Study of the Counter Anions in the Host-Guest Chemistry of Cucurbit[8]uril and 1-Ethyl-1′-benzyl-4,4′-bipyridinium

Figure 2

From bottom to up, ¹H NMR spectra for BEV-Cl₂ alone, 1 : 1 including complexes of BEV-Cl₂/CB[8], BEV-Br₂/CB[8] and BEV-I₂/CB[8], respectively, and the schematic representation of the assembly of BEV²⁺/CB[8].