Recent developments in the synthesis of red dopants for Alq3 hosted electroluminescence

An isopropyl substituted red fluorescent dye, 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7 9-enyl)-4H-pyran (DCJTI), has been found to be a good dopant in a host MQ(3) matrix which produces organic EL devices with essentially identical luminance efficiency and chromaticity to that of the t-butyl derivative, DCJTB. The key intermediate, 4-(dicyanomethylene)-2-(1-propyl)6-methy 4H-pyran, involved in the synthesis of DCJTI is much easier to manufacture than that of DCJTB. Ln the interest of driving down the cost of OLED materials, DCJTI may prove to be a cheaper alternative for the red dopant DCJTB. (C) 2000 Published by Elsevier Science S.A. All rights reserved.