Controllable synthesis of externally functional dendronized polymers

Abstract

Through a controllable "reactivate" "graft" synthetic route, two asymmetrical "Janus" dendronized polymers (DPs) were successfully synthesized. Dendrons were grafted to a linear polymer motherboard by a story-by-story constructionmethod. Due to the heterogenetic "Janus" structure, with orderly arranged chromophore moieties, the polymers demonstrated extremely large second-order nonlinear optical (NLO) coefficients and excellent NLO thermal stability. DP-4l and DP-6l had high d33 values of 232 and 227 pm/V, respectively, which reached the highest value reported so far for linear-based polymers containing simple azo-chromophore moieties. The controllable synthesis sheds light on the structure-property relationships of NLO polymers and other dendronized-structure functionalpolymers.