Synthesis, optical and redox properties of novel segmented cyano-PPV derivatives

We report the detailed synthesis and physical characterization of two novel segmented PPV derivatives 6 and 7, that contain cyanomodified DSB-segments covalently linked with different ether groups. The polymers were synthesized by step growth polymerization via the knoevenagel reaction. They exhibit high molecular weights (Mn ~20,000 VPO) and can be cast from solution to give transparent, orange films with high PL quantum efficiencies (40 %). In comparison to the cyano-free polymers the electrochemical reduction potential is remarkably low (ERed -1.30 V vs. Ag/AgCl in solid state), indicating a high electron affinity. Thus, the new polymers offer promise as electron transporting materials for photoconductive or light-emitting devices and as novel materials for X(3) NLO applications.