Crystal structures of two solvates of (18-crown-6)potassium acetate.

The crystal and mol-ecular strutures of two solvated forms of [K(18c6)]OAc (18c6 = 18-crown-6 = 1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane and OAc = acetate) were determined by single-crystal X-ray diffraction, namely (acetato-κ(2)O,O')(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ(6)O)potassium dihydrate, [K(CH(3)COO)(C(12)H(24)O(6))]·2H(2)O (1) and (acetato-κ(2)O,O')aqua-(1,4,7,10,13,16-hexa-oxa-cyclo-octa-decane-κ(6)O)potassium acetic acid monosolvate [K(CH(3)COO)(C(12)H(24)O(6))(H(2)O)]·CH(3)COOH (2). In both compounds, the acetate anion is bonded to the potassium ion in a chelating fashion and the metal atom is consequently slightly displaced from the O(6) plane of the crown ether. In the crystals, O-H⋯O hydrogen bonds lead to a polymeric ladder structure in the dihydrate 1, while the acetic acid hydrate 2 features inversion dimers.