Transition metal complexes and use thereof in organic light-emitting diodes V

1. A metal complex, comprising a ligand of formula (I):

wherein:

Y 5 and Z 4 are each independently CD, CR 1 , CH, or N;

D is deuterium;

X 1 is N;

X 2 , X 3 , Y 1 , Y 2 , and Y 3 are each independently N or C;

X 4 is CD, CR 1 , CH, N, NR 1 , S or O;

X 5 is CD;

Y 4 and Y 6 are each independently CD, CR 1 , CH, N, NR 1 , S, or O;

Z 1 , Z 2 , and Z 3 are each independently CD, CR 1 , CH, or N;

R 1 is independently an unsubstituted or substituted alkyl, unsubstituted or substituted cycloalkyl, unsubstituted or substituted heterocycloalkyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, unsubstituted or substituted alkenyl, unsubstituted or substituted cycloalkenyl, unsubstituted or substituted alkynyl, SiR 2 3 , halogen, a substituent with donor or acceptor action, whereby, in the case that R 1 is bonded to a nitrogen atom, R 1 is independently an unsubstituted or substituted alkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl, whereby any two R 1 radicals together may additionally form an alkylene or arylene bridge;

R 2 is independently an unsubstituted or substituted alkyl, unsubstituted or substituted aryl, or unsubstituted or substituted heteroaryl;

m and n are each 1; and

wherein the metal complex comprises a deuterium atom.

2. The metal complex according to claim 1 , wherein at least one of X 4 , Y 4 , Y 5 , Y 6 , Z 1 , Z 2 , Z 3 , and Z 4 is CD.

3. The metal complex according to claim 1 , wherein at least one of X 1 and Y 1 is N.

4. The metal complex according to claim 1 , wherein:

X 1 is N;

X 2 , Y 1 , Y 2 , and Y 3 are each C;

X 3 is C or N;

X 4 is CR 1 , CD, N, NR 1 , O, or S;

X 5 is CD;

Y 4 , Y 5 , and Y 6 are each independently CH, CD, or CR 1 ; and

Z 1 , Z 2 , Z 3 , and Z 4 are each independently CH, CD, CR 1 , or N.

5. The metal complex according to claim 3 , wherein:

X 1 is N;

X 4 is CD or CR 1 ; and

X 5 is CD.

6. The metal complex according to claim 5 , wherein:

X 3 is N;

X 4 and Z 3 are each CR 1 ; and

Y 4 , Y 5 , Y 6 , Z 1 , Z 2 , and Z 4 are each CD.

7. The metal complex according to claim 1 , wherein:

R 1 is independently an unsubstituted or substituted alkyl, unsubstituted or substituted aryl, unsubstituted or substituted heteroaryl, SiR 2 3 , F, OR 2 , SR 2 , NR 2 2 , CF 3 , or CN, whereby each R 1 , in the case that R 1 is bonded to a nitrogen atom, is independently an unsubstituted or substituted alkyl or unsubstituted or substituted aryl; and

R 2 is independently an unsubstituted or substituted alkyl or unsubstitulted or substituted aryl.

8. The metal complex according to claim 1 , wherein the metal complex has formula (II):

wherein:

M is a transition metal atom from group IB, IIB, IIIB, IVB, VB, VIB, VIIB, or VIII of the Periodic Table of the Elements (CAS version), in any oxidation state possible for the metal atom;

J is a mono- or dianionic ligand which is optionally mono- or bidentate;

K is an uncharged, mono- or bidentate ligand which is optionally photoactive;

o is 1, 2, 3, or 4, whereby o is 1, 2, or 3 when M is Ir(III), and is 1 or 2 when M is Pt(II) or Os(II);

p is 0, 1, 2, 3, or 4, whereby p is 0, 1, 2, 3, or 4 when M is Ir(III), and is 0, 1, or 2 when M is Pt(II) and Os(II), and p is a number of bonding sites to the metal atom M;

q is 0, 1, 2, 3, or 4, whereby q is 0, 1, or 2 when M is IR(III), is 0 or 1 when M is Pt(II), and is 2 or 3 when M is Os(II), and q is a number of bonding sites to the metal atom; and

wherein o, p, and q depend on the oxidation state and coordination number of the metal atom present and on charge of the ligands.

9. The metal complex according to claim 8 , wherein the metal complex has formula (IIa):

wherein:

M is a transition metal atom from group IB, IIB, IIIB, IVB, VB, VIB, VIIB, or VIII of the Periodic Table of the Elements (CAS version), in any oxidation state possible for the metal atom;

is a bidentate monoanionic ligand which optionally comprises a deuterium atom;

o is 1, 2, 3, or 4, whereby o is 1, 2, or 3 when M is Ir(III), and is 1 or 2 when M is Pt(II);

p′ is 0, 1, or 2, whereby p′ is 0, 1, or 2 when M is Ir(III), and is 0 or 1 when M is Pt(II), wherein p′ is a number of

ligands; and

wherein o and p′ depend on the oxidation state and coordination number of the metal atom present.

10. The metal complex according to claim 9 , wherein L in the bidentate monoanionic ligand is in each case independently selected the group consisting of from O, N, and C.

11. The metal complex according to claim 9 , wherein the metal complex has formula (IIaa):

wherein:

D is deuterium; and

R 3 is independently deuterium or R 1 .

12. The metal complex according to claim 9 , wherein:

M is Ir(III) or Pt(II);

o is 1, 2, or 3 when M is Ir(III), and is 1 or 2 when M is Pt(II);

p is 0, 1, or 2 when M is Ir(III); and is 0 or 1 when M is Pt(II); and

wherein a sum of o+p′ is 3 when M is Ir(III) and is 2 when M is Pt(II), and o is at least 1.

13. An organic light-emitting diode, comprising a metal complex according to claim 1 .

14. A light-emitting layer, comprising a metal complex according to claim 1 .

15. An organic light-emitting diode, comprising a light-emitting layer according to claim 14 .

16. A device, selected from the group consisting of a stationary visual display unit, an illumination, and a mobile visual display unit, comprising an organic light-emitting diode according to claim 13 .

17. A device, selected from the group consisting of a stationary visual display unit, an illumination, and mobile visual display unit, comprising an organic light-emitting diode according to claim 15 .