Pyrazole has two ring nitrogen atoms in which N1 is pyrrolic and N2 is pyridine-like. The N1 nitrogen is not reactive but is deprotonated in the presence of a base-forming anion. Protonation of pyrazole in weak carboxylic acids leads to pyrazolium ionic liquids. Pyrazolium ionic liquids are structural isomers of imidazolium ionic liquids. Unlike ammonium and imidazolium ionic liquids that are yellowish, only pyrazolium ionic liquids are clear, colorless liquids. Pyrazolium based ionic liquids are great candidates for battery electrolytes...
