Phosphonium ionic liquids based on bulky phosphines: synthesis, structure and properties (original) (raw)

A series of new ionic liquids based on sterically hindered decyl(tri-tert-butyl)phosphonium (DTBP) or decyl(tricyclohexyl)phosphonium (DCHP) cations were prepared using quaternisation of tri-tert-butylor tricyclohexylphosphine with decylbromide and subsequent bromide exchange with the weakly-coordinating anions BF 4 -, PF 6 -, SO 3 CF 3 -, N(SO 2 CF 3 ) 2 -. The salts obtained melt below 100 • C and possess a broad electrochemical window. Density functional theory combined with X-ray crystallography, IR and Raman spectroscopy has been used to analyze the molecular and supramolecular structures of the compounds obtained and their possible influence on their physical properties.