Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A compound having a formula M(L.sub.A)(L.sub.B)(L.sub.C) is disclosed. Each of ligands L.sub.A and L.sub.B are mono-anionic bidentate ligands coordinated to metal M forming a 5-member cyclometalated ring. Ligands L.sub.A and L.sub.B are covalently linked by a first linking group, where there is at least one loop of M-L.sub.A-first linking group-L.sub.B-M having only carbocyclic or heterocyclic groups in the loop other than M. Wherein the first linking group includes multiple aliphatic or aromatic rings that are separated by at least one single bond, where each ring in the first linking group is part of the backbone of the loop. Devices, such as organic light emitting diodes, including the compounds are also disclosed.