¹³C and 2D WISE NMR studies of the host mobility in two aromatic complexes of p-tert-butyl-calixarene

Solid-state NMR techniques are used to study the effect of the inclusion of toluene and benzene on the mobility of p-tert-butylcalixarene. We attribute the great increase in host mobility upon complexation to the lack of strong directional intermolecular interactions. The differences in the behaviour of the host in the two complexes are explained in terms of the steric effects of the guest methyl group.