distonic ion true OBSOLETE A radical cation or anion in which the charge site and the unpaired electron spin cannot be both formally located in the same atom or group of atoms as it can be with a conventional ion. For example, CH2-OH2+ is a distonic ion whereas the radical cation of methanol, CH3OH+ is a conventional ion. MS This child of the former purgatory term ion chemical type was made obsolete. MS:1000362