Organic electroluminescence device using a metal-complex compound

Abstract

An organic electroluminescence device which has one or more organic thin film layers including at least a light emitting layer sandwiched between a pair of electrodes containing a novel metal complex compound in at least one layer in the organic thin film layer. The organic electroluminescence device exhibits a great efficiency of light emission and has a long lifetime.

1 - 4 . (canceled) 
   
   
       5 . An electroluminescence device comprising
 an anode,   a cathode and   one or more organic thin film layers comprising at least a light emitting layer sandwiched between the anode and the cathode,   wherein at least one layer in the organic thin film layers comprises a metal complex compound represented by general formula (1)
   (L A ) m M(L B ) n   (1) 
   wherein M represents iridium atom or platinum atom, L A  and L B  represent bidentate ligands different from each other, a partial structure represented by (L A ) m  has a structure represented by following general formula (2):   
     
       
         
         
             
             
         
       
       wherein L 1  represents an arylene group having 3 to 50 ring atoms which may have substituents or an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, L 2  represents an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, the group represented by L 1  is bonded with the metal represented by M via a covalent bond (a solid line), the group represented by L 2  is bonded with the metal represented by M via a coordinate bond (an arrow); and 
       Z 1  represents a group crosslinking the groups represented by L 1  and L 2 , which is a single bond, —O—, —S—, —CO—, —(CR′R″) a —, —(SiR′R″) a — or —NR′—(R′ and R″ each independently represent hydrogen atom, an aryl group having 6 to 50 ring carbon atoms which may have substituents, an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, an alkyl group having 1 to 50 carbon atoms which may have substituents or an alkenyl group having 2 to 50 carbon atoms which may have substituents, a represents an integer of 1 to 10, and the atoms and the groups represented by R′ and R″ may be same with or different from each other); 
       a partial structure represented by (L B ) n  has a structure represented by following general formula (3): 
     
     
       
         
         
             
             
         
       
       wherein L 3  represents an arylene group having 3 to 50 ring atoms which may have substituents or an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, L 4  represents an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, the group represented by L 3  is bonded with the metal represented by M via a covalent bond, the group represented by L 4  is bonded with the metal represented by M via a coordinate bond; and 
       Z 2  represents a vinylidene group crosslinking the groups represented by L 3  and L 4  to each other, a group represented by L 3 -Z 2 -L 4  having a structure represented by a following formula: 
     
     
       
         
         
             
             
         
       
       wherein R a  and R b  each independently represent hydrogen atom, an alkyl group having 1 to 50 carbon atoms which may have substituents, an alkenyl group having 2 to 50 carbon atoms which may have substituents, 
       an aryl group having 6 to 50 ring carbon atoms which may have substituents, hydroxyl group, mercaptan group, a group —SiR′ 3  having silicon atom, a group —NR′ 2  having a nitrogen atom or a group —PR′ 2  having phosphorus atom wherein R′ is defined above, and the atoms and the groups represented by L 3  and R a , and L 4  and R b  do not form a cyclic structure, R a  and R b  may be bonded to each other to form a cyclic structure; and 
       m represents an integer of 0 to 2, n represents an integer of 1 to 3, m+n specifying a valence of the metal represented by M. 
     
   
   
       6 . The electroluminescence device according to  claim 5 , wherein the light emitting layer comprises the metal complex compound as a light emitting material. 
   
   
       7 . The electroluminescence device according to  claim 5 , wherein the light emitting layer comprises the metal complex compound as a dopant. 
   
   
       8 . The electroluminescence device according to  claim 5 , wherein at least one of an electron injecting layer or an electron transporting layer is sandwiched between the light emitting layer and the cathode, and at least one of the electron injecting layer or the electron transporting layer comprises a π-electron-deficient heterocyclic derivative having a nitrogen atom as an essential component. 
   
   
       9 . The electroluminescence device according to  claim 5 , wherein a reducing dopant is added into an interfacial region of the cathode and the organic thin film layer. 
   
   
       10 . The electroluminescence device according to  claim 5 , wherein the partial structure represented by (L A ) m  having the structure represented by general formula (2) is a partial structure represented by following general formula (4): 
     
       
         
         
             
             
         
       
       wherein R 1  to R 8  each independently represent hydrogen atom, an alkyl group having 1 to 30 carbon atoms which may have substituents, a halogenated alkyl group having 1 to 30 carbon atoms which may have substituents, an alkoxyl group having 1 to 30 carbon atoms which may have substituents, a heterocyclic group having 3 to 20 ring atoms which may have substituents, an aryl group having 6 to 40 ring carbon atoms which may have substituents, an aryloxyl group having 6 to 40 ring carbon atoms which may have substituents, an aralkyl group having 7 to 40 carbon atoms which may have substituents, an alkenyl group having 2 to 30 carbon atoms which may have substituents, an arylamino group 6 to 80 ring carbon atoms which may have substituents, an alkylamino group having 1 to 60 carbon atoms which may have substituents, an aralkylamino group having 7 to 80 carbon atoms which may have substituents, an alkylsilyl group having 1 to 30 carbon atoms which may have substituents, an arylsilyl group having 6 to 40 carbon atoms which may have substituents, a halogen atom, cyano group, nitro group, —S(R)O 2  or —S(R)O [R representing a substituent], and adjacent atoms and groups among the atoms and the groups represented by R 1  to R 8  may be bonded to each other to form a cyclic structure; and 
       M and m are each as defined above. 
     
   
   
       11 . The electroluminescence device according to  claim 5 , wherein a group represented by M←L 4 ←Z 2  in general formula (3) has a structure having a metal-carbene bond represented by following general formula (5): 
     
       
         
         
             
             
         
       
       wherein an arrow in C (carbon atom)→M represents a carbene bond, N represents nitrogen atom, R c  to R e  each independently represent hydrogen atom, an alkyl group having 1 to 50 carbon atoms which may have substituents, an alkenyl group having 2 to 50 carbon atoms which may have substituents, an aryl group having 6 to 50 ring carbon atoms which may have substituents or an aromatic heterocyclic group having 3 to 50 ring atoms which may have substituents, and adjacent atoms and groups may be bonded to each other to form a cyclic structure; and 
       M and Z 2  are each as defined above. 
     
   
   
       12 . The electroluminescence device according to  claim 5 , wherein M represents iridium atom. 
   
   
       13 . The electroluminescence device according to  claim 5 , wherein
 L 4  represents an aromatic heterocyclic group comprising a five membered nitrogen heterocycle.