Hydronium bis(trifluoromethanesulfonyl)amide–18-crown-6 (1/1)

Abstract

The structure of the title compound, H3O+·C2F6NO4S2−·C12H24O6 or [H3O+·C12H24O6][N(SO2CF3)2−], which is an ionic liquid with a melting point of 341–343 K, has been determined at 113 K. The asymmetric unit consists of two crystallographically independent 18-crown-6 molecules, two hydronium ions and two bis(trifluoromethanesulfonyl)amide anions; each 18-crown-6 molecule complexes with a hydronium ion. In one 18-crown-6 molecule, a part of the ring exhibits conformational disorder over two sets of sites with an occupancy ratio of 0.533 (13):0.467 (13). One hydronium ion is complexed with the ordered 18-crown-6 molecule via O—H...O hydrogen bonds with H2OH...OC distances of 1.90 (6)–2.19 (7) Å, and the other hydronium ion with the disordered crown molecule with distances of 1.85 (6)–2.36 (6) Å. The hydronium ions are also linked to the anions via O—H...F hydrogen bonds. The crystal studied was found to be a racemic twin with a component ratio of 0.55 (13):0.45 (13).

Keywords

• crystal structure
• hydronium
• crown ether
• complex cation
• ionic liquid