[5]-helicene and dibenzofluorene materials for use...

Stock material or miscellaneous articles – Composite – Of inorganic material

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C428S917000, C313S504000, C564S426000, C548S136000, C548S143000, C548S262200, C252S301160

Reexamination Certificate

active

06686065

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to the field of electroluminescent (EL) devices, and in particular to organic materials for organic light emitting devices (OLEDs).
2. Description of the Related Art
OLEDs are typically comprised of at least a layer of organic luminescent material sandwiched between an anode, typically comprised of a transparent conductor, such as indium-tin oxide and a cathode, typically a low work-function metal, such as magnesium, calcium, aluminum, or the alloys thereof, with other metals. When a bias is applied between the electrodes, positive charges (holes) and negative charges (electrons) are respectively injected from the anode and cathode into the luminescent layer. The holes and the electrons form excitons in the organic layer to emit light.
OLEDs having multiple organic layers are also known. A multilayer OLED may comprise one or more organic hole transport layers adjacent the anode, and one or more organic layers adjacent the cathode which function as both an emissive layer and an electron transport layer. In other structures, a hole transport layer, an emissive layer and an electron transport layer are positioned, in that order, between the anode and the cathode.
Organic materials for EL devices are attractive due to their high luminescence efficiency and because of their high brightness and ease of fabrication by solution processing, such as by spin casting and lithographic printing. On the other hand, it is still desired to find materials having pure emission spectra and good stability to produce cost effective OLEDs having lower driving voltages and higher efficiencies.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an organic material based on [5] helicene or dibenzofluorene suitable for EL devices, having good thermal and morphological stability. In preferred embodiments, these materials are provided with hole transport or electron transport capabilities, in addition to emissive characteristics. These materials are expected to have improved charge injection mobility and charge recombination properties and pure emission spectra.
In preferred embodiments, aromatic amines are bonded to the [5] helicene or dibenzofluorene structures to provide hole transport capability to the subject compounds. Alternatively, electron transport moieties can be bonded to the [5] helicene or dibenzofluorene structures to provide electron transport capability to the materials. Electron deficient species, such as (without limitation) oxadiazole, thiadiazole, and triazole units, may be used for this purpose.
The invention may be embodied as an electroluminescent device, comprising a transparent anode, a cathode, and a layer of emissive [5] helicene or dibenzofluorene material between the anode and the cathode. Electroluminescent devices according to the invention may include an optional hole injection layer adjacent the anode or an electron transport layer adjacent the cathode. In another aspect, the invention encompasses an EL device incorporating a [5] helicene compound or a dibenzofluorene compound having both light emissive and hole transport ability, or both light emissive and electron transport ability.
The invention also encompasses a method of making emissive, hole transport organic materials based on [5] helicenes or dibenzofluorenes by aminating a dibromo [5] helicene or dibenzofluorene in the presence of a phosphorous ligand and Pd(0) catalyst in basic conditions. Similarly, emissive electron transport materials based on [5] helicenes or dibenzofluorenes can be synthesized by attaching an electron withdrawing group, also by means of a Pd(0) catalyst.
This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiment thereof in connection with the attached drawings.


REFERENCES:
patent: 4720432 (1988-01-01), VanSlyke et al.
patent: 4767873 (1988-08-01), Katz et al.
patent: 4813772 (1989-03-01), Kowel et al.
patent: 5066796 (1991-11-01), Law
patent: 5151629 (1992-09-01), VanSlyke
patent: 5403520 (1995-04-01), Ashitaka et al.
patent: 5698740 (1997-12-01), Enokida et al.
patent: 5925472 (1999-07-01), Hu et al.
patent: 5936087 (1999-08-01), Benson et al.
patent: 5958917 (1999-09-01), Crowell et al.
patent: 5993700 (1999-11-01), Katz et al.
patent: 6013383 (2000-01-01), Shi et al.
patent: 6017470 (2000-01-01), Katz et al.
patent: 6051719 (2000-04-01), Benson et al.
patent: 6132641 (2000-10-01), Rietz et al.
patent: 6169163 (2001-01-01), Woo et al.
patent: 6214514 (2001-04-01), Evans et al.
patent: 0832 881 (1998-04-01), None
patent: 0842208 (2000-05-01), None
patent: 5-273614 (1993-10-01), None
patent: 7-285924 (1995-10-01), None
patent: 7-304720 (1995-11-01), None
patent: 9-3023 (1997-01-01), None
patent: 9-77767 (1997-03-01), None
patent: 2000-195673 (2000-07-01), None
patent: WO 97/08262 (1997-03-01), None
patent: WO 99/54385 (1999-10-01), None
patent: WO 00/46321 (2000-08-01), None
patent: WO 01/16252 (2001-03-01), None
Harvey, R. G., et al., “A New General Synthesis of Polycyclic Aromatic Compounds Based on Enamine Chemistry”, J. Org. Chem., 1991, vol. 56, pp. 1210-1217 (No Month).
Willmore, N. D. et al., “A Diels-Alder Route to [5]-and [6]-Helicenes”, Angewandte Chemie, Aug. 1992, vol. 31, pp. 1093-1095.
Miyaura, N. and Suzuki A., “Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds”, Chemical Reviews, Nov. 1995, vol. 95, No. 7, pp. 2457-2483.
Wang, Z. Y., et al., “New Route to the Introduction of Axial and Helical Chiral Units into Poly(arylene ether)s”, Macromolecules, 1997, pp. 8091-8093. (No Month).
Nishiyama, M., et al., “Synthesis of N-Arylpiperazines from Aryl Halides and Piperazine Under a Palladium Tri-tert-butylphosphine Catalyst”, Tetrahedron Letters, Feb. 1998, vol. 39, pp. 617-620.
Hartwig, J. F., “Transition Metal Catalyzed Synthesis of Arylamines and Aryl Ethers from Aryl Halides and Triflates: Scope and Mechanism”, Angewandte Chemie, Aug. 1998, vol. 37, pp. 2047-2067.
Wolfe, J. P., et al., “Rational Development of Practical Catalysts for Aromatic Carbon-Nitrogen Bond Formation”, Acc. Chem Res., Dec. 1998, vol. 31, pp. 805-818.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

[5]-helicene and dibenzofluorene materials for use... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with [5]-helicene and dibenzofluorene materials for use..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and [5]-helicene and dibenzofluorene materials for use... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3325037

All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.