Polyhalogenoheterocyclic compounds—321: Radical-anions from halopyridines

Electrochemical reduction of pentafluoropyridine and other polyhalopyridines gives bipyridyl derivatives etc. and it is inferred from the structures of the products that, in the intermediate radical-anion, charge- and spin-density is concentrated at the 1- and 4-positions. This is further supported by measurement of Ep_{$\text{1}\text{2}$} values. Trapping experiments with hydroquinone and carbon dioxide are described.