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The synthesis and characterization of cationic platinum complexes of the type [(R(2)PC(2)H(4)PR(2))PtMe(OEt(2))]BAr(F) (R = Cy, Et) are reported. These electrophilic platinum cations are found to react quantitatively with arenes (benzene, toluene) at room temperature by undergoing intermolecular C-H activation with concomitant C-C coupling to generate complexes of the type [[Pt(R(2)PC(2)H(4)PR(2))](2)(mu-eta(3):eta(3)-biaryl)][BAr(F)](2). The dianionic biaryl ligands in these compounds exhibit a rare mu-eta(3):eta(3)-bis-allyl bonding mode and can be removed from the complex with stoichiometric oxidants to generate the free biaryl and [(R(2)PC(2)H(4)PR(2))Pt(mu-X)](2)[BAr(F)](2) (R = Cy, Et; X = Cl, I). The cationic platinum complexes [(R(2)PC(2)H(4)PR(2))PtMe(OEt(2))]BAr(F) (R = Cy, Et) are also quite reactive with water, forming the bridging hydroxide complexes [(R(2)PC(2)H(4)PR(2))Pt(mu-OH)](2)[BAr(F)](2) (R = Cy, Et). A possible mechanism is proposed for the C-C coupling reaction based upon the structures of these bridging biphenyl complexes, which provides a new perspective for the related palladium-catalyzed oxidative coupling of arenes to form biaryls. 相似文献
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The first triethylphosphine-stabilized Pt-Au cluster compounds, [Pt(AuPEt(3))(10)](2+) (2) and [Pt(AuPEt(3))(9)](3+) (3), were prepared by the direct reaction of Pt(PEt(3))(3) with AuPEt(3)NO(3) under a dihydrogen atmosphere. Cluster 2 is the highest-nuclearity homoleptic Pt(AuPR(3))(n)() cluster yet prepared. The reactivity and structures of these clusters are in agreement with the well-established electron-counting arguments. The 18-electron cluster 2 was converted into the 16-electron cluster 3 by oxidation with 2 equiv of ferricinium ion [Fe(eta(5)-C(5)H(5))(2)](+). Cluster 3 was converted into 2 by reduction with H(2) in the presence of [AuPEt(3)](+). Cluster 3 was also observed to cleanly add the 2-electron donors CO and PEt(3) to form the 18-electron clusters [(CO)Pt(AuPEt(3))(9)](3+) (4) and [(PEt(3))Pt(AuPEt(3))(9)](3+) (5), respectively. Single-crystal X-ray diffraction results show that 3 has a flattened, toroidal structure in which the PtAu(9) framework has a Pt-centered, tricapped trigonal prismatic geometry. Crystal data for [Pt(AuPEt(3))(9)](NO(3))(3) is as follows: hexagonal P6(3)/m, a = 15.134(5) ?, c = 23.48(1) ?, V = 4657 ?(3), Z = 2, residuals R = 0.056, and R(w)() = 0.053 for 1489 observed reflections and 81 variables, Mo Kalpha radiation. Compound 3 was found to reversibly add H(2) in solution to form the dihydride cluster [(H)(2)Pt(AuPEt(3))(9)](3+) (6). The equilibrium constant for this addition reaction is 1.1 x 10(3) M(-)(1) (CD(2)Cl(2) solution, 25 degrees C), slightly smaller than that for [Pt(AuPPh(3))(8)](2+). The rate of the addition is also slower than that with [Pt(AuPPh(3))(8)](2+). Cluster 3 is an excellent homogeneous catalyst for H(2)-D(2) equilibration giving a turnover rate for HD production of 0.13 s(-)(1) (nitrobenzene solvent, 30 degrees C, 1 atm). The PEt(3)-containing clusters give similar rates and follow the same general trends previously observed with PPh(3)-ligated clusters. The chemistry of these new clusters is explained by consideration of the steric and electronic properties of the PEt(3) ligand. These new compounds will be useful as models for hydrogen activation by Pt-Au clusters and as precursors for supported Pt-Au catalysts. 相似文献
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本文研究了连续时间的集值序上鞅,在一定的假设下我们证明了集值序上鞅有h-Riesz分解,然后证明了集值序上鞅的Doob-Meyer分解定理。 相似文献
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YUE Ke YU Yu-Hong XU Hu-Shan SUN Zhi-Yu WANG Jian-Song XIAO Zhi-Gang HU Zheng-Guo CHEN Ruo-Fu ZHANG Xue-Ying WV Xiao-Lin CHEN Jun-Ling ZHAN Wen-Long 《中国物理C(英文版)》2010,34(8)
In the construction of a large area neutron detector(neutron wall)that is used to detect neutrons at GeV energies,the performances of all the sampling paddle modules prepared for the neutron wall areinvestigated with a specially designed test bench.Tested by cosmic rays,an average intrinsic time resolution of 222.5 ps is achieved at the center of the modules.The light attenuation length and the effective speed of the light in the module are also investigated. 相似文献
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LIANG Yu-Tie MAO Ya-Jun YOU Zheng-Yun LI Wei-Dong BIAN Jian-Ming CAO Guo-Fu CAO Xue-Xiang CHEN Shen-Jian DENG Zi-Yan FU Cheng-Dong GAO Yuan-Ning HAN Lei HAN Shao-Qing HE Kang-Lin HE Miao HU Ji-Feng HU Xiao-Wei HUANG Bin HUANG Xing-Tao JIA Lu-Kui JI Xiao-Bin LI Hai-Bo LIU Bei-Jiang LIU Chun-Xiu LIU Huai-Min LIU Ying LIU Yong LUO Tao LU Qi-Wen MA Qiu-Mei MA Xiang MAO Ze-Pu MO Xiao-Hu NING Fei-Peng PING aong-Gang QIU Jin-Fa SONG Wen-Bo SUN Sheng-Sen SUN Xiao-Dong SUN Yong-Zhao TIAN Hao-Lai WANG Ji-Ke WANG Liang-Liang WEN Shuo-Pin WU Ling-Hui WV Zhi XIE Yu-Guang XU Min YAN Jie YAN Liang YAO Jian YUAN Chang-Zheng YUAN Ye ZHANG Chang-Chun ZHANG Jian-Yong ZHANG Lei ZHANG Xue-Yao ZHANG Yao ZHENG Yang-Heng ZHU Yong-Sheng ZOU Jia-Heng 《中国物理C(英文版)》2009,33(7)
Cosmic-ray data of 90 M events have been collected and used for calibration, alignment as well as detector tuning. A special tracking algorithm for the BESⅢ muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESⅢ muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data. 相似文献
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Time-resolved photoluminescence (TRPL) was applied to investigate the transient process in GaP1-xNx (x = 0.12%) alloy. The filling, transferring and decay processes among nitrogen pairs are directly observed. The NN4 pair, either not present or only a small obscure peak under a proper excitation condition in the steady-state photoluminescence spectrum, is well resolved by TRPL. 相似文献
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本文研究了连续时间的集值序上鞅.在一定的假设下我们证明了集值序上鞅有h-Riesz分解,然后证明了集值序上鞅的Doob-Meyer分解定理. 相似文献