A Highly Efficient Chelating Polymer for the Adsorption of Uranyl and Vanadyl Ions at Low Concentrations

A new polymer containing double amidoxime groups per repeating unit was synthesized to enhance the metal ion uptake capacity. The adsorption properties of this new polymeric adsorbent, amidoximated poly(N,N-dipropionitrile acrylamide), for U(VI), V(V), Cu(II), Co(II) and Ni(II) ions were investigated by batch and flow-through processes at very low concentration levels (ppb). The chelating polymer showed high adsorption capacity for uranyl as well as vanadyl ions. In selectivity studies from a mixture of metal ions in aqueous solutions, the adsorbent showed high selectivity for uranyl and vanadyl ions in the following order: U(VI) > V(V) Co(II) = Cu(II) Ni(II) as determined by calculating the distribution coefficients D, of corresponding ions. The adsorption of uranyl and vanadyl ions from natural seawater by the new adsorbent was also examined in flow through mode.     

Electrochemical studies of tetraphenylporphyrin and vanadyl porphyrin

The electrochemical reductions and oxidations of tetraphenylporphyrin (TPP) and vanadyl por-phyrin (TPP-VO) were investigated in dimethylformamide at platinum,glass carbon and microdisk electrodes.A new eleetrode reaction mechanism of TPP and TPP-VO is proposed.The kinetic parameters have also been determined.In addition,the theory of molecular hybrid orbitals is used to explain the reduction and oxidation regularity of the transition metal porphyrms     

Coupling of high temperature glass capillary columns to a mass spectrometer. GC/MS analysis of metalloporphyrins from Julia Creek oil shale samples

This paper reports on the instrumental and experimental prerequisites of the combination of high temperature gas chromatography (HTGC) with electron impact- (El) and chemical ionization (Cl) mass spectrometry (HTGC/EI/CIMS). It describes a newly developed high temperature GC/MS interface in detail and discusses the particular problems arising in HTGC/MS. The capabilities of the system are demonstrated by direct analyses of nickel- and vanadyl porphyrins, extracted from Julia Creek oil shale. The use of CI/NH₃ in the GC/MS analysis of metalloporphyrins is demonstrated for the first time.     

钒氧酞菁的合成及其薄膜结构与光电性能的研究

自从60年前^[1]金属酞菁被发现以来,就引起人们的广泛兴趣,其原因主要在于它们在染料颜料、光化学、催化、和成像中的应用. 和许多其它酞菁衍生物一样,钒氧酞菁具有光导和半导体特性,这使得它在光电子学、电子成像、化学传感器、甚至于微电子器件中有潜在的十分光明的应用前景^[2]. 例如, 钒氧酞菁在电子成像体系中已成为有用的感光材料. 近年来,金属酞菁等有机材料的结晶薄膜开始不断地吸引人们的注意力. 人们考察了不同的金属酞菁如: 酞菁铜、酞菁铅、酞菁镍、和酞菁锡 等的光电导和光电压^[3]. 通常酞菁以几种不同的多晶异构体、即以不同的晶体排列结构方式存在. 因此,其光电特性不仅取决于分子中心的金属原子、而且取决于它们的晶体结构. 总之,值得我们研究钒氧酞菁薄膜的光电特性以及它与吸收光谱和薄膜晶体结构的关系.     

Immobilization of a vanadium complex onto functionalized nanoporous MCM‐41 and its application as a catalyst for the solvent‐free chemoselective oxidation of sulfide to sulfoxide

A complex moiety containing VO(IV) was anchored covalently into organic‐modified Si‐MCM‐41 to prepare a new catalyst. The prepared materials were characterized using various techniques. Several types of aromatic and aliphatic sulfides were successfully oxidized to the corresponding sulfoxides in good to excellent yields using H₂O₂ in the presence of a catalytic amount of the catalyst under solvent‐free conditions. The results showed that the OH groups of the various compounds such as 2,2‐(phenylthio)ethanol and 2‐(methylthio)ethanol remained intact under similar conditions. Meanwhile the catalyst was stable in the reaction system, and could be reused at least four times without significant loss of its activity and chemoselectivity. Copyright © 2016 John Wiley & Sons, Ltd.     

大港沥青对正戊烷溶剂中卟啉钒化合物的吸附动力学研究

利用静态实验,研究了在正戊烷溶剂中,大港沥青质对卟啉钒模型化合物的吸附动力学,并对吸附机理进行了探讨。通过对吸附卟啉钒化合物前后的大港沥青质进行FT-ICR MS和元素（C/H/N/O）分析,发现大港沥青质上吸附了一定量的卟啉钒化合物。沥青质对卟啉钒的吸附过程受到沥青质的加入量（0.010 0和0.020 0 g）、戊烷溶液中初始卟啉钒的浓度（10和15 μg/mL）以及吸附温度（15、20和25 ℃）等因素的影响。分别采用拟一级、拟二级、Elovich和粒子内扩散等方程对实验数据进行了拟合,结果发现沥青质对卟啉钒的吸附符合拟二级动力学方程。     

锂离子电池电极材料磷酸氧钒锂的研究进展

介绍了磷酸氧钒锂(α-LiVOPO4、β-LiVOPO4和αⅠ-LiVOPO4)电极材料的结构和电化学性能;综述了现有的LiVOPO4电极材料的合成方法(包括高温固相法,化学还原法,溶胶-凝胶法,溶剂热法,离子交换法等)及其改性研究现状。最后对其未来的发展趋势进行了展望。     

Mechanosynthesis and mechanochemical treatment of bismuthdoped vanadium phosphorus oxide catalysts for the partial oxidation of n-butane to maleic anhydride

Three Bi-doped vanadyl pyrophosphate catalysts were prepared via dihydrate route （VPD method）, which consisted of different preparation methods including mechanosynthesis, mechanochemical treatment, and the conventional reflux method. The catalysts produced by the above three methods were characterized by x-ray diffraction （XRD）, scanning electron microscopy （SEM）, and temperature programmed reduction （TPR）. Catalytic evaluation for the partial oxidation of n-butane to maleic anhydride （MA） was also carried out. The XRD patterns of all the Bi-doped catalysts showed the main peaks of pyrophosphate phase. Lower intensity peaks were observed for the mechanochemically treated Bi-doped catalyst （VPDBiMill） with two additional small peaks corresponding to the presence of a small amount of V5＋ phase. The TPR profiles showed that the highest amount of active oxygen species, i.e, V4＋–O- pair, responsible for n-butane activation, was removed from VPDBiMill. Furthermore, from the catalytic test results, the graph of selectivity to MA as a function of the conversion of n-butane demonstrated that VPDBiMill was the most selective catalyst. This suggests that the mechanochemical treatment of vanadium phosphate catalyst （VPDBiMill） is a potential method to improve the catalytic properties for the partial oxidation of n-butane to maleic anhydride.     

Substitutional location for a vanadyl ion in three water coordinated triaqua(1,10-phenanthroline-k2N,N′) (sulfato-kO)magnesium(II) complex: a rare observation

Vanadyl ion substitutes for the central ion, if the doped complex has at least four water molecules. However, the present EPR, XRD, FT-IR and optical absorption studies on vanadyl-doped triaqua(1,10-phenanthroline-k²N,N′)(sulfato-kO)magnesium(II) suggest a substitutional defective nature, which is a rare observation. Single crystal EPR studies in three mutually orthogonal planes indicate two chemically non-equivalent sites with different intensities. However, the lower intensity site could not be analysed due to its weaker intensity and overlap with other sites during crystal rotations. The spin Hamiltonian parameters obtained for the major site are as follows: g _xx =1.973, g _yy =1.972, g _zz =1.930; A _xx =7.15, A _yy =6.77, A _zz =18.92 mT. The direction cosines of principal g and A values suggest that the impurity has entered the lattice substitutionally, which is a very uncommon phenomenon. Admixture coefficients, Fermi contact, dipolar interaction and covalency of metal–ligand bonds have also been evaluated. Optical, FT-IR and powder XRD techniques confirm the structure of the complex.