Synthesis, Polymorphs, and Luminescent Properties of Oligomeric Zn₃ppo₆

Oligomeric Zn₃ppo₆, where ppo is 2-(2-hydroxyphenyl)-5-phenyl-1,3-oxazole, has been synthesized as a new blue-emitting material for organic light-emitting diodes (OLEDs). The electroluminescence maximum wavelength is 450 nm and the Commission Internationale de l'Eclairage (CIE) coordinates are x = 0.15, y = 0.11 for blue chromaticity. The luminance efficiency and the maximum luminance were about 1.3 lm/W at 6 V, 5.8 mA/cm² (139 cd/m²), and 8140 cd/m² at 11.4 V. Zn₃ppo₆ shows two trimeric polymorphs and a monomeric structure at different sublimation temperatures.