Cyclometallated iridium(III) complex with 2-(benzo[b]thiophen-2-yl)pyridyl and norbornene-substituted pyrazolonate ligands and related electroluminescent red light-emitting polymers

Abstract

New cyclometallated iridium(III) complex, (NBEpz)Ir(Btp)2 (I) (NBEpzH is 1-phenyl-3-methyl-4-(5-bicyclo[2.2.1]hept-5-en-2-yl)-5-pyrazolone, and BtpH is 2-(benzo[b]thiophen-2-yl)pyridine), is synthesized. The structure of the compound is determined by X-ray diffraction analysis (CIF file CCDC no. 1406737). Copolymers with the carbazole and iridium-containing fragments in the side chains (P1–P3) are prepared from monomer I using the ROMP method (ROMP is Ring-Opening Metathesis Polymerization). Their photoluminescence and electroluminescence properties are studied. Copolymers P1–P3 exhibit an intense photoluminescence and electroluminescence of red color. The maximum current efficiency (17.9 cd/A) and power efficiency (9.1 lm/W) are reached using emitter P2.