Molecular inclusion in functionalized macrocycles. Part 6. The crystal and molecular structures of the calix[4]arene from p-(1,1,3,3-tetramethylbutyl)phenol and its 1 : 1 complex with toluene
The cyclic tetramer (1a) isolated from the reaction mixture of the base-catalysed reaction of p-(1,1,3,3-tetramethylbutyl)phenol and formaldehyde crystallizes from acetone without including the solvent whereas in the presence of toluene a 1 : 1 complex between (1a) and toluene is formed. Crystals of the empty phase are monoclinic, space group P21/a, a= 12.753(8), b= 38.778(16), c= 11.370(7)Å, β= 101.98(9)°, Z= 4, final R value 0.092; the toluene complex is orthorhombic, space group Fmm2, a= 21.227(16), b= 21.227(17), c= 14.522(14)Å, Z= 4, final R value 0.069. The macrocycle exists in the cone conformation both in the empty form and in the complex, where the guest molecule occupies intermolecular cavities of channel type in the host lattice.