On the quenching of MLCT luminescence by amines: The effect of nanoaggregation in the decrease of the reorganization energy

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• 作者：Larisa L.B. Bracco ; Mario R. Fé ; liz ; Ezequiel Wolcan
• 关键词：Amines ; Rhenium ; MLCT ; Quenching ; Spin– ; orbit coupling
• 刊名：Journal of Photochemistry and Photobiology A: Chemistry
• 出版年：2010
• 出版时间：5 February 2010
• 年：2010
• 卷：210
• 期：1
• 页码：23-30
• 全文大小：563 K

文摘

The MLCT luminescence quenching of pyRe(CO)₃bpy⁺ and/or the polymer {[(vpy)₂-vpyRe(CO)₃bpy]CF₃SO₃}_n–200 by amines proceeds via an electron transfer reaction which produces amine radical cations and pyRe^I(CO)₃(bpy)/–Re^I(CO)₃(bpy), respectively. The quenching follows a typical Stern–Volmer kinetics for both pyRe(CO)₃bpy⁺ and {[(vpy)₂-vpyRe(CO)₃bpy]CF₃SO₃}_n–200. The observed rate constants for the quenching of the Re^I-polymer luminescence by amines show “vestiges” of the inverted effect predicted by Marcus while the quenching of pyRe(CO)₃bpy⁺ luminescence follow the Rehm–Weller type of behavior. The lower value obtained for the total reorganization energy of the Re^I-polymer than that for pyRe(CO)₃bpy⁺ is rationalized in terms of the retarded solvent motions inside the nanoaggregates formed by the Re^I-polymer in acetonitrile solutions.