Synthesis and Polarized Electroluminescence of Mesogenic Polyfluorenes Coordinated with Iridium

A series of phosphorescent mesogenic copolymers with various feed ratios of iridium-coordinating monomer as a side group have been prepared. Structure and composition of copolymers were confirmed by Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (H NMR) spectroscopy. Molecular weight of copolymers was determined to be in the range of 7 to 73 kDa by GPC measurement. UV-Vis absorption and photo-and electroluminescence properties of copolymers were investigated. As a result, copolymer IrCP-1 containing 1 mol% iridium-coordinating comonomer showed the highest luminance and current density. Copolymer IrCP-3 with 5 mol% iridium-coordinating comonomer exhibited a satisfactory dichroic ratio of 1.47.