THE 18-CROWN-6 POTASSIUM-SALT OF A MEISSENHEIMER ANION, [K(C7H3CL3N3O6)(C12H24O6)]

The title compound crystallizes as a centrosymmetric dimer, omethyl-1, 3,5-trinitro-2,5-cyclo-hexadien-1-ido)-1 kappa(2)O(1),O-1':2 kappa O-3 ;1 kappa O-3:2 kappa(2)O(1),O-1'-bis[(1,4,7,10,13,16- hexaoxacycloocta decane-kappa(6)O)potassium], [{K(C12H24O6)}(2)(mu-C7H3Cl3N3O6)(2)], in which the coordination of the (18-crown-6)potassium ions is completed by a bidentate para nitro group from one anion and a monodentate orth o nitro group from the other. The CCl3 group is axial and points away from the centre of inversion. The K+ ion is 0.782 (2) Angstrom out of the mean plane of the six crown O atoms.