Crystal structure of cis-anti-cis-di­cyclo­hexane-18-crown-6 aceto­nitrile disolvate

The title compound (systematic name: cis-anti-cis-2,5,8,15,18,21-hexa­oxatri­cyclo­[20.4.0.0(9,14)]hexa­cosane aceto­nitrile disolvate), C(20)H(36)O(6)·2CH(3)CN, crystallizes from an aceto­nitrile solution of di­cyclo­hexane-18-crown-6 on evaporation. The mol­ecule is arranged around a center of symmetry with half the crown ether mol­ecule and one mol­ecule of aceto­nitrile symmetry independent. All O—C—C—O torsion angles are gauche while all C—O—C—C angles are trans. The sequence of torsion angles is [(tg(+)t)(tg(−)t)](3); the geometry of oxygen atoms is close to pseudo-D (3d) with three atoms below and three atoms above the mean plane, with an average deviation of ±0.16 (1) Å from the mean plane. This geometry is identical to that observed in metal ion complexes of di­cyclo­hexane-18-crown-6 but differs significantly from the conformation of a free unsolvated mol­ecule. Each aceto­nitrile mol­ecule connects to a crown ether mol­ecule via two of its methyl group H atoms (C—H⋯O). Weaker inter­actions exist between the third H atom of the aceto­nitrile methyl group and an O atom of a neighbouring crown ether mol­ecule (C—H⋯O); and between the N atom of the aceto­nitrile mol­ecule and a H atom of another neighbouring crown ether mol­ecule. All these inter­molecular inter­actions create a three-dimensional network stabilizing the disolvate.