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.