Synthesis and electro-optical properties of 9,10-substituted anthracene derivatives for flexible OLED devices

A silylated anthracene derivative, bis[2-(p-trimethylsilyl)phenylethynyl] anthracene (1), was synthesized by using Sonogashira reaction. Compound 1 showed two absorption maxia(max,abs) at 444 and 447nm, and fluorescence maximum (max,em) at 478nm. Compound 1 had higher melting temperature of 274C compared to anthracene 210C presumably due to confinement of -conjugated system by trimethylsilyl end-capping, which will be beneficial in the high temperature operation condition of OLED devices. As compared to the commercially available, blue-light emitting, material 4 and tert-butylated compound 2, the compound 1 showed small red-shift of 9nm in the OLED emission from the by PL max due to the increased electron density in the anthracene ring. The compound 1 was also found to be easily fabricated in the flexible OLED devices and showed a low threshold voltage and high current efficiency compared with other anthracene derivatives.