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541.
Saturated Red‐Light‐Emitting Gold(III) Triphenylamine Dendrimers for Solution‐Processable Organic Light‐Emitting Devices 下载免费PDF全文
Man‐Chung Tang Dr. Carmen Ka‐Man Chan Dr. Daniel Ping‐Kuen Tsang Yi‐Chun Wong Dr. Maggie Mei‐Yee Chan Dr. Keith Man‐Chung Wong Prof. Vivian Wing‐Wah Yam 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15233-15241
A novel isoquinoline‐containing C^N^C ligand and its phosphorescent triphenylamine‐based alkynylgold(III) dendrimers have been synthesized. These alkynylgold(III) dendrimers serve as phosphorescent dopants in the fabrication of efficient solution‐processable organic light‐emitting devices (OLEDs). The photophysical, electrochemical, and electroluminescence properties were studied. A saturated red emission with CIE coordinates of (0.64, 0.36) and a high EQE value of 3.62 % were achieved. Unlike other red‐light‐emitting iridium(III) dendrimers, a low turn‐on voltage of less than 3 V and a reduced efficiency roll‐off at high current densities were observed; this can be accounted for by the enhanced carrier transporting ability and the relatively short lifetimes in the high‐generation dendrimers. This class of alkynylgold(III) dendrimers are promising candidates as phosphorescent dopants in the fabrication of solution‐processable OLEDs. 相似文献
542.
Kevin K. H. Chan S. W. Tsang Harrison K. H. Lee F. So S. K. So 《Journal of Polymer Science.Polymer Physics》2013,51(8):649-658
We use frequency dependent capacitance measurements to probe carrier mobilities and transport parameters of six representative semiconducting polymers and some of their bulk heterojunction (BHJ) blends. With a suitable choice of a hole injection layer, well-defined signals for hole transport characterization can be obtained for the pristine polymers [J. Appl. Phys. 99, 013706 (2006)]. However, ill-defined signals with negative capacitances, arising from undesirable electron leakages, are obtained for the BHJ blends. The problem of electron leakage can be circumvented by inserting an electron blocking and trapping layer under the cathode. As a result, hole transport properties of BHJ blends can be obtained. For the BHJ of poly(3-hexylthiophene) blended with [6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PC61BM), the hole mobilities seem to be insensitive to the composition of the BHJ, indicating the P3HT component in the BHJ is well connected. On the other hand, for poly[N-9“-hepta-decanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadia zole)] doped with [6,6]-phenyl-C71-butyric acid methyl ester (PCDTBT:PC71BM), a clear reduction of the hole mobility is observed as the polymer composition is reduced. Temperature dependent experiments were performed. The data are analyzed by the Gaussian Disorder Model. We found that the energetic disorder is independent of the composition of the BHJ. Organic photovoltaic performances of BHJ blends are also measured in this contribution. The correlation between device performance and energetic disorder of the BHJ will be discussed. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013 相似文献
543.
Ian J. McPherson Tim Sudmeier Joshua P. Fellowes Ian Wilkinson Tim Hughes S. C. Edman Tsang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17594-17602
Molten LiCl and related eutectic electrolytes are known to permit direct electrochemical reduction of N2 to N3? with high efficiency. It had been proposed that this could be coupled with H2 oxidation in an electrolytic cell to produce NH3 at ambient pressure. Here, this proposal is tested in a LiCl–KCl–Li3N cell and is found not to be the case, as the previous assumption of the direct electrochemical oxidation of N3? to NH3 is grossly over‐simplified. We find that Li3N added to the molten electrolyte promotes the spontaneous and simultaneous chemical disproportionation of H2 (H oxidation state 0) into H? (H oxidation state ?1) and H+ in the form of NH2?/NH2?/NH3 (H oxidation state +1) in the absence of applied current, resulting in non‐Faradaic release of NH3. It is further observed that NH2? and NH2? possess their own redox chemistry. However, these spontaneous reactions allow us to propose an alternative, truly catalytic cycle. By adding LiH, rather than Li3N, N2 can be reduced to N3? while stoichiometric amounts of H? are oxidised to H2. The H2 can then react spontaneously with N3? to form NH3, regenerating H? and closing the catalytic cycle. Initial tests show a peak NH3 synthesis rate of 2.4×10?8 mol cm?2 s?1 at a maximum current efficiency of 4.2 %. Isotopic labelling with 15N2 confirms the resulting NH3 is from catalytic N2 reduction. 相似文献
544.
Thy Truong Kei G. I. Webber S. Madisyn Johnston Hannah Boekweg Caleb M. Lindgren Yiran Liang Alissia Nydegger Xiaofeng Xie Tsz-Ming Tsang D. A. Dasun N. Jayatunge Joshua L. Andersen Samuel H. Payne Ryan T. Kelly 《Angewandte Chemie (International ed. in English)》2023,62(34):e202303415
We combined efficient sample preparation and ultra-low-flow liquid chromatography with a newly developed data acquisition and analysis scheme termed wide window acquisition (WWA) to quantify >3,000 proteins from single cells in rapid label-free analyses. WWA employs large isolation windows to intentionally co-isolate and co-fragment adjacent precursors along with the selected precursor. Optimized WWA increased the number of MS2-identified proteins by ≈40 % relative to standard data-dependent acquisition. For a 40-min LC gradient operated at ≈15 nL/min, we identified an average of 3,524 proteins per single-cell-sized aliquot of protein digest. Reducing the active gradient to 20 min resulted in a modest 10 % decrease in proteome coverage. Using this platform, we compared protein expression between single HeLa cells having an essential autophagy gene, atg9a, knocked out, with their isogenic WT parental line. Similar proteome coverage was observed, and 268 proteins were significantly up- or downregulated. Protein upregulation primarily related to innate immunity, vesicle trafficking and protein degradation. 相似文献
545.
Guoliang Liu Hualong Ma Ivo Teixeira Zhenyu Sun Qineng Xia Prof. Xinlin Hong Prof. Shik Chi Edman Tsang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(9):2910-2914
A simple but effective method to exfoliate bulk MoS2 in a range of solvents is presented for the preparation of colloid flakes consisted of one to a few molecular layers by application of ultrasonic treatment in N2H4. Their high yield in solution and exposure of more active surface sites allows the synthesis of corresponding solid catalysts with remarkably high activity in hydrodeoxygenation of 4‐methylphenol and this method can also be applied to other two dimensional materials. 相似文献
546.
Derek P. Gates Chi-Wing Tsang Vincent A. Wright Mandy Yam 《Macromolecular Symposia》2003,196(1):271-278
The C=C bond plays numerous roles in polymer science. This moiety is used as a precursor to polymers by addition polymerization and has been incorporated into π-conjugated polymers. The addition polymerization reaction has been extended to P=C bonds and the first example of a poly(methylenephosphine) has been prepared. The new macromolecule is of moderate molecular weight (ca. 104 g/mol) and the oxidized polymers are air-stable. Poly(p-phenylenephosphaalkene), the first π-conjugated polymer containing P=C bonds in the backbone, has been prepared. The UV/Vis spectrum of this polymer shows a red shift in λmax when compared with molecular model systems. 相似文献