2.1 Organic Electron Donors in Electron-Transfer Reactions

Abstract

The field of organic electron donors is large and diverse, both in terms of the structures of the donors and the structures of the acceptors. In the past 15 years, organic donors have been developed that show remarkable strength, with ground-state or excited-state oxidation potentials rivalling even the most reactive metals. At the other end of the scale of reactivity, highly reactive oxidizing agents are now available upon photoactivation of a number of organic structures. The first part of this chapter reviews organic electron donors that are based upon an alkene that is activated by strongly electron-releasing substituents; these donors can be active in the ground and/or excited states. The chapter also covers anionic organic donors that emerged in the field of SRN1 and base-induced homolytic aromatic substitution (BHAS) reactions, as well as substrate-based anionic donors including borates and silicates. The use of photoexcited organic dyes as electron donors is described and, finally, some of the recent research with very weak organic donors is highlighted.