(18-crown-6)-bis(tetrahydrofuran)potassium iodide

The title compound, [K(C12H24O6)(C4H8O)(2)]I, has iodide anions on crystallographic twofold rotation axes and cations in general positions. The coordination of potassium is distorted hexagonal bipyramidal, with an 18-crown-6 ligand as an equatorial belt and two axial tetralrydrofuran ligands. Distortion is marked, consisting mainly of a significant bending of the axial arrangement [O - K - O = 148.53 (13)degrees] and a shortening of the two equatorial K - O bonds closest to the axial O atoms. This conformation is unprecedented in the previous reports of this cation, with almost thirty different occurrences in nearly twenty crystal structures.