Process for forming a composite including an aluminum trisquinoline complex
View Patent ↗A process for forming a film of the facial-isomer of an aluminum trisquinoline complex comprises depositing a film of an aluminum trisquinoline complex on a support, depositing an inert barrier layer over the layer of aluminum trisquinoline complex that encapsulates aluminum trisquinoline complex to form a multilayer composite, and then heating the composite at a temperature below the melting point temperature of the complex for a time sufficient to convert the aluminum trisquinoline complex to at least 99 mol % of the facial-isomer that fluoresces with a maximum emission intensity below 510 nm. The product has a blue hue.
1. A process for forming a film of the facial-isomer of an aluminum trisquinoline complex comprising depositing a film of an aluminum trisquinoline complex on a support, depositing an inert barrier layer over the layer of aluminum trisquinoline complex that encapsulates aluminum trisquinoline complex to form a multilayer composite, and then heating the composite at a temperature below the melting point temperature of the complex for a time sufficient to convert the aluminum trisquinoline complex to at least 99 mol % of the facial-isomer that fluoresces with a maximum emission intensity below 510 nm.
2. A process according to claim 1 wherein the multilayer composite is heated at a temperature not more than 150° C. below the melting point of the complex.
3. A process according to claim 1 wherein the composite is heated at a temperature at least 50° C. below the melting point temperature of the complex.
4. A process according to claim 1 wherein heating is continued until at least 99 mol % of the facial-isomer is one polymorph.
5. A process according to claim 1 wherein the inert barrier layer comprises an inorganic material.
6. A process according to claim 1 wherein the inert barrier layer comprises a metal.
7. A process according to claim 1 wherein the inert barrier layer comprises aluminum or silver.
8. A process according to claim 1 wherein the inert barrier layer comprises an organic material having a glass transition temperature greater than the heating temperature.
9. A process according to claim 1 wherein the inert barrier layer comprises a hole-transporting material or an electron-transporting material.
10. A process according to claim 1 , wherein the barrier layer comprises an anode or a cathode.
11. A process according to claim 1 , wherein the support comprises a cathode or an anode.
12. A process according to claim 1 , wherein a second material is co-deposited with the aluminum trisquinoline complex in an amount of 0.5 to 10% by volume of the layer.
13. A process according to claim 12 , wherein the second material emits light.
14. A process according to claim 1 wherein the aluminum trisquinoline complex comprises tris(2-methyl-8-quinolinolato)aluminum(III).
15. A process according to claim 14 wherein heating is continued until at least 99 mol % of the δ-phase of facial -tris(2-methyl-8-quinolinolato)aluminum(III) is formed.
16. A process according to claim 14 wherein the multilayer is heated at a temperature of 370° C. or lower.
17. A process according to claim 14 wherein the multilayer is heated at a temperature of 360° C. or lower.
18. A process according to claim 14 wherein the multilayer is heated at a temperature below 350° C.
19. A multilayer composite comprising at least three layers wherein the first layer comprises a support layer, the second layer includes an aluminum trisquinoline complex which is at least 99% of the facial-isomer wherein at least 99% of the facial-isomer comprises the δ-phase of facial-tris(2-methyl-8-quinolinolato)aluminum(III). and the third layer comprises a barrier layer, and provided that the barrier layer comprises a metal or an organic material.
20. A composite according to claim 19 , wherein the facial-isomer of the aluminum trisquinoline complex fluoresces with a maximum emission intensity below 510 nm.
21. A composite according to claim 19 , wherein the barrier layer includes an organic material having a glass transition temperature greater than the heating temperature.
22. A composite according to claim 19 , wherein the support layer includes an organic material having a glass transition temperature greater than the heating temperature.
23. A composite according to claim 19 wherein the inert barrier layer includes a hole-transporting material or an electron-transporting material.
24. A composite according to claim 19 wherein the inert barrier layer includes a metal.
25. A composite according to claim 19 wherein the support layer is a hole-transporting material or an electron-transporting material.
26. A composite according to claim 19 , wherein the barrier layer comprises an anode or a cathode.
27. A composite according to claim 19 , wherein the support comprises a cathode or an anode.
28. A composite according to claim 19 , wherein the second layer contains a second material in an amount of 0.5 to 10% by volume of the layer.
29. A composite according to claim 28 , wherein the second material emits light.
30. An electroluminescent device comprising the composite of claim 19 .
31. An OLED device comprising the composite of claim 19 wherein at least two layers of the device are vacuum deposited.
32. A display comprising the electroluminescent device of claim 30 .
33. The process of claim 1 wherein the barrier layer is deposited to form a conforming layer over the aluminum trisquinoline complex.
34. The composite of claim 19 wherein the barrier layer forms a conforming layer over the aluminum trisquinoline complex.