Organometallic compounds for use in electroluminescent devices

Abstract

An organic light emitting device is provided. The device has an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further comprising an emissive material having the structure: M is a metal having an atomic weight greater than 40. R 5 is an aromatic group. The emissive material itself is also provided. The emissive material provides an improved stability and efficiency.

What is claimed is:  
     
         1 . An emissive material having the structure::  
       
         
           
           
               
               
           
         
       
       wherein M is a metal having an atomic weight greater than 40; 
 R 5  is a substituent selected from the group consisting of aryl and heteroaryl, wherein said aryl or heteroaryl is unsubstituted or optionally, substituted with non-aromatic groups;  
 R 3  is a substituent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 4  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 6  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 each R is independently selected from the group consisting of H, alkyl, alkylaryl and aryl;  
 ring A is an aromatic heterocyclic or a fused aromatic heterocyclic ring with at least one nitrogen atom that is coordinated to the metal M, wherein the ring can be optionally substituted;  
 (X-Y) is an ancillary ligand;  
 m is a value from 1 to the maximum number of ligands that may be attached to the metal;  
 and m+n<the maximum number of ligands that may be attached to the metal.  
 
     
     
         2 . The emissive material of  claim 1 , wherein the emissive material has the structure:  
       
         
           
           
               
               
           
         
       
     
     
         3 . The emissive material of  claim 2 , wherein n is zero and m is the maximum number of ligands that may be attached to the metal M.  
     
     
         4 . The emissive material of  claim 2 , wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Au, and Ag.  
     
     
         5 . The emissive material of  claim 4 , wherein M is Ir.  
     
     
         6 . The emissive material of  claim 4 , wherein M is Pt.  
     
     
         7 . The emissive material of  claim 5 , wherein n is zero.  
     
     
         8 . The emissive material of  claim 5 , wherein R 5  is substituted or unsubstituted phenyl, naphthyl or pyridyl.  
     
     
         9 . The emissive material of  claim 8 , wherein R 5  is phenyl.  
     
     
         10 . The emissive material of  claim 9 , wherein m is 3 and n is zero.  
     
     
         11 . The emissive material of  claim 1 , wherein the material is incorporated into a polymer.  
     
     
         12 . The emissive material of  claim 1 , wherein the material is incorporated into a dendrimer.  
     
     
         13 . The emissive material of  claim 1 , wherein the emissive material has the structure:  
       
         
           
           
               
               
           
         
       
     
     
         14 . The emissive material of  claim 13 , wherein R 5  is substituted or unsubstituted phenyl, naphthyl or pyridyl.  
     
     
         15 . The emissive material of  claim 14 , wherein R 5  is phenyl.  
     
     
         16 . An emissive material comprising a ligand having the structure:  
       
         
           
           
               
               
           
         
       
       wherein the ligand is attached to a metal having an atomic weight greater than 40; 
 R 5  is a substituent selected from the group consisting of aryl and heteroaryl, wherein said aryl or heteroaryl is unsubstituted or optionally, substituted with non-aromatic groups;  
 R 3  is a substituent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 4  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 6  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 each R is independently selected from the group consisting of H, alkyl, alkylaryl and aryl;  
 ring A is an aromatic heterocyclic or a fused aromatic heterocyclic ring with at least one nitrogen atom that is coordinated to the metal M, wherein the ring can be optionally substituted.  
 
     
     
         17 . The emissive material of  claim 16 , wherein R 5  is substituted or unsubstituted phenyl, naphthyl or pyridyl.  
     
     
         18 . The emissive material of  claim 17 , wherein R 5  is phenyl.  
     
     
         19 . The emissive material of  claim 16 , wherein the ligand has the structure  
       
         
           
           
               
               
           
         
       
     
     
         20 . An organic light emitting device, comprising: 
 (a) an anode;    (b) a cathode; and    (c) an emissive layer disposed between the anode and the cathode, the emissive layer further comprising an emissive material having the structure:                           wherein M is a metal having an atomic weight greater than 40; 
 R 5  is a substituent selected from the group consisting of aryl and heteroaryl, wherein said aryl or heteroaryl is unsubstituted or optionally, substituted with non-aromatic groups;  
 R 3  is a substituent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 4  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 6  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 each R is independently selected from the group consisting of H, alkyl, alkylaryl and aryl;  
 ring A is an aromatic heterocyclic or a fused aromatic heterocyclic ring with at least one nitrogen atom that is coordinated to the metal M, wherein the ring can be optionally substituted;  
 (X-Y) is an ancillary ligand;  
 m is a value from 1 to the maximum number of ligands that may be attached to the metal;  
 and m+n< the maximum number of ligands that may be attached to the metal.  
   
     
     
         21 . The device of  claim 20 , wherein the emissive material has the structure:  
       
         
           
           
               
               
           
         
       
     
     
         22 . The device of  claim 21 , wherein R 5  is a substituted or unsubstituted phenyl, naphthyl or pyridyl.  
     
     
         23 . The device of  claim 22 , wherein R 5  is a phenyl group.  
     
     
         24 . The device of  claim 23 , wherein m is 3 and n is zero.  
     
     
         25 . The device of  claim 21 , wherein the emissive material has the structure:  
       
         
           
           
               
               
           
         
       
     
     
         26 . The device of  claim 21 , wherein the device has an operational half-life of at least about 1000 hours at an initial photon flux of at least about 10 18  photons/SR.m 2 .s.  
     
     
         27 . An organic light emitting device, comprising: 
 (a) an anode;    (b) a cathode; and    (c) an emissive layer disposed between the anode and the cathode, the emissive layer further comprising an emissive material, wherein the emissive material comprises a ligand having the structure:                           wherein the ligand is attached to a metal having an atomic weight greater than 40 R 5  is a substituent selected from the group consisting of aryl and heteroaryl, wherein said aryl or heteroaryl is unsubstituted or optionally, substituted with non-aromatic groups; 
 R 3  is a substituent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 4  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 R 6  is a substitutent selected from the group consisting of H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF 3 , C n F 2n+1 , trifluorovinyl, CO 2 R, C(O)R, NR 2 , NO 2 , OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group;  
 each R is independently selected from the group consisting of H, alkyl, alkylaryl and aryl;  
 ring A is an aromatic heterocyclic or a fused aromatic heterocyclic ring with at least one nitrogen atom that is coordinated to the metal M, wherein the ring can be optionally substituted.  
   
     
     
         28 . The device of  claim 27 , wherein the ligand has the structure:  
       
         
           
           
               
               
           
         
       
     
     
         29 . The device of  claim 28 , wherein R 5  is a R 5  is substituted or unsubstituted phenyl, naphthyl, or pyridyl.  
     
     
         30 . The device of  claim 29 , wherein R 5  is a phenyl group.