Abstract:
Data characterising the contribution of electron transfer processes to the stereochemistry of reactions of organic compounds are discussed and the stereochemical changes accompanying electron transfer are analysed. It is shown that the decrease of the barrier to rotation in electron transfer facilitates the cis–trans isomerisation of ethylenes and an increase of the difference between the energies of the rotational isomers of certain radical-ions relative to neutral molecules decreases the rate of mutual rotation. The influence of the formation of ion pairs by the anionic and cationic components of the radical-ion salts on the stabilisation of unusual geometrical forms of the molecule is discussed. The conversion of cyclopolyenes into ionic forms with a ring current of delocalised electrons, which fixes the ring atom in a single plane, is considered as a special case of electron transfer. The chemical and physical properties of cyclo-octatetraene, azocine, and their ionic forms are compared. The bibliography includes 143 references.