https://commons.ru.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:25548 Wed 12 May 2021 20:07:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29926 Wed 12 May 2021 19:50:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4538 Wed 12 May 2021 19:02:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4537 Wed 12 May 2021 17:56:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4545 Wed 12 May 2021 17:12:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:29122 90% cell survival. The photodynamic activity of water insoluble porphyrins improved when encapsulated into the micelles. Novel asymmetrical phthalocyanines were also synthesised for nonlinear optics (NLO) studies in solution and thin films.]]> Wed 12 May 2021 16:05:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:41337 Wed 12 May 2021 15:02:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42174 Wed 12 May 2021 15:00:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:42052 Wed 12 May 2021 14:30:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4553 600 nm) in dimethylsulphoxide solution. All the ligands were transformed into the dihydroxy silicon octaphenoxyphthalocyanine with varying degrees of phototransformation quantum yields ranging in order from 10⁻³ to 10⁻⁵ depending on the axial ligand involved. During and after axial ligand transformations a photodegredation of the dihydroxy silicon octaphenoxy phthalocyanine was observed upon continued irradiation. The oligomers were found to undergo the same axial ligand transformation process with a phototransformation quantum yield of 10⁻⁵ The singlet oxygen quantum yields of the unaggregated monomeric silicon octaphenoxy phthalocyanines were all found to be approximately 0.2 with the exception of a compound with two (trihexyl)siloxy axial substituents that had a singlet oxygen quantum yield of approximately 0.4 in dimethylsulphoxide solutions. The oligomers showed a surprising trend of an increase in singlet oxygen quantum yield with an increase in phthalocyanine ring number up to the pentamer and then a dramatic decrease to the nonamer. The triplet quantum yield and triplet lifetime were determined by laser flash photolysis for selected compounds and no correlation was observed with any of these properties and the singlet oxygen quantum yields. These selected compounds all fluoresce and a very good correlation was found between the fluorescence lifetimes determined experimentally by laser photolysis and the Strickler-Berg equation for the non-aggregated compounds. Electrochemical measurements also indicate the importance of the axial ligands upon the behaviour of the phthalocyanines as cyclic voltammetric behaviour was determined by the nature of the axial ligand.]]> Thu 13 May 2021 14:52:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4543 Thu 13 May 2021 11:46:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:30589 50Îll viability at concentrations≤ 160μg/mL, however the conjugates showed<50% cell viabilityatconcentrations≤ 160μg/mLprobably due to the enhanced singlet oxygen quantum yield. The findings from this work show the importance of linking photosensitises such as phthalocyanines to metal nanoparticles for the enhancement ofsinglet oxygen quantum yield and ultimately the photodynamic effect.]]> Thu 13 May 2021 08:10:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4278 Thu 13 May 2021 07:14:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4541 Thu 13 May 2021 07:06:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4554 SnPc>ZnPc. Triplet lifetimes of the GePc (168-340μs) are very similar to that of the ZnPc (197 - 366μs), but the triplet lifetimes of the SnPc are ten fold shorter (10 - 32μs ). Triplet quantum yields are higher for the GePc (0.20 - 0.50) and SnPc (0.08 - 0.45) than for the ZnPc (0.02 - 0.25). Fluorescence lifetimes of GePc ( 4.0 - 5.1 ns) are significantly longer than that of ZnPc (1.9 - 3.0 ns) and SnPc (0.2 - 0.4 ns). Fluorescence quantum yields decrease in the following order: GePc(0.21-0.31)>ZnPc(0.02-0.21)>SnPc(0.02- 0.06). Ring-substituted cobalt phthalocyanine complexes of the form CoPc(R)4 (R= NH2, N02, C(CH3)3, S03H and COOH) are compared for their catalytic activities towards the oxidation of cysteine. The potential for the electrocatalytic oxidation of cysteine is closely related to the Com/Co11 couple of the CoPc(R)4 complexes in acidic media and to the Con/Co1 couple in basic media. The catalytic current and the oxidation potential for cysteine are dependent on the pH of the solution, the potential becoming less positive and the currents increasing with increase in pH.]]> Thu 13 May 2021 06:41:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5580 Thu 13 May 2021 06:37:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4544 Thu 13 May 2021 03:36:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:27821 Thu 13 May 2021 01:17:53 SAST ]]>