Organometallic complexes which emit in the red to green spectral region and their use in OLEDs

1. An organometallic complex of the general formula (I)

M[L 1 ] q [L 2 ] r [L 3 ] s   (I)

in which

M is a metal atom selected from the group consisting of Ir, Co, Rh, Ni, Pd, Pt, Fe, Ru, Os, Cr, Mo, W, Mn, Tc, Re, and Au;

L 1 is a monoanionic bidentate ligand based on a compound of the formula (IIa)

in which:

R 1 is a radical of the formula

where Q is in each case independently CR a or N, where at least one Q group in an ortho-position to the bonding site is N and R a is hydrogen;

or a radical of the formulae

where Q is in each case independently CR a or N, where at least one Q group in an ortho-position to the bonding site is N, and Q′ is CR a 2 , O, S or NR c and R b and R c are each independently hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, amino, CF 3 , CN, alkoxy or F;

wherein R 1 may optionally bear a fused group;

R 2 , R 3 , and

R 4 are each independently substituted or unsubstituted C 1 -C 20 -alkyl, substituted or unsubstituted C 0 -C 20 -alkylene-C 3 -C 18 -cycloalkyl, substituted or unsubstituted C 0 -C 20 -alkyleneheterocycloalkyl having 3-18 ring atoms, substituted or unsubstituted C 0 -C 20 -alkylene-C 1 -C 20 -alkoxy, substituted or unsubstituted C 0 -C 20 -alkylene-C 6 -C 18 -aryloxy, substituted or unsubstituted C 0 -C 20 -alkylene-C 6 -C 18 -aryl, or substituted or unsubstituted C 0 -C 20 -alkyleneheteroaryl having 5 to 18 ring atoms, wherein the substituent is C 1 -C 8 -alkyl, C 1 -C 8 alkoxy, halogen, or pseudohalogen;

o is from 0 to 3, where the R 3 radicals, when o>1, may be the same or different;

p is from 0 to 2, where the R 4 radicals, when p>1, may be the same or different;

n is 0;

X 2 is N, CH or CR 2 ;

X 3 is N, CH or CR 3 ;

X 4 are each independently N, CH or CR 4 ;

L 2 is a mono- or dianionic ligand which may be mono- or bidentate;

L 3 is an uncharged mono- or bidentate ligand;

q is the number of ligands L 1 , where q is 1, 2 or 3 and the ligands L 1 , when q>1, may be the same or different;

r is the number of ligands L 2 , where r is from 0 to 4 and the ligands L 2 , when r>1, may be the same or different;

s is the number of ligands L 3 , where s is from 0 to 4 and the ligands L 3 , when s>1, may be the same or different;

and the sum of q+r+s depends on the oxidation state and coordination number of the metal used and on the denticity of the ligands L 1 , L 2 and L 3 and also on the charge of the ligands L 1 and L 2 .

2. The organometallic complex according to claim 1 , wherein ligand L 1 has a triplet energy of 16 000 cm −1 to 19 500 cm −1 .

3. The organometallic complex according to claim 1 , wherein the radicals and indices in the triphenylene derivative of the formula (IIa) are each defined as follows:

R 2 , R 3 , and

R 4 are each independently C 1 -C 20 -alkyl, C 0 -C 20 -alkylene-C 3 -C 18 -cycloalkyl, C 0 -C 20 -alkyleneheterocycloalkyl having from 3 to 18 ring atoms, C 0 -C 20 -alkylene-C 1 -C 20 -alkoxy, C 0 -C 20 -alkylene-C 6 -C 18 -aryloxy, C 0 -C 20 -alkylene-C 6 -C 18 -aryl, C 0 -C 20 -alkyleneheteroaryl having from 5 to 18 ring atoms, where the aforementioned radicals are optionally substituted with C 1 -C 8 -alkyl, C 1 -C 8 alkoxy, halogen or pseudohalogen;

o is from 0 to 3, where the R 3 radicals, when o>1, may be the same or different;

p is from 0 to 2, where the R 4 radicals, when p>1, may be the same or different;

n is 0;

X 2 is CH or CR 2 ;

X 3 is CH or CR 3 ; and

X 4 are each independently CH or CR 4 .

4. The organometallic complex according to claim 1 , wherein the metal atom M is selected from the group consisting of Ir, Rh, Pd, Pt, and Ru in any oxidation state possible for the corresponding metal atom.

5. The organometallic complex according to claim 1 , wherein

M is Ir(III);

L 2 is a monoanionic bidentate ligand;

q is 1 or 2;

r is 1 or 2; and

s is 0

and the sum of q+r=3.

6. The organometallic complex according to claim 1 , wherein L 2 is selected from the group consisting of β-diketonates, picolinate, amino acid anions and monoanionic bidentate ligands of the general formula (b)

in which

R 5 is hydrogen, C 1 -C 6 -alkyl, C 0 -C 4 -alkylene-C 3 -C 8 -cycloalkyl, or C 0 -C 4 -alkylene-C 6 -C 18 -aryl;

X′ is N;

Y″ is N − ;

n′ is 1, 2, 3 or 4; and

o′ is 1, 2, 3, 4 or 5.

7. A process for preparing organometallic complexes according to claim 1 by

(a) reacting metal salts or metal complexes which comprise the desired metal M and optionally comprise one or more ligands L 3 with a first ligand L 1 or L 2 to give metal complexes which bear either one or more ligands L 1 or one or more ligands L 2 , optionally in addition to one or more ligands L 3 ; and

(b) reacting the metal complexes obtained in (a) with a second ligand L 1 when the metal complex obtained in (a) comprises one or more ligands L 2 , or with a second ligand L 2 , when the metal complex obtained in (a) comprises one or more ligands L 1 , to obtain an organometallic complex of the formula (I), provided this reaction is dispensed with in the case that the organometallic complex of the formula (I) does not comprise any ligand L 2 , or when r in the organometallic complex of the formula (I) is 0.

8. A mixture comprising at least one matrix material and at least one organometallic complex prepared according to claim 7 .

9. A method of preparing an organic light-emitting diode, comprising providing an organometallic complex according to claim 1 in the organic light-emitting diode.

10. The method according to claim 9 , wherein the organometallic complex is an emitter material.