A pure blue light emitting binaphthyl derivative: Synthesis and properties

A binaphthyl derivative with pyrene on 3 and 3′ positions was synthesized and characterized via Suzuki coupling reaction. Emission maximum in solution was located at 390 nm with a quantum efficiency of 68% by taking 9,10-diphenyl anthracene as reference, while it is shifted to 450 nm with FWHM of 104 nm resulting from aggregation state in solid film. Glass transition temperature (Tg) and decomposition temperature were measured to be 184 and 447 °C, respectively, by DSC and TGA. Unlike its photoluminescence spectrum, electroluminescent spectrum peaked at about 460 nm and shows a FWHM of 69 nm corresponding to a pure blue emission. The turn-on voltage, luminance and efficiency maximum were 5 V, 2953 cd/m2 and 1.37 cd/A with CIE color coordinate of (0.16, 0.15), in the device structure of ITO/NPB (40 nm)/PY-BN-PY (15 nm)/BPhen (40 nm)/Mg:Ag.