Selective Synthesis of Facial and Meridianal Isomers of Alq3

Alq3 was synthesized by mixing 8-quinolinol and Al(OH)3 at about 95 degrees C. The reaction time of 24h leads to formation of -phase Alq3 which is formed by meridianal Alq3, while the reaction time of 100h leads to -Alq3 which is formed by facial Alq3. Unlike the conventional method, -Alq3 was obtained without heating -Alq3 at about 400 degrees C. The and phases were determined by X-ray diffraction, and confirmed by photoluminescence spectra with vibronic structure. Organic light emitting diode (OLED) fabricated using mer-Alq3 shows higher green Alq3 electroluminescence and longer lifetime than OLED fabricated using fac-Alq3.