Addition of perfluoroolefins to trifluoromethyl hypofluorite for the preparation of low molecular weight perfluorinated oxygen containing fluids kinetics and byproducts.

Author(s): VENTURINI F., METRANGOLO P., RESNATI G., NAVARRINI W., TORTELLI V.

Source: Chimica Oggi – Chemistry Today.

Volume: 26 Pages: 36-38. Published: Aug. (2008).

ABSTRACT:

The products deriving from the addition of CF2=CFOCF3 to CF3OF are proved to be low Ostwald coefficient fluids suitable for producing high stable micro bubbles that can be used as ultrasound imaging contrast agents. The standard gas-liquid fast radical chain reaction between trifluoromethyl hypofluorite CF3OF and reactive perfluoroolefins like CF2=CFOCF3produces oligomerization and dimerization byproducts. Therefore a purification procedure is needed in order to separate the low Ostwald coefficient products from the reaction mixture. Surprisingly we have found that the selectivity of the reaction can be increased by modifying the experimental reaction conditions adopted. This behaviour is an experimental evidence for the presence of two different reaction schemes that can be switched by tuning the hypofluorite concentration in the reaction media.