AN INCLUSION COMPLEX OF URANYL IN A DIAZACROWN - (DIAZA-18-CROWN-6)(2-) AND [UO2(DIAZA-18-CROWN-6)](+).CF3SO3-().2CF(3)SO(3)()

The structures of two compounds involving the macrocycle 1,4,10,13-tet raoxa-7,1 6-diazacyclooctadecane (diaza-18-crown-6, C12H26N2O4) are re ported. In 1,4,10,13-tetraoxa-7,16-diazoniacyclooctadecane bis(trifluo romethanesulfonate), C12H28-N2O42+.2CF(3)SO(3)(-), (I), the two N atom s are protonated, resulting in a ring conformation different to that o f the neutral crown. The second compound, 3-tetraoxa-7,16-diazocyclooc tadecanido(1-)]uranium trifluoromethanesulfonate, [UO2(C12H25N2O4)]CF3 SO3, (II), is composed of [UO2(diaza-18-crown-6)](+) cations and CF3SO 3- anions. The linear uranyl moiety is included into the macrocycle wi th hexagonalbipyramidal coordination geometry; one of the N atoms is d eprotonated and the two N atoms are thus at different distances from t he U atom and have different geometries.