CHAPTER 4: Polyphenylenes

Poly(p-phenylene) PPP is one of the most fundamental π-conjugated polymers and has long attracted the interest of organic, theoretical and polymer scientists. PPP is synthesized by various methods including (a) oxidizing polymerization of benzene with CuCl₂ and AlCl₃, (b) aromatization of poly(cyclohexadiene)s and (c) dehalogenative organometallic polymerization of 1,4-dihalobenzene. Recent development of organometallic chemistry makes it possible to prepare a variety of PPPs having side chains and side rings. This chapter deals with the preparation of PPP, its related polymers and PPPs with side chains and side rings. A brief discussion about the mechanism of organometallic polymerization is also included.