Effect of a cationic guest on the characteristics of the molecular capsule of resorcinarene: A diffusion NMR study

[GRAPHIC] NMR diffusion measurements were used to probe the differences in the characteristics of the hexameric capsule of [c]-undecane resorcin[4]arene (1b) in a CDCl3 solution in the absence and presence of tetrahexylammonium bromide (THABr). It was found that the nonencapsulated THABr forms a 1:1 complex with 1b, which is in fast exchange with its constituents. We found that water molecules seem not to participate in the construction of the THABr hexameric capsule of 1b in a CDCl3 solution, in contrast to the finding in the absence of THABr, where the major species in CDCl3 seems to be [(1b)(6)(H2O)(8)].