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91.
Kean H. Khoo K. Rodney Fernando Richard J. Fereday Chee-Yan Chan 《Journal of solution chemistry》1995,24(10):1039-1048
The solubility of thallium(I) chloride has been determined in aqueous solutions of strontium chloride and barium chloride at concentrations up to 1.5 mol kg–1. The data were analyzed using Pitzer's equations without making explicit assumption of association to ion pairs by assuming =3 instead of =2, with the (1) term for TlCl being equivalent to the (2) term for 2-2 electrolytes. Best values of (0) and (1) for TlCl are recommended together with K
s
, the activity solubility product. These were used to fit the present solubility data and derive the Pitzer model mixture parameters relevant to the systems, fTIN and fTINCl (N=Sr, Ba). Mixture parameters for TlCl+MCl+H2O systems are also derived to complete the parameter base. The fit of the experimental data was found to be worse when higher-order terms for asymmetrical mixing were included in the analysis. Activity coefficients for thallium(I) chloride in the mixtures are derived. 相似文献
92.
93.
Behaviour of electrolytes confined in cylindrical and slit pores are studied by computer simulations at the molecular level. Previous equilibrium and structural properties obtained by Monte Carlo techniques using the restrictive primitive model are discussed. Transport properties are calculated by the canonical molecular dynamics technique for ions with Lennard–Jones cores. Assuming an external electric potential, the chemical potential of individual ions can be balanced without the need for a grand canonical procedure. The mobility of the counterion is affected by the surface charge density. At a high surface charge, the mean square axial displacement of the counterion calculated is lower than the bulk value due to its high concentration near the charged wall. 相似文献
94.
A simple and efficient palladium-catalyzed carbon-oxygen bond formation is reported. The palladium-tri-tert-butylphosphine complex was found to be effective in converting haloarenes to corresponding substituted phenols. This methodology offers a direct transformation of aryl halides to phenols, as well as the straightforward application to generate a wide variety of diaryl or alkyl/aryl ethers. 相似文献
95.
Ma DL Shum TY Zhang F Che CM Yang M 《Chemical communications (Cambridge, England)》2005,(37):4675-4677
Platinum(II) terpyridine complexes with glycosylated acetylide and arylacetylide ligands bind to DNA with binding constants approximately 10(5) mol(-1) dm(3); the glycosylated arylacetylide complexes exhibit emission at lambda(max) approximately 620 nm in water and are up to approximately 100-times higher in potency than the clinical cisplatin drug in killing cancer cells. 相似文献
96.
Substituted cyclopenta[b]indoles are selectively brominated in good yields with excess pyridine ‐ Br2 charge‐transfer complex (PyBr2) in a one‐pot reaction to provide 5 and/or 7‐bromoindoles. The mechanism involves the formation of an adduct (addition of bromine on the central double bond) which is subsequently reduced in situ with Zn and AcOH. A variety of functional groups in the cyclopentyl and the benzenoid rings are tolerated. 相似文献
97.
E. coli peptide deformylase (PDF) catalyzes the deformylation of nascent polypeptides generated during protein synthesis. While PDF was originally thought to be a zinc enzyme, subsequent studies revealed that the active site metal is iron. In an attempt to understand this unusual metal preference, high-resolution structures of Fe-, Co-, and Zn-PDF were determined in complex with its deformylation product, formate. In all three structures, the formate ion binds the metal and forms hydrogen-bonding interactions with the backbone nitrogen of Leu91, the amide side chain of Gln50, and the carboxylate side chain of Glu133. One key difference, however, is how the formate binds the metal. In Fe-PDF and Co-PDF, formate binds in a bidentate fashion, while in Zn-PDF, it binds in a monodentate fashion. Importantly, these structural results provide the first clues into the origins of PDF's metal-dependent activity differences. On the basis of these structures, we propose that the basis for the higher activity of Fe-PDF stems from the better ability of iron to bind and activate the tetrahedral transition state required for cleavage of the N-terminal formyl group. 相似文献
98.
Lu W Mi BX Chan MC Hui Z Zhu N Lee ST Che CM 《Chemical communications (Cambridge, England)》2002,(3):206-207
Tridentate cyclometalated platinum(II) complexes bearing sigma-alkynyl ligands exhibit tunable photoluminescence and enhanced stability during vacuum deposition; OLEDs based on these materials display orange to red electrophosphorescence with low turn-on voltages (approximately 4 V), maximum luminance approaching 10,000 cd m-2 and efficiency up to 4.2 cd A-1. 相似文献
99.
The regioselection in the alkylation of trimethylsilylallyl anion can be controlled by the use of Schlosser's base to give predominately γ-product with trans-geometry at the double bond. Application of this approach to the synthesis of Z-9-tricosene and the Gypsy moth sex pheromone is demonstrated. 相似文献
100.
Robin T. Macaluso H. Lee M. Moldovan Julia Y. Chan 《Journal of solid state chemistry》2003,174(2):296-301
A new compound, CePdGa6, and its isostructural analog, LaPdGa6 have been synthesized by flux growth and characterized by single-crystal X-ray diffraction. The compounds adopt a tetragonal structure with P4/mmm space group, Z=1. The lattice parameters for CePdGa6 are and and and for LaPdGa6. Magnetic and thermal measurement have revealed that CePdGa6 is a heavy-fermion with the specific heat coefficient and Ce f moments order antiferromagnetically along c-axis at . Reconfiguration of spin occurs at to induce a ferromagnetic component only in the a-b plane. This strong anisotropy in the magnetism might be related to its unique layered structure. 相似文献