Pt(II) complexes are promising phosphorescent materials for organic light-emitting diode (OLED) applications in the fields of display, lighting, healthcare, aerospace, and so on. A series of novel biphenyl (bp)-based tetradentate 6/5/6 Pt(II) emitters using oxygen or carbon as a linking atom was designed and developed. The intermolecular interactions in crystal packing, electrochemical, and photophysical properties of the bp-based Pt(II) emitters and also their excited-state properties were systematically studied, which could be effectively regulated by ligand modification through linking group control; however, their emission spectra nearly showed no change. All the bp-based Pt(II) emitters exhibited vibronically featured emission spectra with dominant peaks at 502−505 nm and photoluminescent quantum yields of 24−34% in dichloromethane solution. Green OLED using Pt(bp-12) as an emitter achieved a maximum brightness (L max ) of 16,644 cd/m 2 .

An efficient and practical synthesis of 2,7-bis­(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)­triphenylene 4 from two cheap commodity chemicals in five steps with a total yield of 48.6% was developed. This process had been successfully applied in the synthesis of electron transport material (ETM) BPyTP-2 in the gram scale with a total yield of 47.2%. This practical development of the key intermediate 4 opens a door in its further application in the synthesis of other triphenylene-based ETMs and host materials in the materials field.