Universal Display Corporation
Organic electroluminescent materials and devices

Abstract:

A compound comprising a ligand L.sub.A of Formula I: ##STR00001## as well as, devices and formulations containing the compound of Formula 1 are disclosed. In the compounds, having a ligand La of Formula I: wherein R.sup.1 represents mono, or di-substitution, or no substitution; wherein R.sup.2 represents di, tri, or tetra-substitution; wherein R is selected from hydrogen, deuterium, alkyl, cycloalkyl, and combinations thereof; wherein R.sup.1 and R.sup.2 are each independently selected from hydrogen, deuterium, alkyl, cycloalkyl, aryl, and combinations thereof; wherein at least one pair of adjacent R.sup.2 substitutions are joined to form a fused ring; wherein the ligand L.sub.A is coordinated to a metal M; and wherein the ligand L.sub.A is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand.