Advanced Materials Research Vols. 1033-1034

Abstract: Characteristics of absorption of activated carbon on methylene blue were studied. It was demonstrated that adsorption of activated carbon on methylene blue was very stable on monomolecular adsorption and when multimolecular adsorption existed adsorption became to be weak. An improved method was suggested that many samples were tested adsorption of activated carbon on methylene blue in parallel experiment and certain sample was selected to use in next experiment, its color should approximate to the color of 0.4% CuSO₄ but darker slightly and activated carbon loaded methylene blue was added some fresh phosphate buffer solution to desorb methylene blue on the activated carbon, testing absorption value total concentration of methylene blue in the solutionin (merging the first and second experiment) by spectrophotometer, calculating adsorption value on difference method which original volume of methylene blue added subtracts rest of methylene blue in the solution after adsorption. The new method was simple, rapid and easy. word times would shorten obviously.

Abstract: Pyrochlore oxides La₂Zr₂O_7, Ce₂Zr₂O₇ and their solid solutions were studied by in situ x-ray diffraction (XRD) measurement at high pressures. Pressure dependence of cationic disordering was derived from Rietveld refinement of the XRD patterns. The results indicated that the mixed occupancy in the cation site enhanced the compressibility obviously. All the pyrochlore structure became unstable at ~20 GPa and an orthorhombic high-pressure phase formed. The cations changed from the ordered state in pyrochlore to a disordered state in the high-pressure phase. The high-pressure phase is about 8% denser than the pyrochlore phase and not stable at ambient conditions and a disordered defect-fluorite structure was quenched for all the samples.

Abstract: A new oxovanadium (IV) complex, [VO(o-van-phe)(phen)] (1) (o-van-phe = Schiff base derived from o-vanillin and L-phenylalanine, phen =1,10-phenanthroline), has been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The results show that complex 1 belongs to triclinic crystal system, with P-1 space group, a=10.646(2) Å, b=11.089(3) Å, c=14.143(4) Å, α=67.374(4)°, β=79.685(4)°, γ=89.711(4)°, Z=2, V=1512.5(7) ų, Dc =1.195 mg·m^–3, μ=0.366 mm^–1, F(000)=562. In the molecular structure, the V(IV) ion is six coordinated to form a distorted octahedral geometry. In the crystal, a dimer is formed by intermolecular hydrogen bonding and π–π stacking interactions.

Abstract: (R)-tert-butyl (1-hydroxybut-3-yn-2-yl) carbamate, an intermediate of the natural product jaspine B, which was isolated from various sponges and endowed with cytotoxic activity against several human carcinoma cell lines, was synthesized from L-Serine in overall yield 30% through seven steps, including esterification, Bn protection, Boc protection, TBS protection, reduction, Corey-Fuchs reaction.

Abstract: (R)-methyl 2-((tert-butoxycarbonyl) amino)-3-((tert-butyldimethylsilyl) thio) propanoate, an key intermediate of the natural product Biotin which is a water-soluble vitamin, involved in an essential part of the metabolic cycle causing catalytic fixation of carbon dioxide in the biosynthesis of fatty acids, sugars, and α-amino acids, was synthesized from L-cystine in overall yield 67% through three steps, which synthesis included esterification, protection of amine and thiol.

Abstract: A novel method for the determination of platinum in waste platinum-loaded carbon catalyst samples was established by inductively coupled plasma optical emission spectrometry after samples digested by Teflon pressure digestion vessel with aqua regia. Such experiment conditions were investigated as the influence of sample dissolution methods, digestion time, digestion temperature and interfering ions on the determination. Under the optimized conditions, the limit of detection (LODs) of Pt for tested solution was 15 ng mL^-1. The relative standard deviations (RSDs) for Pt was 2.35 % (C_Pt = 5 mg L^-1, n = 7). The linear range of calibration graph for Pt was 0 ~ 150.00 mg L^-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: A technique for determination of Ru in waste ruthenium catalysts using ICP-OES after sample digestion by high temperature fusion with NaOH-NaNO₃ mixture was described. Such experiment conditions were investigated as the influence of sample digestion methods, fusion time, fusion temperature, the dosage of NaOH-NaNO₃ mixture and interfering ions on the determination. Under the optimized conditions, the limits of detection (LODs) of Ru for tested solutions were 10 ng mL^-1. The relative standard deviations (RSDs) for Ru were 2.01 (C_Ru = 1 mg L^-1, n = 7). The linear ranges of calibration graphs for Ru were 0 ~ 100.00 mg L^-1. The proposed method was applied to determine the practical samples with good recoveries and satisfactory results.

Abstract: This paper proposes parameter optimization method of GP-MSE based on extraction parameters model. First, we identify the function relationship between dependent and independent variables by using neural networks. Second, independent variable set is made by interpolating the original independent variables, and then input these independent variables to fitted function to generate the dependent variable set. Last, we find the maximum value on dependent variable set to confirm the optimal parameters. Experimental result shows that the proposed method is not only simple and fast, but also ideal for recovery of single analyte.

Abstract: Nanomaterials are playing a more and more important role in all fields, leading to increasing its release into the environment. Nanomaterials may pose a potential threat to environment and human health. Thus, there is a growing need for adaptable methods and technologies to analyze and characterize the properties of nanoparticle for purpose of understanding and minimizing the potentially unforeseen health or environmental hazards. Nuclear Magnetic Resonance (NMR) method, as a powerful analytical tool which based on the theory of solvent relaxation, breaks through some limitations of conventional methods, making it feasible in analysis and characterization of nanoparticles in aqueous phase. This paper has sketched recent research about specific surface area determination and competitive adsorption between components on the surface of nanoparticles. It also pointed out the pros and cons of NMR and conventional methods. As a result, NMR solvent relaxation will be a promising application in future.

Abstract: The title complex, [Mo₂O₂S₆Cu₆I₂(4,4'-bipy)₃]_n 1, is consists of cluster cation [Mo₂O₂S₆Cu₆I]⁺ and counterion I^-. The cluster cation consists of two nest-shaped [MoOS₃Cu₃]²⁺ fragments interconnected through iodides [Cu-I distance:3.1951(16) Å,and Cu-I-Cu bond angle:180° ]. From a topological viewpoint, each building cluster [MoOS₃Cu₃]⁺, linked by another three crystallographically equivalent [MoOS₃Cu₃]⁺ units through single 4,4’-bipy bridges, can be regarded as a 6-connected node, affording a novel two-dimensional layered structure.