A chlorophobic pocket in the p-tert-butylcalix[4]arene cavity: a test site for molecular recognition investigated by 13C CP MAS NMR and X-ray crystallography†
Abstract
Five-membered aliphatic guests X(CH2)3Y (X, Y = Me, OH, Cl, Br) adopt equilibrium positions in the asymmetric p-tert-butylcalix[4]arene cavity formed in the solid state and reveal a marked aversion of the host pocket for halogen end-groups.