Heteroleptic light-emitting complexes

1. A heteroleptic light emitting complex having the general formula M(L 1 ) m (L 2 ) n wherein

a) L 1 is selected from substituted or unsubstituted 2-phenylquinoline and substituted or unsubstituted 1-phenylisoquinoline ligands of formulae (3) and (4)

wherein R 8 to R 13 , which may be the same or different at each occurrence, are selected from the group consisting of H, halogen, NO 2 , CN, N(R 6 ) 2 , B(OR 6 ) 2 , COOH, C(O)R 6 , CO 2 R 6 , CON(R 6 ) 2 , OR 6 , SR 6 , SO 3 H, S(═O)R 6 , S(═O) 2 R 6 , P(R 6 ) 2 , P(═O)(R 6 ) 2 , Si(R 6 ) 3 , alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups, with R 6 , which may be the same or different, being selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups,

p, u and v, independent of one another, represent an integer of from 0 to 4, t represents an integer from 0 to 3 and s and w, independent of one another represent an integer of from 0 to 2,

b) ligand L 2 is selected from the group consisting of 1-(2,6 disubstituted phenyl)-2-phenyl-1H-imidazole ligands or 5-(2,6 disubstituted phenyl)-1-phenyl-1H-pyrazole ligands of formulae 1 or 2

wherein

R 1 and R 2 , which may be the same or different, each represent a C 1 to C 20 alkyl or haloalkyl group, a cycloalkyl group, a C 5 to C 30 aryl group or a C 2 to C 30 heteroaryl group, said cycloalkyl, aryl and heteroaryl groups being un-substituted or substituted by substituents selected from the group consisting of halogen, alkyl, alkoxy, amino, cyano, alkenyl, alkynyl, arylalkyl, aryl and heteroaryl groups; and

R 3 is selected from the group consisting of H, halogen, NO 2 , CN, N(R 4 ) 2 , B(OR 4 ) 2 , COOH, C(O)R 4 , CO 2 R 4 , CON(R 4 ) 2 , OR 4 , SR 4 , SO 3 H, S(═O)R 4 , S(═O) 2 R 4 , P(R 4 ) 2 , P(═O)(R 4 ) 2 , Si(R 4 ) 3 , alkyl, cycloalkyl, haloalkyl, alkoxy,alkenyl, alkynyl, aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups, with the proviso that R 3 is not aryl if ligand L 2 is represented by formula 1,

R 4 which may be the same or different, are selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups,

R and R′, independently of one another, are selected from the group consisting of H, halogen, NO 2 , CN, N(R 5 ) 2 , B(OR 5 ) 2 , COOH, C(O)R 5 , CO 2 R 5 , CON(R 5 ) 2 , OR 5 , SR 5 , SO 3 H, S(═O)R 5 , S(═O) 2 R 5 , P(R 5 ) 2 , P(═O)(R 5 ) 2 , Si(R 5 ) 3 , alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, heteroaryl, substituted heteroaryl and heterocyclic groups,

R 5 which may be the same or different, are selected from the group consisting of H, alkyl, alkenyl, alkynyl, aryl, substituted aryl, alkylaryl, halogen, heteroaryl, substituted heteroaryl and heterocyclic groups,

a is an integer of from 0 to 3 and b is an integer of from 0 to 2, and c is an integer of from 0 to 3,

c) M is Ir, m is 2, and n is 1.

2. The heteroleptic light emitting complex in accordance with claim 1 , wherein ligand L 2 is selected from 1-(2,6 disubstituted phenyl)-2-phenyl-1H-imidazole ligands of formula (1) wherein R 3 is H or a C 1 to C 20 alkyl group.

3. The heteroleptic light emitting complex in accordance with claim 1 wherein ligand L 2 is selected from 5-(2,6 disubstituted phenyl)-1-phenyl-1H-pyrazole ligands of formula (2) wherein R 3 is H or a C 1 to C 20 alkyl group.

4. The heteroleptic light emitting complex in accordance with claim 1 wherein at least one of R 1 and R 2 is a C 1 to C 20 alkyl group.

5. The heteroleptic light emitting complex in accordance with claim 4 wherein R 1 and R 2 are independently selected from C 1 to C 8 alkyl groups.

6. The heteroleptic light emitting complex in accordance with claim 5 wherein R 1 and R 2 are independently selected from methyl and isopropyl.

7. The heteroleptic light emitting complex in accordance with claim 1 represented by any one of formulae (5) to (8):

wherein R 1 to R 3 have the meanings as defined in claim 1 and wherein the phenylquinoline and phenylisoquinoline ligands may be substituted or unsubstituted.

8. The heteroleptic light emitting complex in accordance with claim 1 wherein ligand L 1 is a 2-phenylquinoline ligand and ligand L 2 is a ligand of formula (2).

9. The heteroleptic light emitting complex in accordance with claim 1 wherein the triplet energy level of ligand L 2 is higher than the triplet energy level of ligand L 1 .

10. An emitting layer of an organic light emitting device comprising the heteroleptic light emitting complex according to claim 1 .

11. An organic light emitting device comprising an emissive layer, said emissive layer comprising a heteroleptic light emitting complex according to claim 1 .

12. An organic light emitting device comprising an emissive layer, said emissive layer comprising a heteroleptic light emitting complex according to claim 1 as dopant and a host material represented by general formulae (9) or (10) :

wherein A is a single bond or a divalent residue of biphenyl, triphenyl,

in each of which one or more hydrogen atoms attached in the carbon atoms may be replaced by a substituent other than hydrogen, wherein Z is any one selected from N, O, S, and SiR 16 , Y is N—R 16 , O, S, Si(R 16 ) 2 where R 16 is C 1 -C 20 alkyl or C 1 -C 20 aryl, R 14 and R 15 are independently selected from hydrogen or C 1 -C 20 alkyl;

X 1 to X 4 are independently selected from substituents other than spirobifluorenyl;

1, p and q are integers between 0 to 4;

m is an integer between 0 to 3,

wherein B 1 and B 2 are independently selected from hydrogen, and a heterocyclic group;

r is an integer between 0 to 3; and X 1 to X 4 , m, p, and q are as defined for Formula (9).