4-Ethyl-anilinium perchlorate-18-crown-6 (1/1).

The asymmetric unit of the title compound, C(8)H(12)N(+)·ClO(4) (-.)C(12)H(24)O(6), contains one half of the cationic (C(2)H(5)-C(6)H(4)-NH(3))(18-crown-6) moiety and one half of the ClO(4) (-) anion. Two O atoms of the crown ether, four C atoms and the N atom of the ethylanilinium unit and the Cl and two O atoms of the anion lie on a mirror plane. In the crystal structure, the -NH(3) (+) group lies in the 18-crown-6 ring, forming a supra-molecular rotator-stator-like structure linked by intra-molecular N-H⋯O hydrogen bonds. The six O atoms of the crown ether lie approximately in a plane, the mean deviation being 0.1771 (3) Å; the N atom lies approximately 0.855 (3) Å from the centroid of the crown ether ring.