Perfluorobenzene complex

That charge-transfer effects are not involved follows from the fact that the rate of triplet decay in perfluorobenzene is larger than that in benzene. If the benzophenone triplet were to act as acceptor and the benzene derivative as donor in a charge-transfer complex, the substitution of perfluorobenzene for benzene should render this type of process much less probable due to the strongly electron-withdrawing character of the fluorine atoms. 

Zirconocene complexed with activated magnesium159 reduces perfluorobenzene to 1.2,4,5-tet-rafluorobenzene (4) (for the procedure159 see Section 2.1.1.1.). The quantitative generation of pentafluorobenzene is observed by l9F NMR spectroscopy prior to the formation of 4 and deuterium incorporation when performed in tetrahydrofuran-r/8. Unlike more reactive substrates. perfluorobenzene does not exhibit any reactivity toward activated magnesium in the absence of zirconocene.159... 

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