Room temperature fast synthesis four-membered red iridium(III) complexes containing Ir–S–P–S structures for OLEDs

Abstract

One S atom contained ligand triethylamine salt of diphenylphosphinodithioic acid (dpss) was firstly developed for two four-membered red-emitting iridium(III) complexes with Ir–S–P–S structures, (tfmpiq)2Ir(dpss) and (tfmpqz)2Ir(dpss), in which 1-(4-(trifluoromethyl)phenyl)isoquinoline (tfmpiq) and 4-(4-(trifluoromethyl)phenyl)quinazoline (tfmpqz) were employed as the cyclometalated ligands, respectively. Owing to strong bonding ability of sulfur and iridium atom, two Ir(III) complexes were obtained rapidly and efficiently at room temperature in 5 min. The computational Gibbs free energy changes of the complexes formation reactions further indicate that they are exothermic and thermodynamically beneficial processes. They show similar PL emissions at 620 and 621 nm, respectively. Using the two complexes as dopants, both organic light-emitting devices (OLEDs) exhibit good properties with the maximum luminance of 16 400 cd/m2 and the maximum external quantum efficiency of 19.38%.