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991.
A variety of heterobiaryl compounds have been synthesized by the Suzuki‐Miyaura coupling reactions of heteroaryl halides with potassium aryltrifluoroborates. Pd (OAc)2 was found to be highly efficient for the Suzuki‐Miyaura coupling reactions of various heteroaryl halides with potassium aryltrifluoroborates in aqueous systems, delivering the corresponding heterobiaryl compounds in good to excellent yields. 相似文献
992.
993.
994.
Four Zn(II) complexes, [Zn L 2(SO4)]n ( 1 ), [Zn L 4(H2O)2]?2(NO3)?4EtOH ( 2 ), [Zn L 2Cl2]? L ( 3 ), and [Zn L 2Br2]? L ( 4 ) ( L = uniconazole), were synthesized using a hydrothermal method and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. Complex 1 formed a one‐dimensional polymer chain. However, complexes 2 ‐ 4 were obtained as zero‐dimensional mononuclear coordination compounds. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all complexes show better antifungal activities than their ligands and mixtures. In addition, the interactions between the metal salts of complexes 1 ‐ 4 and uniconazole seem to be synergistic. Furthermore, the polymer chain structure of complex 1 significantly enhanced the bioactivity, especially against Botryosphaeria ribis ( I ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity after the formation of Zn(II) complexes. The resulting data show that the HOMO–LUMO energy gaps of complexes 1 ‐ 4 (0.0578, 0.0946, 0.1053, and 0.1245 eV) are smaller than that of the free ligand (0.1247 eV) and correlate with the antifungal activity of the zinc complexes. 相似文献
995.
A series of ethylene‐bridged C1‐symmetric ansa‐(3‐R‐indenyl)(fluorenyl) zirconocene complexes ( 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ) incorporating a pendant arene substituent on the 3‐position of indenyl ring have been synthesized. The structure of complex 4 was further confirmed by X‐ray diffraction analysis. When activated with methylaluminoxane, four sterically less encumbered complexes 1 , 2 , 4 and 5 could catalyze the dimerization of propylene in toluene at 100°C to afford 2‐methyl‐1‐pentene with high selectivities up to 95.7–98.4% and moderate activities of 2.00 × 104 to 7.89 × 104 g (mol‐Zr?h)?1. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
996.
L.J. Song J. Ma D. Yan X.G. Wang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2012,66(8):1-5
We introduce a method of quantum tomography for a continuous variable system in position and momentum space. We consider a single two-level probe interacting with a quantum harmonic oscillator by means of a class of Hamiltonians, linear in position and momentum variables, during a tunable time span. We study two cases: the reconstruction of the wavefunctions of pure states and the direct measurement of the density matrix of mixed states. We show that our method can be applied to several physical systems where high quantum control can be experimentally achieved. 相似文献
997.
Enantioselective Self‐Assembly of Triangular Dy3 Clusters with Single‐Molecule Magnet Behavior 下载免费PDF全文
Three pairs of enantiopure chiral triangular Ln3 clusters, [Ln3LRRRRRR/SSSSSS(μ3‐OH)2(H2O)2(SCN)4]?xCH3OH?yH2O ( R ‐Dy3 , Ln=Dy, x=6, y=0; S ‐Dy3 , Ln=Dy, x=6, y=1; R ‐Ho3 , Ln=Ho, x=6, y=1; S ‐Ho3 , Ln=Ho, x=6, y=1; R ‐Er3 , Ln=Er, x=6, y=0; S ‐Er3 , Ln=Er, x=6, y=1), have been successfully synthesized by a rational enantioselective synthetic strategy. The core of triangular Ln3 is bound in the central N6O3 of the macrocyclic ligand, and the coordination spheres of Ln ions are completed by four SCN? anions and two H2O molecules in axial positions of the macrocycle. The circular dichroism (CD) and vibrational circular dichroism (VCD) spectra of the enantiomers demonstrate that the chirality is successfully transferred from the ligands to the resulting Ln3 clusters. Ac susceptibility measurements reveal that single‐molecule magnet behavior occurs for both enantiopure clusters of R ‐Dy3 and S ‐Dy3 . This work is one of the few examples of the successful design of a pair of triangular Dy3 clusters showing simultaneously slow magnetic relaxation and optical activity, and this might open up new opportunities to develop novel multifunctional materials. 相似文献
998.
Shu‐Ting Wu Zhen‐Wen Cai Qiao‐Yan Ye Chen‐Hao Weng Xi‐He Huang Xiao‐Lin Hu Chang‐Cang Huang Nai‐Feng Zhuang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(47):13074-13078
Circular dichroism is known to be the feature of a chiral agent which has inspired scientist to study the interesting phenomena of circularly polarized light (CPL) modulated molecular chirality. Although several organic molecules or assemblies have been found to be CPL‐responsive, the influence of CPL on the assembly of chiral coordination compounds remains unknown. Herein, a chiral coordination polymer, which is constructed from achiral agents, was used to study the CPL‐induced enantioselective synthesis. By irradiation with either left‐handed or right‐handed CPL during the reaction and crystallization, enantiomeric excesses of the crystalline product were obtained. Left‐handed CPL resulted in crystals with a left‐handed helical structure, and right‐handed CPL led to crystals with a right‐handed helical structure. It is exciting that the absolute asymmetric synthesis of a chiral coordination polymer could be enantioselective when using CPL, and provides a strategy for the control of the chirality of chiral coordination polymers. 相似文献
999.
The sorption equilibria of carbon dioxide on three types of silica gel (SG) with different pore size distributions in the presence of water were studied experimentally using a volumetric method at 275?K with pressures from 0 to 3.7?MPa. Both the pore size distribution of the silica gel and the quantity of pre-sorbed water impact the formation of the CO2 hydrates. For wet silicon gel A(SG-A) with water loading ratio of 0.75, the highest CO2 sorption was about 2.5?mmol of CO2 per gram of dry sorbent at 275?K. Similarly, the highest sorption was about 2.7?mmol for wet SG-B with R w =0.81. However, CO2 hydrate did not form on the wet surface of SG-C due to its large pore sizes. 相似文献
1000.
Fabrication of large-scale ripples on fluorine-doped tin oxide films by femtosecond laser irradiation 下载免费PDF全文
The large-scale uniform self-organized ripples are fabricated on fluorine-doped tin oxide (FTO) coated glass by femtosecond laser. They can be smoothly linked in a horizontal line with the moving of XYZ stage by setting its velocity and the repetition rate of the laser. The ripple-to-ripple linking can also be realized through line-by-line scanning on a vertical level. The mechanism analysis shows that the seeding effect plays a key role in the linking of ripples. 相似文献