Preparation of blue-emitting phosphorescent iridium(III) complex under ultrasound reaction

F2MeIrpic (Iridium(III)bis[2-(2',4'-difluorophenyl)-4-methyl pyridinato-N,C2'] picolinate) was synthesized to develop a blue-emitting phosphorescent Ir(III) complex. The synthesized F2MeIrpic showed sky blue light with the maximum PL peak at 470nm. Generally the reaction time and maximum yield of F2MeIrpic were known to be 78 hours and 28%, respectively. The reaction is composed of three steps which are the synthesis of ligand (F2Meppy), Ir-dimer and F2MeIrpic with Ir-dimer and picolinic acid. The synthesis of F2MeIrpic is a rate determining step. The solubility and dispersibility of Ir-dimer in solvent are important reaction parameters which determine reaction time and yield, because Ir-dimer is not soluble in almost all solvent. Among various solvents Tetrahydrofuran(THF) was the best solvent to solve Ir-dimer. Ir-dimer was dispersed well by an ultra-sonication in the solvent during reaction. The reaction time was reduced to 36 hours and yield was enhanced to 45% by ultra sound in THF.