Universal Display Corporation
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

Abstract:

A compound comprising a ligand L.sub.A of Formula I, ##STR00001## is disclosed. In Formula I, each of Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4, Z.sup.5, and Z.sup.6 is C or N; K is selected from a direct bond, O, and S; if K is O or S, then Z.sup.6 is C; ligand L.sub.A is coordinated to a metal by the dash lines; M is coordinated to at least one other ligand; L.sup.1 is an organic linker; if M is selected from Ru, Os, or Ir, then K is O or S; if M is selected from Pt, Pd, Cu, Ag, or Au, and K is a direct bond, then M forms at least one bond to oxygen or sulfur; when M is selected from Pt, Pd, Cu, Ag, or Au, and K is O or S, then L.sup.1 is selected from --CR.dbd.N--, --CR'R''CR'R''--, --NR'BR'--, --CR'R''O--, --CR'R''S--, --CR'.dbd.CR''O--, --CR'.dbd.CR''S--, --CR'.dbd.CR'NR--, --CR'.dbd.CR''CR.sub.2--, --C(.dbd.N--)--, and --C(.dbd.CR--)--.