Liquid-Liquid Phase Separation of Viologen Bistriflimide/Benzene Mixtures: Role of the Dual Ionic and Organic Nature of Ionic Liquids.

Liquid-liquid phase separation occurs at room temperature when mixing an excess of benzene with solid viologen bistriflimide salts with various alkyl side-chain lengths. A liquid phase composed of (almost) pure benzene is above the other sponge-like liquid phase with salt absorbed in benzene. Nuclear magnetic resonance experiments indicate that the mole ratio of benzene/salt in the sponge-like phase remains unchanged upon varying the amounts of (nonexcessive) salt or benzene.