Binuclear and trinuclear metal complexes composed of two inter-linked tripodal hexadentate ligands for use in electroluminescent devices

1. A compound of formula (1) or formula (2):

wherein

M is on each occurrence, identically or differently, iridium or rhodium;

Q is an aryl or heteroaryl group having 6 to 10 aromatic ring atoms and which is coordinated to each of the two or three M identically or differently in each case via a carbon or nitrogen atom and which is optionally substituted by one or more radicals R; and wherein the coordinating atoms in Q are not bonded in the ortho position to one another;

D is on each occurrence, identically or differently, C or N;

X is on each occurrence, identically or differently, CR or N;

p is 0 or 1;

V is on each occurrence, identically or differently, a group of formulae (3) or (4):

wherein one of the dashed bonds is the bond to the corresponding 6-membered aryl or heteroaryl ring group of formula (1) or (2) and the two other dashed bonds are each the bonds to part-ligands L;

L is on each occurrence, identically or differently, a bidentate, monoanionic part-ligand;

X 1 is on each occurrence, identically or differently, CR or N;

A 1 is on each occurrence, identically or differently, C(R) 2 or O;

A 2 is on each occurrence, identically or differently, CR, P(═O), B, or SiR, with the proviso that, when A 2 is P(═O), B, or SiR, A 1 is O and the A bonded to this A 2 is not —C(═O)—NR′— or —C(═O)—O—;

A is on each occurrence, identically or differently, —CR═CR—, —C(═O)—NR′—, —C(═O)—O—, —CR 2 —CR 2 —, —CR 2 —O—, or a group of formula (5):

wherein the dashed bond is the position of the bond from a bidentate part-ligand L or from the corresponding 6-membered aryl or heteroaryl ring group of formula (1) or (2) to this structure and * is the position of the linking of the unit of formula (5) to the central cyclic group of formulae (3) or (4);

X 2 is on each occurrence, identically or differently, CR or N or two adjacent groups X 2 together are NR, O, or S, so as to define a five-membered ring, and the remaining X 2 are, identically or differently on each occurrence, CR or N; or two adjacent groups X 2 together are CR or N if one of the groups X 3 in the ring are N, so as to define a five-membered ring; with the proviso that a maximum of two adjacent groups X 2 are N;

X 3 is on each occurrence C, or one group X 3 is N and the other group X 3 in the same ring is C; with the proviso that two adjacent groups X 2 together are CR or N if one of the groups X 3 in the ring is N;

R is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 1 ) 2 , CN, NO 2 , OR 1 , SR 1 , 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 , COO(cation), SO 3 (cation), OSO 3 (cation), OPO 3 (cation) 2 , O(cation), N(R 1 ) 3 (anion), P(R 1 ) 3 (anion), a straight-chain alkyl 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 group having 3 to 20 C atoms, wherein the alkyl, alkenyl, or alkynyl group is in each case optionally substituted by one or more radicals R 1 , wherein one or more non-adjacent CH 2 groups are optionally replaced by Si(R 1 ) 2 , C═O, NR 1 , O, S, or CONR 1 , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which in each case is optionally substituted by one or more radicals R 1 ; and wherein two radicals R also optionally define a ring system with one another;

R′ is on each occurrence, identically or differently, H, D, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl group is in each case optionally substituted by one or more radicals R 1 and wherein one or more non-adjacent CH 2 groups are optionally replaced by Si(R 1 ) 2 , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is in each case optionally substituted by one or more radicals R 1 ;

R 1 is on each occurrence, identically or differently, H, D, F, Cl, Br, I, N(R 2 ) 2 , CN, NO 2 , OR 2 , SR 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 , COO(cation), SO 3 (cation), OSO 3 (cation), OPO 3 (cation) 2 , O(cation), N(R 2 ) 3 (anion), P(R 2 ) 3 (anion), a straight-chain alkyl 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 group having 3 to 20 C atoms, wherein the alkyl, alkenyl, or alkynyl group is in each case optionally substituted by one or more radicals R 2 , wherein one or more non-adjacent CH 2 groups are optionally replaced by Si(R 2 ) 2 , C═O, NR 2 , O, S, or CONR 2 , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is in each case optionally substituted by one or more radicals R 2 ; and wherein two or more radicals R 1 also optionally define a ring system with one another;

R 2 is on each occurrence, identically or differently, H, D, F, or an aliphatic, aromatic, or heteroaromatic organic radical having 1 to 20 C atoms, wherein one or more H atoms are optionally replaced by F;

cation is selected on each occurrence, identically or differently, from the group consisting of proton, deuteron, alkali metal ions, alkaline-earth metal ions, ammonium, tetraalkylammonium, and tetraalkylphosphonium; and

anion is selected on each occurrence, identically or differently, from the group consisting of halides, carboxylates R 2 —COO − , cyanide, cyanate, isocyanate, thiocyanate, thioisocyanate, hydroxide, BF 4 − , PF 6 − , B(C 6 F 5 ) 4 − , carbonate, and sulfonates.

2. The compound of claim 1 , wherein the compound is selected from the group consisting of compounds of formulae (1a) and (2a):

wherein the radical R in the ortho position to D is in each case selected, identically or differently on each occurrence, from the group consisting of H, D, F, CH 3 , and CD 3 .

3. The compound of claim 1 , wherein Q in formula (1) is a group of formulae (Q-1) through (Q3) and Q in formula (2) is a group of one of formulae (Q-4) through (Q-15) when p is 0 or a group of formulae (Q-16) through (Q-19) when p is 1:

wherein

the dashed bond in each case indicates the linking within the formula (1) or (2); and

* indicates the position at which the group is coordinated to M.

4. The compound of claim 1 , wherein the group of formula (3) is selected from the group consisting of structures of formulae (6) through (9) and wherein the group of formula (4) is selected from group consisting of structures of formulae (10) to (14):

5. The compound of claim 1 , wherein the group of formula (3) has a structure of formula (6′) and wherein the group of formula (4) has a structure of formula (10′) or (10″):

6. The compound of claim 1 , wherein A is selected, identically or differently on each occurrence, from the group consisting of —C(═O)—O—, —C(═O)—NR′— or a group of formula (5), wherein the group of formula (5) is selected from the group consisting of structures of formulae (15) through (39):

7. The compound of claim 1 , wherein the group of formula (3) is selected from the group consisting of formulae (3a) through (3m) and the group of formula (4) is selected from the group consisting of formulae (4a) through (4m):

8. The compound of claim 1 , wherein the group of formula (3) is a group of formula (6a′″):

9. The compound of claim 1 , wherein all four part-ligands L when p is 0 or all six part-ligands L when p is 1 are identical and are identically substituted.

10. The compound of claim 1 , wherein the bidentate part-ligands L are selected, identically or differently on each occurrence, from the structures of formulae (L-1), (L-2), and (L-3):

wherein

the dashed bond is the bond from the part-ligand L to the group of formula (3) or (4);

CyC is, identically or differently on each occurrence, a substituted or unsubstituted aryl or heteroaryl group having 5 to 14 aromatic ring atoms, which is coordinated to M via a carbon atom and which is bonded to CyD via a covalent bond;

CyD is, identically or differently on each occurrence, a substituted or unsubstituted heteroaryl group having 5 to 14 aromatic ring atoms, which is coordinated to M via a nitrogen atom or via a carbene carbon atom and which is bonded to CyC via a covalent bond; and

a plurality of the optional substituents optionally define a ring system with one another.

11. A process for preparing the compound of claim 1 , comprising reacting the free ligand with metal alkoxides of formula (58), metal ketoketonates of formula (59), metal halides of formula (60), or metal carboxylates of formula (61), or with iridium or rhodium compounds which carry both alkoxide and/or halide and/or hydroxyl and ketoketonate radicals,

wherein

Hal is F, Cl, Br, or I; and

the iridium and rhodium starting materials are optionally in the form of the corresponding hydrates.

12. A mixture comprising at least one compound of claim 1 and at least one further compound, in particular a host material.

13. The mixture of claim 12 , wherein the at least one further compound is a host material.

14. A formulation comprising at least one mixture of 12 and at least one solvent.

15. A formulation comprising at least one compound of claim 1 and at least one solvent.

16. An electronic device comprising at least one compound of claim 1 .

17. The electronic device of claim 16 , wherein the electronic device is an organic electroluminescent device, wherein the at least one compound is employed as an emitting compound in one or more emitting layers of the organic electroluminescent device.

18. The compound of claim 1 , wherein R 2 is a hydrocarbon radical.