In the interest of developing a complete high fidelity combustion kinetics model for PFAS, we have undertaken a study of reactions R1 -R5 below. Reactions R1 -R4 are the association reactions of the C 1 -C 3 unbranched n-perfluoroalkyl radicals to form the C 2 -C 4 unbranched n-perfluoroalkanes. Reaction R5 is the bimolecular well-skipping reaction over the C 4 F 10 well.