Synthesis of organometallic cyclometallated transition metal complexes

1. A process for forming a tris-cyclometallated iridium or rhodium complex comprising reacting in the presence of a solvent:

a) a bis-cyclometallated complex comprising an Ir (III) or Rh (III) metal, two bidentate ligands, two monodentate ligands and a counterion, with

b) a heterocyclic compound capable of forming an organometallic cyclometallated complex.

2. A process according to claim 1 wherein the metal is Ir (III).

3. A process according to claim 1 wherein the bis-cyclometallated complex is cationic and the counterion is anionic.

4. A process according to claim 1 wherein the bis-cyclometallated complex is anionic and the counterion is cationic.

5. A process according to claim 1 wherein at least one bidendate ligand comprises a 2-phenylpyridine group.

6. A process according to claim 1 wherein at least one bidendate ligand comprises a 3-phenylisoquinoline group.

7. A process according to claim 1 wherein at least one bidendate ligand comprises a 1-phenylisoquinoline group.

8. A process according to claim 3 wherein at least one monodentate ligand is an aliphatic nitrile.

9. A process according to claim 3 wherein at least one monodentate ligand is acetonitrile.

10. A process according to claim 3 wherein the counter ion comprises fluoride.

11. A process according to claim 3 wherein the counter ion comprises BF 4 − or PF 6 − .

12. A process according to claim 4 wherein at least one monodentate ligand is thiocyanate.

13. A process according to claim 1 wherein the heterocyclic compound comprises a 2-phenylpyridine group.

14. A process according to claim 1 wherein the heterocyclic compound comprise a 3-phenylisoquinoline group.

15. A process according to claim 1 wherein the heterocyclic compound comprise a 1-phenylisoquinoline group.

16. A process according to claim 1 wherein the solvent is an alcohol.

17. A process according to claim 1 wherein the solvent is a diol.

18. A process according to claim 1 wherein the solvent is an organic ester.

19. A process according to claim 1 wherein the bis-cyclometallated complex is represented by Formula (1):

[(L 1 ) 2 M(L 2 ) 2 ]X  (1)

wherein:

M represents Ir or Rh;

X represents a counterion;

each L 1 represents an independently selected bidentate cyclometallating ligand; and

each L 2 represents an independently selected monodentate ligand.

20. A process according to claim 19 wherein at least one of L 1 represents a phenylpyridine group.

21. A process according to claim 19 wherein at least one of L 2 represents an aliphatic nitrile.

22. A process according to claim 19 wherein at least one of L 2 represents acetonitrile.

23. A process according to claim 19 wherein at least one of L 2 represents thiocyanate.

24. A process according to claim 1 wherein the tris-cyclometalled complex is represented by Formula (2):

M(L 1 )(L 2 )(L 3 )  (2)

wherein:

M represents Ir or Rh; and

L 1 , L 2 , and L 3 , represent independently selected bidentate cyclometallating ligands.

25. A process according to claim 24 wherein L 1 , L 2 , and L 3 represent the same bidentate ligand.

26. A process according to claim 24 wherein L 1 , L 2 , and L 3 represent independently selected phenylpyridine groups.

27. A process according to claim 24 wherein at least one of L 1 , L 2 , and L 3 represents a 1-phenylisoquinoline group.

28. A process according to claim 24 wherein at least one of L 1 , L 2 , and L 3 represents a 3-phenylisoquinoline group.