Instantaneous Electron Transfer and Interaction Absorption

ISOTOPIC exchange by electron transfer between complex ions containing an element in different oxidation states has been demonstrated for quite a number of elements. In some instances, such as: the exchange is so rapid as to seem instantaneous 1 . Systems containing an element in two oxidation states sometimes exhibit abnormally deep and intense colorations. For example, crystals of (NH 4 ) 2 SbCl 6 , which are believed to contain the complex ions [SbCl 6 ] 3− and [SbCl 6 ] − , are jet black 2 . The coloration of both solid (NH 4 ) 2 SbCl 6 and its solutions is so much more intense than that produced by the component complex ions separately that it is described as arising from interaction absorption.