New Pyrene Derivatives Having Rigid Imidazole Moiety for Blue Emitters.

Pyrene, imidazole and dibenzofuran were used to synthesize new blue emitters of 1-(4-(dibenzo[b,d]furan-4-yl)phenyl)-2-(pyren-1-yl)-1H-phenanthro[9,10-d] imidazole (BFP-PI) and 1-(4-(dibenzo[b,d]furan-4-yl)phenyl)-4,5-diphenyl-2-(pyren-1-yl)-1H-imidazole (BFP-DPI). In the film state, BFP-PI and BFP-DPI show photoluminescence (PL) maximum values of 462 nm and 459 nm. The relative PL quantum efficiency (PLQY) of BFP-PI and BFP-DPI is 89.16% and 79.2% by using reference compound of 9,10-diphenylanthracene. The device using BFP-PI in the non-doped state as emitting material showed current efficiency (C.E.) of 3 cd/A and external quantum efficiency (E.Q.E.) of 2.15%, and the device using BFP-DPI as emitting material exhibited C.E. of 2.64 cd/A and E.Q.E. of 1.6%.