Abstract The synthesis is reported of NN′-alkylated α, α′-, β, β′ and γ, γ′-bipyridylium diiodides (Type I), and of N, N′-alkylated α, α′-, β, β′-and γ, γ′-bipiperidylium diiodides (Type II) listed in Table I. It was found that when the bipyridyls were hydrogenated in absolute methanolic or ethanolic solution in the presence of a nickel catalyst not only reduction of the pyridine rings took place, but also N-alkylation by the alcohols. This nickel ...