Figure 1. Eight anions and five cations were combined to make up the forty ionic pairs. Starting from the top left: hexafluorophosphate, chloride, bromide, iodide, tetracyanoborate, tetrafluoroborate, bis(fluorosulfonyl)imide, bis(trifluoromethylsulfonyl)imide. Bottom row represents the cations: triethylpropyl-ammonium, 1-butyl-pyridinium, 1-butyl-1-methylpyrrolidinium, 1-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium.