A NEW TELOGEN FOR TELECHELIC OLIGOMERS OF CHLOROTRIFLUOROTHYLENE

Elemental iodine is slightly soluble in liquid chlorotrifluoroethylene (CTFE) under autogenous pressure at room temperature. Exposure of a m ixture of no more than 0.22 mol of iodine with 1 mol of CTFE in a boro silicate glass Carius tube to sunlight, an artificial UV source or to gamma-radiation resulted in complete conversion of all the solid iodin e initially to ICF2CFCII (1), which was isolated and characterised. Th e reaction is reversible, the equilibrium constant for I-2+ CTFE(liq). reversible arrow 1 being ca. 0.22. Thus with light or heat, isolated unconfined 1 reverted to iodine and CTFE. Additional irradiation of 1 confined with excess liquid CTFE led to the irreversible formation of telomers I(CF2CFCl)(n)I (2). The average value of n in the distributio n of telomers increased with dose giving liquids (n = 2-4) or greases (n = 2-10) which were much more stable than 1. Upon bromination, indiv idual telomers in the series Br(CF2CFCl)(n)Br were isolated and charac terised.