Electroluminescent materials and devices

1. An electroluminescent chemical complex represented by the general chemical formula:

wherein:

(A) the letters M, t and n represent one of the following combinations:

(i) M is selected from the group consisting of ruthenium, rhodium, and iridium; t is 3; and n is 1 or 2;

(ii) M is selected from the group consisting of palladium or platinum; t is 2; and n is 1;

(iii) M is osmium; t is 3; and n is 1 or 2; and,

(iv) M is osmium; t is 4; and n is 1, 2 or 3;

(B) R 1 , R 2 , R 3 and R 4 can be the same or different and are independently selected from the group consisting of:

substituted and unsubstituted hydrocarbyl groups;

substituted and unsubstituted monocyclic and polycyclic heterocyclic groups;

substituted and unsubstituted hydrocarbyloxy or carboxy groups;

fluorocarbyl groups;

halogen;

nitrile;

amino;

alkylamino;

dialkylamino;

arylamino;

diarylamino; and

thiophenyl; and,

(C) p, q, r and s are independently selected from the integers 0, 1, 2 or 3;

subject to the proviso that, where any one of p, q, r and s is 2 or 3, only one of the R 1 , R 2 , R 3 and R 4 entities can be an entity other than saturated hydrocarbyl or halogen.

2. The complex of claim 1 , wherein M is iridium.

3. The complex of claim 1 , wherein n is 1 and t is 3.

4. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is a substituted or unsubstituted aliphatic or cycloaliphatic group and also wherein at least one of p, q, r and s is 1, 2 or 3.

5. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is alkyl or alkoxy and also wherein at least one of p, q, r and s is 1, 2 or 3.

6. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is methyl, ethyl, n-propyl, i-propyl, s-butyl, t-butyl, cyclohexyl, methoxy or ethoxy and also wherein at least one of p, q, r and s is 1, 2 or 3.

7. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is a substituted or unsubstituted monocyclic or polycyclic aromatic, aryloxy or heterocyclic structure and also wherein at least one of p, q, r and s is 1, 2 or 3.

8. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is phenyl, tolyl, fluorophenyl, biphenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl or carbazolyl and also wherein at least one of p, q, r and s is 1, 2 or 3.

9. The complex of claim 1 , wherein at least one of R 1 , R 2 , R 3 and R 4 is fluoro, chloro, methylamino, dimethylamino, benzylamino or dibenzylamino and also wherein at least one of p, q, r and s is 1, 2 or 3.

10. The complex of claim 1 , wherein M is iridium, n is 1, t is 3 and p, q, r and s are 0.

11. An electroluminescent device comprising: (i) a first electrode;

(ii) a second electrode; and, (iii) an electroluminescent layer of a complex according to claim 1 located between said first and second electrodes.

12. The device of claim 11 , wherein a layer of a hole transmitting material is located between the first electrode and the electroluminescent layer.

13. The device of claim 12 , wherein the hole transmitting material is an aromatic amine.

14. The device of claim 12 , wherein the hole transmitting material is a polyaromatic amine.

15. The device of claim 12 , wherein the hole transmitting material is a film of a material selected from the group consisting of: α-NPB; poly(vinylcarbazole); N,N′-diphenyl-N,N′-bis (3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD); polyaniline; substituted polyanilines; polythiophenes; substituted polythiophenes; polysilanes; and substituted polysilanes.

16. The device of claim 12 , wherein the hole transmitting material is a copolymer of aniline.

17. The device of claim 12 , wherein the hole transmitting material is a conjugated polymer.

18. The device of claim 17 , wherein the conjugated polymer is selected from the group consisting of poly (p-phenylenevinylene) (PPV) and copolymers of PPV.

19. The device of claim 11 , wherein the electroluminescent layer further comprises a hole transmitting material.

20. The device of claim 11 , wherein one of said first and second electrodes is a cathode and further wherein a layer of an electron transmitting material is located between the cathode and the electroluminescent layer.

21. The device of claim 20 , wherein the electron transmitting material is a metal quinolate.

22. The device of claim 21 , wherein the metal quinolate is selected from the group consisting of aluminum quinolate, zirconium quinolate, and lithium quinolate.

23. The device of claim 20 , wherein the electron transmitting material has the general chemical formula Ax(DBM) n where Ax is a metal, DBM is dibenzoyl methane, and n is an integer equal to the valency of Ax.

24. The device of claim 20 , wherein the electron transmitting material is 9,10-dicyanoanthracene.

25. The device of claim 11 , wherein the electroluminescent layer further comprises an electron transmitting material.

26. The device of claim 11 , wherein the first electrode is a transparent electrically conducting glass electrode.

27. The device of claim 11 , wherein the second electrode comprises a material selected from the group consisting of: aluminum, barium, rare earth metals, transition metals, calcium, lithium, magnesium and alloys thereof, and silver/magnesium alloys.

28. The device of claim 11 , wherein the second electrode comprises a material selected from the group consisting of metals having a metal fluoride layer formed thereon.

29. The device of claim 28 , wherein the metal fluoride is selected from the group consisting of lithium fluoride, potassium fluoride, caesium fluoride, and rare earth fluorides.

30. An electroluminescent composition comprising a complex according to claim 1 together with an electron-transporting host material or a hole-transporting host material.

31. A composition according to claim 30 wherein the host material is present in an amount ranging from about 0.1-20 wt. %.

32. An electroluminescent compound represented by the general chemical formula:

wherein:

M is selected from the group consisting of ruthenium, rhodium, osmium, and iridium;

n is 1 or 2;

R 1 , R 2 , R 3 and R 4 can be the same or different and are independently selected from the group consisting of:

substituted and unsubstituted hydrocarbyl groups;

substituted and unsubstituted monocyclic and polycyclic heterocyclic groups;

substituted and unsubstituted hydrocarbyloxy or carboxy groups;

fluorocarbyl groups;

halogen;

nitrile;

amino;

alkylamino;

dialkylamino;

arylamino;

diarylamino; and

thiophenyl; and,

p, q, r and s are independently selected from the integers 0, 1, 2 or 3;

subject to the proviso that, where any one of p, q, r and s is 2 or 3, only one of the R 1 , R 2 , R 3 and R 4 entities can be an entity other than saturated hydrocarbyl or halogen.