Proceedings of the Royal Society of London A Mathematical and Physical Sciences · 1958 · 73 citations · 1 references
Natural SciencesChemistryChemical KineticsOrganic ChemistryPhysical ChemistryChemical Reaction KineticsChemical ReactionsPhotochemical KineticsPhotochemistryRadical ReactionsReaction MechanismsDissociation Rate ConstantsKinetic Data AnalysisPhotochemical Reaction KineticsQuinone ChemistryRate ConstantsSolvent Effects On Reaction RatesTriplet State ChemistryTriplet State Photochemistry
Abstract Kinetic studies of the semiquinone radical, the radical ion and the triplet state of duroquinone in solution are reported. A scheme of reaction is given which is consistent with all the kinetic data and is in excellent agreement with the assignments of part I. Values are obtained for the rate constants of the reactions 2QH. → Q + QH2, 2Q-. → Q + Q2-, QH. → Q-. + H+ and of the constant for the equilibrium (Q-)(H+)/(QH.). It is shown that, in liquid paraffin, the primary reaction with solvent occurs mainly via the excited singlet and not the triplet state. In ethanol, the dissociation of QH. to Q-. and H+ is observed directly and leads to the conclusion that the primary process is one of hydrogen, rather than electron, abstraction.
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