Syntheses and Properties of Novel Quarterphenylene-based Materials for Blue Organic Light-emitting Devices

A series of quarterphenylene-based compounds were prepared and investigated as the hole-transport layer and the host materials in organic light-emitting devices (OLEDs). These compounds have wide HOMO–LUMO energy gaps (ca. 3.57 eV) due to the twisted backbone. A maximum external efficiency of 17% was achieved for blue organic light-emitting device using iridium(III)–bis[2-(4,6-difluorophenyl)pyridinate-N,C2′]picolinate (FIrpic) as an emitting material.