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91.
Rafael Bou-MorenoSimon A. Cotton Verity HunterKathryn Leonard Andrew W.G. PlattPaul R. Raithby Stefanie Schiffers 《Polyhedron》2011,30(17):2832-2836
The new cobalt(II) phosphine oxide complexes Co(Cy3PO)2Cl2 (1), Co(Cy3PO)2Br2 (2), Co(Cy3PO)2I2 (3), Co(Ph2CyPO)2Cl2 (4), Co(Ph2CyPO)2Br2 (5), Co(Ph2CyPO)2I2 (6), Co(Ph2EtPO)2Br2 (7), Co(Cy3PO)2(NCS)2 (8) and Co(Cy3PO)2(NO3)2 (9) have been prepared mainly by the reaction of anhydrous CoX2 (X = Cl, Br, I, NCS, NO3) with the appropriate phosphine oxide. The complexes were characterised by single-crystal X-ray crystallography supported by IR and UV-Vis absorption spectroscopy. The structural analyses show that the cobalt(II) centre adopts a distorted tetrahedral coordination geometry except for 9 which displays an octahedral geometry. Systematic structural features of these complexes are explained within this paper. 相似文献
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Stefanie Sonner Messoud A. Efendiev Hermann J. Eberl 《Mathematical Methods in the Applied Sciences》2011,34(13):1667-1684
We analyze a system of reaction–diffusion equations that models quorum‐sensing in a growing biofilm. The model comprises two nonlinear diffusion effects: a porous medium‐type degeneracy and super diffusion. We prove the well‐posedness of the model. In particular, we present for the first time a uniqueness result for this type of problem. Moreover, we illustrate the behavior of model solutions in numerical simulations. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
95.
Qin T Wiedemair W Nau S Trattnig R Sax S Winkler S Vollmer A Koch N Baumgarten M List EJ Müllen K 《Journal of the American Chemical Society》2011,133(5):1301-1303
We present a novel core-shell-surface multifunctional structure for dendrimers using a blue fluorescent pyrene core with triphenylene dendrons and triphenylamine surface groups. We find efficient excitation energy transfer from the triphenylene shell to the pyrene core, substantially enhancing the quantum yield in solution and the solid state (4-fold) compared to dendrimers without a core emitter, while TPA groups facilitate the hole capturing and injection ability in the device applications. With a luminance of up to 1400 cd/m(2), a saturated blue emission CIE(xy) = (0.15, 0.17) and high operational stability, these dendrimers belong to the best reported fluorescence-based blue-emitting organic molecules. 相似文献
96.
Monobromoferrocene (1) was obtained in 95% yield from ferrocene via lithiation with tert-BuLi/KO-tert-Bu and bromination with dibromotetrachloroethane. Starting from 1 mixtures of 1,2-dibromoferrocene (2) and apparently unreacted 1 (ranging from 80:20 to 50:50, depending on the reaction conditions) can be obtained via a lithiation- zincation- bromination sequence. These mixtures can be transferred directly with a tenfold excess of Lithium-tetramethylpiperidinide, followed by bromination with 1,1,2,2-tetrabromoethane to pentabromoferrocene (3), in an overall yield of 36% starting from ferrocene. The molecular structures of 3 and of 1,2,3-tribromoferrocene (4) have been determined by X-Ray diffraction. 相似文献
97.
Beel R Kobialka S Schmidt ML Engeser M 《Chemical communications (Cambridge, England)》2011,47(11):3293-3295
SOMO catalysis has lately obtained large interest as a new and powerful version of enantioselective organocatalysis which includes radical steps initiated by a one-electron oxidation. The intermediate enamine radical cation has been postulated, but has not been observed directly so far. This communication now reports the direct detection of this key intermediate. 相似文献
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Stefanie Schwamborn Dr. Leonard Stoica Prof. Dr. Wolfgang Schuhmann 《Chemphyschem》2011,12(9):1741-1746
PtAg bimetallic nanoparticles for oxygen reduction reaction (ORR) in alkaline media were prepared by pulse electrodeposition (PED). During PED the reduction of Ag+ ions predominates, thus an increased Ag content in the co‐deposit is accomplished. The mechanism for this anomalous co‐deposition was elucidated by potential pulse experiments, which revealed that nuclei formation mainly occurs via the reduction of Pt2+ ions. The growth of the particles is diffusion controlled leading to the formation of a Ag shell covering a PtAg alloyed region. However, the shell is not growing homogeneously on the PtAg alloy. Hence, regions of the PtAg alloy are exposed, which exhibit an enhanced ORR activity compared to a pure Ag surface. 相似文献