Rh(II)-catalyzed formation and rearrangement of trifluoroacetyl-containing sulfur ylides

A facile, convenient, efficient, and high yielding Rh(II)-catalyzed formation and rearrangement of trifluoroacetyl-containing sulfur ylides are reported. It is a Rh₂(OAc)₄-catalyzed [2,3]-sigmatropic rearrangement of sulfur ylide intermediates generated from α-diazo compounds.     

Native and stearic acid modified ceria-zirconia supports in normal and reversed-phase HPLC

Porous ceria-zirconia composite with narrow particle size distribution and large specific surface area was synthesized by a sol-gel process. Chromatographic properties of the native supports was investigated in normal phase mode for the separation of test mixtures of basic, neutral and acidic compounds. The new packing material exhibited polar and basic properties, which are suitable for the separation of basic compounds. Lypophilic packing has been obtained by the modification of the ceria-zirconia with stearic acid, which exhibited strong hydrophobicity relative to the native packing. Therefore, the modified ceria-zirconia behaves as a reversed-phase packing material. Different selectivity towards basic compounds was observed on the new packing compared to the native ceria-zirconia and conventional ODS stationary phase.     

High-dimensional architectures from the self-assembly of lanthanide ions with benzenedicarboxylates and 1,10-phenanthroline

Six new coordination polymers, [Eu(1,2-BDC)(1,2-HBDC)(phen)(H(2)O)](n) (1), [Eu(2)(1,3-BDC)(3)(phen)(2)(H(2)O)(2)](n).4nH(2)O (2), [Eu(1,4-BDC)(3/2)(phen)(H(2)O)](n) (3), [Yb(2)(1,2-BDC)(3)(phen)(H(2)O)(2)](n).3.5nH(2)O (4), [Yb(2)(1,3-BDC)(3)(phen)(1/2)](n) (5), and [Yb(2)(1,4-BDC)(3)(phen)(2)(H(2)O)](n) (6), were synthesized by hydrothermal reactions of lanthanide chlorides with three isomers of benzenedicarboxylic acid (H(2)BDC) and 1,10-phenanthroline (phen), and characterized by single-crystal X-ray diffraction. 1 has a 2-D herringbone architecture with a Z-shaped cavity. 2 and 5 have different 3-D networks, but both are formed by 1,3-BDC anions bridging metal centers (Eu or Yb) via carboxylate groups. 3 and 6 possess similar layer structures which are further constructed to form 3-D networks by hydrogen bonds and/or pi-pi aromatic interactions. 4 comprises 1-D chains that are further interlinked via hydrogen bonds, resulting in a 3-D network. In the three europium complexes, all the europium ions are eight-coordinated, while the coordination numbers of the ytterbium ions in other three-coordination polymers range from six to eight. Crystal data: for 1, monoclinic, space group P2(1)/c, with a = 12.565(6) A, b = 16.005(8) A, c = 12.891(6) A, beta = 102.173(8) degrees, and Z = 4; for 2, monoclinic, space group P2(1)/c, with a = 20.979(4) A, b = 11.5989(19) A, c = 20.810(3) A, beta = 110.391(3) degrees, and Z = 4; for 3, triclinic, space group P1, with a = 10.331(5) A, b = 10.887(5) A, c = 11.404(5) A, alpha = 107.660(7) degrees, beta = 91.787(7) degrees, gamma = 112.946(6) degrees, and Z = 2; for 4, triclinic, space group P1, with a = 11.517(5) A, b = 13.339(5) A, c = 13.595(6) A, alpha = 87.888(7) degrees, beta = 67.759(6) degrees, gamma = 68.070(6) degrees, and Z = 2; for 5, orthorhombic, space group C222(1), with a = 8.174(2) A, b = 24.497(7) A, c = 29.161(8) A, and Z = 8; for 6, triclinic, space group P1, with a = 10.349(3) A, b = 11.052(3) A, c = 19.431(6) A, alpha = 105.464(4) degrees, beta = 91.300(5) degrees, gamma = 93.655(5) degrees, and Z = 2. The magnetic properties of 1 and 4 were investigated. The photophysical properties of 1 were also studied.     

Fluorescence resonance energy transfer in doubly-quantum dot labeled IgG system

The mouse immunoglobulin G (mouse IgG) as a kind of bio-molecule was labeled with two different luminescent colloidal semiconductor quantum dots (QDs), green-emitting CdTe quantum dots and red-emitting CdTe quantum dots in this work. As a result of the fluorescence resonance energy transfer (FRET) between the two different sizes nanoparticles with mouse IgG as the binding bridge, a significant enhancement of the emission of the red-emitting CdTe quantum dots and the corresponding quenching of the emission of green-emitting CdTe quantum dots were observed. The relationship between the concentration of the mouse immunoglobulin G and the fluorescence intensity ratio (I_a/I_d) of acceptors and donors was studied also. Under optimal conditions, the calibration graph is linear over the range of 0.1–20.0 mg/L mouse IgG.     

The design of an irradiator for the continuous processing of liquid latex

This paper presents anew design concept for a gamma irradiation plant for the continuous processing of pumpable liquids. Typical applications of such a plant include

• * the irradiation vulcanisation of natural latex rubber

• * disinfection of municipal sewage sludge for agricultural use

• * sterilisation of liquids in the pharmaceutical and cosmetics industries

• * industrial processing of bulk liquids

The authors describe the design and operation of the latex irradiator now operating on a small production scale in Malaysia and proposed developments.

The design allows irradiation processing to be carried out under an inert or other gaseous environment.

State-of-the-art computer control system ensures the fully automatic processing operation needed by industrial computers.     

可再生甲壳素吸附铬（Ⅵ）的特性研究

可再生甲壳素吸附铬（Ⅵ）的特性研究陈炳稔＊汤又文李国明万春华（华南师范大学化学系广州５１０６３１）关键词可再生甲壳素，制备，铬（Ⅵ），吸附１９９７－０８－１９收稿，１９９７－１２－２３修回广东省科委及高教厅资助课题利用甲壳素作为铬（Ⅵ）的捕集剂已有报...     

Separation of Dyes from Aqueous Solutions by Paper Adsorption

Separation of the dyes methyl violet, methylene blue, and congo red from aqueous solutions by paper capillary permeation adsorption method was studied using paper. Nearly 100% of the investigated dyes could be separated under the optimum conditions. The effect of pH on the separation efficiency was studied in particular. At pH 5–9, 1.3–11, and 7–11, the maximum separation was achieved for methyl violet, methylene blue and congo red, respectively. The effects of dye concentration and some foreign ions on the separatability were examined. Moreover, the selective separation of some dyes was attempted by elution with chemical reagents.     

Identification and quantification of 13 components in Angelica sinensis (Danggui) by gas chromatography-mass spectrometry coupled with pressurized liquid extraction

Angelica sinensis (Danggui in Chinese), a well-known traditional Chinese medicine, is also used as a health food product for women's care in Europe and America. Therefore, the demand for Danggui is enormous throughout the world. Due to the shortage of Angelica sinensis, Angelica acutiloba and Angelica gigas are commonly used as the substitutes of Danggui in the market of southeast Asia. However, the three common Angelica roots showed variation in their genetic and chemical composition. Up to date, it is thought that ferulic acid, ligustilide and other phthalides such as butylidenephthalide are the biologically active components of Danggui. In this paper, the contents of 13 compounds including ferulic acid, Z-ligustilide, E-ligustilide, Z-butylidenephthalide, E-butylidenephthalide, 3-butylphthalide, 3-butylidene-4-hydroxyphthalide, senkyunolide A, 6,7-epoxyligustilide, senkyunolide F, senkyunolide H, senkyunolide I, and 6,7-dihydroxyligustilide were determined or estimated by using gas chromatography-mass spectrometry (GC-MS) coupled with pressurized liquid extraction (PLE). The results showed that GC-MS coupled with PLE offered a simple, rapid and high sensitive method to analysis of components in Angelica root. And the contents of investigated compounds in Angelica sinensis, Angelica acutiloba and Angelica gigas, which are used as Danggui in China, Japan and Korea, respectively, were highly variant. It is thought that interaction of multiple chemical compounds contributes to the therapeutic effects of Chinese medicines. However, the overall clinical efficacy of these different Danggui has not been determined. Therefore, comparison of chemical components and pharmacological activities of different Angelica root is helpful to elucidate the mechanism of therapeutic effects of Danggui.     

Retroracemization using new forms of Belokon's original ligand: ­intermediate NiII complexes of N‐({2‐[N‐(S)‐alkylprolylamino]phenyl}phenylmethylene)‐(S)‐phenylalanine (alkyl is 2‐picolyl, 3‐picolyl or ethyl)

In the title compounds, [N‐(phenyl{2‐[N‐(S)‐(2‐picolyl)­prolyl­amino]­phenyl}methyl­ene)‐(S)‐phenyl­alaninato]­nickel(II), [Ni(C₃₃H₃₀N₄O₃)], (I), [N‐(phenyl{2‐[N‐(S)‐(3‐picolyl)­prolyl­amino]­phenyl}methyl­ene)‐(S)‐phenyl­alaninato]­nickel(II) hemihydrate, [Ni(C₃₃H₃₀N₄O₃)]·0.5H₂O, (II), and [N‐({2‐[N‐(S)‐ethyl­prolyl­amino]­phenyl}phenyl­methyl­ene)‐(S)‐phenyl­ala­nin­ato]­nickel(II), [Ni(C₂₉H₂₉N₃O₃)], (III), the Ni^II centres have approximate square‐planar coordination geometries from N₃O donor sets. The picolyl N atoms in (I) and (II) are too remote from the metal centres to interact significantly, but the metal coordination geometries experience tetrahedral distortion and/or displacement of the metal centre from the N₃O plane. These are linked to conformational differences between the ligands of the symmetry‐independent complexes (Z′ = 2), which in turn are related to molecular packing. In (III), where a less sterically demanding ethyl group replaces the picolyl substituents, there are none of the distortions or displacements seen in (I) and (II).