Solvent-Extraction Behavior of Cobalt(II), Nickel(II), Copper(II), and Palladium(II) with Tri-n-butylphosphate

Abstract

A systematic study of the extraction behavior of cobalt(II), nickel(II), copper(II), and palladium(II) with TBP from thiocyanate system in various ranges of acid concentrations has been performed. The thiocyanate medium leads to enhanced extractions in all these cases compared to those in the previously used chloride medium. For palladium, the chloride and nitrate systems have been critically examined. Sixty-two per cent extraction occurs from 4 M hydrochloric acid using 100% TBP in a single run and the extraction becomes quantitative (>99%) after four successive equilibrations. A simpler method has been proposed for rapid extraction of palladium(II) as the thiocyanate complex. Quantitative extraction occurs in the presence of 1.2% thiocyanate solution from 0.5 to 2 M hydrochloric acid (initial) up to pH 8.0. The extractable species of cobalt(II), nickel(II), copper(II), and palladium(II) from thiocyanate medium are probably similar and of the type [M(CNS)₄]^2? [K·TBP·3H₂O]₂ ⁺ (buffer solution) and [M(CNS)₄]^2? [H·TBP·3H₂O]⁺ ₂ (acid solution). A simple extraction scheme has been worked out for the separation of palladium(II) from iron(III), cobalt(II), nickel, manganese(II), copper(II), and platinum.     

Synthesis,Characterization and Properties of Four 3-D Supramolecular Architectures Assembled by Ni(II), Co(II), Zn(II), Cu(II) and 4-Nitro-1,3-benzenedicarboxylic Acid

Four new complexes M(NO₂–HBDC)₂(H₂O)₄·2H₂O [M = Ni (1), Co (2) and Zn (3)] and [Cu(NO₂–BDC)(H₂O)₃]₂ (4) (NO₂–H₂BDC = 4-nitro-1,3-benzenedicarboxylic acid) were prepared under hydrothermal conditions and were determined by single-crystal X-ray diffraction. X-ray structural analysis reveals that hydrogen bonds among the coordination water molecules and carboxyl oxygen atoms in complexes 1–3 bridge molecules forming an infinite chain, which is further interconnected to form a 3-D framework by a novel infinite 1-D metal–water chain containing the cyclic uudd water tetramer. In complex 4, Two five-coordinated Cu atoms are interlinked by NO₂–BDC ligands and coordinated water molecules to form a 3-D framework via hydrogen bonds and π···π stacking interactions. The elemental analysis, IR spectra, UV–vis and thermogravimetric analysis of complexes 1–4 were examined. The photoluminescence properties of complex 3 and temperature-dependent magnetic susceptibility for complex 4 were also studied.     

Synthesis, Characterization and Antiproliferative Activity of the Co(II), Ni(II), Cu(II), Pd(II) and Pt(II) Complexes of 2-(4-Thiazolyl)Benzimidazole (Thiabendazole)

Complexes of 2-(4-thiazolyi)benzimidazole (thiabendazole, THBD) with Co(II), Ni(II), Cu(ll) of general formula ML(2)(NO(3))(2) H(2)O and complexes of Pd(II) and Pt(II) of general formula ML2Cl(2) H(2)O have been obtained and characterized by elemental analyses, IR and far IR spectroscopy and magnetic measurements. The X-ray crystal structure of the copper(II) complex has been determined. The in vitro cell proliferation inhibitory activity of these compounds was examined against human cancer cell lines A 549 (lung carcinoma), HCV-29 T (urinary bladder carcinoma), MCF-7 (breast cancer), T47D (breast cancer), MES-SA (uterine carcinoma) and HL-60 (promyelocytic leukemia). Pt-THBD has been found to exhibit an antileukemic activity of the HL-60 line cells matching that of an arbitrary criterion.     

Stability constants of adipate complexes of copper(II), nickel(II), zinc(II), cobalt(II), uranyl(II) and thorium(IV) determined by electrophoresis

Stability constants of Copper(II), Nickel(II), Cobalt(II), Zinc(II), Uranyl(II) and Thorium(IV) adipates have been determined by paper electrophoresis. Adipic acid (0.005 mol dm^?3) was added to the background electrolyte: 0.1 mol dm^?3 HClO₄. The proportions of (CH₂)₄COOH COO^? and (CH₂)₄C₂O⁼₂ were varied by changing the pH of the electrolyte. These anions yielded the complexes Zn(CH₂)₄COOH COO⁺, Co(CH₂)₄COOH COO⁺, Ni(CH₂)₄COOH COO⁺, Th(CH₂)₄COOH COO³⁺, Th[(CH₂)₄COOH COO]₄, Cu(CH₂)₄ C₂O₄ and UO₂[(CH₂)₄(C₂O₄)]^2?₂, whose stability constants are found to be 10^2.8, 10^2.8, 10^3.2, 10^5.2, 10^15.3, 10^2.7 and 10^11.8 respectively (μ = 0.1, temp. 40°C).     

Synthesis, Crystal Structure, Fluorescence and Thermostability of Ni(II), Zn(II), Cd(II) Complexes with Schiff Base 2-Acetylpyridine-d-tryptophan

Three novel transition metal coordination polymers, [Ni(C₁₈H₁₆N₃O₂)₂·2CH₃OH] _n (1), [Zn(C₁₈H₁₆N₃O₂)₂·4CH₃OH] _n (2) and [Cd(C₁₈H₁₆N₃O₂)₂·2CH₃OH] _n (3) (C₁₈H₁₆N₃O₂=2-acetylpyridine-d-tryptophan) were synthesized and characterized by elemental analysis, IR, UV, ¹H NMR and X-ray diffraction single crystal analysis. The analyses of the structures indicate that all three materials crystallize in the tetragonal crystal system, space group P4₁2₁2. They have similar structures; i.e., the Schiff base coordinates in its deprotonated form and behaves as a hexadentate (4N+2O) coordinated ligand to form a distorted octahedron geometry. On the other hand, as a result of the alternate arrangement of chains through N–H···O intermolecular hydrogen bonds interactions, 2-D layers are formed for the three complexes. Furthermore, the luminescent properties and thermal stabilities of the three complexes were investigated.     

1-Amino-4-aryl-2(1H)-pyrimidinthione: Acidität und Komplexbildung mit Mn(II), Co(II), Ni(II), Zn(II), Cd(II), Pb(II) und Ag(I)

1-Amino-4-aryl-2(1H)-pyrimidinethiones: Acidity and Complex Formation with Nonferrous Metal Ions and Ag(I) Acid dissociation constants of new 2, 3 and already known 1 substituted 1-amino-4-aryl-2(1H)-pyrimidinethiones and stability constants of their nonferrous metal ion and silver complexes have been measured pH-potentiometrically in a 75% (v/v) mixture of dioxane/water. The influence of the substituents on pK_a- and lgβ_n-values is discussed. The X-ray structure analysis of bis[1-(4-toluenesulfonamido)-4-(4-tolyl)-2(1H)-pyrimidinethionatol]-nickel(II) 5 proves that pyrimidinethiones coordinate via their thione sulphur and aminonitrogen. However, the bond lengths are not levelled in the chelating ring.     

Cobalt(II), Zinc(II) and Cadmium(II)-Squarate Complexes with N-Methylimidazole

Three M(II)-squarate complexes, [Co(sq)(H₂O)(Nmim)₄] (1), [Zn(μ_1,3-sq)(H₂O)₂ (Nmim)₂] _n (2) and [Cd(μ_1,3-sq)(H₂O)₂(Nmim)₂] _n (3) (sq = squarate, Nmim = N-methylimidazole) have been synthesized and characterized by elemental, spectral (IR and UV–Vis.) and thermal analyses. The molecular structures of the complexes have been investigated by single crystal X-ray diffraction technique. The squarate ligand acts as two different coordination modes as a monodentate (in 1) and bis(monodentate) (O ^1– O ³ ) bridging ligand (in 2, 3). The Co(II) atom has a distorted octahedral geometry with the basal plane comprised of three nitrogen atoms of Nmim ligands and a oxygen atom of squarate ligand. The axial position is occupied by a nitrogen atom of Nmim and one aqua ligand. The crystallographic analysis reveals that the crystal structures of 2 and 3 are one-dimensional linear chain polymers along the c and b axis, respectively. The configuration around each metal(II) ions are distorted octahedral geometry with two nitrogen atoms of trans-Nmim, two aqua ligands and two oxygen atoms of squarate-O¹,O³ ligand. These chains are held together by the C–H···π, π···π and hydrogen-bonding interactions, forming three-dimensional network.     

AGGREGATION BEHAVIOR OF COBALT(II), NICKEL(II), AND COPPER(II) BIS(2-ETHYLHEXYL) PHOSPHATE COMPLEXES IN n-HEPTANE

ABSTRACT

The solution behavior of divalent transition metal-bis(2-ethylhexyl) phosphate (M(DEHP)₂, M = cobalt, nickel or copper) complexes in n-heptane have been investigated by vapor pressure osmometry, viscometry and dynamic light scattering. Co(DEHP)₂ complexes tend to form large macromolecular species with a mean aggregation number N_agg as large as 225, and the size of the macromolecular species decreases with increasing Co(DEHP)₂ concentration. In contrast, Cu(DEHP)₂ complexes tend to form small macromolecular species N_agg = 4-8 which increase in size with increasing Cu(DEHP)₂ concentration. On the other hand, Ni(DEHP)₂ complexes (and Ni(DEHP)₂-2H₂O complexes when the molar ratio of H₂O     

Syntheses and characterization of a chelating resin containing ONNO donor quadridentate Schiff base and its coordination complexes with copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI) and uranium(VI),

A new mixed Schiff base N,N′-ethylenemono(3-carboxysalicylideneimine)mono(salicylideneimine) has been synthesized by the condensation of equimolar quantities of ethylenediamine, salicylaldehyde and 3-formylsalicylic acid. A polymer supported Schiff base (PS–CH₂–LH₂) has been synthesized by the reaction of chloromethylated polystyrene (containing 3.9 mmol of chlorine per g of resin and 2% cross-linked with divinylbenzene) and the Schiff base N,N′-ethylenemono(3-carboxysalicylideneimine)mono(salicylideneimine). The polymer-anchored Schiff base reacts with metal salt/metal complex and forms polymer-anchored complexes having the formulae PS–CH₂–LCu, PS–CH₂–LNi, PS–CH₂–LCo, PS–CH₂–LFeCl·DMF, PS–CH₂–LZn, PS–CH₂–LCd, PS–CH₂–LMoO₂ and PS–CH₂–LUO₂. The polymer-anchored complexes have been characterized on the basis of elemental analysis, infrared and electronic spectra and magnetic susceptibility measurements. The shifts of the ν(CN) (azomethine) stretch to lower energy and ν(CO) (carboxylic) to higher energy in the polymer-anchored complexes indicate the ONNO donor behaviour of the chelating resin. The metal ions in the metal bound polymers can be leached by hot dilute formic acid, acetic acid or hydrochloric acid. The coordinated dimethylformamide is completely lost on heating the complexes in air. The complexes PS–CH₂–LCu and PS–CH₂–LCo are paramagnetic with square planar structure, PS–CH₂–LNi is diamagnetic with square planar structure and PS–CH₂–LFeCl·DMF is paramagnetic and octahedral, PS–CH₂–LZn and PS–CH₂–LCd are diamagnetic and tetrahedral, PS–CH₂–LMoO₂ and PS–CH₂–LUO₂ are diamagnetic and have octahedral structure. The stoichiometry and the structure of the metal bound polymers are comparable with those of metal complexes of N,N′-ethylenebis(salicylideneimine). This is the first report of the syntheses of a mixed Schiff base and its coordination complexes.     

Syntheses,characterizations, antitumor activities and cell apoptosis induction of Cu(II), Zn(II) and Cd(II) complexes with hydrazone Schiff base derived from isonicotinohydrazide

Three novel complexes, [Cu₄(L)₄Cl₄]·H₂O (1), Zn(L)₂ (2) and Cd(L)₂ (3), based on HL (where HL = 2-acetylpyridine isonicotinohydrazone) were synthesized and characterized by X-ray diffraction analyses. In the tetranuclear complex 1, each copper(II) ion with a distorted square-planar coordination geometry is five-coordinated by one chloride anion, one ON₂ donor set and one 4-pyridine nitrogen atom from another adjacent actylhydrazone ligand. However, the central ions in complexes 2 and 3 possess distorted octahedral coordination geometry, surrounded by two ON₂ donor sets. In addition, all the complexes have excellent antitumor activity towards human lung cancer (A549) and human gastric cancer (SGC7901 and BGC823) cell lines. Furthermore, cell apoptosis induced by complex 1 was detected through TUNEL and Annexin V/PI staining with flow cytometric analysis and western blotting analysis.     

Unusual metal–organic network constructed from Zn(II), benzenetricarboxylate and bis(1,2,4-triazolyl)pyridine

Hydrothermal reaction of ZnSO₄ · 7H₂O with 1,3,5-benzenetricarboxylic acid (H₃btc) and 2,6-bis(1,2,4-triazolyl)pyridine (btp) afforded a novel metal–organic network {[Zn₃(btc)₂(btp)₂(H₂O)₂] · 4H₂O}_n (1) with a supramolecular cocrystal [H₃btc · btp · H₂O]_n (2). The complex 1 exhibits an unusual network containing two molecular squares and a rectangle. The networks interpenetrate to make a 3D metal–organic framework, which is quite thermal stable. Compound 2 shows a 2D supramolecular network assembled through strong hydrogen bonds.     

Influence of manganese(II), cobalt(II), and nickel(II) additives in electrolyte on performance of graphite anode for lithium-ion batteries

Manganese dissolution into an electrolyte from the spinel LiMn₂O₄ in the lithium-ion cell has been recently investigated. In order to study the influence of the dissolved manganese species on the lithium intercalation/deintercalation into a natural graphite electrode, the electrochemical behavior of graphite was investigated in 1 mol dm⁻³ LiClO₄ electrolyte solution containing a small amount of Mn(II) by the addition of manganese(II) perchlorate. During the charging process, Mn(II) ions were firstly electroreduced on the electrode around 1.0 V versus Li/Li⁺ followed by irreversible decomposition of the electrolyte and lithium intercalation into the graphite. By microscopic observation of the graphite surface, manganese deposition was confirmed after the charge/discharge test. Due to the manganese deposition, the reversible capacity of the graphite electrode was drastically decreased. Furthermore, the cyclability of the anode was degraded with the amount of the manganese additive increasing. We compared these results with those of the cobalt(II) and nickel(II) additives by dissolving the corresponding perchlorates. Furthermore, we discussed the influence in practical cells based on the consideration of electrochemistry of the deposited metals.     

Magnetic polyresorcinol@CoFe2O4@MnS nanoparticles for adsorption of Pb(II), Ag(I), Cr(VI) and bacteria from water solution

Polymer Bulletin - This study devoted to developing an efficient adsorbent with the excellent adsorption performance of heavy metals and bacteria capturing. Polyresorcinol@CoFe2O4 was synthesized...     

Antibacterial Role of SO(4), NO(3), C(2)O(4) and CH(3)CO(2) Anions on Cu(II) and Zn(II) Complexes of a Thiadiazole-derived Pyrrolyl Schiff Base

A condensation reaction of 2-amino-1,3,4-thiadiazole with 2-pyrrolecarboxaldehyde to form tridentate NNN donor Schiff base has been performed. The prepared Schiff base was further used for the formation of metal complexes having stoichiometry [M(L)(2)]X(n), where M=Cu(II) or Zn(II), L=N-(2-pyrrolylmethylene)-2-amino-1,3,4-thiadiazole, X=SO(4) (2-), NO(3) (-), C(2)O(4) (2-) or CH(3)CO(2-) and n=1 or 2. The new compounds described here have been characterized by their physical, spectral and analytical data, and have been screened against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of the Schiff base increased upon chelation/complexation, having the same metal ion (cation) but different anions opening up a novel approach in finding new ways to fight against antibiotic resistant strains.     

Mononickel(II), dimercury(II), and 1-D polymeric silver(I) complexes with a ditopic 18-membered N2O2S2-macrocycle

A ditopic 18-membered N₂O₂S₂-macrocycle (L) incorporating hard (NO₂) and soft (NS₂) binding sites in each side was employed and its three complexes (1–3) exhibiting different stoichiometries, geometries, and topologies have been prepared and structurally characterized. First, nickel(II) nitrate hexahydrate reacts with L to give a mononuclear complex [Ni(L)](NO₃)₂·2H₂O (1) in which the metal center locates inside the macrocyclic cavity adopting a hexa-coordinated octahedral geometry shielded by the strongly bound macrocycle from the anion and solvent. While, silver(I) tetrafluoroborate afforded a one-dimensional coordination polymer {[Ag(L)]BF₄}_n (2) with an L-Ag-L-Ag pattern. In 2, the silver(I) center is penta-coordinate with NO donors from one L and NS₂ donors from an adjacent L to form a sandwich-type adopting a distorted trigonal bipyramidal geometry. Mercury(II) chloride yielded a dinuclear complex [Hg₂(L)Cl₄] (3) in which two mercury(II) ions locate opposite side of L in a chair form. Each mercury(II) center in 3 is penta-coordinate, being bound to one pyridine N atom, two O(S) donors in the compositional disorder, and two chloride ions adopting a distorted square-pyramidal geometry. The comparative NMR studies show the preferential binding affinity of silver(I) over potassium(I) toward L.     

Oxidation of 4‐nitrophenol in water over Fe(III), Co(II), and Ni(II) impregnated MCM41 catalysts

BACKGROUND: Nitrophenols are toxic constituents of the effluents of petroleum, textile, dye, iron and steel, foundries, pharmaceutical and electrical manufacturing industries. Aromatic nitro compounds are particularly resistant to normal chemical or biological oxidation making them environmentally persistent. Advanced oxidation using appropriate catalysts mineralize these organics to harmless final products. In this work, MCM41‐based catalysts incorporating Fe(III)‐, Co(II)‐ and Ni(II)‐ cations were used for oxidizing 4‐nitrophenol in water under variable conditions of reaction time, pH, mole ratio of the reactant and the oxidant, catalyst load, feed concentration, and temperature. RESULTS: The catalysts prepared were characterized with X‐ray diffraction (XRD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), cation exchange capacity (CEC) and atomic absorption spectrometry (AAS) measurements. In typical reaction conditions of temperature 353 K, time 300 min, catalyst load 2 g L^?1 and 10^?3 mol L^?1 4‐nitrophenol, the oxidation was 48.7, 52.2 and 55.2% with H₂O₂ and 42.5, 56.6 and 60.2% without H₂O₂ for Fe(III)‐, Co(II)‐ and Ni(II)‐MCM41, respectively. Pseudo‐first‐order kinetics with kinetic constant of 2.0 × 10^?3 to 5.5 × 10^?3 Lg^?1 min^?1 was proposed along with a possible mechanism. 4‐nitrocatechol, 4‐nitropyrogallol, 1,2,4‐trihydroxybenzene, hydroquinone, acrylic acid, malonic acid, and oxalic acid were identified in the oxidation products. CONCLUSION: Introduction of Fe(III)‐, Co(II)‐ and Ni(II)‐ into MCM‐41 by impregnation produced effective catalysts for wet oxidation of 4‐nitrophenol. The catalysts were able to oxidize 4‐NP even without the presence of an oxidizing agent. The results suggest that the transition metal loaded MCM41 brings about a more effective interaction between 4‐NP molecules and OH radicals. Copyright © 2008 Society of Chemical Industry     

Copper(II) and cadmium(II) complexes with an imide tethered imidazole and a copper(II) coordination polymer through ring opening reaction

The reactions of 2-(3-(1H-imidazol-1-yl)propyl)isoindoline-1,3-dione (L) with copper (II) chloride or copper(II) nitrate resulted in mononuclear complexes [CuL₄Cl₂]·12H₂O (1) or [CuL₄(H₂O)NO₃]NO₃·2H₂O (2) respectively; whereas the copper(II) acetate reacted with L to give a three dimensional coordination polymer {[Cu(L′)₂]·4H₂O}n (3), (where L′ = 2-(3-(1H-imidazol-1-yl)propylcarbamoyl)benzoate). The reaction of cadmium(II) acetate with L led to the formation of a seven-coordinated complex [CdL₃(O₂CCH₃)₂]·2H₂O (4).     

Antibacterial Co(II) and Ni(II) Complexes of N-(2-Furanylmethylene)-2-Aminothiadiazole and Role of SO(4), NO(3), C(2)O(4) and CH(3)CO(2) anions on Biological Properties

Co(II) and Ni(II) complexes with a Schiff base, N-(2-furanylmethylene)-2-aminothiadiazole have been prepared and characterized by their physical, spectral and analytical data. The synthesized Schiff-bases act as tridentate ligands during the complexation reaction with Co(II) and Ni(II. metal ions. They possess the composition [M(L)(2)]X(n) (where M=Co(II) or Ni(II), L=, X=NO(3) (-), SO(4) (2-), C(2)O(4) (2-) or CH(3)CO(2) (-) and n=1 or 2) and show an octahedral geometry. In order to evaluate the effect of anions upon chelation, the Schiff-base and its complexes have been screened for antibacterial activity against bacterial strains e.g., Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.     

Conductometric studies of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) tetrafluoroborates in N,N—dimethylacetamide solutions

Results are reported for the molar conductivities at 25°C of N,N—dimethylacetamide (DMA) solutions of Bu₄NBF₄ and Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) tetrafluoroborates. The limiting molar conductivities of [M(DMA)₆]²⁺ (M  MN, Co, Ni, Cu, Zn) and BF^?₄, as well as association constants for Co(BF₄)₂ in DMA solutions have been calculated. The slight differences between conductometric curves of different metal ions are discussed.     

Novel Nickel(II), Palladium(II), and Platinum(II) Complexes with O,S Bidendate Cinnamic Acid Ester Derivatives: An In Vitro Cytotoxic Comparison to Ruthenium(II) and Osmium(II) Analogues

(1) Background: Since the discovery of cisplatin’s cytotoxic properties, platinum(II) compounds have attracted much interest in the field of anticancer drug development. Over the last few years, classical structure–activity relationships (SAR) have been broken by some promising new compounds based on platinum or other metals. We focus on the synthesis and characterization of 17 different complexes with β-hydroxydithiocinnamic acid esters as O,S bidendate ligands for nickel(II), palladium(II), and platinum(II) complexes. (2) Methods: The bidendate compounds were synthesized and characterized using classical methods including NMR spectroscopy, MS spectrometry, elemental analysis, and X-ray crystallography, and their cytotoxic potential was assessed using in vitro cell culture assays. Data were compared with other recently reported platinum(II), ruthenium(II), and osmium(II) complexes based on the same main ligand system. (3) Results: SAR analyses regarding the metal ion (M), and the alkyl-chain position (P) and length (L), revealed the following order of the effect strength for in vitro activity: M > P > L. The highest activities have Pd complexes and ortho-substituted compounds. Specific palladium(II) complexes show lower IC₅₀ values compared to cisplatin, are able to elude cisplatin resistance mechanisms, and show a higher cancer cell specificity. (4) Conclusion: A promising new palladium(II) candidate (Pd3) should be evaluated in further studies using in vivo model systems, and the identified SARs may help to target platinum-resistant tumors.