were less effective. The comparison of H-TEDA(BF 4 ) 2 and TFA here tracks well with Table . correlates directly with the amount of SF ® . In contrast, ion pair aggregation can occur without chemical shift changes as observed in previous investigations. To verify whether there are specific intermolecular interactions between the components, we performed 1 H 1 H NOESY, 1 H 1 H ROESY and 1 H F HOESY experiments at lower temperatures (230 K). These low temperatures are applied to inhibit exchange processes and promote preferred conformations.