Abstract: Electroredox behaviour of alkyl viologens and polyviologens has been investigated by using differential pulse polarography.The alkyl groups of viologen compounds influence the reduction potentials and the film forming property of reduced products on the electrode.Compared with the low molecular alkyl viologen compounds, the first reduction potentials (E₁) of alkyl polyviologens are rather positive, the potential differences(△E)of two-step reduction potentials are larger.The halogen anions of supporting electrolytes influence the reduction potentials of viologen compounds, the order is I^->Br^->Cl^->F^-.

Key words: Alkyl viologen, Alkyl polyviologen, Differential pulse polarography, Reduction potential