Dimensions of the Ozonide Anion in M([18]crown-6)O₃·x NH₃ with M = K (x = 2), Rb (x = 1) and Cs (x = 8)^†

Reaction of alkali metal ozonides (KO₃, RbO₃ and CsO₃) with [18]crown-6 in liquid ammonia yields compounds of the composition M([18]crown-6)O₃·x NH₃ with M = K (x = 2), Rb (x = 1) and Cs (x = 8). The large intermolecular distance between adjacent radical anions in these compounds leads to almost ideal paramagnetic behavior according to Curie's law. Discrepancies concerning the structure of the ozonide anions in the K and Cs compound compared to a former investigation on Rb([18]crown-6)O₃·NH₃ have been resolved by means of DFT calculations and a single-crystal structure redetermination.