Bridged Ferrocene-Benzoquinone Complex

In the H NMR spectrum of FcCHCBQH in acetone-c g, two doublets at 5 6.88 and 7.02ppm derived from the vinylene protons of FCCHCHBQH2 disappeared and a new singlet appeared at 6.67 ppm. One of the two singlets at 7.60 and 7.81 ppm, due to nonequivalent hydroxyl protons of FCCHCHBQH2, was not detected in 

In summary, an unusual structural change of a vinylene-bridged ferrocene-hydroquinone compound, FCCHCHBQH2, was observed to occur by two-electron oxidation and two-proton elimination in methanol. The oxidation product, FcCHCBQH, which includes an allene and a quinonoid structure, exhibited a unique proton response, leading to an exchange of the magnetic properties. 

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