Ferrocene derivatives anion-radicals

Transition metal paramagnetic complexes that warrant further comment are the radical anions derived from metallocene- (especially ferrocene-) ketyls and related species, such as compounds IX (61), X (45), or XI (146), and metallonitroxides. From the ESR spectra of compounds... 

Calculations have been carried out on the spectroscopy and excited-state energies and geometries of polyenes,84 the 1,5-cyclo-octadiyne radical cation,85 the visual chromophore, ll-c/s-retinal,8 polyene carbaldehydes,87 aromatic hydrocarbon anions and cations,88 trimethylenemethane,89 thiamine derivatives,80 porphyrins,91 lumiflavin,92 chlorophyll,93 nucleic acids,94 and ferrocene.95... 

Although boranes still produce exciting new molecular species like water-stable B(C6Cl5)3 and associated one-electron reduced radical anions, most work in electroanalytical mechanisms is focused on boronie acid derivatives with a more or less strong interaction with a redox active reaction centre. The most literature-abundant redox active boronie acid is ferrocene-boronic acid (as synthesised first by Nesmeyanov ) with a range of selective redox label applications. 

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