THE USE OF THE METHYL VIOLOGEN NEUTRAL SPECIES AS A MEDIATOR

The use of methyl viologen (MV) neutral species as a mediator for the reduction of CH3I and the methanogenic bacterial nickel-containing cofactor F430 is reported. Solutions of MV0 were generated using a potential step electrolysis procedure in which MV.+ is first generated at -0.6 V (Ag/AgCl) and then MV0 at -1.0 V (Ag/AgCl). The resulting spectrum of MV0 has a prominent peak at 367 nm with a shoulder at 398 nm and no peaks in the 525 to 625 nm region. Spectral and total charge transfer comparisons from spectroelectrochemical experiments as well as cyclic voltammetric studies of MV2+ alone and with CH3I and F430, individually, provide evidence for the MV0 mediated reduction of CH3I and F430. To our knowledge, this represents the first use of MV0 as a mediator for the reduction of another species. © 1990.