Date of Graduation

Fall 5-22-2015

Document Type

Thesis

Degree Name

Master of Science in Chemistry

College/School

College of Arts and Sciences

Department/Program

Chemistry

First Advisor

Jeff C. Curtis

Abstract

Chapter 1 describes an overview of electron-transfer reactions. The kinetic equations for ET reactions have also been described in detail.

Chapter 2 describes a series of novel kinetic accelerations which deviate strongly from the predictions of the classical Debye-Huckle theory with a range of different added “inert” electrolytes. The greater catalytic effects seen with the heavier halides and other catalytic electrolytes (especially certain dicarboxylates) indicate an important role for hole-transfer superexchange in the ET transition state. The hypothesis of a catalytic ternary association complex, [RuII--X--RuIII] has also been explored by kinetic modeling of the reaction. An increasing ratio of anion-catalyzed ketx to uncatalyzed ket is obtained when proceeding down the halide series. Activation parameters show a strong enthalpy-entropy compensation effect according to the identity of the added halide. Interestingly, the enthalpy activation decreases successively upon going to the heavier halides and in fact ∆H becomes negative in the most extreme case of added I-.

Chapter 3 describes a detailed study of electrolyte effects on the position and band shape of the intervalence charge transfer (IVCT) band of dimeric systems in aqueous solution such as (NH3)5RuII-(bis-bipyridylethylene)-RuIII(NH3)5(5+). Unexpectedly, the energetics of optical electron transfer blue shift upon adding F- but red shift upon adding other halides. This interesting observation correlates with the known water structure “making” or “breaking” effects of the added halide anions

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