Polymerization reactions in [Co(NH<inf>3</inf>)<inf>5</inf>(H<inf>2</inf>O)][CoX(CN)<inf>5</inf>] and cis-[Co(NH<inf>3</inf>)<inf>4</inf>(H<inf>2</inf>O)<inf>2</inf>][CoX(CN)<inf>5</inf>] (X = Cl, Br, I, No<inf>2</inf> OR N<inf>3</inf>) double-complex salts

Polymerization reactions of [Co(NH3)5(H2O)][CoX(CN)5] and cis-[Co(NH3)4 (H2O)2][CoX(CN)5] (X = Cl, Br, I, NO2 or N3] have been studied. The compounds undergo aging reactions in the solid state or in solution induced by the ligand X involving solvolytic processes affording polymeric materials with μ-cyano bridges. A mechanistic explanation of these reactions is given and a comparison between both series of compounds together with the parent compound [Co(NH3)6][Co(CN)6] is discussed. © 1987.