Electroluminescent materials and devices
Novel ruthenium, rhodium, palladium, osmium, iridium or platinum complexes of thianthrene ligands are electroluminescent compounds. According to the invention there is provided complexes of Formula (I).
1. An electroluminescent compound having the general chemical formula:
wherein:
L is selected from the group consisting of
M is selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium and platinum;
n is 1 or 2;
R 1 , R 4 and R 5 are 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 and carboxy groups; fluorocarbyl groups; halogen; nitrile; amino; alkylamino; dialkylamino; arylamino; diarylamino; and thiophenyl;
p, s and t are independently selected from the integers 0, 1, 2 and 3, subject to the proviso that where any of p, s and t is 2 or 3 only one of the entities R 1 , R 4 and R 5 can be other than saturated hydrocarbyl or halogen;
R 2 and R 3 are the same or different and are independently selected from the group consisting of substituted and unsubstituted hydrocarbyl groups and halogen; and,
q and r are independently selected from the integers 0, 1 and 2.
2. The compound of claim 1 , wherein M is iridium.
3. The compound of claim 1 , wherein n is 1.
4. The compound of claim 1 , wherein at least one of R 1 , R 4 and R 5 is a substituted or unsubstituted aliphatic or cycloaliphatic group.
5. The compound of claim 4 , wherein least one of R 1 , R 4 and R 5 is alkyl or alkoxy.
6. The compound of claim 5 , wherein at least one of R 1 , R 4 and R 5 is selected from the group consisting of methyl, ethyl, n-propyl, i-propyl. s-butyl, t-butyl, cyclohexyl, methoxy and ethoxy.
7. The compound of claim 1 , wherein at least one of R 1 , R 4 and R 5 is a substituted or unsubstituted monocyclic or polycyclic aromatic, aryloxy or heterocyclic structure.
8. The compound of claim 7 , wherein at least one of R 1 , R 4 and R 5 is selected from the group consisting of phenyl, tolyl, fluorophenyl, biphenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl and carbazolyl.
9. The compound of claim 1 , wherein at least one of R 1 , R 4 and R 5 is selected from the group consisting of fluoro, chloro, methylamino, dimethylamino, benzylamino and dibenzylamino.
10. The compound of claim 1 , wherein at least one of R 2 and R 3 is a substituted or unsubstituted aliphatic group.
11. The compound of claim 10 , wherein at least one of R 2 and R 3 is alkyl.
12. The compound of claim 11 , wherein at least one of R 2 and R 3 is methyl or ethyl.
13. The compound of claim 1 , wherein at least one of R 2 and R 3 is chloro or bromo.
14. The compound of claim 1 , wherein M is Ir, n is 1 and p, q, r, s and t are each 0.
15. An electroluminescent device which comprises: (i) a first electrode; (ii) a second electrode; and (iii) a layer of an electroluminescent compound according to claim 1 located between said first and second electrodes.
16. The device of claim 15 , wherein there is a layer of a hole transmitting material located between the first electrode and the layer of electroluminescent compound.
17. The device of claim 16 , wherein the hole transmitting material is a polyaromatic amine.
18. The device of claim 15 , wherein there is a layer of an electron transmitting material located between an electrode that functions as a cathode and the layer of electroluminescent compound.
19. The device of claim 18 , wherein the electron transmitting material is either a metal quinolate or a material having the general chemical formula Ax(DBM) n where Ax is a metal, DBM is dibenzoyl methane, and n is the valence of Ax.
20. The device of claim 19 , wherein the electron transmitting material is a metal quinolate selected from the group consisting of aluminum quinolate, zirconium quinolate and lithium quinolate.