Crystal structure of the inclusion complex 25-benzo-ylmeth-oxy-5,11,17,23-tetra-tert-butyl-26,27,28-trihy-droxy-2,8,14,20-tetra-thia-calix[4]arene-tetra-ethyl-ammonium chloride (1/1).

The asymmetric unit of the title compound, C48H54O5S4·N(C2H5)4 (+)·Cl(-), contains two tetra-tert-butyl-[(benzo-yl)meth-oxy]-trihy-droxy-tetra-thia-calix[4]arene mol-ecules, two tetra-ethyl-ammonium cations and two chloride anions. The two calixarene molecules in the asymmetric unit each display a cone conformation. There are no significant differences between the two independent molecules. The guest species do not sit within the calixarene 'buckets'. In the crystal, extensive O-H⋯O, O-H⋯S and O-H⋯Cl hydrogen bonds and weak C-H⋯O, C-H⋯S and C-H⋯Cl inter-actions link the thia-calixarene mol-ecules, tetra-ethyl-ammonium cations and chloride anions, forming a three-dimensional network encompassing channels running parallel to the a-axis direction. The structure contains a solvent-accessible void of 76†(3)†à (3), but no solvent mol-ecule could reasonably be located. The crystal studied was an inversion twin with a 0.57†(8):0.43†(8) domain ratio.