Perfluorolefins react with silver fluoride in acetonitrile (under nitrogen stream) at room temperature forming perfluoroalkyl silver compounds which are more thermally stable than silver alkyls, soluble in organic solvents and can be isolated in the form of solvates. [2] Thermal decomposition of silver perfluoroalkyls occurs mainly by the formation of free radical (i.e. dimerization) products of perfluoroalkyls and Ag(0). Perfluoroalkyls are sensitive to water, HCl, Br2 and other reagents [[i]]
The silver perfluoroalkyl synthesis reaction proceeds as follows: AgF + C = C → FC-CAg (nucleophilic binding). For example, the reaction of perfluoropropene (CF3-CF = CF2) with silver fluoride in acetonitrile gives perfluoroisopropyl silver which can be isolated in the form of acetonitrile adduct by evaporation at 60 ° C in the form of (CF3) 2CF-Ag (CH3CN). When heated at 100 ° C for 1.5 hours, this solvate decomposes practically completely to form metallic silver and (CF3) 2CF-CF (CF3) 2. Perfluoroisopropyl silver can be dissolved in tetraglyme, dimethylformamide and benzonitrile.
2-Chloroperfluoropropene reacts with AgF analogously to (CF3) 2CClAg, which decomposes at 100°C to give metallic silver and (CF3)2CCl-CCl(CF3)2.
Similarly, perfluoro-1,1-dimethylbutyl silver CF3CF2CF2C (CF3) 2Ag was obtained, but no data on its thermal stability were provided.
MOCVD application
The decomposition of silver
perfluoroalkyls forming metallic silver can be potentially applied for the deposition of metallic silver films by MOCVD.
[i] W.T.Miller, R.J.Burnard J.Amer.Chem.Soc., 1968, 90, 7367 , “Perfluoroalkylsilver compounds”