Carbon Dioxide as a Solubility “Switch” for the Reversible Dissolution of Highly Fluorinated Complexes and Reagents in Organic Solvents: Application to Crystallization

Highly fluorinated organic or organometallic solid compounds can be made to dissolve in liquid hydrocarbons by
the application of 20−70 bar of CO2 gas. Subsequently releasing the gas causes the compounds to precipitate or
crystallize, giving quantitative recovery of the solid. The resulting crystals can be of sufficient quality for single-crystal X-ray crystallography; the structures of Rh2(O2CCF2CF2CF3)4(DMF)2, Rh2(O2C(CF2)9F)4(MeOH)2, Cr(hfacac)3,
and P{C6H3(3,5-CF3)2}3 have been determined from crystals grown in this manner.