Liquid-Liquid Extraction of Ruthenium from Chloride Media by N,N'-Dimethyl- N,N'-Dicyclohexylmalonamide

Abstract

Research on the solvent extraction of ruthenium from hydrochloric acid media has been carried out using N,N'-dimethyl-N,N'-dicyclohexylmalonamide (DMDCHMA) dissolved in 1,2-dichloroethane. Ruthenium extraction percentages (%E) ranging from 50% to 80% have been achieved for HCl concentrations between 5 M and 7 M. Extraction curves exhibiting the dependence of the %E ruthenium on HCl concentration in the aqueous phases are presented, the latter solutions being obtained by dissolution of either Ru(III) or Ru(IV) salts. The influence of some experimental parameters on the %E Ru, such as the equilibration time, extractant concentrations, and hydrogen-ion activities, has been thoroughly investigated. Additionally, DMDCHMA is also adequate for extracting Pd(II) from 5 M to 7 M HCl solutions and under similar experimental conditions, %E Rh(III) is below 5%, and Pt(IV), Ir(III), and Ir(IV) cause the formation of third phases. Both Ru and Pd(II) can be successfully stripped from the loaded organic phases with water. A partition scheme to isolate Ru from a number of some associated elements has also been attempted.     

Characterization of polymeric film of a new manganese phthalocyanine complex octa-substituted with 2-diethylaminoethanethiol, and its use for the electrochemical detection of bentazon

Manganese acetate octakis-(2-diethyaminoethanethiol) phthalocyanine (AcMnODEAETPc) was newly synthesized and characterized by spectroscopic and electrochemical methods. Solution electrochemistry of the complex showed three redox processes assigned to Mn^IIIPc⁻¹/Mn^IIIPc⁻², Mn^IIIPc⁻²/Mn^IIPc⁻² and Mn^IIPc⁻²/Mn^IIPc⁻³ species. The new molecule was polymerized onto a glassy carbon electrode (GCE) to form thin films of different thickness, giving poly-10-AcMnODEAETPc-GCE, poly-20-AcMnODEAETPc-GCE and poly-30-AcMnODEAETPc-GCE, where 10, 20 and 30 represent the number of voltammetry scans during polymerization. Three distinct redox processes were observed on the modified electrode in 0.1 M phosphate buffer solution, pH 5, which confirmed the formation of the polymer. The current signal due to the herbicide, bentazon, was dependent on film thickness; the best signal was obtained on poly-20-AcMnODEAETPc-GCE while poly-10-AcMnODEAETPc-GCE gave the least signal. However, the signals due to the herbicide were better on the different films compared to the bare electrode. Electrochemical impedance spectroscopy (EIS) technique revealed that differences in film thickness offered different charge transfer resistances, R_ct, hence difference in current signals for bentazon oxidation were observed on these films. A Tafel slope of 77 mV/decade, obtained for the herbicide on poly-20-AcMnODEAETPc-GCE, denotes a fast one electron transfer followed by a slow chemical step in the electro-oxidation of bentazon. The voltammetry signals of the herbicide on the films indicated the likely involvement of ring-based redox processes in the detection of the herbicide. A plot of background corrected current response, on this film, versus the concentration of bentazon was linear within the range 50–750 μM with a detection limit of 2.48 × 10⁻⁷ M.     

浅谈导数在经济学中的应用

高等数学中的导数与经济学之间有密切的关系,运用导数理论在经济学中的应用进行研究,可以解决经济学中的一些常见问题。     

派生诉讼中的取证与举证问题研究

派生诉讼中的原告和被告存在严重的信息不对称,这导致原告举证困难.对涉及举证问题的前置请求阶段和审判阶段均从举证责任归属、举证程度要求以及获取证据途径几个方面进行了研究,力求在便利股东提起派生诉讼的同时对公司的经营管理不造成过度的干扰.     

Panchromatic response composed of hybrid visible-light absorbing polymers and near-IR absorbing dyes for nanocrystalline TiO2-based solid-state solar cells

In pursuit of panchromatic sensitizers for mesoporous TiO₂-based solid-state solar cells, a near-IR absorbing zinc phthalocyanine dye (coded TT1) was firstly adsorbed over relatively thin (∼1 μm) TiO₂ mesoporous films and then a visible-light absorbing polymer [regioregular poly(3-hexylthiophene), P3HT] was incorporated into the mesopores as both a second sensitizer and a solid hole conductor. After optimizing some experimental parameters, these hybrid solid-state cells exhibited a clear panchromatic response, and an overall conversion efficiency of around 1% at full sun intensity.     

数控车削复杂节点计算的一般步骤和方法

为解决数控车削加工编程中节点计算的数学处理方法难点的问题,以一个复杂的节点计算为例,介绍了节点计算的一般规律,同时创新性地采用了高等数学方法来简化节点计算过程,在数控编程中具有借鉴意义。     

Environmentally friendly phthalocyanine catalysts for water decontamination—Non-photocatalytic systems

Macrocyclic porphyrin-like compounds known as phthalocyanines (Pcs) have been shown to produce singlet oxygen species upon illumination with light of an appropriate wavelength. Singlet oxygen is an effective agent for complete oxidation of common water-soluble pollutants including chlorinated phenols. The most active are, in this respect, phthalocyanines bearing Al, Zn and Si central atoms. Although these compounds were proofed to be virtually non-toxic, the presence of the Al³⁺ and Zn²⁺ ions may contradict this. On the other hand e.g. iron phthalocyanine (FePc) does not represent any danger from this point of view. However, due to the specific coordination of its central metal ion and also because of the number of electrons occupying its valence orbitals, the FePc cannot be effectively activated by the photon flux. Here we report on an alternative system in the dark. It is based on the initial catalytic decomposition of various peroxo substances by metal Pc, producing oxidising species which can decompose chlorinated phenols. A series of Pcs and peroxo substances were compared and the reaction system optimised. It was shown that the highest activity was revealed for the system comprising of FePc and tert-butylhydroperoxide. Iron phthalocyanine was also successfully immobilised on an Al₂O₃ solid matrix, and this heterogeneous system was tested analogously to the homogeneous one. Virtually zero leaching of the anchored complex was detected and the activity was found to be comfortably high.     

Spectroscopic and photoelectric investigations of resonance effects in selected sulfonated phthalocyanines

Zinc phthalocyanine dyes, which had been symmetrically and asymmetrically substituted with sulfonate groups were investigated using absorption, fluorescence and photoacoustic spectroscopic methods, supported by light-induced optoacoustic spectroscopy and photoelectric measurements; unsubstituted zinc phthalocyanine was employed as reference. Fluorescence quantum yields were determined on the basis of absorption and fluorescence spectra, whereas thermal parameters as well as the yield of triplet state population and the kinetics of thermal relaxation at microsecond intervals were determined using with photoacoustic methods. The effect of the sulfonate groups on photocurrent generation was discussed in terms of the dye's molecular structure and resonance (mesomeric, inductive, steric) effects. Sulfonation of zinc phthalocyanine changed markedly its absorption and fluorescence properties owing to redistribution of the electron density within the molecule as a result of both mesomeric and inductive effects, although other effects cannot be excluded. The enhanced light-generated photocurrent observed for phthalocyanine with two sulfonate groups is explained in terms of mesomeric effects, whereas in phthalocyanine with three and four sulfonate groups, inductive effects are essential and lead to photocurrent decline.     

Spectral derivative feature coding for hyperspectral signature analysis

This paper presents a new approach to hyperspectral signature analysis, called spectral derivative feature coding (SDFC). It is derived from texture features used in texture classification to dictate gradient changes among adjacent bands in characterizing spectral variations so as to improve better spectral discrimination and classification. In order to evaluate its performance, two known binary coding methods, spectral analysis manager (SPAM) and spectral feature-based binary coding (SFBC) are used to conduct comparative analysis. Experimental results demonstrate that the proposed SDFC performs more effectively in capturing spectral characteristics than do SPAM and SFBC.     

咔唑衍生物在有机电致发光材料中的研究进展

综述了近几年来咔唑衍生物在有机电致发光材料中的研究进展,包括提高玻璃化转变温度、提高光量子产率、开发白光OLED材料和AIE效应材料等方面的研究进展情况.