Production of chemically activated fluoroalkanes by direct fluorination

Abstract

Ethane, ethyl fluoride, ethyl chloride and 1,1-difluoroethane have been fluorinated by reaction with molecular fluorine at very large RH/F₂ ratios to give the monosubstituted product in each case. The reaction step R + F₂= RF*+ F is exothermic enough to deposit in the newly formed fluoride enough energy for it to eliminate hydrogen halide RF*= alkene + HF (and HCl in the case of chlorofluoroalkanes). Measurement of the rate constants of this reaction as a result of monofluorination of the compounds above gave [graphic omitted] assuming that ω= 10⁷ s^–1.

The relative rates of attack of fluorine atoms on C(1) or C(2) atoms in C₂H₅Cl, C₂H₅F and 1,1-C₂H₄F₂ have also been obtained.