Monosubstituted diazabenzimidazole carbene metal complexes for use in organic light emitting diodes

Abstract

An organic electronic device, preferably an organic light-emitting diode (OLED), comprising at least one metal-carbene complex comprising one, two or three specific bidentate diazabenzimidazole carbene ligands; a light-emitting layer comprising said metal-carbene complex as emitter material, preferably in combination with at least one host material; the use of said metal-carbene complex in an OLED; an apparatus selected from the group consisting of stationary visual display units, mobile visual display units, illumination units, units in items of clothing, units in handbags, units in accessories, units in furniture and units in wallpaper comprising said organic electronic device, preferably said OLED, or said light-emitting layer; the metal-carbene complex comprising one, two or three specific bidentate diazabenzimidazole carbene ligands mentioned above and a process for the preparation of said metal-carbene complex.

1 .- 16 . (canceled) 
     
     
         17 . An organic electronic device comprising at least one metal-carbene complex, wherein the metal is Ir or Pt, comprising one, two or three bidentate ligands of formula (I) and/or (I′) 
       
         
           
           
               
               
           
         
         wherein 
         R 1    
         is a linear or branched alkyl radical which is linked to the diazabenzimidazole carbene unit via a sp 3  hybridized carbon atom, selected from the group consisting of methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl; 
         A 1  is CR 2  or N; 
         A 2  is CR 3  or N; 
         A 3  is CR 4  or N; 
         A 4  is CR 5  or N; 
         A 1′  is CR 2  or N; 
         A 2′  is CR 3′  or N; 
         A 3′  is CR 4′  or N; 
         A 4′  is CR 5′  or N; 
         R 2 , R 3 , R 4 , R 5 , R 2′ , R 3′ , R 4′  and R 5′   
         are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 30 carbon atoms; a substituted or unsubstituted heterocycloalkyl radical, interrupted by at least one heteroatom selected from the group consisting of O, S and N and having a total of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical, having a total of from 6 to 30 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 30 carbon atoms and/or heteroatoms, selected from the group consisting of O, S and N; or a group with donor or acceptor action; 
         R 9 , R 10 , R 11    
         are each independently a linear or branched alkyl radical, having from 1 to 6 carbon atoms; a substituted or unsubstituted aryl radical, having from 6 to 18 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 18 carbon atoms; 
         or 
         R 2  and R 3 , R 3  and R 4  or R 4  and R 5  or R 2′  and R 3′ , R 3′  and R 4′  or R 4′  and R 5′  form, independently of each other, together with the carbon atoms to which they are bonded, a saturated or unsaturated or aromatic ring, which has a total of from 5 to 18 carbon atoms and/or heteroatoms; 
         ˜ is the bonding site to the metal; 
         whereby 
         substituted aryl means aryl substituted by one or more further radicals selected from the group consisting of C 1 -C 20 -alkyl, C 6 -C 30 -aryl and substituents with donor or acceptor action; 
         substituted heteroaryl means heteroaryl substituted at one, more than one or all substitutable positions by radicals selected from the group consisting of C 1 -C 20 -alkyl, C 6 -C 30 -aryl and substituents with donor or acceptor action; 
         substituted alkyl, substituted cycloalkyl and substituted heterocycloalkyl means alkyl, cycloalkyl and heterocycloalkyl substituted by one or more substituents selected from the group consisting of groups with donor or acceptor action, deuterium, a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 30 carbon atoms, a substituted or unsubstituted heterocycloalkyl radical, interrupted by at least one heteroatom, selected from the group consisting of O, S and N, and having a total of from 3 to 30 carbon atoms and/or heteroatoms, a substituted or unsubstituted aryl radical, having a total of from 6 to 30 carbon atoms, or a substituted or an unsubstituted heteroaryl radical, having a total of from 5 to 30 carbon atoms and/or heteroatoms, selected from the group consisting of O, S and N; and 
         groups with donor or acceptor action are understood to mean the following groups: 
         C 1 -C 20 -alkoxy, C 6 -C 30 -aryloxy, C 1 -C 20 -alkylthio, C 6 -C 30 -arylthio, SiR 32 R 33 R 34 , halogen radicals, halogenated C 1 -C 20 -alkyl radicals, —CO(R 32 ), —C═O(SR 32 ), —C═O(OR 32 ), —OC═O(R 32 ), —SC═O(R 32 ), —NR 32 R 33 , OH, pseudohalogen radicals, —C═O(NR 32 R 33 ), —NR 32 C═O (R 33 ), —P(O) (OR 32 ) 2 , —OP(O) (OR 32 ) 2 , —PR 32 R 33 , —P(O)R 32   2 , —OS(O) 2 OR 32 , —S(O)R 32 , —S(O) 2 OR 32 , —S(O) 2 R 32 , —S(O) 2 NR 32 R 33 , NO 2 , —OB(OR 32 ) 2 , —C═NR 32 R 33 ), borane radicals, stannate radicals, hydrazine radicals, hydrazone radicals, oxime radicals, nitroso groups, diazo groups, vinyl groups, sulfoximines, alanes, germanes, boroxines and borazines; 
         R 32 , R 33  and R 34    
         are each independently hydrogen, substituted or unsubstituted C 1 -C 20 -alkyl or substituted or unsubstituted C 6 -C 30 -aryl or substituted or unsubstituted heteroaryl having 5 to 30 ring atoms. 
       
     
     
         18 . The organic electronic device according to claim  16 , wherein the organic electronic device is selected from organic light-emitting diodes (OLED), light-emitting electrochemical cells (LEEC), organic photovoltaic cells (OPV) and organic field-effect transistors (OFET). 
     
     
         19 . The organic electronic device according to claim  16 , wherein the metal-carbene complex comprising one, two or three bidentate ligands of formula (I) and/or (I′) is employed as emitter material in OLEDs or LEECs or absorption dye in OPVs. 
     
     
         20 . The organic electronic device according to  claim 18 , wherein the OLED comprises
 (a) an anode,   (b) a cathode,   (c) a light-emitting layer between the anode and the cathode,   wherein the metal-carbene complex comprising one, two or three bidentate ligands of formula (I) and/or (I′) is present in the light-emitting layer of the OLED.   
     
     
         21 . The organic electronic device according to claim  16 , wherein the groups A 1 , A 2 , A 3 , A 4 , A 1′ , A 2′ , A 3′  and A 4′  in the ligands of formulae (I) and (I′) have the following meanings:
 A 1  is CR 2 ; 
 A 2  is CR 3 ; 
 A 3  is CR 4 ; 
 A 4  is CR 5 ; 
 A 1′  is CR 2′ ; 
 A 2′  is CR 3′ ; 
 A 3′  is CR 4′ ; 
 A 4′  is CR 5′ ; 
 R 2 , R 3 , R 4 , R 5 , R 2′ , R 3′ , R 4′  and R 5′   
 are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical, having a total of from 3 to 10 carbon atoms; a substituted or unsubstituted heterocycloalkyl radical, interrupted by at least one heteroatom, selected from the group consisting of O, S and N, and having a total of from 3 to 10 carbon atoms and/or heteroatoms; a group with donor or acceptor action, selected from halogen radicals, CF 3 , CN, SiPh 3  and SiMe 3 ; a substituted or unsubstituted aryl radical, having from 6 to 30 carbon atoms. 
 
     
     
         22 . The organic electronic device according to claim  16 , wherein the metal-carbene complex has one of the following formulae (II), (II′) or (II″) 
       
         
           
           
               
               
           
         
         wherein 
         R 1    
         is a linear or branched alkyl radical which is linked to the diazabenzimidazole carbene unit via a sp 3  hybridized carbon atom, selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl; 
         A 1  is CR 2  or N; 
         A 2  is CR 3  or N; 
         A 3  is CR 4  or N; 
         A 4  is CR 5  or N; 
         A 1′  is CR 2′  or N; 
         A 2′  is CR 3′  or N; 
         A 3′  is CR 4′  or N; 
         A 4′  is CR 5′  or N; 
         R 2 , R 3 , R 4 , R 5 , R 2′ , R 3′ , R 4′  and R 5′   
         are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 30 carbon atom; a substituted or unsubstituted heterocycloalkyl radical, interrupted by at least one heteroatom selected from the group consisting of O, S and N and having a total of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical, having a total of from 6 to 30 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 30 carbon atoms and/or heteroatoms, selected from the group consisting of O, S and N; or a group with donor or acceptor action; 
         R 9 , R 10 , R 11    
         are each independently a linear or branched alkyl radical, having from 1 to 6 carbon atoms; a substituted or unsubstituted aryl radical, having from 6 to 18 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 18 carbon atoms; 
         or 
         R 2  and R 3 , R 3  and R 4  or R 4  and R 5  or R 2′  and R 3′ , R 3′  and R 4′  or R 4′  and R 5′  form, independently of each other, together with the carbon atoms to which they are bonded, a saturated or unsaturated or aromatic ring, which has a total of from 5 to 18 carbon atoms and/or heteroatoms; 
         M is Ir; 
         n is 1, 2 or 3; 
         L is a monoanionic bidentate ligand, 
         o is 0, 1 or 2, where, when o=2, the L ligands may be the same or different; 
         n′ is 1 or 2; 
         n″ is 1 or 2; 
         wherein the sum of n′+n″ is 2 or 3; 
         o′ is 0 or 1; 
         wherein the sum of n+o in formulae (II) and (II′) and the sum of n′+n″+o′ in formula (II″) is 3, with the proviso that n in formula (II) and (II′) is at least 1 and n′, as well as n″ in formula (II″) are at least 1. 
       
     
     
         23 . The organic electronic device according to claim  16 , wherein the metal-carbene complex has one of the following formulae (II), (II′) or (II″) 
       
         
           
           
               
               
           
         
         wherein 
         R 1    
         is a linear or branched alkyl radical which is linked to the diazabenzimidazole carbene unit via a sp 3  hybridized carbon atom, selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl and octyl;
 A 1  is CR 2  or N; 
 A 2  is CR 3  or N; 
 A 3  is CR 4  or N; 
 A 4  is CR 5  or N; 
 A 1′  is CR 2′  or N; 
 A 2′  is CR 3′  or N; 
 A 3′  is CR 4′  or N; 
 A 4′  is CR 5′  or N; 
 R 2 , R 3 , R 4 , R 5 , R 2′ , R 3′ , R 4′  and R 5′   
 are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 30 carbon atom; a substituted or unsubstituted heterocycloalkyl radical, interrupted by at least one heteroatom selected from the group consisting of O, S and N and having a total of from 3 to 30 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical, having a total of from 6 to 30 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 30 carbon atoms and/or heteroatoms, selected from the group consisting of O, S and N; or a group with donor or acceptor action; 
 R 9 , R 10 , R 11    
 are each independently a linear or branched alkyl radical, having from 1 to 6 carbon atoms; a substituted or unsubstituted aryl radical, having from 6 to 18 carbon atoms; a substituted or unsubstituted heteroaryl radical, having a total of from 5 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted cycloalkyl radical having a total of from 3 to 18 carbon atoms; 
 or 
 R 2  and R 3 , R 3  and R 4  or R 4  and R 5  or R 2′  and R 3′ , R 3′  and R 4′  or R 4′  and R 5′  form, independently of each other, together with the carbon atoms to which they are bonded, a saturated or unsaturated or aromatic ring, which has a total of from 5 to 18 carbon atoms and/or heteroatoms; 
 M is Pt; 
 n is Pt 1 or 2; 
 L is a monoanionic bidentate ligand, 
 o is 0 or 1; 
 n′ is 1; 
 n″ is 1; 
 wherein the sum of n′+n″ is 2; 
 o′ is 0; 
 
         wherein the sum of n+o in formulae (II) and (II′) and the sum of n′+n″+o′ in formula (II″) is 2, with the proviso that n in formula (II) and (II′) is at least 1 and n′, as well as n″ in formula (II″) are both 1. 
       
     
     
         24 . The organic electronic device according to  claim 21 , wherein
 n is 3;   n′ is 1 or 2,   n″ is 1 or 2,   wherein the sum of n′+n″ is 3.   
     
     
         25 . The organic electronic device according to claim  16 , wherein the monoanionic bidentate ligand L in the metal-carbene complex has following meaning:
 a ligand of formula (A)   
       
         
           
           
               
               
           
         
         in which 
         R 51  is in each case independently a linear or branched alkyl radical having 1 to 6 carbons atoms; a substituted or unsubstituted aryl radical having 6 to 18 carbon atoms; a substituted or unsubstituted heteroaryl radical having a total of 5 to 18 carbon atoms and/or heteroatoms, 
         R 52  is hydrogen; a linear or branched alkyl radical having 1 to 6 carbon atoms; a substituted or unsubstituted aryl radical having 6 to 18 carbon atoms; 
         or 
         L is a carbene ligand of the general formula (B) 
       
       
         
           
           
               
               
           
         
         where 
         A 9′  is CR 12′  or N; 
         A 10′  is CR 13′  or N; 
         R 11′  is a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from O, S and N; a substituted or unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a substituted or unsubstituted heterocycloalkyl radical interrupted by at least one heteroatom, selected from the group consisting of O, S and N, and having 3 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl radical interrupted by at least one heteroatom, selected from the group consisting of O, S and N and having a total of 5 to 30 carbon atoms and/or heteroatoms; 
         R 12′ , R 13′  are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a substituted or unsubstituted heterocycloalkyl radical interrupted by at least one heteroatom, selected from O, S and N, and having 3 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical having 6 to 30 carbon atoms; a substituted or unsubstituted heteroaryl radical interrupted by at least one heteroatom, selected from the group consisting of O, S and N and having a total of 5 to 30 carbon atoms and/or heteroatoms; or a group with donor or acceptor action; 
         if A 9′  is CR 12′  and A 10′  is CR 13′ , CR 12′  and CR 13′  together may form a saturated or unsaturated or aromatic ring, which has a total of from 5 to 18 carbon atoms and/or heteroatoms; 
         A 5′  is CR 14′  or N; 
         A 6′  is CR 15′  or N; 
         A 7′  is CR 16′  or N; 
         A 8′  is CR 17′  or N; 
         R 14′ , R 15′ , 
         R 16′ , R 17′  are each independently hydrogen; deuterium; a linear or branched, substituted or unsubstituted alkyl radical having 1 to 20 carbon atoms, optionally interrupted by at least one heteroatom, selected from the group consisting of O, S and N; a substituted or unsubstituted cycloalkyl radical having 3 to 18 carbon atoms; a substituted or unsubstituted heterocycloalkyl radical interrupted by at least one heteroatom, selected from the group consisting of O, S and N, and having 3 to 18 carbon atoms and/or heteroatoms; a substituted or unsubstituted aryl radical having 6 to 30 carbon atoms; a substituted or unsubstituted heteroaryl radical interrupted by at least one heteroatom, selected from the group consisting of O, S and N and having a total of 5 to 30 carbon atoms and/or heteroatoms; or a group with donor or acceptor action; 
         or 
         R 14′  and R 15′ , R 15′  and R 16′  or R 16′  and R 17′  form, together with the carbon atoms to which they are bonded, a saturated or unsaturated or aromatic ring, which has a total of from 5 to 18 carbon atoms and/or heteroatoms; 
         or 
         if A 9′  is CR 12′ , R 12′  and R 17′  together may form a saturated or unsaturated, linear or branched bridge optionally comprising heteroatoms, selected from the group consisting of O, S and N, to which is optionally fused a five- to eight-membered ring comprising carbon atoms and/or heteroatoms, and which are optionally substituted with aromatic units, heteroaromatic units or groups with donor or acceptor action; 
         q′ is 0 or 1; 
         or 
         L is a ligand of the general formula (C) 
       
       
         
           
           
               
               
           
         
         in which the symbols are each defined as follows: 
         D are each independently CR 34′″  or N; 
         W is C or N; 
         E are each independently CR 35′″ , N, NR 36′″  or O; 
         1 is 1 or 2; 
         R 34′″ , R 35′″ , R 36′″ 
 are each independently hydrogen; substituted or unsubstituted or branched alkyl; 
 substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl; 
 
         or 
         in each case two R 34′″ , R 3′″  or R 36′″  radicals together form a fused ring which may optionally comprise at least one heteroatom; 
         or 
         R 34′″ , R 35′″ , R 36′″  or R 37′″  a radical having donor or acceptor action; 
         where the line means an optional bridge between one of the D groups and one of the E groups; 
         where the bridge may be defined as follows: 
         alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR 38′″ , O, S, SiR 41′″ R 42′″ , and (CR 43′″ R 44′″ ) v , where one or more nonadjacent (CR 43′″ R 44′″ ) groups may be replaced by NR 38′″ , O, S, SiR 41′″ R 42′″ , where 
         v is from 2 to 10; 
         and 
         R 38′″ , R 41′″ , R 42′″ , R 43′″ , R 44′″ 
 are each H, alkyl, aryl or heteroaryl. 
 
       
     
     
         26 . The organic electronic device according to claim  16 , wherein the metal-carbene complex is employed in combination with at least one host material. 
     
     
         27 . A light-emitting layer comprising at least one metal-carbene complex as defined in claim  16  as emitter material. 
     
     
         28 . An apparatus selected from the group consisting of stationary visual display units; mobile visual display units; illumination units; units in items of clothing; units in handbags, units in accessories, units in furniture and units in wallpaper, comprising the organic electronic device according to claim  16 . 
     
     
         29 . Metal-carbene complex, wherein the metal is Ir or Pt, comprising one, two or three bidentate ligands of formula (I) and/or (I′) as described in claim  16 . 
     
     
         30 . A process for preparing a metal carbene complex according to  claim 28 , by contacting suitable compounds comprising Ir or Pt selected from the group consisting of [Ir(COD)Cl] 2 , [Ir(COE) 2 Cl] 2  IrCl 3 ×H 2 O, Ir(acac) 3 , Ir(COD) 2 BF 4 , Ir(COD) 2 BARF (BARF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate)), Pt(COD)Cl 2 , Pt(acac) 2 , [Pt(C 6 H 10 )Cl 2 ] 2 , K 2 PtCl 6 , Pt(pyridine) 2 Cl 2 , [PtMe 2 (SMe 2 )] 2 , Pt(SMe 2 ) 2 Cl 2 , Pt(SEt 2 ) 2 Cl 2 , Pt(phenanthroline)Cl 2 , Pt(NH 3 ) 2 Cl 2  and mixtures thereof with ligand precursors of formula (IV), wherein the ligand precursors are reacted with the suitable Ir or Pt comprising compounds and the carbene can be released from precursors of the carbene ligands by removing methanol or ethanol,
 wherein the ligand precursor used is a compound of the general formula (IV) 
 
       
         
           
           
               
               
           
         
         wherein R 1 , A 1 , A 2 , A 3 , A 4 , A 1′ , A 2′ , A 3′  and A 4′  are each as already defined in claim  16 , and 
         R 12  is defined as follows: 
         R 12  is independently SiR 13 R 14 R 15 , aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl, 
         R 13 , R 14 , 
         R 15  are each independently aryl, heteroaryl, alkyl, cycloalkyl or heterocycloalkyl. 
       
     
     
         31 . An apparatus selected from the group consisting of stationary visual display units; mobile visual display units; illumination units; units in items of clothing; units in handbags, units in accessories, units in furniture and units in wallpaper comprising the light-emitting layer according to  claim 26 .