CARBENE METAL COMPLEXES AS OLED MATERIALS

• US 20100007273A1
• Filed: 08/31/2009
• Published: 01/14/2010
• Est. Priority Date: 05/18/2004
• Status: Active Grant

• Current Assignee: Bert Alleyne, Bin Ma, Chun Lin, Jason Brooks, Jui-Yi Tsai, Mark Thompson, Peter B. Mackenzie, Peter Djurovich
• Original Assignee: Bert Alleyne, Bin Ma, Chun Lin, Jason Brooks, Jui-Yi Tsai, Mark Thompson, Peter B. Mackenzie, Peter Djurovich
• Inventors: Lin, Chun, Brooks, Jason, Alleyne, Bert, MacKenzie, Peter B., Tsai, Jui-Yi, Ma, Bin, Thompson, Mark E., Djurovich, Peter
• Granted Patent: US 8,114,533 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: C07F 15/0033 Iridium compounds
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/321 Metal complexes comprising a group IIIA element, e.g. Tris (8-hydroxyquinoline) gallium [Gaq3]
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/656 comprising two or more different heteroatoms per ring H10K85/652 takes precedence
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An organic light emitting device having an anode, a cathode and an organic layer disposed between the anode and the cathode is provided. In one aspect, the organic layer comprises a compound having at least one zwitterionic carbon donor ligand. In another aspect, the organic layer comprises a carbene compound, including the following:

In another aspect, the organic layer comprises a carbene compound, including:

In another aspect, the organic layer comprises a carbene compound that includes a triazole ring and has the structure:

In another aspect, the organic layer comprises a carbene compound that includes a tetrazole ring and has the structure:

Claims

1. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound comprising one or more ligands coordinated to a metal center, and wherein at least one ligand is a zwitterionic carbon donor ligand.

2. The device of claim 1, wherein the compound is selected from the group consisting of:

wherein M is a metal; and

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand,

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

3. The device of claim 2, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

4. The device of claim 3, wherein M is Ir.

5. The device of claim 4, wherein m is 3 and n is 0.

6. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound further comprising one or more carbene ligands coordinated to a metal center, and the compound has the structure;

and wherein M is a metal;

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form independently a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand,

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

7. The device of claim 6, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

8. The device of claim 7, wherein M is Ir.

9. The device of claim 8, wherein m is 3 and n is 0.

10. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound further comprising one or more carbene ligands coordinated to a metal center, and wherein the compound has the structure;

wherein M is a metal;

ring D is independently an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring, wherein ring D can be optionally substituted with one or more substituents R₂;

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

Z₁ and Z₂ are independently selected from a bond, O, S, or NR′

;

A₁, A₂, A′

, and A″

is independently selected from C, N, or P;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand;

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

11. The device of claim 10, wherein the compound is selected from:

wherein c is 0, 1, or 2.

12. The device of claim 10, wherein the compound is selected from the group consisting of:

wherein c is 0, 1, or 2.

13. The device of claim 10, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

14. The device of claim 13, wherein M is Ir.

15. The device of claim 14, wherein m is 3 and n is 0.

16-21. -21. (canceled)

22. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a compound further comprising one or more carbene ligands coordinated to a metal center, and wherein the compound has the structure;

wherein M is a metal;

ring D is an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring with at least one carbon atom coordinated to metal M; and

wherein ring D can be optionally substituted with one or more substituents R₂;

R₂ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

a is 0, 1, 2, 3, or 4.

23. The device of claim 22, wherein the compound has the structure:

24. The device of claim 23, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

25. The device of claim 24, wherein M is Ir.

26. The device of claim 25, wherein m is 3 and n is 0.

27. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a zwitterionic carbon donor ligand.

28. The device of claim 27, wherein the ligand is selected from the group consisting of:

wherein R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)NR′

, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

a is 0, 1, 2, 3, or 4;

bis 0, 1, 2, or 3.

29. The device of claim 28, wherein the ligand is selected from the group consisting of:

wherein R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂ NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3.

30. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a carbene ligand coordinated to a metal center, the carbene ligand having the structure;

wherein ring D is independently an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring, wherein ring D can be optionally substituted with one or more substituents R₂;

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

Z₁ and Z₂ are independently selected from a bond, O, S, or NR′

;

A₁, A₂, A′

, and A″

is independently selected from C, N, or P;

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3.

31. The device of claim 30, wherein the ligand is selected from:

wherein c is 0, 1, or 2.

32. The device of claim 30, wherein the ligand is selected from the group consisting of:

wherein c is 0, 1, or 2.

33-35. -35. (canceled)

36. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) an organic layer disposed between the anode and the cathode, wherein the organic layer comprises a carbene ligand coordinated to a metal center, the carbene ligand having the structure;

wherein ring D is an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring;

wherein ring D can be optionally substituted with one or more substituents R₂; and

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

a is 0, 1, 2, 3, or 4.

37. The device of claim 36, wherein the ligand has the structure:

38. A compound selected from the group consisting of:

wherein M is a metal; and

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand,

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

39. The compound of claim 38, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

40. The compound of claim 39, wherein M is Ir.

41. A compound, selected from the group consisting of:

wherein M is a metal; and

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂ NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand,

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

42. The compound of claim 41, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

43. The compound of claim 42, wherein M is Ir.

44. The compound of claim 43, wherein m is 3 and n is 0.

45. A compound comprising one or more carbene ligands coordinated to a metal center, wherein the compound has the structure:

wherein M is a metal;

ring D is independently an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring, wherein ring D can be optionally substituted with one or more substituents R₂;

R₁ and R₂ are independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

Z₁ and Z₂ are independently selected from a bond, O, S, or NR′

;

A₁, A₂, A′

, and A″

is independently selected from C, N, or P;

(X—

Y) is selected from a photoactive ligand or an ancillary ligand;

a is 0, 1, 2, 3, or 4;

b is 0, 1, 2, or 3;

m is a value from 1 to the maximum number of ligands that may be attached to metal M;

m+n is the maximum number of ligands that may be attached to metal M.

46. The compound of claim 45, wherein the compound is selected from:

wherein c is 0, 1, or 2.

47. The compound of claim 46, wherein the compound is selected from the group consisting of:

wherein c is 0, 1, or 2.

48. The compound of claim 47, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

49. The compound of claim 48, wherein M is Ir.

50. The compound of claim 49, wherein m is 3 and n is 0.

51-56. -56. (canceled)

57. A compound comprising one or more carbene ligands coordinated to a metal center, wherein the compound has the structure:

wherein M is a metal;

ring D is an aromatic cyclic, heterocyclic, fused cyclic, or fused heterocyclic ring with at least one carbon atom coordinated to metal M; and

wherein ring D can be optionally substituted with one or more substituents R₂;

R₂ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, CN, CF₃, CO₂R′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, SO₃R′

, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group;

R₃ is independently selected from hydrogen, alkyl, alkenyl, alkynyl, aralkyl, aryl, heteroaryl, substituted aryl, substituted heteroaryl, or a heterocyclic group; and

additionally or alternatively, two R groups on the same or adjacent ring, together form a 5 or 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl; and

wherein said cyclic group is optionally substituted by one or more substituents J;

each substituent J is independently selected from the group consisting of R′

, CN, CF₃, C(O)OR′

, C(O)R′

, C(O)NR′

₂, NR′

₂, NO₂, OR′

, SR′

, SO₂, SOR′

, or SO₃R′

, and additionally, or alternatively, two J groups on adjacent ring atoms form a fused 5- or 6-membered aromatic group;

each R′

is independently selected from halo, H, alkyl, alkenyl, alkynyl, heteroalkyl, aralkyl, aryl, and heteroaryl;

a is 0, 1, 2, 3, or 4.

58. The compound of claim 57, having the structure:

59. The compound of claim 58, wherein M is selected from the group consisting of Ir, Pt, Pd, Rh, Re, Ru, Os, Tl, Pb, Bi, In, Sn, Sb, Te, Al, Ga, Au, and Ag.

60. The compound of claim 59, wherein M is Ir.

61. The compound of claim 60, wherein m is 3 and n is 0.