An access route to polyferrocenes via modular conjugation

The application of copper-catalyzed azide/alkyne cycloaddition to monomers containing a ferrocene unit leads to polyferrocenes with ferrocene in the backbone. Catalyst performance and kinetic studies of a model system comprising 1,1'-bis(azidoethyl)ferrocene and propargyl ether revealed the usage of CuI and DBU as the catalyst in DMF at 50 degrees C as efficient reaction conditions for the synthesis. The resulting polymers display molecular weight-averages up to (M) over bar (n) = 10 000 and (M) over bar (w) = 33 000. The polyaddition of monomers both containing ferrocene units led to polyferrocenes with (M) over bar (n) between 4 000 and 11 000 ((M) over bar (w) up to 78 000). The present study thus provides a pathway to polyferrocenes based on modular ligation chemistry.