Liquid-liquid extraction of cerium(IV) from nitric acid media by di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP)

In this paper, the extraction of Ce(IV) from nitric acid solutions is investigated using di-(2-ethylhexyl) 2-ethylhexyl phosphonate (DEHEHP, B) in heptane as extractant. Ce(IV) can be extracted effectively from nitric acid solution, whereas it is poorly extracted from sulfuric acid solution. Compared with some other organophosphorus esters, DEHEHP has moderate extractablity for Ce(IV). The extraction efficiency varies with diluent in the order: aliphatic hydrocarbons > nitrobenzene > aromatic hydrocarbons > carbon tetrachloride > chloroform. Regeneration and loading capacities of DEHEHP have also been examined. Ce(IV) extraction in HNO3 solutions as well as extraction of HNO3 and H2O have been systematically studied. The Ce(IV) extraction increases with an increasing of HNO3 concentration and exhibits the maximum distribution ratio at 1-1.5 mol/L HNO3. Nitric acid, as a source of nitrate ion, enhances the extraction of metal ion. But it also competes with metal ions for extractant molecules by its own extraction under high acidities. The proposed extraction process is described by the following equilibrium equations

Heptaaquatetra-mu(3)-hydroxy-hexa-mu(2)-L-leucine-(L-leucine)tetraytterbium(III) tetrachlorozinc(II) trichlorohydroxyzinc(II) tetrachloride octahydrate

The title bimetallic compound, [Yb-4(mu(3)-OH)(4)(C6H13NO2)(7)-(H2O)(7)][ZnCl4][ZnCl3(OH)]Cl-4.8H(2)O, was synthesized at near physiological pH (6.0). The compound exhibits some novel structural features, including an asymmetric [Yb-4(mu(3)-OH)(4)(L-leucine)(7)(H2O)(7)](8+) complex cation in which four OH groups act as bridging ligands, linking four Yb3+ cations into a Yb4O4 structural unit. Each pair of adjacent Yb3+ ions is further bridged by one carboxy group from a leucine ligand. Water molecules and a monodentate leucine ligand also coordinate to Yb3+ ions, completing their eight-coordinate square-antiprismatic coordination. The Yb-4(mu(3)-OH)(4)(L-leucine)(7)(H2O)(7)](8+) cation, the [ZnCl4](2-), [ZnCl3OH](2-) and Cl- anions, and the lattice water molecules are linked via hydrogen bonds.

Tetra-mu-L-isoleucine-bis[tetraapuasamarium(III)] hexaperchlorate

The title complex, [Sm-2(C6H13NO2)(4)(H2O)(8)](ClO4)(6), contains dimeric [Sm-2(Ile)(4)(H2O)(8)](6+) cations (Ile is L-isoleucine) and perchlorate anions. The two Sm3+ cations lie on a crystallographic twofold rotation axis. The four isoleucine molecules act as bridging ligands, linking two Sm3+ ions through their carboxyl O atoms. Each Sm3+ ion is also coordinated by four water molecules to complete eightfold coordination in a square antiprismatic fashion. One of the three perchlorate anions in the asymmetric unit is disordered.

Coordination reactions in the extraction of cerium(IV) and fluorine(I) by DEHEHP from mixed nitric acid and hydrofluoric acid solutions

The coordination reactions during the solvent extraction of cerium(IV) and fluorine(l) from mixed nitric acid and hydrofluoric acid solutions by di-(2-ethylhexyl)-2-ethylhexylphosphonate, L (DEHEHP) in heptane have been investigated. The extraction data have been analyzed by graphical methods taking into account all plausible species extracted into the organic phase. Different variables influencing the extraction of Ce(IV), such as the concentrations of nitrate ions, hydrofluroric acid, nitric acid, and extractant have been studied. The results demonstrate that DEHEHP can extract not only Ce(NO3)(4) as Ce(NO3)4.2L and HF as HF (.) H2O (.) L, but both together as Ce(HF)(NO3)(4) (.) L. The extraction equilibrium equations are determined according to slope analysis and IR spectra. The equilibrium constants of the extracted complexes have been calculated, taking into account complexation between the metal ion and inorganic ligands in the aqueous phase and all plausible complexes extracted into the organic phase. It is also shown that boric acid, which was added into the mixed solutions to complex with F(I) is not extracted by DEHEHP, and neither does it affect the extraction of cerium(IV) and HF, nor change the extraction mechanism.

Sequential deprotonation of meso-(p-hydroxyphenyl)porphyrins in DMF: From hyperporphyrins to sodium porphyrin complexes

Sequential deprotonations of meso-(p-hydroxyphenyl)porphyrins (p-OHTPPH2) in DMF + H2O (V/V = 1:1) mixture have been verified to result in the appearance of hyperporphyrin spectra. However, when the deprotonations of these p-OHTPPH2 are carried out in DMF, the spectral changes differ considerably from those in the mixture mentioned above. At low [OH-], the optical spectra in the visible region are still considered to have characteristics of hyperporphyrin spectra. Further deprotonation at much higher basicity makes the optical spectra form three-banded spectra similar to those in the acidic solution. To clarify the molecular origins of these changes, UV-vis, resonance Raman (RR), proton nuclear magnetic resonance (H-1 NMR) experiments are carried out. Our data give evidence that p-OHTPPH2 in DMF can be further deprotonated of pyrrolic-H by higher concentrated NaOH, due to an aprotic medium like DMF effectively weakening the basicity of the porphyrin relative to that of the NaOH, and coordinates with two sodium ions (except the sodium ions that interact with the peripherial phenoxide anions) to form the sodium complexes of p-OHTPPH2 (Na2P, to lay a strong emphasis on the sodium ions that coordinate with the central nitrogen atom), which can be regarded as the porphyrin anions being perturbed by the sodium cations due to their highly ionic character.

Covalent linking of near-infrared luminescent ternary lanthanide (Er3+, Nd3+, Yb3+) complexes on functionalized mesoporous MCM-41 and SBA-15

The near-infrared (NIR) luminescent lanthanide ions, such as Er(III), Nd(III), and Yb(III), have been paid much attention for the potential use in the optical communications or laser systems. For the first time, the NIR-luminescent Ln(dbm)(3)phen complexes have been covalently bonded to the ordered mesoporous materials MCM-41 and SBA-15 via a functionalized phen group phen-Si (phen-Si = 5-(N,N-bis-3-(triethoxysilyl)propyl)ureyl-1,10-phenanthroline; dbm = dibenzoylmethanate; Ln = Er, Nd, Yb). The synthesis parameters X = 12 and Y = 6 h (X denotes Ln(dbM)(3)(H2O)(2)/phen-MCM-41 molar ratio or Ln(dbM)(3)(H2O)(2)/phenSBA-15 molar ratio and Y is the reaction time for the ligand exchange reaction; phen-MCM-41 and phenSBA-15 are phen-functionalized MCM-41 and SBA-15 mesoporous materials, respectively) were selected through a systematic and comparative study. The derivative materials, denoted as Ln(dbM)(3)phen-MCM-41 and Ln(dbm)(3)phen-SBA-15 (Ln = Er, Nd, Yb), were characterized by powder X-ray diffraction, nitrogen adsorption/desorption, Fourier transform infrared (FT-IR), elemental analysis, and fluorescence spectra. Upon excitation of the ligands absorption bands, all these materials show the characteristic NIR luminescence of the corresponding lanthanide ions through the intramolecular energy transfer from the ligands to the lanthanide ions.

一种小晶粒FeZSM5沸石分子筛的制备方法

一种小晶粒FeZSM5沸石分子筛的制备方法，以含硅物质、无机铁盐、无机钠盐、有机胺类、无机酸和无离子水为原料，各组分的组成(摩尔比)为Fe3+:SiO2:Na2O:Na+:R:H2O＝1:(90-1600):(8.3－13):(13－25):(25－40):(2500－4000)采用水热合成法，在搅拌速度400－500转/分钟、以2℃/分钟的速率由室温升至100－140℃，恒温130小时，完成结晶，然后降温、过滤、洗涤、烘干、焙烧得到晶粒小于1μm分子筛，不需要重复交换一次完成，制备简单。

Syntheses, structures, and characterizations of four new silver(I) sulfonate coordination polymers with neutral ligands

In this paper, four novel silver(I) sulfonate coordination polymers containing neutral ligands, namely, [Ag(2)Ll (biim)(2)]center dot 2H(2)O (1). AgL2(biim) (2), [Ag(HL3)(Pic)(2)]center dot H2O (3), and [Ag-3(L3)(HL3)(4,4'-bipy)(3)(H2O)(2)]center dot 4H(2)O (4), have been synthesized [L1 = 3-carboxy-4-hydroxybenzenesulfonate, L2 = p-aminobenzenesulfonate, H(2)L3 = p-hydroxybenzenesulfonic acid, biim = 1,1'-(1.4-butanediyl)-bis(imidazole), Pic = beta-picoline, 4,4'-bipy = 4,4'-bipyridine]. For compounds 1 and 2, Ag(I) cations are bridged by biim ligands to form a one-dimensional (1D) "zigzag" chain, and L1 and L2 sulfonate ligands are not coordinated to the silver cation. Compound 3 has a dimeric structure in which two silver cations are bridged by two HL3 ligands. For compound 4, L3 ligand coordinates to a silver cation as a monodentate ligand, and Ag(l) cations are bridged by 4,4'-bipy ligands to form a ID chain. Compound 1 contains water dimers, while compound 4 contains water trimers. Compounds 1-3 display room-temperature photoluminescence.

Two new Cu-II coordination polymers: Studies of topological networks and water clusters

Two new Cull coordination polymers, namely [Cu-2(BDC)(2)(L)(4)(H2O)(2)]center dot 14H(2)O (1) and [Cu-1.5(BTC)(L)(1.5)(H2O)(0.5)]center dot 2H(2)O (2), where L = 1,1'-(1,4-butanediyl)bis(imidazole), BDC = 1,4-benzene dicarboxylate, and BTC = 1,3,5-benzenetricarboxylate, have been synthesized at room temperature. Complex 1 exhibits an unusual, square-planar, four-connected 2D (2)(6)4 net, which has been predicated by Wells. Interestingly, three types of water clusters, namely (H2O)(6), (H2O)(8), and (H2O)(10), are observed in the hydrogen-bonded layers constructed by the BDC ligands and water molecules. The BTC anion in compound 2 is coordinated to the Cu" cation as tetradentate ligand to form a (6(6))(2)(4(2)6(4)8(4))(2)(6(4)810) net containing three kinds of nonequivalent points, Thermogravimetric analyses (TGA) and IR spectra for 1 and 2 are also discussed in detail.

Room-temperature strategy for networked nonspherical gold nanostructures from Au(III)-[G-2]-CO2H dendrimer complex

The present work describes a convenient approach to fabricate networked nonspherical gold nanostructures by using [G-2]-CO2H dendrimer and toluene as capping and bridging agents in a CH2Cl2 and H2O biphasic system. A controlled linear assembly is achieved without the use of any catalyst at room temperature. UV-vis spectrum, transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) analysis show that the product is well networked nanostructures with diameter of 4-10 nm and consists of coalesced face-centered cubic gold nanocrystals. Extended experiments reveal that both benzene and dimethylbenzene can also inhabit the gold ions to make them crosslinked, prolong the nucleation points and eventually facilitate the formation of the networks.

Observation of a water-anion layer constructed from water tetramers and nitrate anions in the crystal host of a cobalt complex

A novel self-assembled layer consisting of water tetramers and nitrate anions has been observed in the [Co(1,10-phenanthroline)(2)(NO3)]center dot(NO)(3)center dot 4H(2)O complex. X-ray crystallography and FT-IR spectroscopy indicate that although the water tetramers exist in an energetically less stable uudd configuration, the anionic host environments may play an important role in the formation and stabilization of the water clusters.

Syntheses, crystal structures and magnetic properties of two heterometallic coordination polymers

Two heterometallic chain coordination polymers with the chemical formula {[Cu2Mn2L2(CH3OH)(H2O)] center dot 0.5CH(3)OH center dot 0.5CH(3)CH(2)OH}(n) (1) and {[Cu2Co2L2(H2O)(2)] center dot H2O}(n) (2) have been synthesized and characterized by IR, UV spectroscopy and single-crystal X-ray structural analysis, where H4L = 2-hydroxy-3-[(E)-({2-[(2-hydroxybetizoyl)amino]ethyl}imino)methyl] benzoic acid. Magnetic measurements showed that the two compounds exhibit antiferromagnetic coupling exchange interactions, and satisfactory fittings to the observed magnetic susceptibility data were obtained by assuming a linear four-spin arrangement with two isotropic magnetic exchange interactions.

An investigation on air stability of copper phthalocyanine-based organic thin-film transistors and device encapsulation

The device performances of copper phthalocyanine (CuPc)-based organic thin-film transistors (OTFTs) in main components of air were studied. We found that the device stored in O-2 humidified by water exhibited the changes of electric characteristics including positive-shifted threshold voltage and lower I-on/I-off but unchanged mobility, which was similar to the device exposed to room air. These changes are attributed to O-2 doping to copper phthalocyanine thin film assisted by water. Furthermore, a cross-linked polyvinyl alcohol film was used as encapsulation layer to prevent the permeation of O-2 and water, which resulted in excellent stability even when devices were placed in air for over a year. Therefore, current studies will push the development of OTFTs for practical applications.

Syntheses, structures and luminescence of silver(I) sulfonate complexes with PPh3 ligand

In this paper, four new luminescent silver(I) sulfonate complexes with PPh3, namely Ag(L1)(PPh3)(2) (1), Ag(L2)(PPh3)(3) (2), [Ag-2(L3)(PPh3)(4) (H2O)center dot 1.5CH(3)CN center dot 0.5H(2)O (3) and [Ag-4(L4)(PPh3)(10)]center dot 8H(2)O (4), where L1=p-toluenesulfonate, L2=1-naphthalenesulfonate, L3=3-carboxylate-4-hydroxybenzenesulfonate, L4=1, 3, 6, 8-pyrenetetrasulfonatc and PPh3=triphenylphosphine, have been synthesized and characterized. The crystal structures were determined by single-crystal X-ray diffraction method. Compounds 1, 2, 3 and 4 adopt discrete structures rather than polymeric structures. Compounds I and 2 show mononuclear structures while 3 and 4 are dinuclear and tetranuclear molecules, respectively. Moreover the numbers of PPh3 molecules coordinating to one silver center are two or three. The photoluminescent properties of 1, 2 and 3 are discussed.

一种制备碳载高合金化Pt-Ru催化剂的方法

提出了在四氢呋喃(THF)和H2O混合溶液中用一般的化学还原法在室温下制备碳载Pt-Ru(Pt-Ru/C)催化剂的新方法。与在纯水中制得的Pt-Ru/C催化剂相比,其Pt-Ru粒子的合金化程度高、平均粒径较小且相对结晶度低,因此,该催化剂对甲醇氧化的电催化活性远高于在纯水中制得的Pt-Ru/C催化剂。高合金化程度的原因是H2PtCl6和RuCl3在THF和H2O混合溶液中的起始还原电位相近。此外,在THF和H2O混合溶液中,THF和H2O的体积比的改变并不影响制得的Pt-Ru/C催化剂中Pt-Ru粒子的合金化程度,但对Pt-Ru粒子的粒径以及相对结晶度有较大影响。