one is SAWCO in Natal and the other is the project that is starting here in the East Cape. Does NUMSA have a policy on co-operatives? NUMSA in its Central Committee has taken a decision to support co-ops. But NUMSA is still busy thinking of how we can formulate a policy on co-operatives. We are working towards such a policy. So what is NUMSA's aim in giving support to co-ops? In other words, how can organised workers benefit from the support that NUMSA is giving to these co-op activities? Interview with Cde John Gomomo NUMSA East Cape Regional Chairperson We, the organised workers on the shop floor are becoming more and more mobilised and politicised. We do not believe that the struggle should just end on the shop floor. The struggle of organised workers should also benefit the community. Co-operatives is such an activity that can be of interest to all groups of oppressed people. We, the organised workers with all the skills we have gathered in the organisation, we believe that if we take the lead, co-ops could be fully democratised organisations in the community.
- Full Text:
- Authors: NUMSA
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/114271 , vital:33961
- Description: There are two main co-operative activities that are supported by NUMSA. The one is SAWCO in Natal and the other is the project that is starting here in the East Cape. Does NUMSA have a policy on co-operatives? NUMSA in its Central Committee has taken a decision to support co-ops. But NUMSA is still busy thinking of how we can formulate a policy on co-operatives. We are working towards such a policy. So what is NUMSA's aim in giving support to co-ops? In other words, how can organised workers benefit from the support that NUMSA is giving to these co-op activities? Interview with Cde John Gomomo NUMSA East Cape Regional Chairperson We, the organised workers on the shop floor are becoming more and more mobilised and politicised. We do not believe that the struggle should just end on the shop floor. The struggle of organised workers should also benefit the community. Co-operatives is such an activity that can be of interest to all groups of oppressed people. We, the organised workers with all the skills we have gathered in the organisation, we believe that if we take the lead, co-ops could be fully democratised organisations in the community.
- Full Text:
Nyokong is the top woman scientist in Africa
- Authors: Lang, Steven
- Language: English
- Type: Article
- Identifier: vital:7197 , http://hdl.handle.net/10962/d1006361
- Full Text:
- Authors: Lang, Steven
- Language: English
- Type: Article
- Identifier: vital:7197 , http://hdl.handle.net/10962/d1006361
- Full Text:
Nyokong puts women in Science on the map
- Authors: Matiwana, Zamuxolo
- Language: English
- Type: Article
- Identifier: vital:7171 , http://hdl.handle.net/10962/d1006076
- Description: Tebello Nyokong has again been honored for her outstanding work in the field of Science when she was awarded an Honorary Doctorate of Philosophy from The University of South Africa recently. Nyokong is a professor at Rhodes University and currently DST / NRF Research Professor of medicinal chemistry and nanotechnology and Director of the DST/ Mintek Nanotechnology Innovation Centre -Sensors. She is also an Adjunct Professor at the University of Tromso in Norway.
- Full Text:
- Authors: Matiwana, Zamuxolo
- Language: English
- Type: Article
- Identifier: vital:7171 , http://hdl.handle.net/10962/d1006076
- Description: Tebello Nyokong has again been honored for her outstanding work in the field of Science when she was awarded an Honorary Doctorate of Philosophy from The University of South Africa recently. Nyokong is a professor at Rhodes University and currently DST / NRF Research Professor of medicinal chemistry and nanotechnology and Director of the DST/ Mintek Nanotechnology Innovation Centre -Sensors. She is also an Adjunct Professor at the University of Tromso in Norway.
- Full Text:
Nyokong wins Prestigious L'Oreal - Unesco Award for Woman in Science
- Authors: Peter, Kerry
- Language: English
- Type: Article
- Identifier: vital:7192 , http://hdl.handle.net/10962/d1006356
- Description: Rhodes University’s Professor Tebello Nyokong, has won the Africa-Arab State 2009 L’Oréal-Unesco Award for Women in Science for her pioneering research into photodynamic therapy which looks at harnessing light for cancer therapy and environmental clean-up. Nyokong is the third South African Scientist to receive this award, and reaffirms Rhodes’s place as one of the top research institutions in the country. University of Cape Town’s Professor Jennifer Thompson was previously recognised for her work on genetic engineering while Wits University’s Professor Valerie Mizrahi was recognised for her tuberculosis research.
- Full Text:
- Authors: Peter, Kerry
- Language: English
- Type: Article
- Identifier: vital:7192 , http://hdl.handle.net/10962/d1006356
- Description: Rhodes University’s Professor Tebello Nyokong, has won the Africa-Arab State 2009 L’Oréal-Unesco Award for Women in Science for her pioneering research into photodynamic therapy which looks at harnessing light for cancer therapy and environmental clean-up. Nyokong is the third South African Scientist to receive this award, and reaffirms Rhodes’s place as one of the top research institutions in the country. University of Cape Town’s Professor Jennifer Thompson was previously recognised for her work on genetic engineering while Wits University’s Professor Valerie Mizrahi was recognised for her tuberculosis research.
- Full Text:
Ons woon en werk met afval in Frankdale
- The environmental advisory unit
- Authors: The environmental advisory unit
- Subjects: The environmental advisory unit
- Language: Afrikaans, Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/168783 , vital:41647
- Description: Ons woon langsaan ‘n vullishoop, 25km buite Kaapstad, oppad na Malmesbury. Ons plek se naam is Frankdale. Ons het geen skole, toilette of elektrisiteit, en ook geen gesondheidsklinieke nie. ‘n Mobiele kliniek kom een keer per maand.
- Full Text:
- Authors: The environmental advisory unit
- Subjects: The environmental advisory unit
- Language: Afrikaans, Xhosa
- Type: text
- Identifier: http://hdl.handle.net/10962/168783 , vital:41647
- Description: Ons woon langsaan ‘n vullishoop, 25km buite Kaapstad, oppad na Malmesbury. Ons plek se naam is Frankdale. Ons het geen skole, toilette of elektrisiteit, en ook geen gesondheidsklinieke nie. ‘n Mobiele kliniek kom een keer per maand.
- Full Text:
Opening address to Conference of Headmasters and Headmistresses of Private Schools - 1977
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7353 , http://hdl.handle.net/10962/d1017082
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7353 , http://hdl.handle.net/10962/d1017082
- Full Text:
Opening of Rhodes Summer School 1975 - East London Library, November 3rd 1975
- Authors: Henderson, Derek Scott
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7333 , http://hdl.handle.net/10962/d1017061
- Full Text:
- Authors: Henderson, Derek Scott
- Subjects: Rhodes University
- Language: English
- Type: Text
- Identifier: vital:7333 , http://hdl.handle.net/10962/d1017061
- Full Text:
Opening of Robert Niven Trust school at Amanzi farm 1978
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7368 , http://hdl.handle.net/10962/d1017248
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7368 , http://hdl.handle.net/10962/d1017248
- Full Text:
Opening of the NIC - Sensors by the Minister of Science Me Naledi Pandor
- Authors: Nyokong, Tebello
- Identifier: vital:7229 , http://hdl.handle.net/10962/d1006048
- Description: Opening of the NIC - Sensors by the Minister of Science Me Naledi Pandor on 13 September 2010
- Full Text: false
- Authors: Nyokong, Tebello
- Identifier: vital:7229 , http://hdl.handle.net/10962/d1006048
- Description: Opening of the NIC - Sensors by the Minister of Science Me Naledi Pandor on 13 September 2010
- Full Text: false
Opening Professor Scully's multi-image presentation
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7385 , http://hdl.handle.net/10962/d1017274
- Full Text:
- Authors: Henderson, Derek Scott
- Language: English
- Type: Text
- Identifier: vital:7385 , http://hdl.handle.net/10962/d1017274
- Full Text:
Optical nonlinearities and photophysicochemical behaviour of green and blue forms of lutetium bisphthalocyanines
- Sekhosana, Kutloano Edward, Amuhaya, Edith, Mack, John, Nyokong, Tebello
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7316 , http://hdl.handle.net/10962/d1020543
- Description: A rare earth sandwich-type phthalocyanine: bis-{2,3,9,10,16,17,23,24-octa(4-tert-butylphenoxy) phthalocyaninato} lutetium(III) has been synthesized. The photophysical and nonlinear optical behavior of both the “green” and “blue” forms ([LuIIIPc2] and [LuIIIPc2]−, respectively) of the complex have been investigated. High triplet state and singlet oxygen quantum yield values were obtained for the neutral blue form which contains no unpaired electrons. Relatively high third order susceptibility and hyperpolarizability values of the order of 10−10 and 10−28 esu were obtained for both the green and blue forms, respectively. A very low threshold intensity of 0.00051 J cm−2 was obtained for the blue form. Hence the complex shows promise for non-linear optical applications. , Original publication is available at http://dx.doi.org/10.1039/C4TC00505H
- Full Text:
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7316 , http://hdl.handle.net/10962/d1020543
- Description: A rare earth sandwich-type phthalocyanine: bis-{2,3,9,10,16,17,23,24-octa(4-tert-butylphenoxy) phthalocyaninato} lutetium(III) has been synthesized. The photophysical and nonlinear optical behavior of both the “green” and “blue” forms ([LuIIIPc2] and [LuIIIPc2]−, respectively) of the complex have been investigated. High triplet state and singlet oxygen quantum yield values were obtained for the neutral blue form which contains no unpaired electrons. Relatively high third order susceptibility and hyperpolarizability values of the order of 10−10 and 10−28 esu were obtained for both the green and blue forms, respectively. A very low threshold intensity of 0.00051 J cm−2 was obtained for the blue form. Hence the complex shows promise for non-linear optical applications. , Original publication is available at http://dx.doi.org/10.1039/C4TC00505H
- Full Text:
Optical nonlinearities in non-peripherally substituted pyridyloxy phthalocyanines: a combined effect of symmetry, ring-strain and demetallation
- Sanusi, Kayode, Antunes, Edith M, Nyokong, Tebello
- Authors: Sanusi, Kayode , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7301 , http://hdl.handle.net/10962/d1020375
- Description: The optical nonlinearities of six non-peripherally-substituted pyridyloxy phthalocyanines have been studied at 532 nm using a nanosecond Z-scan technique in a dimethyl sulphoxide solution. Ring-strain effects and the absence of a metal center were found to greatly reduce the inherent high nonlinearities expected of some of these phthalocyanine complexes. Of the six molecules investigated, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyaninato lead(II) 3, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyanine 5, and 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyanine 6 were found to exhibit negligible nonlinear optical behavior, due to either the absence of asymmetry or central metal and/or the presence of a ring-strain effect. A two-photon absorption process was found to be the major contributor to the observed reverse saturable absorption (RSA) in 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyaninato lead(II) 4, 1(4)-mono-(2-pyridyloxy)phthalocyaninato lead(II) 7, and 1(4)-mono-(4-pyridyloxy)phthalocyaninato lead(II) 8, with large two-photon absorption cross-section, high hyperpolarizability and high third-order susceptibility values in the range of 4.53 × 10−43–5.33 × 10−42 cm4 s per photon, 1.61 × 10−28–1.89 × 10−27 esu and 9.73 × 10−12–7.05 × 10−11 esu respectively. , Original publication is available at http://dx.doi.org/10.1039/C3DT52462K , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
- Full Text:
- Authors: Sanusi, Kayode , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7301 , http://hdl.handle.net/10962/d1020375
- Description: The optical nonlinearities of six non-peripherally-substituted pyridyloxy phthalocyanines have been studied at 532 nm using a nanosecond Z-scan technique in a dimethyl sulphoxide solution. Ring-strain effects and the absence of a metal center were found to greatly reduce the inherent high nonlinearities expected of some of these phthalocyanine complexes. Of the six molecules investigated, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyaninato lead(II) 3, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyanine 5, and 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyanine 6 were found to exhibit negligible nonlinear optical behavior, due to either the absence of asymmetry or central metal and/or the presence of a ring-strain effect. A two-photon absorption process was found to be the major contributor to the observed reverse saturable absorption (RSA) in 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyaninato lead(II) 4, 1(4)-mono-(2-pyridyloxy)phthalocyaninato lead(II) 7, and 1(4)-mono-(4-pyridyloxy)phthalocyaninato lead(II) 8, with large two-photon absorption cross-section, high hyperpolarizability and high third-order susceptibility values in the range of 4.53 × 10−43–5.33 × 10−42 cm4 s per photon, 1.61 × 10−28–1.89 × 10−27 esu and 9.73 × 10−12–7.05 × 10−11 esu respectively. , Original publication is available at http://dx.doi.org/10.1039/C3DT52462K , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
- Full Text:
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
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