1-[1,4-Bis(but-3-en-1-yl-oxy)]-2,3,4,5-(1,4-dimeth-oxy)pillar[5]arene-1,4-di-bromo-butane 1:1 inclusion complex.

In the title compound, C 51 H 58 O 10 ·C 4 H 8 Br 2 , both the host and guest are completed by crystallographic twofold symmetry (one carbon atom of the host lies on the rotation axis). The penta-gonal-shaped macrocycle has a pair of butene-oxy substituents on one of its faces and one mol-ecule of 1,4-di-bromo-butane is encapsulated within the cavity of the pillararene, forming a 1:1 inclusion complex. The terminal alkene parts, which project outwards from the pillararene ring, exhibit positional disorder over two sets of sites in a 0.52 (2): 0.48 (2) ratio. The host and guest inter-act via C-H⋯O, C-H⋯Br and C-H⋯π inter-actions and adjacent host mol-ecules inter-act via C-H⋯O and C-H⋯π bonds.