https://commons.ru.ac.za/vital/access/manager/Index en-us 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:4286 Wed 12 May 2021 22:28:40 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4445 Wed 12 May 2021 20:55:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4363 Wed 12 May 2021 20:21:09 SAST ]]> 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:24712 Wed 12 May 2021 19:31:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4419 Wed 12 May 2021 19:14:46 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:4326 Wed 12 May 2021 18:29:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:20695 Wed 12 May 2021 18:14:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4328 10⁻² mol dm⁻³), direct two-electron oxidation of the (Pc(-2 )LnPc - 2)]⁻ species to (Pc(-1)LnPc(-1)]⁻ occurs. Spectroelectrochemical behaviours of Sn^IVPc₂ have been also studied. The cyclic voltammetry ofSnPc₂ in CH₂CI₂/TBAP show two reduction couples at -0.56 V and -0.89 V versus saturated calomel electrode (SCE) and one oxidation couple at 0.35 V versus SCE. In DMFITEAP system, the reduction couples are observed at -0.44 V and -0.81 V versus SCE whereas the oxidation couple occurred at 0.43 V versus SCE. The oxidation couple corresponds to [Pc(-2 )Sn^IVPc(-2 )]/[Pc(-2)Sn^IVPc( -I)] . and the reduction couples to [Pc(-2)Sn^IVPc( -2 )]/[Pc(-2 )Sn^IVPc( -3 )]⁻ and [Pc(-2)Snl^IVPc( -3)] ⁻/[Pc(-3 )Sn^IVPc(-3)]²⁻, respectively. The electronic absorption spectra of these reduced and oxidized species are reported.]]> Wed 12 May 2021 18:13:53 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:4295 Wed 12 May 2021 17:51:50 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:4333 Wed 12 May 2021 16:52:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4418 Wed 12 May 2021 16:25:06 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4335 Wed 12 May 2021 16:06:41 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:4310 Tue 24 Aug 2021 16:28:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:20790 Thu 13 May 2021 16:20:28 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:4464 Thu 13 May 2021 14:21:31 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4427 Thu 13 May 2021 13:48:05 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:4377 Thu 13 May 2021 10:50:32 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:4447 Thu 13 May 2021 07:13:40 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:4396 Thu 13 May 2021 06:27:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:19967 Thu 13 May 2021 06:21:13 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4089 Thu 13 May 2021 05:24:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4321 Thu 13 May 2021 05:22:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:20805 Thu 13 May 2021 04:57:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4561 Thu 13 May 2021 04:25:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4329 Thu 13 May 2021 04:20:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4277 Thu 13 May 2021 03:57:19 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4365 Thu 13 May 2021 03:50:26 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4313 Thu 13 May 2021 03:38:11 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:4457 Thu 13 May 2021 03:30:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4391 Thu 13 May 2021 02:29:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4336 Thu 13 May 2021 01:13:15 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4435 Thu 13 May 2021 00:36:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4282 Thu 13 May 2021 00:27:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4551 Thu 07 Jul 2022 16:08:45 SAST ]]>