CHAPTER 15: Donor–Acceptor Alternating Copolymers

Donor-acceptor alternating copolymers enable independent fine tuning of HOMO and LUMO energy levels and the bandgap of conjugated polymers. Therefore, these novel materials have received a significant amount of attention and undergone rapid progress in various research fields, in particular, organic photovoltaics and organic filed transistors. In this chapter, we will first briefly review the origin of the donor–acceptor concept. Then we will introduce the fundamentals of crosscoupling reactions, and summarize noteworthy synthetic issues from the perspective of coupling reactions and step growth polymerization. We will discuss two recent advancements in the synthesis of D–A copolymers. The last section, also the bulk of this chapter, we dedicate to specific procedures including the syntheses of monomers, catalyst purification, polymerization via Stille coupling, Soxhlet extraction, metal residue removal, end capping, etc. We will present, in detail, three representative syntheses of D–A copolymers, followed by common characterization methods to conclude this chapter.