Synthesis and Properties of an Acetal-bridged Ladder Poly(p-phenylene)

摘要: Ladder π-conjugated polymers are promising materials for broad applications in organic-based devices, including light-emitting diodes, thin film transistors, and solar cells. Their rigid coplanar structures promise resistance to deformation enhanced π-conjugation, which lead a set of desirable properties, such as intense luminescence, high carrier mobility environmental stability. Most the studies this field have been focused on poly(p-phenylene)based step ladder-type poly(phenylenes) fully poly(phenylenes). There are, however, only limited reports ladder poly(p-phenylenes) with heteroatom bridges. This is mainly due lack useful synthetic routes terms efficacy well accessible structural diversity. The exploration conceptually new methodology thus compelling subject chemistry. We recently developed BBr3-promoted cyclization produce an ether ester-bridged poly(pphenylenes). method constitutes significant improvements over other because fast quantitative. Versatility reaction another advantage our prepare polymers. As entry into class polymers, we introduce herein novel poly(p-phenylene) acetalbridge. strategy construct acetal-bridged system based chemical method. Thus, phenoxide, generated by demethylation, acts nucleophile nucleophilic addition neighboring ketone, causing (Scheme 1). constructs hemiacetal-bridged triphenylene skeleton 2 one spot. subsequent methylation using methanol TFA produces desired structure 3, model corresponding 6, also quantitative yield. photophysical electrochemical properties 6 further described communication.