Studies on the synthesis and optical properties of novel blue light‐emitting polymers containing phosphorus and oxadiazole structures

Novel phosphorus‐containing polymers with high‐electron‐affinity oxadiazole were synthesized and characterized by thermal analysis and spectroscopy (infrared, ultraviolet‐visible, photoluminescence, cyclic voltammetry) measurements. These new polymers can be used as blue electroluminescent materials and as electron‐transport layers in polymer light‐emitting diodes. In this study, aromatic polyethers containing electron‐transporting chromophores and emission chromophores were synthesized from 2,5‐bis‐(4‐fluoroaryl)‐1,3,4‐oxadiazole and 2‐(6‐oxido‐6 H ‐dibenz<c,e><1,2> oxaphosphorin‐6‐yl)‐1,4‐naphthalenediol (DOPO‐NBQ). The effects of reaction temperature and time on the formation of polyethers were investigated to obtain optimum conditions for polyether manufacturing. All the resulting polymers were thermally stable at <460 °C. The absorption peaks of these polymers were at 350–365 nm, whereas the photoluminescent peaks were at 460–481 nm. But, the intensity of polymer absorption decreased and a blue shift was observed in the photoluminescent spectra as the temperature increased. In addition, these polymers containing the electron‐transporting oxadiazole indeed showed extra reduction potentials in cyclic voltammetry measurements.