An insight into ion-transport by calixarenes; the structure of the dipotassium complex of p-tert-butylcalix[8]arene crystallised from a protogenic, coordinating solvent [ethanol/diethylcarbonate (10:1)]

The structure of the dipotassium complex of the dianion of p-tert-butylcalix[8]arene crystallised from a protogenic, coordinating solvent (ethanol–diethylcarbonate, 10:1) shows that the metal ions are bound above and below the cavity of the calix[8]arene, which adopts a ‘pinched’ conformation.