Publications by authors named "Lanka Wickramasinghe"
Article Synopsis
- Two new ruthenium complexes, [Ru(tpy)(qdppz)](PF) and [Ru(qdppz)](PF), were studied as potential phototherapeutic agents due to their ability to produce singlet oxygen when exposed to visible light.
- These complexes display strong metal-to-ligand charge transfer (MLCT) absorption, with specific absorption maxima indicating effective energy transfer capabilities; however, only one complex shows measurable luminescence at room temperature.
- The differences in ligand geometry impact the lifetimes of MLCT states and photocleavage abilities, with [Ru(qdppz)] being more effective at intercalating DNA and producing singlet oxygen for DNA photocleavage.
We have prepared the amphiphilic molecular catalyst [Co(L)(pyrr)]ClO (1), where L is the deprotonated form of N, N'-[4,5-bis(octadecyloxy)-1,2-phenylene]dipicolinamide. Species 1 can be anchored onto a carbon black support to yield the assembly 1@CB, which can catalyze water oxidation at an affordable onset overpotential of 0.32 V, with a current density of 10 mA/cm at 0.
View Article and Find Full Text PDFIn this paper we analyze the changes in molecular orientation triggered by electrochemical reduction of an iron-containing surfactant in Langmuir-Blodgett films deposited onto gold electrodes. The metallosurfactant [Feiii(LN2O3)] (1) is an established molecular rectifier capable of unidirectional electron transfer between two electrodes. A gradual decrease in the activity is observed in sequential current vs.
View Article and Find Full Text PDFElectromodified Langmuir-Blodgett films of a phenolate-rich [Co(III)(L(N2O3))H2O] metallosurfactant support water oxidation at an overpotential of 0.5 V. Gradual enhancement of catalytic activity is observed between 1 and 9 deposited layers.
View Article and Find Full Text PDFAmphiphilic five-coordinate iron(III) complexes with {N2 O2 Cl} and {N2 O3 } coordination spheres are studied to elucidate the roles of electronic structure on the mechanisms for current rectification. The presence of an apical chlorido or phenolato ligand plays a crucial role, and the [Fe(III) {N2 O2 Cl}] species supports an asymmetric mechanism while its [Fe(III) {N2 O3 }] counterpart seems to allow for unimolecular mechanism. The effects of electron-donating and electron-withdrawing substituents in the ligand frameworks are also considered.
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- The ligand 2-(pyrid-2'-yl)-8-(1″,10″-phenanthrolin-2″-yl)-quinoline (ppq) has a unique structure that allows it to effectively bind first-row transition metals like iron (Fe), forming a stable, square planar complex.
- When reacted with FeCl3, ppq forms a μ-oxo-bridged dimer, which has a water molecule bound to one of its metal sites, and this structure, along with a comparison to another ligand (dpa), has been confirmed through X-ray analysis.
- In electrochemical studies, the ppq complex shows a two-electron oxidation process leading to oxygen evolution, with significantly higher
Langmuir-Blodgett films of metallosurfactants were used in Au|molecule|Au devices to investigate the mechanisms of current rectification.
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