421-79-4Relevant academic research and scientific papers
Synthesis and polymerisation of fluorinated monomers bearing a reactive lateral group. Part 5 - Radical addition of iodine monobromide to chlorotrifluoroethylene to form a useful intermediate in the synthesis of 4,5,5-trifluoro-4-ene-pentanol
Ameduri,Boutevin,Kostov,Petrova
, p. 117 - 127 (2007/10/03)
The synthesis of the new halogenated alcohol BrCF2CFClCH2CHICH2OH as a precursor of 4,5,5 trifluoro-4-ene pentanol F2C=CFC3H6OH is based on a two-step process. First, the radical addition of iodine monobromide to chlorotrifluoroethylene (CTFE) led to the expected BrCF2CFClI (I) and ICF2CFClBr (II), but also to BrCF2CFClBr (III) and ICF2CFClI (IV), the amount of which determined by 19F NMR depended on the reaction conditions: by feeding CTFE into IBr continuously or in batches; photochemical or thermal initiations, and with various initial [IBr]0/[CTFE]0 molar ratios. In most cases, isomer (I) was mainly produced. The second step concerned the addition of such a mixture to allyl alcohol yielding the polyhalogenoalcohol with a quantitative conversion of (I). The reactivity of different halogeno end-groups of these isomers toward the allyl alcohol was discussed. Reduction of the iodine atom into hydrogen and the halogenated alcohol was accompanied by that of the bromine atom leading to BrCF2CFClC3H6OH and HCF2CFClC3H6OH (V). Dehalogenation of the former alcohol in the presence of zinc led to F2C=CFC3H6OH while dehydrochlorination of (V) into trifluorovinyl hydroxy monomers was achieved in the presence of potassium hydroxide but in poor yields. Strategies starting from the radical additions of iodine monochloride and of iodine monobromide were compared showing that the former led to better overall yields of trifluorovinyl alcohol than the latter.
A new telogen for telechelic oligomers of chlorotrifluoroethylene
Chambers, Richard D.,Greenhall, Martin P.,Wright, Anthony P.,Caporiccio, Gerardo
, p. 87 - 94 (2007/10/02)
Elemental iodine is slightly soluble in liquid chlorotrifluoroethylene (CTFE) under autogenous pressure at room temperature.Exposure of a mixture of no more than 0.22 mol of iodine with 1 mol of CTFE in a borosilicate glass Carius tube to sunlight, an artificial UV source or to γ-radiation resulted in complete conversion of all the solid iodine initially to ICF2CFClI (1), which was isolated and characterised.The reaction is reversible, the equilibrium constant for I2 + CTFEliq ->/- 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)nI (2).The average value of n in the distribution of telomers increased with dose giving liquids (n = 2-4) or greases (n = 2-10) which were much more stable than 1.Upon bromination, individual telomers in the series Br(CF2CFCl)nBr were isolated and characterised. - Keywords: Telogens; Telechelic oligomers; Chlorotrifluoroethylene; NMR spectroscopy; Mass spectrometry; IR spectroscopy
