Electron transport agents for organic electronic devices

Abstract

Compounds and compositions are provided that can be used as electron transport agents in organic electronic devices such as organic electroluminescent devices. The compounds are non-polymeric and have an aromatic core conjugated to end capping groups. The aromatic core contains an arylene group having a pendant heteroaryl group that includes a —C═N— unit.

1 . A method of making an organic electroluminescent device comprising: 
 (a) preparing a donor sheet comprising a transfer layer that comprises a first compound having a first aromatic core and two first end capping groups conjugated to the first aromatic core, the first compound being of Formula IV:                          wherein    each Ar 1  is independently a radical of benzene, naphthalene, anthracene, phenanthrene, 9,10-dihydrophenanthrene, 4,5,9,10-tetrahydropyrene, fluorene, 9-silafluorene, 6,1 2-dihydroindeno[1,2-b]fluorene, 5,1 2-dihydro-6H-indeno[1,2-b]phenanthrene, 5,6,12,13-tetrahydrodibenzo[a,h]anthracene, 2-phenyl-9H-fluorene, or acenaphthene that is unsubstituted or substituted with one or more groups selected from alkyl, alkenyl, alkoxy, fluoro, fluoroalkyl, perfluoroalkyl, heteroalkyl, and combinations thereof, wherein when Ar 1  is a radical of benzene, the group                          is selected from                          each a is independently 1 or 2;    each E y  is independently a structure of Formula II or Formula III:                          each X is independently O, S, or NR 1 , where R 1  is alkyl, aryl, heteroaryl, heteroalkyl, or combinations thereof;    each Ar 2  is independently an aryl group that is unsubstituted or substituted with one or more groups selected from alkyl, alkenyl, alkoxy, aryl, aryloxy, fluoro, fluoroalkyl, perfluoroalkyl, heteroalkyl, alkyl oxadiazolyl, aryl oxadiazolyl, alkyl triazolyl, aryl triazolyl, diarylamino, aryldiarylamino, and combinations thereof;    each asterisk (-*) indicates the location of a bond to another group in the compound; and    each end capping group (EC) is independently an aryl, heteroaryl without a —C═N— unit, or tertiary amino aryl group that is unsubstituted or substituted with one or more groups selected from alkyl, alkenyl, alkoxy, aryl, aryloxy, fluoro, fluoroalkyl, perfluoroalkyl, heteroalkyl, heteroaryl without a —C═N— unit, and combinations thereof, wherein said end capping groups are conjugated to the aromatic core; and    (b) transferring the transfer layer from the donor sheet to a receptor sheet, wherein the transfer layer forms at least part of a light emissive structure.    
   
   
       2 . The method of  claim 1 , wherein the  
     
       
         
         
             
             
         
       
     
     moiety in Formula IV is a divalent radical of  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     that is unsubstituted or substituted with one or more groups selected from a C 1-20  alkyl, C 2-20  alkenyl, C 1-20  alkoxy, fluoro, C 1-20  fluoroalkyl, C 1-20  perfluoroalkyl, C 1-20  heteroalkyl, and combinations thereof,  
     wherein 
 each R is independently a C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 1-30  heteroalkyl, or combinations thereof; and  
 each R 3  is independently selected from hydrogen, C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 1-30  heteroalkyl, and combinations thereof  
 
   
   
       3 . The method of  claim 1 , wherein at least one end capping group comprises a monovalent radical of  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     that is unsubstituted or substituted with one or more groups selected from C 1-20  alkyl, C 2-20  alkenyl, C 1-20  alkoxy, C 6-20  aryl, C 6-20  aryloxy, fluoro, C 1-20  fluoroalkyl, C 1-20  perfluoroalkyl, C 1-20  heteroalkyl, C 3-20  heteroaryl without a —C═N— unit, and combinations thereof,  
     wherein 
 each R is independently selected from C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 6-20  aryl, C 6-20  aryloxy, C 3-20  heteroaryl without a —C═N— unit, C 1-30  heteroalkyl, and combinations thereof; and  
 each X is independently O, S, or NR 1 , where R 1  is a C 1-30  alkyl, C 6-20  aryl, C 3-30  heteroaryl without a —C═N— unit, C 1-30  heteroalkyl, or combinations thereof  
 
   
   
       4 . The method of  claim 3 , wherein the end capping group further comprises a moiety conjugated to a group of Formula CVI to CXXVII, said moiety selected from a divalent radical of  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     that is unsubstituted or substituted with one or more groups selected from C 1-20  alkyl, C 2-20  alkenyl, C 1-20  alkoxy, C 6-20  aryl, C 6-20  aryloxy, fluoro, C 1-20  fluoroalkyl, C 1-20  perfluoroalkyl, C 1-20  heteroalkyl, C 3-20  heteroaryl without a —C═N— unit, and combinations thereof,  
     wherein 
 each R is independently selected from C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 6-30  aryl, C 6-30  aryloxy, C 3-30  heteroaryl without a C═N— unit, C 1-30  heteroalkyl, and combinations thereof, and  
 each R 3  is independently selected from hydrogen, C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 6-30  aryl, C 6-30  aryloxy, C 3-30  heteroaryl without a —C═N— unit, C 1-30  he and combinations thereof.  
 
   
   
       5 . The method of  claim 3 , wherein the end capping group further comprises a moiety conjugated to a group of Formula CVI to CXXVII, said moiety selected from a divalent radical of  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
     that is unsubstituted or substituted with one or more groups selected from C 1-20  alkyl, C 2-20  alkenyl, C 1-20  alkoxy, C 6-20  aryl, C 6 - 2 o aryloxy, fluoro, C 1-20  fluoroalkyl, C 1-20  perfluoroalkyl, C 1-20  heteroalkyl, C 3-20  heteroaryl without a —C═N— unit, and combinations thereof,  
     wherein 
 each R is independently selected from C 1-30  alkyl, C 2-30  alkenyl, C 1-30  alkoxy, C 6-30  aryl, C 6-30  aryloxy, C 3-30  heteroaryl without a —C═N— unit, C 1-30  heteroalkyl, and combinations thereof;  
 each X is independently O, S, or NR 1 , where R 1  is a C 1-30  alkyl, C 6-20  aryl, C 3-30  heteroaryl without a —C═N— unit, C 1-30  heteroalkyl, or combinations thereof , and  
 each t is an integer equal to 0 to 4.  
 
   
   
       6 . The method of  claim 1 , wherein the compound of Formula IV is  
     
       
         
         
             
             
         
       
       
         
         
             
             
         
       
       
         
         
             
             
         
       
     
   
   
       7 . The method of  claim 1 , wherein the compound of Formula IV is amorphous.  
   
   
       8 . The method of  claim 1 , wherein the compound of Formula IV is an electron transporting material.  
   
   
       9 . The method of  claim 1 , wherein the compound of Formula IV is both an electron and hole transporting material.  
   
   
       10 . The method of  claim 1 , wherein the compound of Formula IV is both a light emitting material and an electron transporting material.  
   
   
       11 . The method of  claim 1 , wherein the transfer layer further comprises a second compound selected from a charge transporting material, a charge blocking material, a light emitting material, a color conversion material, a polymeric binder, or a combination thereof.  
   
   
       12 . The method of  claim 11 , wherein the second compound is selected from a charge transporting material, a charge blocking material, a light emitting material, a color conversion material, or a combination thereof, said second compound having 
 an aromatic radical that comprises the first aromatic core of the first compound, wherein the aromatic radical of the second compound can be unsubstituted, substituted with a substituent of a same type that is present on the first aromatic core of the first compound, or substituted with a substituent that is absent on the first aromatic core of the first compound; or    a second end capping group that comprises the first end capping group of the first compound, wherein the second end capping group can be unsubstituted, substituted with a substituent of a same type that is present on the first end capping group, or substituted with a substituent that is absent on the first end capping group; or    a divalent radical that comprises a divalent radical of the first end capping group of the first compound, wherein the divalent radical in the second compound can be unsubstituted, substituted with a substituent of a same type that is present on the first end capping group, or substituted with a substituent that is absent on the first end capping group; or    a combination thereof.    
   
   
       13 . The method of  claim 11 , wherein the second compound is non-polymeric.  
   
   
       14 . The method of  claim 11 , wherein the second compound is polymeric.  
   
   
       15 . The method of  claim 1   1 , wherein the transfer layer comprises a hole transporting material and an electron transporting material.  
   
   
       16 . The method of  claim 1   1 , wherein the transfer layer comprises a hole transporting material, an electron transporting material, and a light emitting material.  
   
   
       17 . The method of  claim 1 , wherein the donor sheet comprises a base substrate, the transfer layer, and a light-to-heat conversion layer between the base substrate and the transfer layer.  
   
   
       18 . The method of  claim 1 , wherein the transfer layer has a multilayer construction.  
   
   
       19 . The method of  claim 1 , wherein the transfer layer is thermally annealed after transferring.  
   
   
       20 . The method of  claim 1 , wherein the transfer layer is amorphous and solution processable.