Gilch Synthesis of Poly(ortho -Phenylene Vinylenes): A Powerful Access to High-Molecular-Weight Blue-Emitting Polymers

For the first time, the successful Gilch synthesis of poly(ortho-phenylene vinylenes) (ortho-PPVs) is reported. The molar mass of the constitutionally homogeneous ortho-PPVs reaches values as high as Mw ≈ 300 000 Da. The ortho-connectivity of the repeating units forces the chains to assume closely packed conformations even in good solvents. Significant perturbation of the π–electron systems and considerable shortening of the conjugation lengths are the consequences. UV–vis absorption and photoluminescence maxima consequently are shifted clearly toward shorter wavelengths compared to, e.g., classic para-PPVs.