A series of alkoxy-substituted poly(p-phenylene) derivatives were synthesized using the well-known Suzuki reaction. The present polymers have strong UV-visible absorption bands around 340 approx. 450 nm and their PL spectra give a highest peak around 430 approx. 550 nm in the blue-green region. In this paper, π-conjugated chain lengths were molecularly regulated, leading to the color tune from PPP-based materials. Their EL spectra in a single-layered device show a highest peak around 430 approx. 550 nm in the blue-green region with the operating voltage of lower than 7V. Also, the photo-oxidation for poly(p-phenylene) derivatives in air was studied.
Shin, S. H., Park, J. S., Park, L. W., & Kim, H. K. (1999). Poly(p-phenylene)-based materials for light-emitting diodes: electroluminescence and photo-oxidation. Synthetic Metals, 102(1–3), 1060–1062. https://doi.org/10.1016/S0379-6779(98)90076-5