Voltammetric detection of vitamin B1 at carbon paste electrodes and its determination in tablets
- Authors: Oni, Joshua , Westbroek, Philippe , Nyokong, Tebello
- Date: 2002
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289692 , vital:56663 , xlink:href="https://doi.org/10.1002/1521-4109(200209)14"
- Description: The voltammetric behavior of vitamin B1 in alkaline medium at carbon paste electrode (CPE) is discussed. A method based on cyclic voltammetry for the determination of vitamin B1 at carbon paste electrode modified with manganese phthalocyanine (MnPc-CPE) is presented. In pH 10 buffer, the modified electrode showed catalytic activity towards the oxidation of vitamin B1 by considerably increasing the oxidation current of one of the observed waves compared to the oxidation current obtained at an unmodified electrode. The modified electrode was stable towards the determination of vitamin B1 compared to the unmodified electrode that is completely poisoned after a few scans. A linear relationship between the oxidation current and the concentration of vitamin B1 in solution was observed. The detection limit for vitamin B1 at the modified electrode was of the order of 10−5 mol dm−3. Commercial vitamin B1 tablets were analyzed using the modified electrodes.
- Full Text:
- Date Issued: 2002
Optimal template removal from molecularly imprinted polymers by pressurized hot water extraction
- Authors: Batlokwa, Bareki Shima , Mokgadi, Janes , Nyokong, Tebello , Torto, Nelson
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247813 , vital:51620 , xlink:href="https://doi.org/10.1007/s10337-010-1884-3"
- Description: An optimal extraction method for the removal of templates from molecularly imprinted polymers (MIPs) is presented. The extraction method is based on pressurized hot water extraction (PHWE). PHWE was evaluated by application to three distinctly colored MIPs for chlorophyll (green), quercetin (yellow) and phthalocynine (dark blue) with subsequent monitoring of template removal and template bleeding by an ultraviolet spectrophotometer. The templates were washed-off and the extraction efficiency (EE) was compared to that of soxhlet and ultrasonic extraction methods. PHWE employed hot water at an optimal temperature of 220 °C, pressure of 50 bars and flow rate of 2 mL min−1 to thoroughly wash-off the respective templates from their MIPs. The EE evaluated for PHWE was over 99.6% for all the MIPs with no subsequent or minimal template bleeding (more than 0.01%). The washing procedure was simple and relatively fast as it was achieved in 70 min at the most. At 95% confidence level (n = 3), soxhlet and ultrasonic recorded EE that was not significantly different (more than 94.5% in all cases) from that of PHWE (less than 99.6% in all cases). Soxhlet and ultrasonic had washing procedures that were slower (over 18 h) and employed large quantities (400 mL) of organic solvents modified with acids. The percentage relative standard deviations (%RSD) for the EE and recovery results were less than 2.3% in all cases indicating the high reproducibility of the method. Overall, the three methods performed comparably in extracting templates. PHWE seems to be the method of choice as it employed water which poses no environmental threat.
- Full Text:
- Date Issued: 2011
Opposing responses elicited by positively charged phthalocyanines in the presence of CdTe quantum dots
- Authors: Moeno, Sharon , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264506 , vital:53740 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.10.027"
- Description: Tetrapositively charged phthalocyanines and CdTe quantum dots (QDs) capped with thioglycolic acid (TGA) and mercaptopropionic acid (MPA) were synthesized. The response of the tetrapositively charged zinc phthalocyanines in the presence of quantum dots was studied. Aggregation and charge transfer were observed for [tetramethyl-2,(3)-[tetra-(2-mercaptopyridinephthalocyaninato)]zinc(II)]4+ (TmTMPyZnPc), however aggregation proved to be the more prominent process of the two. Fluorescence resonance energy transfer (FRET) was observed with [tetramethyl-2,(3)-[tetra-(2- pyridyloxyphthalocyaninato)]zinc(II)]4+ (TmTPyZnPc). In the FRET study the efficiency of FRET with TmTPyZnPc was determined to be 21% for both MPA and TGA capped CdTe QDs. For the charge transfer study the fluorescence of the quantum dots was quenched by the TmTMPyZnPc used, and from these quenching studies the quenching constants, binding constants and number of binding sites on the quantum dots were determined.
- Full Text:
- Date Issued: 2009
Excited state dynamics of zinc and aluminum phthalocyanine carboxylates
- Authors: Idowu, Mopelola , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271228 , vital:54523 , xlink:href="https://doi.org/10.1016/j.saa.2007.01.025"
- Description: Photophysical parameters for zinc and aluminium tetracarboxylphthalocyanines (ZnTCPc and AlTCPc, respectively) and their octacarboxy substituted counterparts (ZnOCPc and AlOCPc) were studied. Data for the fluorescence quenching of the complexes by benzoquinone (BQ) were treated using the Stern–Volmer analysis, and the quenching was found to follow a diffusion-controlled (dynamic) bimolecular mechanism. Theoretical values of bimolecular rate constant for complex-BQ interactions were determined using the Stokes–Einstein–Smoluchowski model; and the values, together with the Stern–Volmer quenching constants were used in calculating the fluorescence lifetimes of the complexes. The thermodynamics of the MPc-BQ interaction, in terms of solvent reorientation energy is also discussed.
- Full Text:
- Date Issued: 2007
Synthesis and characterization of Na (Y, Gd) F4 upconversion nanoparticles and an investigation of their effects on the photophysical properties of an unsubstituted tetrathiophenoxy phthalocyanine
- Authors: Taylor, Jessica M , Litwinski, Christian , Nyokong, Tebello , Antunes, Edith M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241437 , vital:50939 , xlink:href="https://doi.org/10.1007/s11051-015-2889-5"
- Description: Sphere- and star-shaped Na(Y,Gd)F4:Yb/Er(Tm)upconversion nanoparticles (UCNP) were successfully synthesized utilizing a methanol-assisted thermal decomposition approach and their spectroscopic (absorption, emission and luminescence lifetime) properties fully characterized. The factors affecting the size and shape of the UCNPs were studied and discussed in detail. The size of the nanoparticles was determined using TEM primarily and found to be approximately 19 and 30 nm for the Er and Tm spheres, respectively, while the Er and Tm “stars” were found to be much larger with sizes ranging from 110 to 240 nm, respectively (as determined along the width of the nanoparticle). In addition, their influence on the spectroscopic properties of an unsubstituted tetrathiophenoxy phthalocyanine (H2Pc) was investigated. The UCNP were found to produce characteristic upconversion luminescence emissions in the blue, green, red and NIR regions. Simple mixing with an H2Pc in toluene was found to exert no obvious changes in the spectroscopic properties of the Pc, although a considerable increase in the radiative lifetimes is observed for the Pc in the presence of the UCNPs. The singlet oxygen generation mediated by the red light excitation of the H2Pc mixed with UCNP was found to decrease in the presence of the NPs.
- Full Text:
- Date Issued: 2015
Interaction of water-soluble thiol capped CdTe quantum dots and bovine serum albumin
- Authors: Idowu, Mopelola , Lamprecht, Emmanuel , Nyokong, Tebello
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/265974 , vital:53906 , xlink:href="https://doi.org/10.1016/j.jphotochem.2008.02.008"
- Description: Luminescent water-soluble CdTe quantum dots (QDs) capped with different thiol carboxylic acids were synthesized in aqueous medium and then cross linked to bovine serum albumin (BSA) with 1-ethyl3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enhancement of fluorescence emission intensity occurred for QDs in the presence of bovine serum albumin (BSA, mixed or linked) signifying inhibition of non-radiative recombination of the surface vacancies. Fluorescence studies reveal a positive deviation behaviour suggesting the occurrence of static and dynamic mechanisms of quenching together which was accounted for by the modified Stern–Volmer equation.
- Full Text:
- Date Issued: 2008
Solvent-free axial ligand substitution in octaphenoxyphthalocyaninato silicon complexes using microwave irradiation
- Authors: Maree, M David , Nyokong, Tebello
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304830 , vital:58494 , xlink:href="https://journals.sagepub.com/doi/epdf/10.3184/030823401103168974"
- Description: Several axially substituted octaphenoxy silicon phthalocyanines were prepared by condensation of the complexes used as axial ligands with octaphenoxyphthalocyaninato (dichloro) silicon under microwave irradiation.
- Full Text:
- Date Issued: 2001
The Dangers of Student-Centered Learning-A Caution about Blind Spots in the Scholarship of Teaching and Learning
- Authors: McKenna, Sioux
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187362 , vital:44624 , xlink:href="https://doi.org/10.20429/ijsotl.2013.070206"
- Description: Student-centered learning is an increasingly popular approach that shifts the focus from the teacher to the student. The approach argues that we need to have a clear understanding of who our students are and what their needs are in order for us to provide quality education. This paper applauds the focus on the student but raises two concerns about absences in this approach. Firstly, student-centered approaches rarely consider the actual knowledge being taught and learnt. There is little consideration of how the disciplinary knowledge is constructed and what norms and values underpin such constructions. Secondly, student-centered approaches are often undertaken within the dominant autonomous discourse where student success or failure is seen to result from characteristics inherent in the student. She is understood as an individual rather than as a member of a larger social group and there is equally little acknowledgement of the socially constructed nature of universities and the practices within them.
- Full Text:
- Date Issued: 2013
Mechanisms and indicators for assessing the impact of biofuel feedstock production on ecosystem services
- Authors: Gasparatos, Alexandros , Romeu-Dalmau, Carla , von Maltitz, Graham P , Johnson, Francis X , Shackleton, Charlie M , Jarzebski, Marcin P , Jumbe, Charles , Ochieng, Caroline , Mudombi, Shakespear , Nyambane, Anne , Willis, Katherine J
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181368 , vital:43727 , xlink:href="https://doi.org/10.1016/j.biombioe.2018.01.024"
- Description: Biofuel feedstock production can be a significant driver of landscape modification, ecosystem change and biodiversity loss. There is growing body of literature that shows how biofuel landscapes provide various ecosystem services (e.g., feedstock for fuel, carbon sequestration) and compromise other ecosystem services (e.g., food, freshwater services). These effects are context-specific and depend largely on prior land use conditions and feedstock production practices. Changes in the flow of ecosystem services due to the conversion of natural and agricultural areas can have ripple effects on human wellbeing. Despite some recent attempts to apply to biofuel settings concepts and methods rooted in the ecosystem services literature, this is the exception rather than the rule within both the biofuel and the ecosystem services research communities. This paper synthesizes the current knowledge about the impact of biofuels on ecosystem services. It focuses especially on the feedstock production phase and outlines the main mechanisms through which landscape conversion affects the provisions of ecosystem services. It proposes conceptually coherent indicators to reflect these mechanisms and offers a critical discussion of key issues at the interface of biofuels and ecosystem services.
- Full Text:
- Date Issued: 2018
Gazing at Exhibit A
- Authors: Krueger, Anton
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229643 , vital:49696 , xlink:href="http://liminalities.net/9-1/exhibit.pdf"
- Description: Brett Bailey recently toured a new work in Europe and South Africa, called The Exhibit Series (2010-2013). In different countries the work has appeared under different titles—Exhibit A and Exhibit B, while Exhibit C will be produced in 2014. These productions replicate and parody ethnographic spectacles of the nineteenth century, interrogating European colonial atrocities in Africa, as well as contemporary xenophobia. They consist of a series of installations housed in individual rooms that audience members enter one by one. Inside these rooms one is confronted by beautifully arranged spectacles referencing historical atrocities committed in Namibia by German speaking peoples, as well as atrocities under the Belgian and French colonial regimes in the two Congos. The “exhibits” also include references to more recent incidents of European racism against migrants from Africa. The work has been both applauded and derided. In Berlin, for example, activists called it “a human zoo” and protested that this was “the wrong way to discuss a violent colonial history,”1 while others have called the work “haunting”, praising the production for its “dignity” and “beauty.”2
- Full Text:
- Date Issued: 2013
Photophysical and photochemical properties of zinc and aluminum phthalocyanines in the presence of magnetic fluid
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281298 , vital:55710 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.12.013"
- Description: The effect of magnetic fluid (MF) on the photophysical and photochemical parameters of zinc and aluminum phthalocyanines are reported. The complexes studied are zinc (II) phthalocyanine (ZnPc), chloroaluminum phthalocyanine ((Cl)AlPc) and tetrasulfonated aluminum phthalocyanine ((Cl)AlTSPc). The parameters are studied in dimethylsulfoxide (DMSO) for all complexes and also in aqueous media for (Cl)AlTSPc. The triplet lifetimes for (Cl)AlTSPc and ZnPc decreased while the triplet quantum yields increased in the presence of MF. For (Cl)AlPc, the triplet lifetimes were found to increase with decrease in laser energy while there was photoreduction to the Pc−3 species. Singlet oxygen and photodegradation quantum yields decreased in the presence of MF, suggesting quenching.
- Full Text:
- Date Issued: 2007
Photophysics and photochemistry of octaglucosylated zinc phthalocyanine derivatives
- Authors: Iqbal, Zafar , Ogunsipe, Abimbola , Nyokong, Tebello , Lyubimtsev, Alexey , Hanack, Michael , Ziegler, Thomas
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244416 , vital:51255 , xlink:href="https://doi.org/10.1142/S1088424612500630"
- Description: The ground state electronic absorption spectra, photophysics and photochemistry of amphiphilic octaglucosylated zinc phthalocyanines containing oxygen or sulfur bridges are presented. Triplet quantum yield values for the two dyes (in DMF and DMSO) vary between 0.71 and 0.84, while singlet quantum yield values lie between 0.63 and 0.75. Fluorescence lifetimes were determined experimentally by time correlated single photon counting and semi-empirically by fluorescence quenching techniques; and values from both methods were within the same range. Kinetic data were obtained for the quenching of the triplet state of the phthalocyanines by ground state molecular oxygen; the bimolecular collisional quenching rate constant range between 2.35 × 108 and 1.13 × 109 M-1.s-1. These values suggest that triplet states of the dyes are effectively quenched by ground molecular oxygen.
- Full Text:
- Date Issued: 2012
Comparative photocatalytic efficiency of oxotitanium (IV) phthalocyanines for the oxidation of 1-hexene
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/271193 , vital:54520 , xlink:href="https://doi.org/10.1016/j.molcata.2007.04.005"
- Description: The comparative photocatalytic activities of aryloxy and arylthio tetrasubstituted oxotitanium(IV) phthalocyanine complexes for the oxidation of 1-hexene in DCM are reported for the first time. The singlet oxygen quantum yield, photostability and photocatalytic properties are investigated. The catalysts effectively catalyse 1-hexene to 1,2-epoxyhexane and 1-hexen-3-ol as major and minor products respectively. The photooxidation products are formed via two reaction mechanisms, namely via singlet oxygen (Type II) and radical (Type I) reaction pathways. These are also dependent on the singlet oxygen quantum yields and photostabilities of the phthalocyanines. Complex 1a that is peripherally substituted with phenoxy groups exhibited the best activity in terms of overall performance.
- Full Text:
- Date Issued: 2007
Tyrannical masters no more?: Promissory insurance warranties after Viking Inshore Fishing (Pty) Ltd v Mutual and Federal Insurance Co Ltd
- Authors: Glover, Graham B
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186701 , vital:44526 , xlink:href="https://hdl.handle.net/10520/EJC-1b0c21b6eb"
- Description: Federal Insurance Co Ltd for the law on promissory insurance warranties are considered. The article begins with an overview of the traditional position, which has been that such warranties are to be strictly interpreted and enforced, no matter the harshness of the result. Thereafter, the article discusses the contrasting decisions in Viking Inshore Fishing (Pty) Ltd v Mutual and Federal Insurance Co Ltd in the Western Cape High Court and the SCA. Wallis JA suggested on appeal that the strict traditional approach to promissory warranties was no longer appropriate, but without having to decide the point. The article next considers the implications of an obiter dictum of the SCA, in a matter relating to a court exercising admiralty jurisdiction, on insurance law in general. Thereafter, the article proposes that Wallis JA’s comments indicate an important change to our law on promissory warranties, specifically in relation to the need for there to be a causal link between the insured’s breach of the warranty and the loss suffered, before an insurer may exercise the power to repudiate the contract. Although others have made the causal-link argument before, this article tries to explain and situate this development in two doctrinal contexts: the modern law on contractual interpretation; and the doctrine of public policy. A supplementary argument relates to the drawing together of the law on promissory warranties with the rules relating to cancellation for major breach, in cases where an insurer pursues that remedy.
- Full Text:
- Date Issued: 2019
Electrocatalytic activity of nanocomposites of sulphur doped graphene oxide and nanosized cobalt phthalocyanines
- Authors: Shumba, Munyaradzi , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188530 , vital:44762 , xlink:href="https://doi.org/10.1002/elan.201600226"
- Description: In this work we explore the electrocatalytic activity of nanocomposites of reduced sulphur doped graphene oxide nanosheets (rSDGONS) and cobalt phthalocyanine (CoPc) or cobalt tetra amino phthalocyanine (CoTAPc) towards hydrogen peroxide. Transmission electron microscopy, scanning electron microscopy, X-ray photon spectroscopy, X-ray diffraction, chronoamperometry, linear scan voltammetry and cyclic voltammetry were used to characterize the nanocomposites. Nanosized CoPc showed superior (in terms of currents) electrocatalytic oxidation and reduction of hydrogen peroxide compared to CoTAPc nanoparticles (CoTAPcNP). The lowest detection limit was obtained for hydrogen peroxide oxidation on electrodes modified with CoPcNP-rSDGONS at 1.49 µM. The same electrode gave a high adsorption equilibrium constant of 1.27×103 mol−1 and a Gibbs free energy of −17.71 kJ/mol, indicative of a spontaneous reaction on the electrode surface.
- Full Text:
- Date Issued: 2016
Reproductive phenology of two Mimusops species in relation to climate, tree diameter and canopy position in Benin (West Africa)
- Authors: Sinasson Sanni, Giséle K , Shackleton, Charlie M , Sinsin, Brian
- Date: 2018
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180337 , vital:43354 , xlink:href=" https://doi.org/10.1111/aje.12457"
- Description: Assessing species phenology provides useful understanding about their autecology, to contribute to management strategies. We monitored reproductive phenology of Mimusops andongensis and Mimusops kummel, and its relationship with climate, tree diameter and canopy position. We sampled trees in six diameter classes and noted their canopy position. For both species flowering began in the dry season through to the rainy season, but peaked in the dry season, whilst fruiting occurred in the rainy season and peaked during the most humid period. Flowering was positively correlated with temperature. Conversely, fruiting was negatively correlated with temperature and positively with rainfall, only in the Guineo-Sudanian zone. For M. andongensis, flowering and fruiting prevalences were positively linked to stem diameter, while only flowering was significantly related to canopy position. For M. kummel, the relationship with stem diameter was significant for flowering prevalence only and in the Guineo-Sudanian zone. Results suggest that phylogenetic membership is an important factor restricting Mimusops species phenology. Flowering and fruiting of both species are influenced by climate, and consequently climate change might shift their phenological patterns. Long-term investigations, considering flowering and fruiting abortion, will help to better understand the species phenology and perhaps predict demographic dynamics.
- Full Text:
- Date Issued: 2018
The contribution of land tenure diversity to the spatial resilience of protected area networks
- Authors: de Vos, Alta , Cumming, George S
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/416421 , vital:71347 , xlink:href="https://doi.org/10.1002/pan3.29"
- Description: The relationship between diversity and resilience is relatively well‐established for ecological systems, but remains much less explored for socio‐economic systems. Institutional diversity can have particular relevance for protected areas, whose managerial responses to environmental change depend on their legal basis, ability to make and enforce rules and socio‐political acceptance and endorsement. 2. Protected area expansion strategies are increasingly turning to private land con‐ servation to increase the configuration and connectivity of national protected area networks. Yet, we know little about the relative role of privately owned pro‐ tected areas in protecting threatened and poorly protected (under‐represented) habitats, and in the overall connectivity of the national protected area network. 3. We present an empirical assessment of protected area tenure diversity across South Africa.
- Full Text:
- Date Issued: 2019
Accounting student's success factors: an exploratory investigation
- Authors: Stack, Elizabeth M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/2134 , vital:20258
- Description: This presentation is aimed at identifying possible success factors leading to the success of students studying accounting, as well as to hightlight some of the problems they may face.
- Full Text:
- Date Issued: 2014
Physicochemical behavior of nanohybrids of mono and tetra substituted carboxyphenoxy phthalocyanine covalently linked to GSH–CdTe/CdS/ZnS quantum dots
- Authors: Oluwole, David O , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189480 , vital:44850 , xlink:href="https://doi.org/10.1016/j.poly.2014.10.024"
- Description: Zinc monocarboxyphenoxy and tetracarboxyphenoxy phthalocyanines were covalently linked with three different sizes of glutathione capped core/shell/shell {CdTe/CdS/ZnS(4.2), CdTe/CdS/ZnS(5.1) and CdTe/CdS/ZnS(6.7)}; a core shell {CdTe/CdS(3.1)} and core {CdTe(2.4)} quantum dots. The physicochemical behavior and Förster resonance energy transfer (FRET) processes of the nanohybrids were investigated. The highest FRET efficiency was observed with CdTe/CdS/ZnS(6.7) nanohybrids with 98% and the least efficiency was observed with CdTe(2.4) nanohybrids with 85%. The CdTe/CdS/ZnS(6.7) also showed the best physicochemical behavior. These good physicochemical properties make the synthesized nanohybrids viable photosensitizers.
- Full Text:
- Date Issued: 2015
Photophysical and photochemical studies of long chain-substituted zinc phthalocyanines
- Authors: Durmus, Mahmut , Ahsen, Vefa , Nyokong, Tebello
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/281310 , vital:55711 , xlink:href="https://doi.org/10.1016/j.jphotochem.2006.08.025"
- Description: Photochemical and photophysical measurements were conducted on peripheral and non-peripheral tetra(13,17-dioxanonacosane-15-hydroxy)-substituted zinc phthalocyanines (1, 2). General trends are described for quantum yields of photodegradation, fluorescence yields, triplet lifetimes and triplet quantum yields as well as singlet quantum yields of these compounds in dimethylformamide (DMF) and toluene. The effects of the solvents on the photophysical and photochemical parameters of the zinc(II) phthalocyanines (1, 2) are reported.
- Full Text:
- Date Issued: 2007