Syntheses and structures of cadmium(II) and cobalt(II) coordination polymers based on 1,1′-(2,2′-oxybis(ethane-2,1-diyl))bis(1H-imidazole) and carboxylate ligands

Two novel coordination polymers containing Cd(II) and Co(II) metals, connected via 1,1′-(2,2′-oxybis(ethane-2,1-diyl))bis(1H-imidazole) (L) ligand, have been synthesized. Compound [Cd(L)₂(p-BDC)] · 2H₂O (1) (p-BDC = 1,4-benzenedicarboxylate anion) is a three-dimensional interdigitated supramolecular architecture. Compound [Co(L)(BTCA)_0.5] (2) (BTCA = 1,2,3,4-butanetetracarboxylate anion) possesses a unique (3,4)-connected 3D framework with (8³)₂(8⁵ · 10) topology.     

Hydrothermal Synthesis of Cd(II), Mn(II) and Ni(II) Coordination Polymers Derived from Benzopenone-2,4′-carboxylate and N-door Ligands

Three new coordination polymers [Cd(L)(4,4′-bipy)_0.5]_n (1), {[Mn(L)(bpp)]·H₂O}_n (2) and [Ni(L)(2,2′-bipy)(H₂O)₂]_n(3) [H₂L = Benzopenone-2,4′-dicarboxylic acid, 4,4′-bipy = 4,4′-bipy ridine, bpp = 1,3-di(4-pyridyl) propane and 2,2′-bipy = 2,2′-bipyridine] have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses revealed that the H₂L ligand acts as a bridge, exhibiting three coordination modes to link metal ion: bidentate chelating, bis-monodentate, monodentate. Compound 1 has 3-connected metal–organic framework with the (6³) topology notation; Compounds 2 and 3 are one-dimensional chain structures. The luminescent properties for compound 1 was investigated.     

Adsorption Behavior of Cadmium(II) and Lead(II) on Mesoporous Silicate MCM‐41

Abstract

This investigation examines metal ion adsorption on mesoporous silicate, MCM‐41, synthesized from sodium silicate solution and cethyltrimethylammonium bromide (CTAB). MCM‐41 has potential as an adsorbent material, with a regular hexagonal pore structure, large specific surface area, and large pore volume. The MCM‐41 synthesized for this investigation is characterized using powder X‐ray diffraction and nitrogen adsorption and desorption isotherms data. The adsorption behavior for cadmium(II) and lead(II) onto MCM‐41 was studied by contacting the mesoporous silicate with an aqueous solution of metal salts and acetylacetone. Both Cd²⁺ and Pb²⁺ were found to quantitatively adsorb onto MCM‐41. The results of this study suggest that MCM‐41 may have applications in the recovery of toxic metals from waste waters.     

Coordination of cobalt(III), nickel(II), copper(II), palladium(II) and platinum(II) with N-ethyl-N′-(4′-methylthiazol-2′-yl)thiourea (HL)

Coordination complexes of formula [ML₂], [CoL₃], [Pd(HL)Cl₂], [CuLCl(H₂O)] and [CuL₂(H₂O)₂] {L=anion of N-ethyl-N^′-(4^′-methylthiazol-2′-yl)thiourea; M=Pt^II, Pd^II or Ni^II} were prepared and characterized by elemental analyses, magnetic susceptibilities, and by IR, NMR, electronic and mass spectral measurements.     

Syntheses and Characterization of New Nano-porous Soft Copper(II) Metal–organic Framework and Nano-porous Two-dimensional Manganese(II) and Zinc(II) Coordination Polymers with 4,4′-Bipyridine and 2-Sulfobenzoic Acid

Three new Cu(II), Mn(II), and Zn(II) coordination polymers with 4,4′-bipyridine (4,4′-bipy) and 2-sulfobenzoic acid (2-H₂sb) ligands, [M(4,4′-bipy)(2-sb)(H₂O)]_n, have been synthesized and characterized by IR spectroscopy and elemental analyses. The structures were determined by single-crystal X-ray crystallography. The structural studies show that the metal atoms have six-coordinate geometry with a distorted octahedral environment constructed with 4,4′-bipy and 2-sb²⁻ linkers stacked over each other to generate a two-dimension motif. Self-assembly of these compounds in the solid state is likely caused by coordination and hydrogen-bonds. While polymers containing Zn(II) and Mn(II) have analogous structures, the Cu(II)-containing nano-porous soft metal–organic framework presents a different structure.     

Removal efficiency of Pb(II), Zn(II), Cd(II) and Cu(II) from aqueous solution and natural water by ketoenol–pyrazole receptor functionalized silica hybrid adsorbent

In this study, we reported an efficient, alternative, and low-cost adsorbent for the efficient removal of Pb(II), Zn(II), Cd(II) and Cu(II) from water. The new hybrid material has been prepared by immobilizing a conjugated system (2Z)-1-(1,5-dimethyl-1H-pyrazol-3-yl)-3-hydroxybut-2-en-1-one on silica gel previously doped with 3-aminopropyltrimethoxysilane. The formed surface (SiNPz) was perfectly analyzed. Adsorption studies have demonstrated the ability to highlight the surface designed for efficient removal of above toxic metals from aqueous solutions using FAAS. The new material was used for the extraction of metals from natural water and showed efficiency results for toxic heavy metals.     

Cyano-Bridged Heteropolynuclear Ni(II), Cu(II) and Cd(II) Complexes, [M(deten)2Ni(μ-CN)2(CN)2] n

Three new complexes [M(deten)₂Ni(μ-CN)₂(CN)₂] _n (M = Ni, Cu and Cd, deten = N,N-diethylethylenediamine) have been synthesized and characterized by chemical, thermal analysis, FT-IR and Raman spectroscopies. The crystal structure of the Cd complex has been determined by X-ray single crystal diffraction. Structural study reveals that the Ni²⁺ and Cd²⁺ ions are located on inversion centers, and adopt slightly distorted square-planar and octahedral geometries, respectively. In the crystal structure, the intermolecular N–H⋯N hydrogen bonds link the polymeric chains into a two dimensional network. Vibrational spectral data indicate the presence of two ν(C≡N) for complexes can be assigned to the terminal and bridging cyanides. The decomposition reaction take places in the temperature range 30–1000 °C in the static air atmosphere.     

叔胺萃取分离钴(II)、铁(II)

研究了不必预先氧化二价铁,直接用叔胺从氯化物溶液中萃取分离钴(II)、铁(II)的新方法. 考察了不同改性剂对叔胺萃取钴(II)、铁(II)的影响以及各种因素对钴(II)、铁(II)萃取、洗涤及反萃的影响. 提出了用叔胺萃取分离钴(II)、铁(II)的最佳工艺参数.     

First 3D heterotrimetallic Mn(II)–Cu(II)–K(I) polymer and three 3D Cu(II)/Mn(II) open network based on pyridine-2,3,5,6-tetracarboxylic acid

Four novel 3D coordination polymers, {[K₃Cu₂(H_0.5pdtc)₂ (H₂O)₆]·(H₂O)₂}_n (1), {[trans-K₂Mn₃(pdtc)₂ (H₂O)₁₁]·H₂O}_n (2), {[trans-K₂Mn₃(pdtc)₂ (H₂O)₁₀]·H₂O}_n (3) and {[cis-K₂Cu₂Mn(pdtc)₂ (H₂O)₁₀]·H₂O}_n (4), were synthesized by the self-assembly of potassium pyridine-2,3,5,6-tetracarboxylate (K₄pdtc) with metal salts. All of them contain infinite 1D stepwise chain. Notably, 2–4 have 2D network structures depending on the trans- and cis- hexacoordinated Mn(II) acting as connecters between the chains. Then, they further assemble into 3D or twin-plane structures by K(I) ions. 4 is the first Cu/Mn/K heterotrimetallic complex with H₄pdtc. The (H₂O)₆ clusters in 1 arranged stepwise along the complex chains owing to the host chains' template effect. The variable–temperature magnetic measurements reveal that weak antiferromagnetic interactions exist in complexes 1 and 4.     

防霉涂料(II)

4.5.2 颜料分散、润湿剂[1,5]带有颜料的分散系统的分散机理是相当复杂的，但多数研究者在概念上具有如下的一致看法：分散过程首先是展色剂对颜料的浸润改良，即通过降低展色剂和颜料粉体界面的张力，增大浸润速度，借助于颜料的附聚或过度絮凝状态，除去主要存在于颜料表面的空气层。接着，经机械研磨，使颗粒达到原级粒子状态，最后，要防止这种已经分离的粒子重新相互结合，并保持稳定的分散状态。润湿分散剂的作用就是能吸附在上述的展色剂－颜料界面上，使之更迅速地形成更稳定的分散系统。水性防霉涂料用颜料分散剂一般是表面活性剂…     

Mass Transfer and Immobilized Organic Phase Instability Studies for Cobalt(II)–Nickel(II) Separation by PEHFSD

Pseudo-emulsion-based hollow-fiber strip dispersion (PEHFSD) technique was examined as an alternative to solvent extraction for simultaneous separation and concentration of cobalt(II)–nickel(II) mixture using Cyanex-272 as the extractant. Experiments were carried out by continuous recirculation of the feed and pseudo-emulsion phases through a hollow-fiber module. The separation factor increased rapidly after 60 min of operation. The maximum value after 120 min of operation was ～128 (pH = 6.5) for the operating conditions studied. The mass transfer resistance from the extraction reaction appeared to be dominant. The results of mathematical modeling of the mass transfer process indicated that higher separation factor and extraction rate can be achieved using PEHFSD in comparison to solvent extraction. Mixing of the stripping and the feed solution was observed at high dispersed phase volume fraction in the pseudo-emulsion and low flow rate of this phase. The maximum value of backtransport flux from the stripping phase due to mixing was estimated to be approximately two orders lower than the initial extraction rates.     

Synthesis and characterization of poly(N-acryloyl’-methyl piperazinium(+1)) tetrachlorometallate (II) compounds

Summary The interactions of metal ions with poly(N-acryloyl N-methyl piperazine) in the solid state were studied. The Cu(II) and Zn(II) compounds were prepared and characterized by means of elemental analysis; FT-IR, electronic spectroscopies, and thermogravimetric analysis. PM3 semiempirical calculations on the polymer conformations and the Zn(II) complex have been performed. The piperazine group in the polymer shows the conformations; namely; the chair and a distorted chair conformation. Both structures differ by just ca. 10 kcal/mol. In the compounds MCl₄(PAPH)₂ the MCl₄ ^2- complex ion presents a distorted tetrahedral geometry. The electronic spectrum of the yellow Cu(II) coordination compound shows a band at 894 nm. In the IR spectra, an absorption band at 3020 cm^-1 has been assigned to the v(N-H) stretching mode of the NH⁺ group. The protonated nitrogen atom is the one bonded to the methyl group due to the larger basicity according to the calculated electronic charge density and to the lower steric hindrance. The interaction of the MCl₄ ^2- anion and the polymer is achieved by hydrogen bonding at the NH⁺ group and the chloride with N-H ···Cl distances lying betwen 1.7 to 3.3 A°.     

First macrocyclic oxamide Cu(II)–Co(II) complex: synthesis,crystal structure and magnetic properties

A oxamido-bridged binuclear complex, [Cu(L)Co(bpy)₂](ClO₄)₂·0.5C₂H₅OH·H₂O has been synthesized, and structurally and magnetically characterized, where L = 1,4,8,11- tetraazacyclotradecanne-2,3-dione and bpy = 2,2^′-bipyridine. In the complex, the copper atom from the macrocyclic oxamido-copper(II) precursor in a square-planar and cobalt atoms in a distorted octahedral environment is bridged by the oxamidate group, Cu⋯Co separation of 5.359 Å. The metal–metal separations are consistent with the sequence of decrease of the ion radius of the metal ion. The magnetic properties of the complex have been investigated. The χ_MT versus T plots is typical of antiferromagnetically coupled Cu(II)–Co(II).     

Metal-Ion Type Effect on the Crystal Structure and Optical Properties of 2,2′-bipyridine Complexes of Pb(II) and Cd(II)

To investigate the effect of metal ion type on the crystal structure and optical and thermal behaviors of coordination compounds, two homometal and one heterometal 2,2′-bipyridine complexes of Pb(II) and Cd(II) have been synthesized and characterized by elemental analysis, PXRD, FT-IR and single crystal X-ray diffraction. Crystal structure analysis of heterometal coordination polymer, [Pb₂Cd(2,2′-bipy)₄(NO₃)₆]_n, displays the attendance of a centrosymmetric 1D coordination polymer that crystallizes in the triclinic system with the space group of \({\text{p}}_{1}^{ - }\). Thermal behavior of prepared coordination compounds was examined under air atmosphere by thermogravimetric analysis. The study of optical properties of compounds showed that metal ion type of coordination compounds is influential on their photophysical properties. Moreover, heterometal coordination polymer was doped into a PVK:PBD blend in two different concentrations as a light emitting material in the fabrication of two organic light-emitting diodes.     

1-D networks formed by metal⋯sulfur van der Walls contacts: Novel tetrazole–thiolato Pd(II) and Pt(II) complexes

Pd(II)– and Pt(II)–azido complexes, [M(N₃)(PMe₃)₂(C–L)] {LH = 2-(2′)-thienyl pyridine; M = Pd (1), Pt(2)}, which contain σ-bonded heterocycles (L), were treated with aryl isothiocyanate (Me₂C₆H₃–NCS) to afford the corresponding Pd(II) and Pt(II) tetrazole–thiolato complexes, trans-{M[SCN₄(2,6-Me₂C₆H₃)](PMe₃)₂(C–L)} {M = Pd (3), Pt (4)}. Complexes 3 and 4 have a 1-D helical network formed by the intermolecular M?S van der Waals contacts.     

Removal of Zinc(II) and Manganese(II) from Crude Phosphoric Media by Bis(2,4,4‐Trimethylpentyl) Phosphinic Acid (Cyanex‐272)

Purification of commercial phosphoric acid produced by the wet process from toxic heavy metals such as zinc and manganese is considered to be a very important environmental and economical process. The commercial bis(2,4,4‐trimethylpentyl)‐ phosphinic acid (Cyanex‐272) is proposed as an extractant for the efficient removal of Zn(II) and Mn(II) from crude phosphoric acid samples of concentrations of 25% and 45%. Various parameters affecting the extraction rate of Zn(II) and Mn(II) were investigated. The results were assessed to obtain the optimum conditions for the fast and efficient removal of both cations from crude phosphoric acid using Cyanex‐272 as an extractant in various diluents. The selectivity sequence of different diluents for Zn(II) and Mn(II) extraction were: kerosene > n‐hexane > cyclohexane > toluene > benzene > chloroform. The stripping of the investigated metal ions is efficiently performed with ammonium thiocyanate which has been selected as a suitable stripping agent.     

电渗析与萃取耦合技术分离Ni(II)与Co(II)

为实现混合溶液中Ni(II)与Co(II)的分离,设计了电渗析与萃取耦合的集成分离技术,借助自行设计的设备,在选P507为萃取剂后,考察了电流密度、酸用量、体积流量、萃取剂皂化率、原料与萃取剂摩尔比、萃取方式等对分离效果的影响.结果表明:在实验范围内,电流密度3.8 mA/cm2,酸用量为理论用量的1.3倍,体积流量60 L/h、皂化率60%,原料与萃取剂摩尔比1:1.7为优取的操作条件;料液循环重复萃取,能显著提高分离效果.由此表明,电渗析与萃取耦合的分离技术,可分离混合体系中的Ni(II)、Co(II),且无需溶剂参与.     

Syntheses,magnetic properties,and reactivity of dinuclear oxovanadium (IV) and copper (II) complexes with (μ-diphenylphosphinato)-bridges

Novel dinuclear oxovanadium (IV) complexes having the formula [(VO)₂(dpp)₃(bpy)₂]NO₃·2H₂O (1), [(VO)₂(dpp)₃(phen)₂]-NO₃·H₂O (2), [(VO)₂(bmp)₃(bpy)₂]NO₃·H₂O (3), and [(VO)₂(bmp)₃(phen)₂]NO₃·H₂O (4), and copper (II) complexes having the formula [Cu₂(bmp)₂(phen)₂](NO₃)₂·MeOH·H₂O (5), and [Cu₂(bmp)₂(bpy)₂](NO₃)₂ (6) (where Hdpp=diphenylphosphinic acid, Hbmp=bis(4-methoxyphenyl)phosphinic acid, bpy=2,2^′-bipyridine, and phen=1,10-phenanthroline) with (μ-phosphinato)-bridges, 1–6, have been prepared and characterized. Crystal structure of complex 2 reveals that two vanadium ions are linked by tris(μ-phosphinato)-bridges. The magnetic susceptibility data for 1–3, and 6 conform to the usual dimer equation with −2J values of 16–24 cm⁻¹, indicating a weak antiferromagnetic interaction between vanadium(IV) ions.The oxidation of cinnamyl alcohol was studied using complexes 1–6 as catalyst and molecular oxygen as an oxidant. In the presence of complex 3 as a catalyst, cinnamyl alcohol was oxidized to cinnamaldehyde 61% yield in 7 h. Consequently, complex 3 activates oxygen, and then alcohol was quite efficiently oxidized by activated oxygen.