Low-temperature enantiotropic k2 phase transition in the ionic 222-cryptand complex with LiClO4.

Crystallographic analyses at 100 and 200 K are reported for the macrobicyclic polyether 4,7,13,16,21,24-hexaoxa-1,10-diaza-bicyclo[8.8.8]hexacosane (denoted as 222-cryptand) that encapsulates a Li+ cation and then forms a complex (I) with ClO4-. Compound (I) undergoes a reversible second-order k phase transition at 253 (2) K from an almost ordered structure… (More)