[(O∧N∧N)PtX] Complexes as a New Class of Light-Emitting Materials for Electrophosphorescent Devices

The synthesis and photophysical properties of the robust Pt(II) emitters [(O∧N∧N)PtX] (HO∧N∧N = 6-(2-hydroxyphenyl)-2,2‘-bipyridine and its derivatives; X = Cl, Br, I, or −C⋮C−Ph) are reported. Yellow electroluminescent devices based on these materials display a low turn-on voltage (1 cd m-2 at 4 V) and a high luminance (37000 cd m-2). Complex 2e, [(FtBu2O∧N∧N)PtCl], has the highest thermal stability and gave the best OLED.