Metal complexes
The present invention relates to metal complexes of formula (1): M(L) n (L′) m (1) which comprises a moiety M(L) n of formula (2): and to electronic devices, in particular organic electroluminescent devices, comprising these metal complexes.
1. A compound of formula (1):
M(L) n (L′) m (1)
which comprises a moiety M(L) n of formula (2):
wherein
M is iridium or platinum;
CyC is an aryl or heteroaryl group having 5 to 18 aromatic ring atoms or a fluorene group, wherein CyC is coordinated to M via a carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyD via a covalent bond wherein CyC and CyD are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
CyD is a heteroaryl group having 5 to 18 aromatic ring atoms, wherein CyD is coordinated to M via a neutral nitrogen atom or via a carbene carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyC via a covalent bond wherein CyD and CyC are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R′, wherein one or more non-adjacent CH 2 groups is optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , or a diarylamino group, diheteroarylamino group, or arylheteroaryl-amino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 ; and wherein two adjacent radicals R optionally form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another;
R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and where one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO 2 , an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , or a diarylamino group, diheteroarylamino group or arylheteroarylamino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 ;
R 2 is on each occurrence, identically or differently, H, D, F or an aliphatic, aromatic, and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by F; and wherein two or more substituents R 2 optionally form a mono- or polycyclic, aliphatic ring system with one another;
L′ is, identically or differently on each occurrence, a co-ligand;
n is 1, 2, or 3;
m is 0, 1, 2, 3, or 4;
and wherein
a plurality of ligands L are optionally linked to one another or L is optionally linked to L′ via a single bond or a divalent or trivalent bridge and thus form a tridentate, tetradentate, pentadentate, or hexadentate ligand system;
a substituent R optionally additionally coordinates to the metal; and
wherein CyD and/or CyC contain(s) two adjacent carbon atoms which are each substituted by radicals R, wherein the respective radicals R, together with the C atoms, form a ring of formula (3) or (4):
wherein R 1 and R 2 are as defined above and the dashed bonds indicate the linking of the two carbon atoms in the ligand;
A 1 is C(R 3 ) 2 , or NR 3 ;
A 2 is C(R 1 ) 2 , O, S, NR 3 , or C(═O);
A 3 is C(R 3 ) 2 , NR 3 , or C(═O);
G is an alkylene group having 1, 2 or 3 C atoms and is optionally substituted by one or more radicals R 2 , —CR 2 ═CR 2 —, or an ortho-linked arylene or heteroarylene group having 5 to 14 aromatic ring atoms optionally substituted by one or more radicals R 2 ; and
R 3 is, identically or differently on each occurrence, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and wherein one or more H atoms is optionally replaced by D or F, an aromatic or hetero aromatic ring system having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , or an aralkyl or heteroaralkyl group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 ; wherein two radicals R 3 bonded to the same carbon atom optionally form an aliphatic or aromatic ring system with one another to form a spiro system; and wherein R 3 optionally forms an aliphatic ring system with an adjacent radical R or R 1 ;
with the proviso that two heteroatoms are not bonded directly to one another in A 1 -A 2 -A 3 and
with the proviso that the radicals R on CyC do not join together to form a ring with the radicals R on CyD.
2. The compound of claim 1 , wherein when M is iridium(III), n is 1, 2 or 3, and when M is platinum(II), n is 1 or 2.
3. The compound of claim 1 , wherein CyC is selected from the group consisting of formulae (CyC-1) to (CyC-19), wherein CyC is in each case bonded to CyD at the position denoted by # and is coordinated to the metal at the position denoted by *:
wherein
X is on each occurrence, identically or differently, CR or N; and
W is on each occurrence, identically or differently, NR, O, S, or CR 2 .
4. The compound of claim 1 , wherein CyC is selected from the group consisting of formulae (CyC-1a) to (CyC-19a), wherein CyC is in each case bonded to CyD at the position denoted by # and is coordinated to the metal at the position denoted by *:
wherein
W is on each occurrence, identically or differently, NR, O, S, or CR 2 .
5. The compound of claim 1 , wherein CyD is selected from the group consisting of formulae (CyD-1) to (CyD-10), wherein CyD is in each case bonded to CyC at the position denoted by # and is coordinated to the metal at the position denoted by *:
wherein
X is on each occurrence, identically or differently, CR or N; and
W is on each occurrence, identically or differently, NR, O, S, or CR 2 .
6. The compound of claim 1 , wherein CyD is selected from the group consisting of formulae (CyD-1a) to (CyD-10a), wherein CyD is in each case bonded to CyC at the position denoted by # and is coordinated to the metal at the position denoted by *:
wherein
W is on each occurrence, identically or differently, NR, O, S, or CR 2 .
7. The compound of claim 1 , wherein CyC comprises a group of formula (3) or (4) and is selected from the group consisting of formulae (CyC-1-1) to (CyC-19-1) and/or CyD comprises a group of formula (3) or (4) and is selected from the group consisting of formulae (CyD 1-1) to (CyD-10-1):
wherein
X is on each occurrence, identically or differently, CR or N; and
W is on each occurrence, identically or differently, NR, O, S, or CR 2 ;
in each case denotes the positions which stand for CR, wherein the respective radicals R, together with the C atoms to which they are bonded, form a ring of formula (3) or (4),
where the group of formulae (CyC-1-1) to (CyC-19-1) is in each case bonded to CyD at the position denoted by # and is coordinated to the metal at the position denoted by *, and where the groups of formula (CyD-1-1) to (CyD-10-1) is in each case bonded to CyC at the position denoted by # and
is coordinated to the metal at the position denoted by *.
8. The compound of claim 1 , wherein the compound is selected from the group consisting of formulae (17) to (22):
wherein
V is a single bond or a bridging unit containing 1 to 80 atoms from the third, fourth, fifth, and/or sixth main group or a 3- to 6-membered homocycle or heterocycle which covalently bonds L to one another or L to L′.
9. An oligomer, polymer, or dendrimer comprising one or more compounds of claim 1 , wherein one or more bonds are present from the compound to the polymer, oligomer, or dendrimer.
10. A formulation comprising a compound of claim 1 and at least one further compound.
11. A formulation comprising an oligomer, polymer, or dendrimer of claim 9 and at least one further compound.
12. An electronic device comprising at least one compound of claim 1 .
13. The electronic device of claim 12 , where the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, and organic laser diodes.
14. An electronic device comprising at least one oligomer, polymer, or dendrimer of claim 9 .
15. The electronic device of claim 14 , wherein the electronic device is selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field-effect transistors, organic thin-film transistors, organic light-emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field-quench devices, light-emitting electrochemical cells, and organic laser diodes.
16. An organic electroluminescent device comprising a compound of claim 1 employed as an emitting compound in one or more emitting layers optionally in combination with a matrix material.
17. The compound of claim 1 , wherein
R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 1 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , or a diarylamino group, diheteroarylamino group, or arylheteroaryl-amino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 .
18. The compound of claim 1 , wherein the structure of formula (3) is selected from the group consisting of formulae (3-A), (3-B), (3-C), (3-D), and (3-E):
wherein
A 1 is C(R 3 ) 2 ,— or NR 3 ;
A 2 is O or NR 3 ;
A 3 is NR 3 ; and
R 1 and R 3 are defined as in claim 1 , and
the structure of formula (4) is selected from the group consisting of formulae (4-A), (4-B) and (4-C):
19. An organic electroluminescent device comprising an oligomer, polymer, or dendrimer of claim 9 employed as an emitting compound in one or more emitting layers optionally in combination with a matrix material.
20. A compound of formula (1):
M(L) n (L′) m (1)
which comprises a moiety M(L) n of formula (2):
wherein
M is iridium or platinum;
CyC is an aryl or heteroaryl group having 5 to 18 aromatic ring atoms or a fluorene group, wherein CyC is coordinated to M via a carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyD via a covalent bond wherein CyC and CyD are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
CyD is a heteroaryl group having 5 to 18 aromatic ring atoms, wherein CyD is coordinated to M via a neutral nitrogen atom or via a carbene carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyC via a covalent bond wherein CyD and CyC are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 1 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , or a diarylamino group, diheteroarylamino group, or arylheteroaryl-amino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 ; and wherein two adjacent radicals R optionally form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another;
R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and where one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO 2 , an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , or a diarylamino group, diheteroarylamino group or arylheteroarylamino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 ; and wherein two or more adjacent radicals R 1 with one another or R 1 with R optionally form a mono- or polycyclic, aliphatic, aromatic, or heteroaromatic ring system;
R 2 is on each occurrence, identically or differently, H, D, F or an aliphatic, aromatic, and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by F; and wherein two or more substituents R 2 optionally form a mono- or polycyclic, aliphatic ring system with one another;
L′ is, identically or differently on each occurrence, a co-ligand;
n is 1, 2, or 3;
m is 0, 1, 2, 3, or 4;
and wherein
a plurality of ligands L are optionally linked to one another or L is optionally linked to L′ via a single bond or a divalent or trivalent bridge and thus form a tridentate, tetradentate, pentadentate, or hexadentate ligand system;
a substituent R optionally additionally coordinates to the metal; and
wherein CyD contain(s) two adjacent carbon atoms which are each substituted by radicals R, wherein the respective radicals R, together with the C atoms, form a ring of formula (3) or (4):
wherein R 1 and R 2 are as defined above and the dashed bonds indicate the linking of the two carbon atoms in the ligand;
A 1 is C(R 3 ) 2 , S, or NR 3 ;
A 2 is C(R 1 ) 2 , O, S, NR 3 , or C(═O);
A 3 is C(R 3 ) 2 , O, S, NR 3 , or C(═O);
G is an alkylene group having 1, 2 or 3 C atoms and is optionally substituted by one or more radicals R 2 , —CR 2 ═CR 2 —, or an ortho-linked arylene or heteroarylene group having 5 to 14 aromatic ring atoms optionally substituted by one or more radicals R 2 ; and
R 3 is, identically or differently on each occurrence, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and wherein one or more H atoms is optionally replaced by D or F, an aromatic or hetero aromatic ring system having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , or an aralkyl or heteroaralkyl group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 ; wherein two radicals R 3 bonded to the same carbon atom optionally form an aliphatic or aromatic ring system with one another to form a spiro system; and wherein R 3 optionally forms an aliphatic ring system with an adjacent radical R or R 1 ;
with the proviso that two heteroatoms are not bonded directly to one another in A 1 -A 2 -A 3 and
with the proviso that the radicals R on CyC do not join together to form a ring with the radicals R on CyD.
21. An organic electroluminescent device comprising a compound of claim 20 .
22. A compound of formula (1):
M(L) n (L′) m (1)
which comprises a moiety M(L) n of formula (2):
wherein
M is iridium or platinum;
CyC is an aryl or heteroaryl group having 5 to 18 aromatic ring atoms or a fluorene group, wherein CyC is coordinated to M via a carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyD via a covalent bond wherein CyC and CyD are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
CyD is a heteroaryl group having 5 to 18 aromatic ring atoms, wherein CyD is coordinated to M via a neutral nitrogen atom or via a carbene carbon atom, is optionally substituted by one or more radicals R, and is bonded to CyC via a covalent bond wherein CyD and CyC are optionally linked to one another via a group selected from the group consisting of C(R 1 ) 2 , C(R 1 ) 2 —C(R 1 ) 2 —, NR 1 , O, and S;
R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OH, COOH, C(═O)N(R 1 ) 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , C(═O)R 1 , P(═O)(R 1 ) 2 , S(═O)R 1 , S(═O) 2 R 1 , OSO 2 R 1 , a straight-chain alkyl, alkoxy, or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 1 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 1 C═CR 1 , C≡C, Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 and wherein one or more H atoms is optionally replaced by D, F, Cl, Br, I, or CN, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 , or a diarylamino group, diheteroarylamino group, or arylheteroaryl-amino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 1 ; and wherein two adjacent radicals R optionally form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system with one another;
R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , Si(R 2 ) 3 , B(OR 2 ) 2 , C(═O)R 2 , P(═O)(R 2 ) 2 , S(═O)R 2 , S(═O) 2 R 2 , OSO 2 R 2 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and where one or more H atoms is optionally replaced by D, F, Cl, Br, I, CN, or NO 2 , an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 , or a diarylamino group, diheteroarylamino group or arylheteroarylamino group having 10 to 40 aromatic ring atoms optionally substituted by one or more radicals R 2 ; and wherein two or more adjacent radicals R 1 with one another or R 1 with R optionally form a mono- or polycyclic, aliphatic, aromatic, or heteroaromatic ring system;
R 2 is on each occurrence, identically or differently, H, D, F or an aliphatic, aromatic, and/or heteroaromatic hydrocarbon radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by F; and wherein two or more substituents R 2 optionally form a mono- or polycyclic, aliphatic ring system with one another;
L 1 is, identically or differently on each occurrence, a co-ligand;
n is 2, or 3;
m is 0, 1, 2, 3, or 4;
and wherein
a plurality of ligands L are optionally linked to one another or L is optionally linked to L′ via a single bond or a divalent or trivalent bridge and thus form a tridentate, tetradentate, pentadentate, or hexadentate ligand system;
a substituent R optionally additionally coordinates to the metal; and
wherein CyD and/or CyC contain(s) two adjacent carbon atoms which are each substituted by radicals R, wherein the respective radicals R, together with the C atoms, form a ring of formula (3) or (4):
wherein R 1 and R 2 are as defined above and the dashed bonds indicate the linking of the two carbon atoms in the ligand;
A 1 is C(R 3 ) 2 , or NR 3 ;
A 2 is C(R 1 ) 2 , O, S, NR 3 , or C(═O);
A 3 is C(R 3 ) 2 , NR 3 , or C(═O);
G is an alkylene group having 1, 2 or 3 C atoms and is optionally substituted by one or more radicals R 2 , —CR 2 ═CR 2 —, or an ortho-linked arylene or heteroarylene group having 5 to 14 aromatic ring atoms optionally substituted by one or more radicals R 2 ; and
R 3 is, identically or differently on each occurrence, a straight-chain alkyl or alkoxy group having 1 to 20 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 C atoms, each of which is optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups is optionally replaced by R 2 C═CR 2 , —C≡C, Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 and wherein one or more H atoms is optionally replaced by D or F, an aromatic or hetero aromatic ring system having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , an aryloxy or heteroaryloxy group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 , or an aralkyl or heteroaralkyl group having 5 to 24 aromatic ring atoms optionally substituted by one or more radicals R 2 ; wherein two radicals R 3 bonded to the same carbon atom optionally form an aliphatic or aromatic ring system with one another to form a spiro system; and wherein R 3 optionally forms an aliphatic ring system with an adjacent radical R or R 1 ;
with the proviso that two heteroatoms are not bonded directly to one another in A 1 -A 2 -A 3 and
with the proviso that the radicals R on CyC do not join together to form a ring with the radicals R on CyD.
23. An organic electroluminescent device comprising a compound of claim 22 .