Separation of phenol and cresols by crystalline complexation with 1,1-di(p-hydroxyphenyl)cyclohexane, and crystal structure analyses of the complexes

This paper is concerned with 1:1 inclusion complexes of the 1,1-di(p-hydroxyphenyl)cyclohexane host with either phenol or one of the cresol derivatives as guest. Selectivity studies showed preferential complexation with a guest according to the sequence;m-cresol > p-cresol > phenol > o-cresol. Crystallographic analyses of the four complexes revealed isomorphous structures [crystal data for the phenol complex:a=6.232, b=10.849, c=14.845 Å, α=95.69, β=93.49, γ=104.31°, space group Pl, Z=2]. The intermolecular arrangements are characterized by layers of efficiently hydrogen bonded entities (host-to-host, host-to-guest and guest-to-host) parallel to ab, every OH group being involved in two H-bonds. Organization of the layers along c is stabilized by weak dispersion forces, thus being most sensitive to structural variation of the guest component. The observed features of selectivity upon crystalline complexation are related to differences in topological complementarity between the constituents of each structure.