The physicochemical properties of novel four tri-n-butylalkylphosphonium- based room-temperature ionic liquids (RTILs), tri-n-butylmethylphosphonium dimethylphosphate ([P4,4,4,1][DMP]), tri-n-butyl(2-hydroxymethyl) phosphonium bis(trifluoromethylsulfonyl)amide ([P4,4,4,2OH][Tf 2N]), tetra-n-butylphosphonium O,O′-diethylphosphorodithioate ([P4,4,4,4][DEPDT]), and tri-n-butyldodecylphosphonium 3,5-bis(methoxycarbonyl)benzenesulfonate ([P4,4,4,12][MCBS]), were examined in this study. All RTILs showed a favorable thermal decomposition temperature exceeding 560 K. Of these, [P4,4,4,12][MCBS] exhibited a fairly high thermal stability compared with common phosphonium cation-based RTILs reported to date. Interestingly [P4,4,4,1][DMP] formed an ionic plastic crystal phase within a range of 279-290 K, but that was not the case with [P4,4,4,4][DEPDT], which is similar in the cation and anion structures to the [P4,4,4,1]+ and [DMP]-. [P4,4,4,2OH][Tf2N] showed a relatively high conductivity of 0.48 mS cm-1 at 303 K among the RTILs consisting of tri-n-butylalkylphosphonium cation and usual fluoroanion.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry