3-STATE MODEL FOR 2-ELECTRON TRANSFER-REACTIONS

Much of electron transfer based catalysis relies upon multielectron ra ther than single-electron transfer processes. If the multielectron eve nts proceed through stable one-electron intermediates, conventional th eory describes the events. However, when an unstable one-electron inte rmediate plays a role, when a stable intermediate lives for a brief pe riod of time, or when concerted multielectron events occur, the electr onic coupling and free energy dependence of the rate is distinct from that arising in one-electron theories. We describe several new feature s that can arise in multielectron processes, predict their experimenta l signature, and show how these ideas can be applied to specific exper imental systems.