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

Abstract An isopropyl substituted red fluorescent dye, 4-(dicyanomethylene)-2- i - propyl -6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4 H -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-( I-propyl )6-methyl 4 H -pyran, involved in the synthesis of DCJTI is much easier to manufacture than that of DCJTB. In the interest of driving down the cost of OLED materials, DCJTI may prove to be a cheaper alternative for the red dopant DCJTB.