The crystal and molecular structure of [H3O·18-crown-6]2[ReCl6] 1 is reported. Crystal data for 1: trigonal, space group R 3, a = 13.857(2) Å, c = 10.154(2) Å, Dc = 2.85 g/cm3, Z = 3, Rf = 0.073, Rw = 0.064. The oxonium ion is observed to be crystallographically disordered lying 0.37 Å on both sides of the plane defined by the crown ether oxygen atoms. The anion resides on a crystallographic 3 position forming a slightly distorted octahedron.</p
