Redox reactions are prevalent for the transition elements.  Two classes of redox reaction are considered: atom-transfer reactions, such as oxidative addition/reductive elimination, and electron-transfer.  A fundamental redox reaction is "self-exchange", which involves the degenerate reaction between an oxidant and a reductant.  For example, permanganate and its one-electron reduced relative manganate exchange one electron:
:[MnO] +  [Mn*O]  →  [MnO] +  [Mn*O]