The systematic synthesis of heterobimetallic double-helical complexes of 2,2′:6′,2″:6″,2‴: 6‴,2â�—-quinquepyridines

2,2′ : 6′,2″: 6″,2‴: 6‴,2â�—-Quinquepyridine ligands (L) form double-helical 2 : 2 or mono-helical 1 : 1 complexes with transition metals; solutions of cobalt(II) complexes contain the monohelical seven-coordinate cation [CoL(S)2]2+(S= H2O, MeOH or MeCN) which reacts with silver(I) or copper(I) to give the heterobinuclear double-helical complexes [CoML2]3+.