Polynuclear Nickel(II) and Cobalt(II) Complexonates with Nitrilotrimethylenephosphonic Acid

Complexation in the Co(II)–H₆X–H₂O, Ni(II)–H₆X–H₂O, and Co(II)–Ni(II)–H₆X–H₂O systems (H₆X is nitrilotrimethylenephosphonic acid) was studied by spectrophotometry. The formation of binuclear complexonates Ni₂H₂X · 7H₂O, Co₂H₂X · 5H₂O, and NiCoH₂X · 6H₂O was demonstrated. These compounds were isolated from the solution, their composition was determined, the thermal stability was studied, and the kinetic parameters of dehydration were calculated.     

原子转移自由基聚合法制备侧链型磺化聚醚醚酮阳离子交换膜

以二氟二苯甲酮、双酚A和邻甲基氢醌为单体先经缩聚反应生成聚醚醚酮(PEEK),PEEK经修饰合成含有溴异丙基侧基的聚醚醚酮,以此为原子转移自由基聚合(ATRP)大分子引发剂,通过ATRP法聚合,在PEEK主链上接枝引入聚苯乙烯磺酸钠侧链,得到侧链型PEEK接枝聚合物(PEEK-g-StSO3Na)。 用傅里叶变换红外(FTIR) 光谱、核磁共振氢谱(1H NMR)、热重分析(TG)和扫描电子显微镜(SEM)等技术手段对PEEK-g-StSO3Na的结构进行表征。 结果表明,苯乙烯磺酸钠成功的被接枝到聚醚醚酮主链上,PEEK-g-StSO3Na膜具有明显的亲水疏水微相分离结构,磺酸基团相互聚集形成离子通道,离子交换容量为2.034 mmol/g的PEEK-g-StSO3Na膜的电导率为8.34×10-2 S/cm,膜的尺寸稳定性优于Nafion 117。     

Simultaneous Determination of Nickel(II) and Cobalt(II) by Second-Derivative Spectrophotometry

4-(2-Pyridylazo) resorcinol, PAR, is shown to be useful for simultaneous determination of cobalt(II) and nickel(II) using second-derivative spectrophotometric method with controlled experimental parameters. This method allows the determination of 0.20-1.25 ppm of nickel(II) and 0.25-1.50 ppm of cobalt(II) in mixtures with good precision and accuracy. This method has advantages of simplicity, speed and requires no prior separations.     

Multi‐Dimensional Cobalt(II) and Nickel(II) Coordination Polymers

A series of metal coordination polymers, [Co₂(NB)₄(bpp)₂(H₂O)]·H₂O ( 1 ), [Co₂(e,e‐trans‐chdc)(e,a‐cis‐chdc)(bpp)₂] ( 2 ), [Ni(e,e‐trans‐chdc)(bpp)(H₂O)₂] ( 3 ), [Ni₂(PDA)₂(bpp)₂(H₂O)₃]·H₂O ( 4 ), and [Ni‐(mBDC)(bpp)] ( 5 ) (NB = 3‐nitrobenzoate anion; bpp = 4,4′‐trimethylene dipyridine; chdc = cyclohexane‐1,4‐dicarboxylate anion; PDA = 1,4‐phenylenediacetate anion; mBDC = 1,3‐benzene dicarboxylate anion), were synthesized from metal ions and organic mixed‐ligands by hydrothermal reactions. The single crystal structure analysis revealed that 1, 3, and 4 were 2D sheets with bilayer (1 and 4) and 2‐fold interpenetrated layers (3), 2 is a 3D binodal (4,5)‐connected framework, and 5 is a 1D chains. The non‐covalent interactions of H‐bonds and π–π stacking caused this conformation of highly cross‐linked networks. Compounds 1‐5 were further characterized by thermal gravimetric analysis, powder X‐ray diffraction, UV‐vis, infrared, and PL spectroscopy.     

Thermal Decompositions of the Molybdotellurates of Nickel(II) and Cobalt(II)

Molybdotellurates [M(H₂O)₆]₃·[TeMo₆O₂₄], with M=Ni(II) and Co(II), were synthesized and characterized by single-crystal X-ray diffraction for compound 1 and X-ray powder diffraction for compound 2, EDAX, IR, electronic spectra in the solid phase and in solution, and magnetic properties. Thermogravimetry and differential scanning calorimetry of both compounds revealed a loss of 11 water molecules through an endothermal process with ΔH=800 kJ mol⁻¹ for the nickel compound and ΔH=833 kJ mol⁻¹ for the cobalt compound. The residual compounds were characterized by chemical analysis, IR and XPS spectroscopy This revised version was published online in July 2006 with corrections to the Cover Date.     

Double Hydrated Cobalt(II) Copper(II) and Nickel(II) Copper(II) Ammine Diphosphates

Synthesis of amorphous and crystalline double hydrated cobalt copper and nickel copper ammine diphosphates with a coordination structure is described.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 369–372.Original Russian Text Copyright © 2005 by Voitenko, Zhilyak, Kopilevich.     

Cobalt(II), Nickel(II), and Copper(II) Complexes with Diphenylthiocarbazide

New [ML(H₂O)₂] complexes (M = Co²⁺, Ni²⁺, or Cu²⁺; H₂L = diphenylthiocarbazide) were synthesized and studied using IR and diffuse reflection electronic spectroscopy, magnetic chemistry, conductometry, and DTA. The metals were shown to coordinate L^2–through nitrogen and sulfur atoms. The complex [CuL(H₂O)₂] is a dimer.     

N-Formamid osalicylaldimine andN-Acetamidosalicylaldimine Complexes of Copper(II), Nickel(II) and Cobalt(II)

Summary N-formamidosalicylaldimine (H₂SF) andN-acetamidosalicylaldimine (H₂SA) complexes of Cu^II, Ni^II and Co^II have been synthesized and characterized by analytical, spectroscopic and magnetic data. The ligands coordinate to the metalvia the hydroxyl, carbonyl and imino groups to yield normal paramagnetic and insoluble complexes which decompose above 250°.     

Water-Soluble Polymeric Complexes of Cobalt(II) and Nickel(II) with Azolate Anions

N-Unsubstituted azoles (1,2,4-triazole, 3-amino-1,2,4-triazole) and 5-R-tetrazoles (R = H, CH₃, C₂H₅, C₄H₉, CH = CH₂, C₆H₅, p-CH₃C₆H₄, NH₂) form water-soluble polymeric complexes in systems containing certain transition metal salts. The data obtained and the results of MP2/6-31G^{* *} calculations of the electronic structures of 5-R-tetrazolate anions show that the ability of azoles for formation of polymeric complexes with transition metal ions is mostly determined by the acid-base properties of azoles. The geometric structure of a polymeric chain with the Co²⁺ ion having the coordination number 6 and the 5-methyltetrazolate anion being a bridging ligand was examined at the STO-3G level. It was shown that the coordination by the 2- and 3-nitrogen atoms of the tetrazole ring is most favored by energy.     

Copper(II), Nickel(II) and Cobalt(II) Complexes of Dibasic Tridentate Schiff Bases

Complexes of Cu(II), Ni(II) and Co(II) with the Schiff bases derived from o-aminobenzoic acid with salicylaldehyde and its 5-chloro and 5-bromo derivatives have been prepared. The 1:1 (metal-ligand) stoichiometry of these complexes is shown by elemental analysis, gravimetric estimations and conductometric titrations while the structures of the complexes are proved by i.r. spectra and thermogravimetric analysis. The magnetic susceptibility and electronic spectra of Cu(II) complexes indicate the nonplanar binuclear structures while that of Ni(II) and Co(II) show their paramagnetic octahedral geometry. The molar conductance values in nitrobenzene indicate the nonelectrolytic behaviour of the complexes. The results show that the complexes of the type (Cu·L)₂, Ni·L·3H₂O and Co·L·3H₂O are formed having solvent molecule in coordination with the metal ion. The monopyridine and monoammonia adducts of Cu(II) complexes were found to be monomeric.     

Complexes of Cobalt(II), Nickel(II) and Copper(II) Chloroacetates with Quinoline N-Oxide

Some 1:1 and 1:2 adducts of cobalt(II), nickel(II) and copper(II) chloroacetates with quinoline N -oxide have been isolated by the interaction of the appropriate metal chloroacetate with quinoline N -oxide (QuinNo). The complexes isolated are of 1:1 stoichiometry of formula [M(CH₃_xClxCOO)₂QuinNO] (when M=Co(II), Ni(II); X=1,2 and 3 and when M=Cu(II), X=l and 2) except copper(II) trichloroacetate which yields an adduct of 1:2 stoichiometry of formula[Cu(CCI₃COO)₂(QuinNO)₂]. The adducts isolated are soluble in common organic solvents.     

Complexes of Cobalt(II), Nickel(II) and Copper(II) Chloroacetates with Quinoline N-Oxide

Some 1:1 and 1:2 adducts of cobalt(II), nickel(II) and copper(II) chloroacetates with quinoline N -oxide have been isolated by the interaction of the appropriate metal chloroacetate with quinoline N -oxide (QuinNo). The complexes isolated are of 1:1 stoichiometry of formula (M(CH_3-xCl_xCOO)₂QuinNO) (when M=Co(II), Ni(Il); X=l, 2 and 3 and when M=Cu(II), X=1 and 2) except copper(II) trichloroacetate which yields an adduct of 1:2 stoichiometry of formula[Cu(CCl₃COO)₂ (QuinNO)₃]. The adducts isolated are soluble in common organic solvents.     

Zinc(II), Cobalt(II) and Nickel(II) Complexes of 5-Substituted-1,3,4-Thiadiazoles

Zn(II), Co(II) and Ni(II) complexes with some 5-substituted-1,3,4-thiadiazoles (L₁-L₄) have been prepared and characterized by conductivity, microanalysis, thermal analysis, infrared and electronic spectra measurements. All complexes behave as 1:1 electrolyte and the ligands are coordinated as bidentate molecules. The stability constants and energy of formation are determined and discussed on the basis of the ligands structure.     

Ion Association and Hydration in Aqueous Solutions of Nickel(II) and Cobalt(II) Sulfate

Aqueous solutions of nickel(II) and cobalt(II) sulfate have been investigated at 25 ^∘C by dielectric relaxation spectroscopy (DRS) over a wide range of frequencies (0.2 ≤ ν (GHz) ≤ 89) and salt concentrations (0.025 ≤ c(mol-L⁻¹) ≤ 1.4). The spectra indicate, as for MgSO₄(aq) studied previously, the simultaneous presence of double solvent-separated, solvent-shared and contact ion pairs in both NiSO₄(aq) and CoSO₄(aq). The stepwise formation constants for each ion-pair type and the overall association constant, obtained from the data are in good agreement with ultrasonic relaxation and other estimates. The DR spectra at higher concentrations (c ≥ 0.5 mol-L⁻¹) suggest the existence of a nonlinear triple ion M₂SO₄²⁺(aq). Consistent with the very strong hydration of the salts, which have ‘effective’ hydration numbers approaching 27 at infinite dilution, there are no significant differences in any of the relaxation or thermodynamic parameters for NiSO₄(aq) and CoSO₄(aq), except that the triple ion appears to be somewhat more stable for the latter.     

Spectrophotometric Determination of Cobalt(II), Nickel(II) and Copper(II) with Acenaphthenequinone Monosemicarbazone (AQSC)

Cobalt(II), nickel(II) and copper(II) complexation with acenaphthenequinone monosemicarbazone (AQSC) has been studied spectrophotometrically. The Co(II), Ni(II) and Cu(II) complexes are soluble in ethanol medium and exhibit maximum absorbance at 410, 420 and 430 nm, respectively. The sensitivity of the reactions are 0.012, 0.02 and 0.01 μg/cm² for cobalt, nickel and copper systems. All the three complexes show maximum and constant absorbance in the pH range 8.4 to 9.8, 6.3 to 8.4 and 5.4 to 8.0 for Co-AQSC, Ni-AQSC and Cu-AQSC, respectively. Nickel and copper in some alloys have also been analysed.     

钴离子配位分子印迹聚合物膜渗透特性的研究

采用分子印迹技术紫外光引发原位聚合的方法制备了带支撑膜的钴离子配位分子印迹聚合物膜. 用扫描电镜测定了膜的表面形貌. 通过膜渗透实验表明, 在一定浓度钴离子存在下, 印迹膜对模板分子表现出良好的渗透选择性. 分别考察了阳离子和阴离子对印迹膜渗透模板分子的影响. 本工作有助于分子印迹技术应用于传感器技术和连续分离技术的研究.     

Analytical Separation of Copper(II), Cobalt(II) and Nickel(II) Using Polymer Bound Anthrantic Acid

Abstract

The preferential complexing tendency of different nietal ions towards chelating agents anchored on a polymer has been used for separation of transition metals. the anthranilic acid group was anchored on the polymeric cellulose back-bone by successive coupling with trifunctional reagent cyanuric chloride, in diozane medium, at pH 7 and 9–10, respectively. This polymer bound chelating agent was used to separate copper(II), nickel(II) and cobalt(II) in the concentration range 1.0–0.1 mmol/L. the separation of a mixture of two components was quantitative using column chromatography.     

A Spectrophotometric Study on Complex Formation of Nickel (II) and Cobalt (II) with Bromopyrogallol Red

Nickel (II) and Cobalt (II) form in 50% ethanolic medium, a bluish violet complex with Bromopyrogallol Red (BPR) in the mole ratio of 1:1 (Ni(II)) and 1:2 (Co(II)), both having at 620 nm, stable in the pH ranges 6.0-7.5 and 5.5-7.0, respectively. The thermodynamic stability constants and overall changes in the free energy of formation, enthalpy and entropy have been determined in both the cases. Beer's law is obeyed over the concentration range 0.5-5.0 ppm of Nickel and 0.2-3.0 ppm of Cobalt at 620 nm. The net molar absorptivities are 1.6 × 10⁴ and 2.9 × 10⁴ and the sensitivities are 0.00367 and 0.00219 μg of Nickel and Cobalt per cm,/². The effect of diverse ions on the metal ions determination is also reported.     

Synthesis,Characterization and Anti-oxidative Activity of Cobalt(II), Nickel(II) and Iron(II) Schiff Base Complexes

Six complexes, M(HL)₂ · nH₂O (M=Co, Ni and Fe; n=4) with two ligands, 2-carboxy-benzaldehydebenzoylhydrazone (H₂L¹) and 2-carboxybenzaldehyde-(4′-methoxy)benzoylhydrazone (H₂L²), have been synthesized and characterized on the basis of elemental analyses, molar conductivities, i.r. spectra and thermal analyses. In addition, the suppression ratio for O₂^- (a) and the suppression ratio for OH^· (b) were determined with a 72 spectrophotometer. The 50% inhibition [IC₅₀ (a) and IC₅₀ (b)] of the complexes were studied. This study demonstrated that the complexes have activity in the suppression of O₂^- (a) and OH^· (b). In general, the antioxidative activities increased as the concentration of these complexes increased up to a selected extent. The complexes exhibit more effective antioxidants than the ligands and the series of the ligand (H₂L²) are better than the series of the ligand (H₂L¹) do.     

Coordination Compounds of Cobalt(II), Nickel(II), and Zinc(II) Valerates and Benzoates with Phenylacethydrazide

Complexes of cobalt(II), nickel(II), and zinc(II) valerates and benzoates with phenylacethydrazide were synthesized. These compounds were characterized by chemical analysis, IR spectroscopy, diffuse reflection spectroscopy, and thermogravimetry.