1-ethyl-4-(1-ethylpyridin-1-ium-4-yl)pyridin-1-ium

1-Propyl-[4,4']bipyridinyl-1-ium

1-propyl-4-(1-propylpyridin-1-ium-4-yl)pyridin-1-ium

4-(2-cyanopyridin-4-yl)pyridine-2-carbonitrile

1-(4-chlorophenyl)-4-[1-(4-chlorophenyl)pyridin-1-ium-4-yl]pyridin-1-ium,dichloride