An example is the variational transition-state theory treatment of reactions like fluorine atom loss or singlet-CF 2 dissociation from n-perfluoroalkyl radicals or the dissociation of the carbon-sulfur bond in perfluorinated sulfonic acids, using bond-stretching coordinates and single-reference density functional methods by Altarawneh and co-workers. While these reactions may be relevant to PFAS thermal decomposition, the series of carbon-carbon bond scissions (and their reverse associations) within perfluoroalkyl chains indicated to be important by bond dissociation energies have not been studied thoroughly. Wardlaw and co-workers have carried out a theoretical study of 2 CF 3 --→ ←--C 2 F 6 using canonical flexible transition state theory, but more refined theoretical studies of this reaction and studies of the size dependence of perfluoroalkyl radical combinations have not been published to our knowledge.