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Fluorescent 2,3,6,7,9,10-hexaphenylanthracene-based derivatives (HPhAn) were synthesized to serve as deep-blue dopants in organic electroluminescent (EL) devices. The fluorescent emissions of HPhAnfluorophores, fine-tuned from 462 to 449 nm with varied fluorinated phenyl rings attached to the central carbons of the anthracene core, produced photoluminescence quantum yields of 82–88% in the solid state. Unlike the known monostyrylamine deep-blue dopant, these blue dopants in dilute solutions showed no pronounced spectral red shift with increasing solvent polarity; the emission color of HPhAndopants is thus insensitive to the polarity of the medium. The highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) energy levels calculated from the oxidation potentials and optical energy gaps are 5.61–5.70 eV and 2.73–2.89 eV, respectively. These thermally robust compounds undergo thermal decomposition at temperatures greater than 300 °C. The relationships among current density, voltage and luminance, the EL efficiency and the operational stability of devices based on the blue HPhAndopants were examined. These HPhAn-doped EL devices are activated at voltages less than 3.5 V and attained an external quantum efficiency as much as 5.3% in the deep-blue light region with Commission Internationale d'Éclairage (CIE) coordinates (0.14, 0.10), near the National Television System Committee (NTSC) standard blue coordinates (0.14, 0.08). [ABSTRACT FROM AUTHOR]

We have synthesized three triptycene derivatives, TCTP (2,6,14-triscarbazolyltriptycene), TATP (2,6,14-tris-(diphenylamino)triptycene) and TPOTP (2,6,14-tris(diphenylphosphoryl)triptycene) which show very high triplet energy gaps (2.94–3.15 eV) and glass transition temperatures (Tgs) 170 °C. The HOMO and LUMO levels of these three materials indicate that TCTP and TATP possess hole transport characteristics, while TPOTP has electron transport characteristics. These carrier-transporting properties are further supported by the current density–voltage characteristics of the hole-only and electron-only devices of the materials. TATP could be employed as a general host for blue, green and red electrophosphorescence devices providing high brightness, and good current and power efficiencies. The devices using TCTP and TPOTP as the host for the phosphorescence emitter FIrpic showed maximum external quantum efficiencies as high as 10.1% and 16.9%, respectively. By using a blend of TCTP and TPOTP as blue co-host for FIrpic (iridium(iii) bis(4,6-difluorophenylpyridinato)picolinate), the device shows an external quantum efficiency of 15.5% at 4.5 V, current efficiency (ηc) of 31.9 cd A−1at 4.5 V, power efficiency (ηp) of 25.1 lm/W at 4.0 V, respectively. The co-host system greatly improves the performance of the device at normal operation brightness due to the decrease of driving voltage and the balance of hole and electron transport in the device. [ABSTRACT FROM AUTHOR]

The feature article surveys the transition metal-catalyzed three-component coupling of allenes and the related allylation reactions. Most of the reactions shown in the article mechanistically proceed via oxidative addition of organic electrophiles to metals, followed by carbometallation of allene and then transmetalation by main group metals or reagents and organometallic reagents. These reactions provide an efficient route for the synthesis of various substituted allyl and vinyl metal reagents and complex organic molecules in highly regio-, stereo- and chemoselective manner in one pot. The metal reagents or π-allyl–metal intermediates obtained from the reaction are utilized for the allylation of aldehydes, ketones and imines, producing various homoallylic alcohols and amines in a highly regio- and stereoselective manner. [ABSTRACT FROM AUTHOR]

The three-component coupling of benzynes with terminal alkynes and activated alkenes in the presence of CuI, PCy3and CsF in a 1 : 1 mixture of CH3CN and THF at 50 °C for 5 h gave 1-alkyl-2-alkynylbenzenes in good to moderate yields. [ABSTRACT FROM AUTHOR]

o-Dihaloarenes acting as aryne precursors react with acetylenes and nitriles catalyzed by the NiBr2(dppe)/dppe/Zn system to give substituted naphthalene, phenanthridine or triphenylene derivatives depending on the reaction conditions in moderate to excellent yields with good tolerance of functional groups. [ABSTRACT FROM AUTHOR]

Benzynes react with allylic acetates or halides and terminal alkynes in the presence of Pd(PPh3)4, CuI and CsF in CH3CN at 50 °C for 5 h to give 1-allyl-2-alkynylbenzene derivatives in good to excellent yields. [ABSTRACT FROM AUTHOR]