Poly(para‐Phenylene Vinylene)s

This chapter provides a brief summary of the available synthetic methods leading to poly(p-phenylene vinylene)s (PPVs), followed by a detailed discussion of the mechanism of PPV synthesis, employing the Gilch route. In the latter case, in situ-generated p-quinodimethanes are shown to be the active monomers. Spontaneously formed diradicals initiate the chain growth, and are the reason why [2.2]paracyclophanes are formed as side products. Oxygen is identified as a highly efficient molar mass-regulating agent, and evidence is provided as to why E-configured halide-bearing vinylene moieties should be perceived as being among the most critical chain defects with respect to the efficiency and durability of (opto)electronic devices based on Gilch-PPVs. Keywords: poly(p-phenylene vinylene); Gilch route; [2.2]paracyclophanes; step-growth polymerization; chain-growth polymerization; anionic chain polymerization; radical chain polymerization