Syntheses and reactions of ferrocene‐containing polymers. III. Cyclopolymerization of 1,1′‐divinylferrocene

Abstract 1,1′‐Divinylferrocene was polymerized with BF3OEt2 and AIBN initiators. Polymers were separated into benzene‐soluble and benzene‐insoluble fractions, the latter probably being crosslinked. The polymers obtained with BF3OEt2 were shown by infrared and NMR spectroscopy to contain both cyclized (70–80%) and uncyclized units, whereas the radical polymer consisted of more than 96% cyclized units. The benzene‐soluble fraction of the cationically obtained polymer softened at temperatures below 150°C, but the insoluble fraction decomposed at 240°C. The radical polymers were stable up to 250–280°C (dec).