I. W. Lawston, M. W. Smith, N. Stansfield
Aug 1, 1992
Citations
0
Influential Citations
2
Citations
Journal
Journal of Fluorine Chemistry
Abstract
Abstract 3-Chloropentafluoropropene ( 1 ) is useful in the production of co-polymers [ U.S. Pat. 3 047 639 (1962) to W.J. Cunningham, R.F. Sweeney and C. Woolf] and elastomers [G.L. Kann and S. Smith, Eur. Polym. J., 24 (1988) 411] or as a precursor to (chlorodifluoromethyl)trifluorooxirane [J. Kvicala and O. Paleta, XIIIth Int. Symp. Fluorine Chemistry, Bochum, September, 1991; Abstr. J. Fluorine Chem., 54 (1991) 69]. It has also been reported that 1 is highly toxic [M. Thun and R.D. Kimbrough, Clin. Toxicol., 24 (1981) 481]. Part of the role of our laboratory is to assess the hazard posed to users, and the public, of toxic industrial, agricultural and pharmaceutical chemicals. To that end we have assessed the ability of activated carbon filters to remove 1 from contaminated airstreams. Compound 1 is poorly retained on standard activated carbon filters and, in contrast to pentafluoro-2-(trifluoromethyl)propene [C.R. Hall, I.W. Lawston and A.M. Tinsley, Chem. Ind. (London), (1989) 145], does not react rapidly with water adsorbed on the surface of BPL carbon. The incorporation of 1% 1,4-diazabicyclo[2.2.2]-octane (TEDA) onto BPL carbon reduces the amount of 1 in the effluent airstream considerably, but leads to the formation of hexafluoropropene (2) as the only volatile reaction product detected in the effluent airstream. This conversion involves the hydrolysis of 1, promoted by TEDA, on the carbon surface to generate fluoride ion. It is nucleophilic attack of fluoride ion on 1 that is responsible for the generation of 2. The reaction pathway, which is complex, will be described in detail.