Abstract
The solvation properties of some room-temperature ionic liquids (RTILs) and the solvent effect on bimolecular fluorescence quenching reaction have been examined at high pressures ranging from 0.1 to 300 MPa. It is found that Kamlet-Taft parameters (π*, β) are sensitive to the type of anions, but not so dependent on the type of imidazolium cations consisting of RTILs. The pressure dependence of microviscosity is found to obey the empirical power-law equation. It is revealed that the rate constant for bimolecular fluorescence quenching reaction is significantly higher than theoretical rate constant of diffusion estimated from microviscosity, suggesting the occurrence of microscopic free space within RTILs which may facilitate the solute diffusion.
