Fig. 7. Evolution of proton resonances in the variable temperature NMR study (a) for PF₆ ^– and (b) for SbF₆ ^–. The cycHC[8] and guest concentrations were 2.6 mM and 1.5 mM in MeOD solution, respectively. At 218 K, the hydrogen signals labelled with blue arise from the host–guest complex and black ones from the free host.