Synthesis of Hyperbranched Polypyridine via a Cross Coupling Approach as an n-Type π-Conjugated Polymer.

The synthesis of an n-type π-conjugated hyperbranched polymer, hyperbranched polypyridine, is described. The polymer is obtained by copolymerization of 2,4,6-tribromopyridine and 2,5-dibromopyridine via chain-growth condensation polymerization catalyzed by Ni(dppp)Cl₂. The NMR and fourier transform infrared results indicate the successful introduction of the branching unit into polypyridine by this cross coupling approach. The results of UV-vis spectroscopy and cyclic voltammetry suggest that the introduction of the branching unit contributes to a quick response during electrochemical doping due to the diffusion of dopant enhanced by the hyperbranched structure. [ABSTRACT FROM AUTHOR]