Synthesis, polymerization, copolymerization, and transition‐metal coordination of 4‐(2,2′:6′,2″‐terpyridin‐4′‐yl)styrene and its polymers and copolymers

Homopolymer 5 from 4‐(2,2′:6′,2″‐terpyridin‐4′‐yl)styrene (4) and copolymers 6–8 from 4 and styrene, vinyl acetate, or acrylic acid were prepared by radical‐initiated polymerization with 2,2′‐azoisobutyronitrile. These polymers containing pendent 2,2′:6′,2″‐terpyridinyl ligands readily formed monotridentate complexes with FeCl2, NiCl2, and CuCl2. By reaction of copolymer 6 with 4′‐(p‐tolyl)‐2,2′:6′,2″‐terpyridyliron(III) trichloride or 4′‐(p‐tolyl‐2,2′:6′,2″‐terpyridylruthenium(III)) trichloride in the presence of ammonium hexafluorophosphate yielded polymer‐metal complexes 11a, 11b containing the corresponding bistridentate complexes. A cyclic voltammogram of 11a containing a bis(2,2′:6′,2″‐terpyridyl)iron(II) complex showed characteristic Fe2+/Fe3+ redox couples at + 1,12 V vs. saturated calomel electrode, which was also observed as a reversible color change between purple and colorless.