Solvatochromic parameters of imidazolium-, hydroxyammonium-, pyridinium- and phosphonium-based room temperature ionic liquids

JUAN M. PADRÓ; RETA, MARIO

JOURNAL OF MOLECULAR LIQUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 213 p. 107 - 114

0167-7322

Solvatochromic solvent parameters of different room temperature ionic liquids based on the imidazolium,hydroxyammonium, pyridinium and phosphonium cations, namely 1-butyl-3-methyl imidazoliumhexafluorophosphate, 1-hexyl-3-methyl imidazolium hexafluorophosphate, 1-octyl-3-methyl imidazoliumhexafluorophosphate, 1-octyl-3-methyl imidazolium tetrafluoroborate, N-octylpyridinium tetrafluoroborate, 2hydroxyethylammoniumformate, 2-hydroxypropylammonium formate, trihexyl-(tetradecyl)phosphoniumchloride, trihexyl-(tetradecyl)phosphonium bromide, trihexyl-(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imideand trihexyl-(tetradecyl)phosphonium dicyanamide were determined at 25 °C usingUV?Vis spectroscopy. Specifically, we have measured the Kamlet?Taft parameters: α (hydrogen-bond donoracidity), β (hydrogen-bond acceptor basicity), π* (dipolarity/polarizability) and the Reichardt´s normalized polarityparameter, ETN.In previous works, we employed the Solvation Parameter Model to predict the partition coefficients for compoundsof biological and pharmacological interest and to elucidate the chemical interactions involved in the partitionprocess of different probe molecules between water and different types of ionic liquids. In this work, wehave used the obtained solvatochromic solvent parameters to explain and understand the relative magnitudesof the chemical interactions obtained with the solvation parameter model.