Molecular inclusion in functionalized macrocycles. Part 9. The crystal and molecular structure of p-t-butylcalix[4]arena–anisole (2 : 1) complex: a new type of cage inclusion compound

Abstract

p-t-Butylcalix[4]arene (1a), the cyclic tetramer obtained by the condensation of p-t-butylphenol and formaldehyde, crystallizes from anisole forming a new type of cage inclusion compound with the solvent. Crystals having a 2 : 1 host–guest stoicheiometry are tetragonal, space group P4/n, a=b= 12.823(6); c= 25.618(8)Å, Z= 2, final R values 0.073. Two molecules of the macrocycle, in the cone conformation, face the methyl groups of the para-substituents creating a closed cavity which encapsulates one molecule of anisole. The guest is disordered in the cavity in at least eight equivalent orientations.