COMPLEXES OF CROWN-ETHERS WITH PERFLUOROCARBOXYLIC ACIDS AND THEIR THERMAL DECARBOXYLATION

Crown ethers form strong proton-acceptor complexes with CF3COOH or C4F 9COOH that undergo thermal decarboxylation at 200-260-degrees-C which results in 60-80 % of CF3H or C4F9H (including up to 20 % of a mixture of C4F8). Critical parameters of the process were determined in relat ion to the temperature and amount of crown ether. The relative activit ies of different crown ethers in decarboxylation were also established . A scheme is proposed that explains the effect of the structure of cr own ethers on this reaction. The data obtained substantiate the view t hat the ''topological correspondence'' concept is insufficient to expl ain the ability of crown ethers to form complexes with cations.