The Mechanism of Fluorination IV
The effect of temperature and of fluorine concentration upon the olefin dimerization reaction. A new fluorination apparatus
The interrelated effects of temperature and fluorine concentration on fluorine-olefin reactions have been investigated with some perhaloolefins. Reactions were carried out at low temperatures in a new apparatus which was equipped with a novel high speed nickel gauze stirrer, gas disperser. Reproducible results were obtained with weight recoveries of 95% or better. With CF3CF=CFCF3, increasing the effective fluorine concentration greatly reduced the formation of dimer addition product relative to simple addition product. Lowering the reaction temperature had a similar effect due to reduction in the rate of the fluorine-olefin free radical initiation reaction. Related experiments with CClF=CClF, CF2=CCl2, and CF2=CClF, and a mixture of CF3CF=CFCF3 and CClF=CClF, are also reported. With CF2=CClF the fluorine-olefin reaction was diffusion rate-controlled at temperatures as low as -150°. The observed effects of reaction conditions on product composition, are shown to be consistent with the general free radical mechanism previously presented for fluorine-olefin reactions and to provide a guide for the choice of synthesis conditions. The liquid phase fluorination procedure described is considered suitable for general use.
W. T. Miller et al., "The Mechanism of Fluorination IV," Journal of the American Chemical Society, American Chemical Society (ACS), Jan 1964.
The definitive version is available at http://dx.doi.org/10.1021/ja01055a013
Article - Journal
© 1964 American Chemical Society (ACS), All rights reserved.