ELECTRON-TRANSFER REACTIONS OF BIS[DICARBONYL(PENTAMETHYLCYCLOPENTADIENYL)IRON] WITH 2,3-DICHLORO-5,6-DICYANOBENZOQUINONE

The thermal and photochemical reactions of [(C5Me5)Fe(CO)2]2 with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) yield the binuclear complex {[(C5Me5)Fe(CO)2]2.(DDQ)2}. EPR studies using nitroso spin traps support the conclusion that the primary products are [(C5Me5Fe(CO)2]+ radicals. The metal-centered radical transfers an electron to DDQ acceptor to yield {[(C5Me5)Fe(CO)2]2.(DDQ)2} as the only Fe-containing product. Spectroscopic evidence for dimerization of DDQ- to form diamagnetic [DDQ]2(2-) in the solid is discussed.