A novel 3D double helix cobalt(II) coordination polymer: Synthesis, crystal structures and third-order non-linear optical properties

One new metal-organic complex formulated as {[Co(bipy)₃][Co₂(μ₂–ox)₃]}_n 1 (bipy = 2,2′-bipyridyl; ox = oxalate) has been synthesized by low-temperature solid-state reaction and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and UV–visible spectra. The complex 1 contains helical chains composed of left-handed and right-handed helices interlaced in pairs. The third-order non-linear optical (NLO) properties of the 1 were also investigated and they exhibit the reverse saturable absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 5.75 × 10⁻³⁰ esu for 1 in a 2.36 × 10⁻⁴ mol dm⁻³ DMF solution.     

[Zn(BDC)(H2O)2]n: a novel blue luminescent coordination polymer constructed from BDC-bridged 1-D chains via interchain hydrogen bonds (BDC = 1,4-benzenedicarboxylate)

A novel coordination polymer [Zn(BDC)(H₂O)₂]_n 1 (where BDC = 1,4-benzenedicarboxylate), has been synthesized and characterized by X-ray diffraction. 1 crystallizes in the monoclinic space group C2/c, a=15.09(2) Å, b=5.058(7) Å, c=12.196(16) Å, β=103.62(2)°, , Z=4. The most striking feature of 1 is that it consists of a high-dimensional network structure constructed from BDC-bridged 1-D chains via interchain hydrogen bonds. The coordination sphere of the zinc(II) ion is a distorted tetrahedron completed by four oxygen atoms from two water molecules and two BDC ligands. BDC adopts the bis-monodentated (syn–anti) coordination mode linking two adjacent zinc(II) ions. 1 shows strong blue photoluminescence as the result of the fluorescence from the intraligand emission excited state.     

Application of Polymer and Supported Membranes with 1-Decyl-4-Methylimidazole for Pertraction of Transition Metal Ions

The facilitated transport of Zn(II), Cd(II), Co(II), and Ni(II) ions from different aqueous chloride source phases (c_Me = 0.001 mol/dm³, pH = 6.0) across supported (SLMs) and polymer inclusion membranes (PIMs) doped with 1-decyl-4-methylimidazole as ion carrier was reported. The membrane is characterized by means of atomic force microscopy (AFM). The results show that Zn(II) can be separated very effectively from other transition metal cations as Cd(II), Co(II), and Ni(II) from different equimolar mixtures of such ions. The higher initial fluxes for Zn(II) were found for PIM (3.62-4.10 μmol/m².s), while the lower values were observed for SLM. However, after taking into account the morphology (porosity, tortuosity) of the membranes, the values of the initial flux of Zn(II) transport across the PIM are lower than those across the SLM. The recovery factor of Zn(II) ions during transport across PIM and SLM from different mixtures of cations is above 95% after 24 hrs. PIM containing 1-decyl-4-methylimidazole are stable for 120 hrs.     

Analytical applications of newly synthesized copolymer resin derived from p‐aminophenol,dithiooxamide, and formaldehyde

A copolymer resin (p‐APDF) has been synthesized using the monomers p‐aminophenol, dithiooxamide, formaldehyde in 1 : 1 : 2M proportions in the presence of 2M HCl as catalyst. The structure of p‐APDF copolymer has been elucidated on the basis of elemental analysis and various physicochemical techniques, i.e., UV‐visible, FTIR, and ¹H‐NMR spectroscopy. The number average molecular weight of copolymer resin was determined by nonaqueous conductometric titration in DMF. Viscosity measurement were carried out in DMF indicate normal behavior. The prepared resin proved to be a selective ion exchange resin for some metal ions. The chelating ion exchange properties of this resin was studied for Fe(III) and Cu(II), Ni(II), Co(II), Zn(II), Cd(II), Pb(II) ions. A batch equilibrium method was used to study selectivity of metal ion uptake over a wide pH range and in media of various ionic strength. The resin showed a higher selectivity for Fe(III), Ni(II), Cu(II) ions than for Co(II), Pb(II), Zn(II), and Cd(II) ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation, crystal structure and properties of two novel metal-organic frameworks assembled from pyridine-3,5-dicarboxylic acid N-oxide

Two novel coordination polymers, [Cu(PDCO) · (H₂O)]_n (1) and [Cd(PDCO)(bipy) · (H₂O) · 5H₂O]_n (2), (H₂PDCO = pyridine-3,5-dicarboxylic acid N-oxide, bipy = 4,4′-bipyridine), have been synthesized under hydrothermal conditions, and their structures were determined by single-crystal X-ray diffraction studies. Polymer 1 features a three-dimensional (3D) network with nonequivalent nodes of (6³)₂(6⁹ · 8⁵ · 10) topology. Polymer 2 exhibits one-dimensional (1D) double-stranded chains. The magnetic character of 1 as well as the gas adsorption and luminescent properties of 2 have been investigated.     

Synthesis,Structure and Luminescence Property of a 3D Diamondoid Interpenetrated Zn(II)-Organic Framework

A new metal–organic framework of Zn(II) ion, [Zn(muco)(bipy)·2H₂O] (where, muco = trans, trans-muconate dianion, bipy = 4,4′-bipyridine) has been synthesized by solvothermal reaction of Zn(II) ion, muco ligand and bipy spacer. X-ray structure determination reveals that compound 1 has a 3D diamondoid (dia) framework with novel fivefold interpenetrating nets. Topological analysis shows the presence of 4-connected Zn(II) nodes with {6⁶} topology. Thermal analysis reveals that the compound is stable up to 340 °C. Photoluminescence study shows the emission of 1 owing to the presence of muco ligand and the intensity of luminescence emission is higher than that of free muco ligand.     

Bilayer and 3-D open framework: Pillared metal-organic frameworks based on zinc and cadmic (6,3)-layers

The (6,3)-layers of transition metals and 3,5-pyridinecarboxylate (3,5-PDC) containing terminal coordinated molecules offer a great potential for obtained porous frameworks via the “pillaring” approach. In this work, we have successfully obtained two porous frameworks based on the zinc and cadmic (6,3)-layers (compounds 1 and 2, respectively) pillared by 4,4′-pyridine (bipy). Interestingly, different metal centers of Zn(II) and Cd(II) in the (6,3)-layers lead to the pillared frameworks into bilayers with {6³}{6⁶} topology (compound 3) and 3-D open framework with {6³}{6⁹·8} hms topology (compound 4), respectively. It is believed that this work deserves further focus to enrich the design strategy of novel porous crystalline metal-organic frameworks (MOFs).     

Crystal structure and magnetic property of a 3D heterometallic coordination polymer constructed by 3-cyanobenzoate and 3-(5H-tetrazol) benzoate ligands

Hydrothermal reaction of Cd(NO₃)₂, Co(NO₃)₂, Na(3-cba) and NaN₃ yielded a 3D heterometallic coordination polymer, [Cd(μ₅-3-tzba)(μ₂-3-cba)(μ₃-OH)Co(H₂O)]_n·2nH₂O 1 (3-H₂tzba = 3-(5H-tetrazol)benzoic acid and 3-Hcba = 3-cyanobenzoic acid), which was characterized by single-crystal X-ray diffraction. The in situ [2 + 3] cycloaddition reaction of nitrile and azide in presence of Cd(II) salt afforded tetrazolate-based 3-tzba^2? ligand. In 1, metal-oxo chains [Cd(μ₃-OH)Co]_n are linked by 3-tzba^2? in an unprecedented μ₅-κN1:κN2:κN3:κN4:κO1,O2 coordination mode to form 2D layers, which are further pillared by 3-cba^? to generate a 3D open framework encapsulating 1D chiral channels. Variable-temperature magnetic studies show that 1 exhibits antiferromagnetic interactions between Co(II) ions bridged by μ₃-OH group.     

A New 3D Coordination Polymer Based on Pentanuclear Cd(II) Rod-Shaped Secondary Building Unit: Synthesis,Crystal Structure and Luminescent Property

A new coordination polymer [Cd_2.5(μ₃-OH)(L)₂(bipy)]_n (1). (L = 1,2-naphthalene dicarboxylate, bipy = 4,4′-bipyridine), was obtained under hydrothermal condition. The structure of 1 has been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis and IR spectrum. Single-crystal X-ray diffraction analyses reveal that complex 1 crystallizes in triclinic system, Pī space group. Complex 1 possesses a 3D pcu net based on a pentanuclear Cd(II) cluster. Each pentanuclear Cd(II) cluster links with neighboring ones and generates a rod-shaped secondary building unit, which is further extended by bipy ligands to forms a three-dimensional network. Furthermore, the luminescent properties of this complex and the free ligand have been investigated. Complex 1 can be excited directly and emit strong soild-state fluorescence at room temperature, which may make them excellent candidates for fluorescent materials.     

Synthesis,characterization, and application of a new chelating resin functionalized with dithiooxamide

Chloromethylated polystyrene‐divinylbenzene has been functionalized with dithiooxamide. The resulting chelating resin (DTOA) has been characterized by elemental analyses, infrared spectroscopy, thermogravimetric analysis, and metal ion sorption capacities. It has been used for the preconcentration and separation of Cu(II), Zn(II), Cd(II), and Pb(II) prior to their determination by FAAS. Parameters such as the amount of the resin, effect of pH, equilibration rate, sorption and desorption of metal ions, and effect of diverse ions have been studied. The maximum sorption capacities found are 0.97, 0.12, 0.08, and 0.12 mmol g^?1 for Cu(II), Zn(II), Cd(II), and Pb(II) at pH 6.0, 5.5, 1.0, and 5.5, respectively. The preconcentration factors are 100, 100, 50, and 50 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. Recoveries of the metal ions were 96 ± 5, 97 ± 6, 96 ± 5, and 96 ± 5 at 95% confidence level, whereas the limits of detection are 2.0, 1.3, 2.5, and 25.0 μg L^?1 for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The calibration curves were linear up to 12 μg mL^?1 (R² = 1.000), 2 μg mL^?1 (R² = 0.998), 2 μg ml^?1 (R² = 1.000), and 5 μg mL^?1 (R² = 0.979) for Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The reliability of the method has been tested by analyzing certified samples. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2281–2285, 2007     

A fluorescent chemosensor for Zn2 + based on 3,8-bis(4-methoxyphenyl)-1,10-phenanthroline

3,8-Bis(4-methoxyphenyl)-1,10-phenanthroline (L) has been found to show high sensitivity toward Zn^2 + than other competitive metal ions, where Zn^2 +-selective chelation-enhanced fluorescence response at 461 nm is attributed to the formation of a 1:1 metal–ligand complex. In addition, two single-crystal structures of ligand L have been included with the same metal and ligand ratio of 1:1, namely one mononuclear Zn(II) complex [Zn(L)Cl₂] (1) and one 1D Cd(II) coordination polymer [Cd(L)(NO₃)₂]_n (2).     

Three-dimensional network constructed with novel one-dimensional Z-shaped chains via intricate noncovalent interactions

Novel coordination polymers {[M(bpmb)(H₂O)₂(C₂H₅OH)₂]·(NO₃)₂}_n (M=Zn 1, Cd 2; bpmb= N,N^′-bis (3-pyridinylmethyl)-1,4-benzenedicarboxamide) have been synthesized by the reaction of bpmb with zinc(II) salt and cadmium(II) salt in ethanol–water solution, respectively. Elemental analysis, IR spectra and X-ray crystal structure analysis were carried out to determine the compositions and crystal structures of the two compounds, which reveal that bpmb bridges the metal centers to from a one-dimensional chain. These chains were linked through noncovalent interactions to form three-dimensional networks.     

Environmental water remediation using covalently functionalized zerovalent iron nanocomposites with 2-pyridinecarboxaldehyde via 3-aminopropyltrimethoxysilane and ethylenediamine

The adsorption technology involving nano zerovalent iron (NZVI) has been widely employed to remediate polluted water based on a number of economic aspects. However, this technology is facing a high challenge in the removal process of pollutants due to hydrolysis and stability characteristics of zerovalent iron. Therefore, this study is aimed to demonstrate a method for encapsulation and functionalization of NZVI nanoparticles with 3-aminopropyltrimethoxysilane (NH₂) and 2-pyridinecarboxaldehyde (PY), respectively to produce the target nanocomposite (NZVI-NH₂-PY). Zerovalent iron nanoparticles are also aimed to functionalize with ethylenediamine (ED) and 2-pyridine carboxaldehyde to produce NZVI-ED-PY nanocomposite. The TEM images showed that the sizes of NZVI-NH₂-PY and NZVI-ED-PY nanocomposites are in the range 3.33–4.35 and 5.42–10.36 nm, respectively. More characterization evidences were concluded by thermal gravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The two novel magnetic nanocomposites have been used for removal of Co(II), Zn(II), Pb(II), Cd(II), Hg(II), Cu(II) beside radioactive isotopes (⁶⁵Zn and ⁶⁰Co) from water. NZVI-NH₂-PY nanocomposite was more selective toward Hg(II), Pb(II) and Cd(II), while NZVI-ED-PY was more selective toward Z(II), Co(II) and Co(II). Different kinetic models were applied and the investigated metal ions were characterized to undergo the pseudo-second order using both NZVI-NH₂-PY and NZVI-ED-PY nanocomposites.     

Elution Behavior of Metal Ions with Mixed Glycine-Nitric Acid Eluents in Dowex 50W-X8 Column: Separation of Th(IV), Ce(IV), Bi(III), Fe(III), and Al(III)

Abstract

Distribution coefficients (K) determined by the batch technique in acidic glycine media using Dowex 50W-X8 cation exchanger (H⁺?form, 100–200 mesh size) revealed that this medium can effectively be employed to separate a number of tetravalent and trivalent metal ions from bivalent metal ions. In fixed glycine (0.40 M) and varying concentration of nitric acid (0.10 to 1.0 M), a number of mixtures containing two or three metal ions were resolved on columns using about 8 g of exchanger. In 0.40 M glycine-1.0 M HNO₃ medium, Th(IV)/Ce(IV) were separated from Al(III)/Fe(III)/Bi(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I) and also Al(III)/Bi(III) from a number of divalent metal ions. In 0.40 M glycine-0.50 M HNO₃ medium, the resolution of following ternary mixtures were also achieved: Th(IV)/Ce(IV)-Al(III)/Bi(III)-Fe(III)/Co(II)/Ni(II)/Cu(II)/Zn(II)/Cd(II)/Hg(II)/Pb(II)/Ag(I). Th(IV)/Al(III)/Fe(III)/Bi(III) were also separated from other divalent metal ions in 1.60 M glycine-0.50 M HNO₃ medium. The values of K, elution characteristics of metal ions, elution curves, and the results of the resolution of a number of mixtures of metal ions along with standard deviations are reported.     

Surface selectivity competition of newly synthesized polyarylidene(keto amine) polymers toward different metal ions

A new series of polyarylidene(keto amine)s (PAKAs) 3_a?3_e based on thiophene moieties in polymer main chains were synthesized with the solution polycondensation technique. The polymers were synthesized by the reaction of the new monomer 1,1′‐(1E,1′E)‐(2‐oxocyclohexane‐1,3‐diylidene)bis(methanylylidene)bis(thiophene‐5,2‐diyl)bis(2‐chloroethanone) ( 2 ) with different diamines. The new monomer was first synthesized under the normal conditions of the Friedel–Crafts reaction. The results obtained from both elemental and spectral analyses were consistent with the chemical structure of the new monomers and the polymers. Moreover, the identification of the polymers was carried out with different characterization techniques. The analytical competition of the newly synthesized PAKA polymers as selected examples ( 3_d and 3_e ) was also evaluated for a selective extraction of metal ions, including Cd(II), Co(II), Cu(II), Cr(III), Fe(III), Ni(II), and Zn(II), before their determination by inductively coupled plasma–optical emission spectrometry. The results of the selectivity study demonstrated that the 3_d and 3_e polymers was the most selective toward Co(II) and Fe(III), respectively. However, the adsorption capacity of 3_d for Co(II) was improved by 10.10% in comparison to that of 3_e for Fe(III) after only 1 h of contact time. Moreover, the adsorption isotherm data also showed that the adsorption process was mainly monolayer on the homogeneous adsorbent surfaces of both polymers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40873.     

Various metal-organic frameworks from 1D, 2D to 3D with 1,6-bis(1,2,4-triazol-1-yl)hexane

Using Zn(II) or Cd(II) salts and the flexible ligand 1,6-bis(1,2,4-triazol-1-yl)hexane(L), a series of novel coordination polymers, {[Zn(L)Cl₂]}_n (1), [Cd(L)₂(SCN)₂]_n (2), {[M(L)₃](ClO₄)₂}_n (M = Zn, 3; Cd, 4), varying from one- to three-dimensionality, have been prepared and their crystal structures determined via X-ray single-crystal diffraction analysis. 1 and 2 are 1D zigzag chain and 2D (4,4) network, respectively. Isostructural compounds 3 and 4 are 3D threefold interpenetrating frameworks. This work suggests that metal/ligand ratio and anion play an important role in the self-assembly of 1D, 2D and 3D coordination polymers based on L.     

Novel Cd(II) and Co(II) 2-D frameworks based on terephthalate and 1-substitutedimidazole mixed-ligands

The two Cd(II) and Co(II) 2-D frameworks have been prepared by means of self-assemblies of Cd(II) or Co(II) salts and 1-substituted imidazole and terephthalic acid, and structurally characterized by X-ray diffraction analyses. In complex 1 2-D frameworks with rhombic cavity are formed, in which the each top point of rhombus contains one hexa and two heptacoordinated Cd(II). In complex 2 2-D networks with rectangular cavities are formed, and the opposite benzene rings from carboxyls in each rectangular cavity are parallel.     

Resin I: Synthesis,characterization, and ion‐exchange properties of terpolymer resins derived from 2,4‐dihydroxypropiophenone,biuret, and formaldehyde

Terpolymers (2,4‐DHPBF) were synthesized by the condensation of 2,4‐dihydro‐xypropiophenone, biuret, and formaldehyde in the presence of acid catalyst with varying the molar ratio of reacting monomers. Terpolymer composition has been determined on the basis of their elemental analysis and their number–average molecular weight of these resin were determined by conductometric titration in nonaqueous medium. The viscosity measurements were carried out in N,N‐dimethyl formamide which indicate normal behavior. IR spectra were studied to elucidate the structure. The terpolymer resin has been further characterized by UV–visible and ¹H‐NMR spectra. The newly synthesized terpolymers proved to be selective chelating ion‐exchange terpolymers for certain metals. The chelating ion‐exchange properties of this terpolymer was studied for Fe (III), Cu (II), Hg (II), Cd (II), Co (II), Zn (II), Ni (II), and Pb (II) ions. A batch equilibrium method was employed in the study of the selectivity of metal ion uptake involving the measurement of the distribution of a given metal ion between the terpolymer sample and a solution containing the metal ion. The study was carried out over a wide pH range and in media of various ionic strengths. The terpolymer showed a higher selectivity for Fe (III), Hg (II), Cd (II), and Pb (II) ions than for Cu (II), Co (II), Zn (II), and Ni (II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Modelling Individual and Competitive Adsorption of Cadmium(II) and Zinc(II) Metal Ions from Aqueous Solution onto Bagasse Fly Ash

Abstract

The present study deals with the competitive adsorption of cadmium (Cd(II)) and zinc (Zn(II)) ions onto bagasse fly ash (BFA) from binary systems. BFA is a waste obtained from the bagasse‐fired boilers of sugar mills. The initial pH≈6.0 is found to be the optimum for the individual removal of Cd(II) and Zn(II) ions by BFA. The equilibrium adsorption data were obtained at different initial concentrations (C ₀ = 10–100 mg/l), 5 h contact time, 30°C temperature, BFA dosage of 10 mg/l at pH ₀ = 6. The Redlich–Peterson (R–P) and the Freundlich models represent the single ion equilibrium adsorption data better than the Langmuir model. The adsorption capacities in the binary‐metal mixtures are in the order Zn(II)>Cd(II) and is in agreement with the single‐component adsorption data. The equilibrium metal removal decreases with increasing concentrations of the other metal ion and the combined action of Cd(II) and Zn(II) ions on BFA is found to be antagonistic. Equilibrium isotherms for the binary adsorption of Cd(II) and Zn(II) ions on BFA have been analyzed by non‐modified Langmuir, modified Langmuir, extended‐Langmuir, Sheindorf–Rebuhn–Sheintuch (SRS), non‐modified R–P and modified R–P adsorption models. The isotherm model fitting has been done by minimizing the Marquardt's percent standard deviation (MPSD) error function using MS Excel. The SRS model satisfactory fits for most of the adsorption equilibrium data of Cd(II) and Zn(II) ions onto BFA.     

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.