Metal complexes comprising azabenzimidazole carbene ligands and the use thereof in OLEDs

A metal-carbene complex of formula (I):

• wherein:
• M is Ir;
• n is an integer selected from 1, 2 and 3, where the ligand(s):
• are each bidentate ligands;
• Y is NR1;
• R1 is ethyl, isopropyl, tert-butyl, neopentyl, CF3, a substituted or unsubstituted cycloalkyl radical having 5 to 20 carbon atoms, or a substituted or unsubstituted aryl radical having 6 to 30 carbon atoms;
• R2, R3, R4 are each independently hydrogen, a linear or branched alkyl radical having 1 to 6 carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action selected from halogen radicals;
• CF3, CN and SiMe3, or
• R2 and R3 or R3 and R4 form, together with the carbon atoms to which they are bonded, an optionally substituted unsaturated, saturated or aromatic ring which is optionally interrupted by at least one further heteroatom, has a total of 5 to 18 carbon atoms and/or heteroatoms and may optionally be fused to at least one further optionally substituted saturated or unsaturated or aromatic ring optionally interrupted by at least one further heteroatom and having a total of 5 to 18 carbon atoms and/or heteroatoms;
• A1 is CR6;
• A2 is CR7;
• A3 is CR8;
• A4 is CR9;
• R6, R7, R8, R9 are each independently hydrogen, a linear or branched alkyl radical optionally bearing at least one functional group, optionally interrupted by at least one heteroatom and having 1 to 20 carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action selected from halogen radicals, CF3, CN and SiMe3, or
• R6 and R7, R7 and R8, or R8 and R9 form, together with the carbon atoms to which they are bonded, a saturated, unsaturated or aromatic, optionally substituted ring which is optionally interrupted by at least one heteroatom, has a total of 5 to 18 carbon atoms and/or heteroatoms and may optionally be fused to at least one further optionally substituted saturated or unsaturated or aromatic ring optionally interrupted by at least one further heteroatom and having a total of 5 to 18 carbon atoms and/or heteroatoms;
• p is 1;
• K is an uncharged mono- or bidentate ligand;
• L is a carbene ligand of formula (II):
• a ligand of the formula (B):
• picolinato,
• salicylato,
• 8-hydroxyquinolato, or
• a heterocyclic noncarbene ligand of formula (III):
• A9 is CR12 or N;
• A10 is CR13 or N;
• R11 is a linear or branched alkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms, substituted or unsubstituted heterocycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms and/or heteroatoms, substituted or unsubstituted aryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having a total of 5 to 18 carbon atoms and/or heteroatoms;
• R12, R13 are each independently hydrogen, a linear or branched alkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms, substituted or unsubstituted heterocycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms and/or heteroatoms, substituted or unsubstituted aryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action;
• A5 is CR14 or N;
• A6 is CR15 or N;
• A7 is CR16 or N;
• A8 is CR17 or N;
• R14, R15, R16, R17 are each independently hydrogen, a linear or branched alkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms, substituted or unsubstituted heterocycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms and/or heteroatoms, substituted or unsubstituted aryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action, or
• R14 and R15, R15 and R16 or R16 and R17 form, together with the carbon atoms to which they are bonded, an unsaturated or aromatic, optionally substituted ring optionally interrupted by at least one heteroatom and having a total of 5 to 18 carbon atoms and/or heteroatoms, and/or
• R12 and R13 form, together with A9 and A10 to which they are bonded, an unsaturated or aromatic, optionally substituted ring optionally interrupted by exactly one heteroatom or two adjacent heteroatoms and having a total of 5 to 18 ring atoms, and/or
• if A9 is CR12, R12 and R17 together form a saturated or unsaturated, linear or branched bridge optionally comprising heteroatoms, aromatic units, heteroaromatic units and/or functional groups and having a total of 1 to 30 carbon atoms and/or heteroatoms, to which is optionally fused a substituted or unsubstituted, five- to eight-membered ring comprising carbon atoms and/or heteroatoms;
• q is 0 or 1;
• R51 is in each case independently a linear or branched alkyl radical having 1 to 6 carbons atoms, substituted or unsubstituted aryl radical having 6 to 20 carbon atoms;
• substituted or unsubstituted heteroaryl radical having a total of 5 to 18 carbon atoms and/or heteroatoms;
• R52 is hydrogen, a linear or branched alkyl radical having 1 to 6 carbon atoms, substituted or unsubstituted aryl radical having 6 to 20 carbon atoms;
• D are each independently CR18 or N;
• W is C, N;
• E are each independently CR19, N, NR20;
• G is CR21, N, NR22, S, or O;
• R18, R19, R21 are each independently hydrogen, a linear or branched alkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms, substituted or unsubstituted heterocycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms and/or heteroatoms, substituted or unsubstituted aryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action, or
• in each case 2 R18, R19 and R21 radicals, together with the carbon atoms to which they are bonded, form a saturated, unsaturated or aromatic, optionally substituted ring optionally interrupted by at least one heteroatom and having a total of 5 to 18 carbon atoms and/or heteroatoms;
• R20, R22 are each independently a linear or branched alkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms, substituted or unsubstituted heterocycloalkyl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 3 to 20 carbon atoms and/or heteroatoms, substituted or unsubstituted aryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical optionally interrupted by at least one heteroatom, optionally bearing at least one functional group and having a total of 5 to 18 carbon atoms and/or heteroatoms, group with donor or acceptor action;
• preferably o,o′-dialkylated aryl radical;
• where the solid curved line is an optional bridge between one of the D groups and the G group, and the bridge is defined as alkylene, arylene, heteroarylene, alkynylene, alkenylene, NR23, O, S, SiR24R25, CR50═N and (CR26R27)d, where one or more nonadjacent (CR26R27) groups may be replaced by NR23, O, S, SiR24R25;
• d is 2 to 10;
• R24, R25, R26, R27, R50 are each H, alkyl, aryl, heteroaryl, alkenyl, alkynyl;
• m is 0, 1 or 2, where, when m is 2, the K ligands may be the same or different;
• and
• o is 0, 1 or 2, where, when o is 2, the L ligands may be the same or different,
• wherein the following compounds are excluded: