Electroluminescent device using azomethine-lithium-complex as electron injection layer

Abstract

In OLEDs, improved efficiency is obtained by novel compounds which can form inter alia electron injection layers of the formula (I) wherein R 1 is a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with one or more C 1 -C 4 alkyl, alkoxy or cyano; R 2 and R 3 together form a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with C 1 -C 4 alkyl, alkoxy or cyano; R 4 is hydrogen, C 1 -C 4 alkyl or aryl; and Ar is monocyclic, bicyclic or tricyclic aryl or heteroaryl which is optionally substituted with one or more C 1 -C 4 -alkyl or alkoxy groups, or an oligomer thereof.

1 .- 32 . (canceled) 
     
     
         33 . A compound of the formula 
       
         
           
           
               
               
           
         
         wherein 
         R 1  is a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with one or more C 1 -C 4  alkyl, alkoxy or cyano; 
         R 2  and R 3  together form a 1-5 ring aryl (including polycyclic), aralkyl or heteroaryl group which is optionally substituted with C 1 -C 4  alkyl, alkoxy or cyano; 
         R 4  is hydrogen, C 1 -C 4  alkyl or aryl; and 
         Ar is monocyclic, bicyclic or tricyclic aryl or heteroaryl which is optionally substituted with one or more C 1 -C 4 -alkyl or alkoxy groups, 
         or an oligomer thereof. 
       
     
     
         34 . The compound of  claim 33 , wherein R 1  is phenyl or substituted phenyl and R 2  and R 3  together form phenyl or substituted phenyl. 
     
     
         35 . The compound of  claim 33 , which is of formula 
       
         
           
           
               
               
           
         
         wherein R 1  is phenyl or phenyl substituted with one or more C 1 -C 4  alkyl groups and R 2  and R 3  together form phenyl or phenyl substituted by one or more C 1 -C 4  alkyl groups. 
       
     
     
         36 . The compound of  claim 35 , wherein R 1  and/or R 2  and R 3  represent phenyl substituted with one or more methyl groups. 
     
     
         37 . The compound of  claim 33 , wherein the compound is selected from the following: 
       
         
           
           
               
               
           
         
       
     
     
         38 . The compound of  claim 33 , wherein the compound is selected from the following: 
       
         
           
           
               
               
           
         
       
     
     
         39 . The compound of  claim 33 , wherein the compound is selected from the following: 
       
         
           
           
               
               
           
         
       
     
     
         40 . The compound of  claim 33 , wherein the compound is 
       
         
           
           
               
               
           
         
       
     
     
         41 . An optical light emitting diode device having a first electrode, a layer comprising the compound as claimed in  claim 33  and a second electrode. 
     
     
         42 . The device of  claim 41 , wherein the second electrode is a cathode and said layer is an electron injection layer located on said cathode. 
     
     
         43 . The device of  claim 42 , which further comprises an electron transport layer between the electron injection layer and an electroluminescent layer, said electroluminescent layer comprising a metal complex. 
     
     
         44 . The device of  claim 43 , wherein the electroluminescent layer comprises lithium, zirconium or hafnium quinolate as host material doped with a dopant. 
     
     
         45 . The device of  claim 43 , wherein the electroluminescent layer comprises aluminium quinolate as the host material doped with a dopant. 
     
     
         46 . The device of  claim 43 , wherein the electroluminescent layer comprises an aromatic tertiary amine as host material doped with a dopant. 
     
     
         47 . The device of  claim 43 , wherein the electroluminescent layer comprises a light emitting material which is a metal or metalloid complex. 
     
     
         48 . The device of  claim 43 , wherein the electroluminescent layer comprises as luminescent material, a metal quinolate, an iridium, ruthenium, osmium, rhodium, iridium, palladium or platinum complex, a boron complex or a rare earth complex or dendrimers of said metal complexes. 
     
     
         49 . The device of  claim 47 , wherein the electroluminescent layer comprises as electroluminescent material, lithium quinolate or aluminium quinolate. 
     
     
         50 . The device of  claim 43 , wherein the electroluminescent layer comprises a light-emitting conjugated polymer or copolymer or a dendrimer. 
     
     
         51 . The device of  claim 43 , having a hole injection layer comprising 
       
         
           
           
               
               
           
         
       
     
     
         52 . The device of  claim 43 , having a hole transport layer comprising α-NBP 
       
         
           
           
               
               
           
         
       
     
     
         53 . An electro-optical or opto-electronic device having a layer comprising the compound as claimed in  claim 33 . 
     
     
         54 . The device of  claim 53 , wherein the device is a flat panel display. 
     
     
         55 . The device of  claim 53 , wherein the device is an imaging member for creation of an electrostatic latent image. 
     
     
         56 . A composition (including a layer in an OLED or other electro-optical device) comprising the compound as claimed in  claim 33  and another organic semiconductor material or a metal. 
     
     
         57 . The composition of  claim 56 , wherein the compound is doped with a metal. 
     
     
         58 . The composition of  claim 56 , wherein the compound as is mixed with an electron transport material. 
     
     
         59 . The composition of  claim 58 , wherein the electron transport material is a metal quinolate or substituted quinolate. 
     
     
         60 . The composition of  claim 56 , wherein the compound is doped with a fluorescent dopant. 
     
     
         61 . The composition of  claim 56 , wherein the compound is doped with a phosphorescent dopant. 
     
     
         62 . The composition of  claim 56 , wherein the compound is doped with a rare earth chelate. 
     
     
         63 . The compound as claimed in  claim 33 , wherein the compound is vacuum sublimable, depositable by OVPD and/or depositable by OVJP. 
     
     
         64 . A composition comprising the compound as claimed in  claim 33  and an organic solvent.