- PHOSPHORESCENT EMITTERS AND HOST MATERIALS WITH IMPROVED STABILITY
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Devices containing a particular combination of organic compounds are provided. In particular, the devices contain twisted aryl compounds having extended conjugation (i.e., the twisted aryl is substituted with an additional aryl group) in combination with dibenzothiophene or dibenzofuran containing host materials. The organic light emitting devices may provide improved stability color, lifetime and manufacturing. Compounds containing a twisted aryl having extended conjugation are also provided.
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- Pyridyl-substituted thioaminyl stable free radicals: Isolation, ESR spectra, and magnetic characterization
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N-[(4-Nitrophenyl)thio]- (1a) and N-[(2,4-dichlorophenyl)thio)]-2,6- diphenyl-4-(3-pyridyl)phenylaminyl (1b), N-[(4-nitrophenyl)thio]- (2a) and N- [(2,4-dichlorophenyl)thio]-4-phenyl-2,6-di(3-pyridyl)-phenylaminyl (2b), and N-[(2,4-dichlorophenyl)thio]-2,6-diphenyl(4-pyridyl)aminyl (3) were generated by PbO2 oxidation of the corresponding precursors. Although 3 was not sufficiently stable to be isolated, both 1 and 2 persisted in solution without decomposition and could be isolated as radical crystals. X-ray crystallographic analysis of 1b revealed that the Ar-N-S-Ar' π-framework is approximately planar and the 2- and 6-phenyl groups are significantly twisted from this plane. The magnetic susceptibility measurements for the isolated radical crystals were carried out using a SQUID magnetometer in the temperature range 1.8-300 K. The susceptibilities of 1a and 2a were explained in terms of a one-dimensional (1D) antiferromagnetic (AFM) regular Heisenberg model with an exchange interaction of 2J/k(B) = -63.4 and -17.8 K, respectively, and that of 1b was interpreted in terms of a 1D AFM alternating Heisenberg model with 2J/k(B) = -12.8 K and α (alternation parameter) = 0.91. On the other hand, that of 2b was explained in terms of a 1D ferromagnetic regular Heisenberg model with 2J/k(B) = 22.4 K.
- Miura, Yozo,Kurokawa, Shinya,Nakatsuji, Masaaki,Ando, Kenjiro,Teki, Yoshio
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p. 8295 - 8303
(2007/10/03)
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- Synthesis of Self-Filled, Vaulted, and Intracavity-Functionalized Cappedophanes
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Two approaches to the synthesis of vaulted cappedophanes 3v are described.In the first, the walls and ceiling were prefabricated as in tetrathiol 5 (10a and 10b, Scheme II, are specific examples), which was then coupled with a m-terphenyl tetrabromide suc
- Vinod, Thottumkara K.,Hart, Harold
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p. 5630 - 5640
(2007/10/02)
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- Non-specific tritiation of some carcinogenic aromatic amines
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2-Aminofluorene, 4-amino-3-methylbiphenyl, 4-amino-biphenyl and 4-amino-4'-fluorobiphenyl were tritiated by acid catalyzed exchange of the corresponding nitro compounds followed by catalytic reduction. The exchange reactions were carried out by heating the nitro compounds in [3H]-trifluoroacetic acid with a catalytic amount of trifluoromethanesulphonic acid (TFMS). No loss of tritium could be detected during the conversion of the tritiated nitro compounds into the corresponding amines by catalytic hydrogenation. Incorporation into the ortho position is very low (4%). During the metabolic activation and binding of the tritiated N-acetyl-2-aminofluorene to rat liver DNA in vivo, no tritium exchange occurred.
- Breeman,Kaspersen,Westra
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p. 741 - 750,748,749
(2007/10/05)
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