The reactions of PhCboSeNa (Cbo = o-C2B10H10), prepared by reductive cleavage of Se-Se bond in (PhCboSe)2 by NaBH4 in methanol, with Na2PdCl4, MCl2(PR3)2 and [M2Cl2(μ-Cl)2(PR3)2] afforded a variety of complexes, viz., [Pd(SeCboPh)Cl] (1), [M(SeCboPh)2(PR3)2], [M2Cl2(μ-SeCboPh)(μ-Cl)(PR3)2] (M = Pd, Pt) and [Pd2Cl(SeCb0Ph)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) have been isolated. These complexes were characterized by elemental analyses and NMR (1H, 31P, 77Se, 195Pt) spectroscopy. The structures of [Pd(SeCboPh)2(PEt3)2] (2), [Pt(SeCboPh)2(PMe2Ph)2] (3), [Pd2Cl2(μ-SeCboPh)(μ-Cl)(PMe2Ph)2] (5) and [Pd2Cl(SeCboPh)(μ-Cl)(μ-SeCboPh)(PEt3)2] (7) were established by X-ray crystallography. The latter represents the first example of asymmetric coordination of selenolate ligands in binuclear bis chalcogenolate complexes of palladium and platinum. Thermolysis of [Pd(SeCboPh)2(PEt3)2] (2) in HDA (hexadecylamine) at 330 °C gave nano-crystals of Pd17Se15. 相似文献
Homoallylic alcohols 4a-d, easily accessible in two steps from cyclopropyl methyl ketone, underwent a highly regioselective reaction with singlet oxygen to yield gamma-hydroxyhydroperoxides 5a-d in 57-72% yield. Acid-catalyzed reaction of 5a-d with acetone, cyclopentanone, and cyclohexanone furnished 1,2,4-trioxepanes 8a-d, 9a-d, and 10a-d in good yields. Homoallylic alcohol 12 also underwent a highly regioselective photooxygenation to yield gamma-hydroxyhydroperoxide 13 in 67% yield, which on reaction with acetone, cyclopentanone, and cyclohexanone, furnished 1,2,4-trioxocanes 16-18 in 41-55% yield. 相似文献
The Common Instrument Middleware Architecture (CIMA) aims at Grid-enabling a wide range of scientific instruments and sensors to enable easy access to and sharing and storage of data produced by these instruments and sensors. This paper describes the implementation of CIMA applied to the field of single-crystal X-ray crystallography. To allow the researchers to easily view the current and past data streams from the instruments or sensors in a laboratory, a crystallography portal and associated portlets were developed for this application. The CIMA-based crystallography system provides an opportunity for anyone with Web access to observe and use crystallographic and other data from laboratories that previously had only limited access. 相似文献
The development of operationally simple and cost-effective methods for CC bond formation reactions are highly important in pharmaceutical, agrochemical and material research. In this article we describe the first copper-catalyzed cross-coupling reaction of thioamides with acceptor/acceptor-substituted and acceptor-only substituted α-diazocarbonyl compounds to yield enaminones. The reaction shows broad substrate scope in terms of thioamides and diazocarbonyl compounds. Primary, secondary and tertiary thioamides all give enanminones when reacted with α-diazodiesters, α-diazoketoesters, α-diazodiketones, α-diazoketoamides, α-diazoesteramides, α-diazoketosulfones and α-diazomonoketones. 相似文献
A quick, efficient, one-pot synthesis of carbazates was accomplished in high yields by the reaction of various tosylates of primary, secondary, and tert alcohols, with a variety of substituted hydrazines using the benzyltrimethylammonium hydroxide (Triton-B)/CO2 system. The reaction conditions are mild with simpler workup procedures than the reported methods. 相似文献
In view of the antidiarrheal properties of sterculia gum and ornidazole, an attempt has been made to synthesize novel hydrogels by functionalization of sterculia gum with poly(vinylpyrrolidone) (PVP) for release of the model antidiarrheal drug ornidazole. These hydrogels were characterized with FTIR, SEM, TGA and swelling behavior. Swelling kinetics of the hydrogels and in vitro release dynamics of ornidazole from the drug loaded hydrogels have been studied to determine the mechanism of swelling and drug release from the drug loaded hydrogels. A Fickian diffusion mechanism has been observed for the release of drug from the hydrogels. These hydrogels may have dual actions for the treatment of diarrhea. 相似文献
Via Sonogashira cross-coupling with different alkynes, 1,6 and 1,7 perylene diimides (PDIs) and perylene tetracarboxylic dianhydrides (PTCDs) were synthesized from the corresponding regioisomeric mixture of 1,6/1,7-dibromo precursors. Both bulky triphenyl propyne (TPP) groups and nonbulky hexyl groups allow for facile chromatographic separation. The optical properties of these compounds are discussed. Neutral bay substituents hypsochromically shift both the absorption and emission through deformation from planarity of the perylene core. 相似文献
Solid-phase extraction (SPE) of phenol and chlorophenols, their derivatization to methyl ethers, headspace single-drop microextraction (HS-SDME) of methyl ethers using 1-butanol as extraction solvent, and direct transfer of the drop into the injector for high performance liquid chromatography with diode array detection (HPLC-DAD) have been reported. A flanged-end polytetrafluoroethylene sleeve, 3 mm × 0.5 mm, placed at the tip of the syringe needle, allowed the use of 10 μL solvent drop for extraction. The procedure has been optimized for variables involved in SPE and HS-SDME. A rectilinear relationship was obtained between the amount of chlorophenols and peak area ratio of their methyl ethers/internal standard (4-methoxyacetophenone) in the range 0.01-10 mg L−1, correlation coefficient in the range 0.9956-0.9996, and limit of detection in the range 1.5-3.9 μg L−1 when HS-SDME alone was used for sample preparation. When using coupled SPE and HS-SDME, the linear range obtained was 0.1-500 μg L−1, correlation coefficient in the range 0.9974-0.9998, and the limit of detection in the range 0.04-0.08 μg L−1. Spiked real samples have been analyzed with adequate accuracy, and application of the method has been demonstrated for the analysis of chlorophenols formed upon bamboo pulp bleaching. 相似文献
This paper presents the numerical analysis of the transient performance of the latent heat thermal energy storage unit established on finite difference method. The storage unit consists of a shell and tube arrangement with phase change material (PCM) filled in the shell space and the heat transfer fluid (HTF) flowing in the inner tube. The heat exchange between the HTF, wall and PCM has been investigated by developing a 2-D fully implicit numerical model for the storage module and solving the complete module as a conjugate problem using enthalpy transforming method. A comparative investigation of the total melting time of the PCM has been performed based on natural convection in liquid PCM during the charging process. The novelty of this paper lies in the fact it includes convection in PCM and this investigation includes a detailed parametric study which can be used as a reference to design latent heat storage. The results indicate that natural convection accelerates the melting process by a significant amount of time. In order to optimize the design of the thermal storage unit, parametric study has been accompanied to analyze the influence of various HTF working conditions and geometric dimensions on the total melting time of the PCM. Another important feature considered in this work is the influence of the inner wall of the tube carrying the HTF on the entire melting time of the PCM. An error of around 7.2% is reported when inner wall of the tube is ignored in the analysis.