Abstract
Ru(bpy)32+ is shown to form a water-insoluble salt with dodecyl sulfate ions (DS) which is solubilized by sodium dodecyl sulfate (SDS) micelles. In the micelles the rate of the reaction of Ru(bpy)32+ with eaq_ is reduced while its rate of reaction with various metal cations in their reduced form (Zn+, Cd+, Co+) is enhanced. This, as well as the ionic strength effect on these rates, clearly indicates that Ru(bpy)32+ resides in a negatively charged ionic atmosphere. In the presence of.SDS micelles the luminescence from the charge transfer excited state of Ru(bpy)32+ is red shifted as compared to its spectrum in the absence of SDS. Since long-chain alcohols have a similar effect it is concluded that Ru(bpy)32+ must strongly intereact with the hydrocarbon chain of the surfactant. Our kinetic results indicate that essentially all of the Ru(bpy)32+ is bound to the micelles under our experimental conditions. The rates of reaction of the lowest charge transfer excited state of Ru(bpy)32+ in micellar solutions are shown to be faster with Cu2+ ions and slower with Fe(CN)63- ions as compared to the rates of the same reactions in simple aqueous solutions. However, the yield of the redox products of the reaction with Cu2+ that can escape to the bulk of the solution is greatly reduced by the micelles.
Original language | English |
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Pages (from-to) | 117-122 |
Number of pages | 6 |
Journal | Journal of the American Chemical Society |
Volume | 100 |
Issue number | 1 |
DOIs | |
State | Published - 1978 |
Externally published | Yes |