Single Crystal to Single Crystal Transformation and Hydrogen-Atom Transfer upon Oxidation of a Cerium Coordination Compound

Trivalent and tetravalent cerium compounds of the octamethyltetraazaannulene (H2omtaa) ligand have been synthesized. Electrochemical analysis shows a strong thermodynamic preference for the formal cerium­(IV) oxidation state. Oxidation of the cerium­(III) congener Ce­(Homtaa)­(omtaa) occurs by hydrogen-atom transfer that includes a single crystal to single crystal transformation upon exposure to an ambient atmosphere.