Impact of the position of the imine linker on the optoelectronic performance of π-conjugated organic frameworks

Abstract

Conjugated organic frameworks are an interesting class of functional porous organic materials having a π-conjugated backbone with permanent porosity. These materials are potential candidates for optoelectronic applications. Although there are several reports on the structure–property relationship between π-conjugated building blocks and optoelectronic performance, the influence of the linker position is hitherto unknown. We report two novel imine-linked 2D π-conjugated polymers which are positional isomers of each other consisting of pyrene and anthracene units. The polymers exhibited similar optical and electronic properties under ambient conditions. Upon I₂ doping, one of the isomers exhibited high radical density and enhanced conductivity due to energetically favoured chemical oxidation. The linker position dramatically affects the optoelectronic performance of these polymers even though they have the same π-conjugated backbone.