The term can be applied to a reaction in which there is an electron transfer
with the formation of an ionic intermediate.
PAC, 1981, 53, 753
(Symbolism and terminology in chemical kinetics (Provisional))
on page 767
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook