Carbazole-based materials adopting the nonconjugated substitution of triphenylsilyl (-SiPh(3)) and trityl (-CPh(3)) side groups are studied as high-triplet-energy, morphologically, and electrochemically stable host materials with tunable carrier-transport properties for organic blue electrophosphorescence. The developed host materials 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-(4-tert-butylphenyl)-3,6-ditrityl-9H-carbazole (CzC), and 9-(4-tert-butylphenyl)-3-(triphenylsilyl)-6-trityl-9H-carbazole (CzCSi) all show high triplet energies of 2.97-3.
View Article and Find Full Text PDFA novel ambipolar spiro-configured D-A blue-light emitter bearing hole-transporting diphenylamino groups and electron-transporting phenylbenzimidazole groups was synthesized, characterized, and incorporated into an efficient single-layer organic light-emitting diode (OLED) device exhibiting blue-emission Commission International d'Eclairage (CIE) coordinates of 0.15 and 0.14, a turn-on potential of 4 V, a maximum brightness of 2800 cd/m2 at 830 mA/cm2 (19 V), and a maximum quantum efficiency of 0.
View Article and Find Full Text PDF2,7-Bis(4-tert-butylphenyl)-9,9'-spirobifluorene exhibits balanced electron and hole mobilities of up to 10(-3) cm(2) V(-1) s(-1), as measured using time-of-flight techniques.
View Article and Find Full Text PDFp-Tolyl-substituted ladder-type oligo(p-phenylene)s containing three, four, and five phenylene rings were readily synthesized. The uniform aryl substitution of these systems allowed us to determine the coplanarity of the pi-conjugated backbones crystallographically. The intramolecular annulations eliminate almost all of the conformational disorder and enhance the degree of pi-conjugation of the backbones, resulting in significant red shifts in the absorption and emission maxima and lower oxidation potentials in the higher homologues.
View Article and Find Full Text PDF[structure: see text] Remarkable UV OLED devices using novel spiro-configured bifluorenes as UV emitters have been successfully achieved with external quantum efficiencies up to 2.6-3.1% and emission wavelengths as short as 370 nm.
View Article and Find Full Text PDFBackground: Cutaneous metastasis from adenoid cystic carcinoma of the salivary gland is very rare.
Objective: To present an unusual case of cutaneous metastasis from adenoid cystic carcinoma of the right parotid gland.
Methods: A 63-year-old woman with multiple subcutaneous nodules on the abdomen and a gradually enlarged mass over the right parotid area was examined.
Dermatol Surg
November 2002
Background: Freckles are melanotic lesions frequently seen on the face and other sun-exposed areas. Previously evaluation of the severity of freckles has relied on the ultimately subjective assessment of the doctor or patient. Intense pulsed light (IPL) is newly introduced to treat facial freckles in Asian skin.
View Article and Find Full Text PDFAn efficient one-pot synthetic protocol for the synthesis of arylboronic esters has been established. The concentrated addition mixture of trimethylborate with aryl Grignard reagents was treated with low molecular weight diols (ethylene glycol, 1,3-propandiol) and toluene, the corresponding arylboronic esters were isolated in a convenient way with high yields. The diols not only serve as water replacement for the workup step, but also as well as the reagent for the preparation of arylboronic esters.
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