title: Three-isotope plot of fractionation in photolysis: a perturbation theoretical expression.
abstract: The slope of the three-isotope plot for the isotopomer fractionation by direct or nearly direct photodissociation is obtained using a perturbation theoretical analysis. This result, correct to first order in the mass difference, is the same as that for equilibrium chemical exchange reactions, a similarity unexpected a priori. A comparison is made with computational results for N2O photodissociation. This theoretical slope for mass-dependent photolytic fractionation can be used to analyze the data for isotopic anomalies in spin-allowed photodissociation reactions. Earlier work on chemical equilibria is extended by avoiding a high-temperature approximation.
authors.affiliation: Noyes Laboratory of Chemical Physics MC 127-72, California Institute of Technology, Pasadena, California 91125, USA. meher@caltech.edu
authors.forename: M K
authors.initials: MK
authors.lastname: Prakash
authors.forename: R A
authors.initials: RA
authors.lastname: Marcus