Mn(II), Zn(II) and VO(II) Schiff

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 3. Synthesis and characterisation of Cu(II), Ni(II), Mn(II), Zn(II) and VO(II) Schiff base complexes derived from o-phenylenediamine and acetoacetanilide. N Raman Y Pitchaikani Raja A Kulandaisamy. Inorganic Volume 113 Issue 3 June 2001 pp 183-189 ...

Antibacterial Co(II, Ni(II, Cu(II and Zn(II complexes with biacetyl-derived Schiff bases

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MUHAMMAD IMRAN

2010-08-01

Full Text Available The condensation reactions of biacetyl with ortho-hydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2(H2O2] where M = Co(II, Ni(II, Cu(II and Zn(II and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR, 13C-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141–160 °C. These compounds were also screened for their in vitro antibacterial activity against four bacterial species, namely: Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtilis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.

Synthesis, characterization and biological studies of 2-(4-nitro phenylaminocarbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

International Nuclear Information System (INIS)

Aqeel Ashraf, M.; Jamil Maah, M.; Yusuf, I.

2012-01-01

Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) salts of 2-(4-nitro phenylaminocarbonyl)benzoic acid were characterized by physical, analytical and spectroscopic studies and checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis (Gram +ve), Escherichia coli (Gram -ve), Pseudomonas aeuroginosa (Gram -ve) and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. The antimicrobial activities of the metal complexes - were found to be greater than those of 2-(4-nitro phenylaminocarbonyl)benzoic acid alone.

Synthesis and characterization of polychelates of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), oxovanadium(IV) and dioxouranium(VI) with 2,4-dihydroxybenzaldehyde-urea-formaldehyde polymer

International Nuclear Information System (INIS)

Patel, G.C.; Pancholi, H.B.; Patel, M.M.

1991-01-01

Polychelates of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), oxovandium(IV) and dioxouranium(VI) with 2,4-dihydroxybenzaldehyde (2,4-DB)-urea(U)-formaldehyde(F) polymer (2,4-DBUF) have been prepared. Elemental analyses of the polychelates indicate a metal:ligand ratio of 1:2. The structures of the polychelates have been assigned on the basis of their elemental analyses, IR, reflectance spectra, magnetic moment, thermal data and their electrical conductivity behaviour. (author). 1 tab., 18 refs

Batch adsorptive removal of Fe(III), Cu(II) and Zn(II) ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

OpenAIRE

Aboul-Magd, Abdul-Aleem Soliman; Al-Husain, Salwa Al-Rashed; Al-Zahrani, Salma Ahmed

2016-01-01

Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III), Cd(II), Zn(II), Cu(II), Mn(II), Mg(II), and Pb(II) from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion ...

Micellar effect on metal-ligand complexes of Co(II, Ni(II, Cu(II and Zn(II with citric acid

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Nageswara Rao Gollapalli

2009-12-01

Full Text Available Chemical speciation of citric acid complexes of Co(II, Ni(II, Cu(II and Zn(II was investigated pH-metrically in 0.0-2.5% anionic, cationic and neutral micellar media. The primary alkalimetric data were pruned with SCPHD program. The existence of different binary species was established from modeling studies using the computer program MINIQUAD75. Alkalimetric titrations were carried out in different relative concentrations (M:L:X = 1:2:5, 1:3:5, 1:5:3 of metal (M to citric acid. The selection of best chemical models was based on statistical parameters and residual analysis. The species detected were MLH, ML2, ML2H and ML2H2. The trend in variation of stability constants with change in mole fraction of the medium is explained on the basis of electrostatic and non-electrostatic forces. Distributions of the species with pH at different compositions of micellar media are also presented.

Synthesis, characterisation and electrochemical behaviour of Cu(II)

Indian Academy of Sciences (India)

Neutral tetradentate N2O2 type complexes of Cu(II), Ni(II), Co(II) and Zn(II) have been synthesised using the Schiff base formed by the condensation of acetylacetone and p-anisidine. Microanalysis, molar conductance, magnetic susceptibility, IR, UV-Vis, 1H NMR, CV and EPR studies have been carried out to determine the ...

Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)] metals

OpenAIRE

Nahid Nishat; Ashraf Malik

2016-01-01

A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). All the polymeric compounds were characterized by (FT-IR) spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA) and antibacterial activities. Polymer complexes of Mn(II), Co(II) and Ni(II) show octahedral geometry, wh...

Application of Carrier Element-Free Co-precipitation Method for Ni(II), Cu(II) and Zn(II) Ions Determination in Water Samples Using Chrysin

International Nuclear Information System (INIS)

Layth Imad Abd Ali; Wan Aini Wan Ibrahim; Azli Sulaiman; Mohd Marsin Sanagi

2015-01-01

A co-precipitation method was developed to separate and pre-concentrate Ni(II), Cu(II) and Zn(II) ions using an organic co precipitant, chrysin without adding any carrier element termed as carrier element-free co-precipitation (CEFC). Analytes were determined using flame atomic absorption spectrometry (FAAS). The influence of analytical conditions, such as pH of the solution, quantity of co-precipitant, standing time, centrifugation rate and time, sample volume, and interference of concomitant ions were investigated over the recovery yields of the trace metals. The limit of detection, the limit of quantification and linearity range obtained from the FAAS measurements were found to be in the range of 0.64 to 0.86 μg L -1 , 2.13 to 2.86 μg L -1 and 0.9972 to 0.9989 for Ni(II), Cu(III) and Zn(II) ions, respectively. The precision of the method, evaluated as the relative standard deviation (RSD) obtained after analyzing a series of 10 replicates, was between 2.6 % to 3.9 % for the trace metal ions. The proposed procedure was applied and validated by analyzing river water reference material for trace metals (SLRS-5) and spiking trace metal ions in some water samples. The recoveries of the analyte metal ions were between 94.7-101.2 %. (author)

Synthesis and Characterization of Some New Cu(II, Ni(II and Zn(II Complexes with Salicylidene Thiosemicarbazones: Antibacterial, Antifungal and in Vitro Antileukemia Activity

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Tudor Rosu

2013-07-01

Full Text Available Thirty two new Cu(II, Ni(II and Zn(II complexes (1–32 with salicylidene thiosemicarbazones (H2L1–H2L10 were synthesized. Salicylidene thiosemicarbazones, of general formula (XN-NH-C(S-NH(Y, were prepared through the condensation reaction of 2-hydroxybenzaldehyde and its derivatives (X with thiosemicarbazide or 4-phenylthiosemicarbazide (Y = H, C6H5. The characterization of the new formed compounds was done by 1H-NMR, 13C-NMR, IR spectroscopy, elemental analysis, magnetochemical, thermoanalytical and molar conductance measurements. In addition, the structure of the complex 5 has been determined by X-ray diffraction method. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60 cells growth and antibacterial and antifungal activities.

Synthesis, characterization and biological studies of 2-(4-nitrophenylamino-carbonyl)benzoic acid and its complexes with Cr(III), Co(II), Ni(II), Cu(II) and Zn(II)

International Nuclear Information System (INIS)

Imran, M; Nazir, S.; Latif, S.; Mahmood, Z.

2010-01-01

Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of 2-(4-Nitrophenyl aminocarbonyl)benzoic acid were synthesized and characterized on the basis of physical, analytical and spectroscopic data. The ligands, as well as its metal complexes were checked for their in-vitro antimicrobial activity against three bacterial strains, Mycobacterium smegmatis, Escherichia coli, Pseudomonas aeuroginosa, and three fungal strains, Nigrospora oryzae, Aspergillus niger and Candida albicans. Disc diffusion method and Tube diffusion test were used for antibacterial and antifungal activities, respectively. The synthesized complexes only show significant antifungal activity but inactive for antibacterial, however, in general, the metal complexes were found to be more active against antimicrobial activities as compared to their un complexed ligand. (author)

Al(III), Pd(II), and Zn(II) phthalocyanines for inactivation of dental pathogen Aggregatibacter actinomycetemcomitans as planktonic and biofilm-cultures

Science.gov (United States)

Kussovski, V.; Mantareva, V.; Angelov, I.; Avramov, L.; Popova, E.; Dimitrov, S.

2012-06-01

The Gram-negative, oral bacterium Aggregatibacter actinomycetemcomitans has been implicated as the causative agent of several forms of periodontal disease in humans. The new periodontal disease treatments are emergence in order to prevent infection progression. Antimicrobial photodynamic therapy (a-PDT) can be a useful tool for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and appears effective in photoinactivation of microorganisms. The phthalocyanine metal complexes of Pd(II)- (PdPcC) and Al(III)- (AlPc1) were evaluated as photodynamic sensitizers towards a dental pathogen A. actinomycetemcomitans in comparison to the known methylpyridyloxy-substituted Zn(II) phthalocyanine (ZnPcMe). The planktonic and biofilm-cultivated species of A. actinomycetemcomitans were treated. The photophysical results showed intensive and far-red absorbance with high tendency of aggregation for Pd(II)-phthalocyanine. The dark toxicities of both photosensitizers were negligible at concentrations used (bacteria was full photoinactivation after a-PDT with ZnPcMe. In case of the newly studied complexes, the effect was lower for PdPcC (4 log) as well as for AlPc1 (1.5-2 log). As it is known the bacterial biofilms were more resistant to a-PDT, which was confirmed for A. actinomycetemcomitans biofilms with 3 log reductions of viable cells after treatment with ZnPcMe and approximately 1 log reduction of biofilms after PdPcC and AlPc1. The initial results suggest that a-PDT can be useful for effective inactivation of dental pathogen A. actinomycetemcomitans.

Synthesis, investigation and spectroscopic characterization of piroxicam ternary complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with glycine and DL-phenylalanine

Science.gov (United States)

Mohamed, Gehad G.; El-Gamel, Nadia E. A.

2004-11-01

The ternary piroxicam (Pir; 4-hydroxy-2-methyl- N-(2-pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide) complexes of Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with various amino acids (AA) such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized by elemental analyses, molar conductance, IR, UV-Vis, magnetic moment, diffuse reflectance and X-ray powder diffraction. The UV-Vis spectra of Pir and the effect of metal chelation on the different interligand transitions are discussed in detailed manner. IR and UV-Vis spectra confirm that Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its carboxylic group, in addition PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its carboxylic and amino groups. All the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. The molar conductance data reveal that most of these chelates are non electrolytes, while Fe(III)-Pir-Gly, Co(II)-, Ni(II)-, Cu(II)- and Zn(II)-Pir-PhA cheletes were 1:1 electrolytes. X-ray powder diffraction is used as a new tool to estimate the crystallinity of chelates as well as to elucidate their geometrical structures.

Electrochemical behavior of free-radical derivatives of tetra(4hydroxyl-3,5-di-tert-butylphenyl) porphyrin

Energy Technology Data Exchange (ETDEWEB)

Pokhodenko, V.D.; Melezhik, A.V.; Platonova, E.P.; Vovk, D.N.

1984-08-01

The electrochemical behavior of free-radical derivatives of tetra(4hydroxyl-3,5-di-tert-butylphenyl) porphyrins and their complexes with Mg(II), Zn(II), Ni(II), CU(II), and Pd(II) ions was studied by the methods of voltamperometry, ESR, and spectrophotometry. It was shown that the introduction of free-radical substituents into the porphin macrocycle leads to a substantial decrease in the oxidation and reduction potentials of the complexes. The degree of conjunction of substituents with the porphin macrocycle is estimated according to the difference of the redox potentials of free-radical and quinoid derivatives of metalloporphyrins.

Physico - chemical investigation on Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO2+2 and VO+2 ions-O-(-N-3,5-dichloro-α-pyridone imino)

International Nuclear Information System (INIS)

Mathur, Praveen; Trivedi, Pradeep; Mehta, R.K.

1983-01-01

Studies on the interaction of newly synthesised ligand, O-(N-3, 5-dichloro-α-pyridone imino) benzene sulphonic acid (H 2 PB) with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), UO 2 +2 and VO +2 have been carried out potentiometrically. Many physico-chemical studies on thermodynamics, elemental analysis, molecular weight, magnetic moment, conductance, electronic and IR spectra have also been made on the solid chelates and their adducts. The dissociation constants of H 2 PB and stabilities of its bivalent chelates have been evaluated potentiometrically at 25deg, 35deg and 45degC in aqueous medium (0.01M, 0.05M and 0.1M NaClO 4 ) by Bjerrum's method. The stability sequence is in agreement with the Irving-William's rule. (author)

Preparation of Schiff s base complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) and their spectroscopic, magnetic, thermal, and antifungal studies

International Nuclear Information System (INIS)

Parekh, H.M.; Patel, M.N.

2006-01-01

The potassium salt of salicylidene-DL-alanine (KHL), bis(benzylidene)ethylenediamine (A 1 ), thiophene-o-carboxaldene-p-toluidine (A 2 ), and its metal complexes of the formula [(M II (L)(A)(H 2 O)] (M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II); A = A 1 or A 2 ) are prepared. They are characterized by elemental analysis, magnetic susceptibility measurements, thermogravimetric analysis, and infrared and electronic spectral studies. The electronic spectral and magnetic moment data suggest an octahedral geometry for the complexes. All of these complexes, metal nitrates, fungicides (bavistin and emcarb), and ligands are screened for their antifungal activity against Aspergillus niger, Fusarium oxysporum, and Aspergillus flavus using a plate poison technique. The complexes show higher activity than those of the free ligands, metal nitrate, and the control (DMSO) and moderate activity against bavistin and emcarb [ru

Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II binary complexes of l-methionine in 1,2-propanediol-water mixtures

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M. Padma Latha

2007-04-01

Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-methionine in 0.0-60 % v/v 1,2-propanediol-water mixtures maintaining an ionic strength of 0.16 M at 303 K has been studied pH metrically. The active forms of ligand are LH2+, LH and L-. The predominant species detected are ML, MLH, ML2, ML2H, ML2H2 and MLOH. Models containing different numbers of species were refined by using the computer program MINIQUAD 75. The best-fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with change in the dielectric constant of the medium is explained on the basis of electrostatic and non-electrostatic forces.

The synthesis and characterization of 1,2-dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene nonane and its complexes with Ni(II), Cu(II), Zn(II) and Cd(II)

International Nuclear Information System (INIS)

Canpolat, E.; Kaya, M.; Gorgulu, A.O.

2002-01-01

1,2-dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene nonane (H 2 L) was synthesized starting from 1,2-O-iso-butylidene-4-aza-6-amino hexane (RNH 2 ) and antichloroglyoxime. Ni(II) and Cu(II) complexes of H 2 L have a metal:ligand ratio 1:2 and the ligand coordinates through two N atoms, as do most of the vic-dioximes. However, Zn(II) and Cd(II) complexes of H 2 L have a metal: ligand ratio 1:1 and one chloride ion and one water molecule are also coordinated to the metal ion. Structures of the ligand and its transition-metal complexes are proposed, according to elemental analysis, IR, 13 C and 1 H NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA). (author)

Synthesis, Characterization, and Biological Activity of Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II Complexes of N-Thiophenoyl-N′-Phenylthiocarbohydrazide

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M. Yadav

2013-01-01

Full Text Available Mn(II, Fe(II, Co(II, Ni(II, Cu(II, Zn(II, and Cd(II complex of N-thiophenoyl -N′-phenylthiocarbohydrazide (H2 TPTH have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, infrared, NMR, electronic, and ESR spectral studies. The complexes were found to have compositions [Mn(H TPTH2], [Co(TPTH (H2O2], [Ni(TPTH (H2O2], [Cu(TPTH], [Zn(H TPTH], [Cd(H TPTH2], and [Fe(H TPTH2(EtOH]. The magnetic and electronic spectral studies suggest square planar geometry for [Cu(TPTH], tetrahedral geometry for [Zn(TPTH] and [Cd(H TPTH2], and octahedral geometry for rest of the complexes. The infrared spectral studies of the 1 : 1 deprotonated complexes suggest bonding through enolic oxygen, thiolato sulfur, and both the hydrazinic nitrogens. Thus, H2TPTH acts as a binegative tetradentate ligand. H2 TPTH and its metal complexes have been screened against several bacteria and fungi.

Thermal, spectral, magnetic and biological studies of thiosemicarbazones complexes with metal ions: Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO2(VI)

International Nuclear Information System (INIS)

Mashaly, M.M.; Seleem, H.S.; El-Behairy, M.A.; Habib, H.A.

2004-01-01

Thiosemicarbazones ligands, isatin-3-thiosemicarbazone(HIT) and N-acetylisatin-3-thiosemicarbazone (HAIT), which have tridentate ONN coordinating sites were prepared. The complexes of both ligands with Cu(II), Co(II), Ni(II), Fe(III), Zn(II), Mn(II) and UO 2 (VI) ions were isolated. The ligands and their metal complexes were characterized by elemental analysis, IR, UV-Vis and mass spectra, also by conductance, magnetic moment and TG-DSC measurements. All the transition metal complexes have octahedral configurations, except Cu-complexes which have planar geometry and the UO 2 (VI) complexes which have coordination number 8 and may acquire the distorted dodecahedral geometry. Thermal studies explored the possibility of obtaining new complexes. Inversion from octahedral to square-planar configuration occurred upon heating the parent Ni-HIAT complex to form the corresponding pyrolytic product. The antifungal activity against the tested organisms showed that some metal complexes enhanced the activity with respect to the parent ligands. (author)

Indolenine meso-substituted dibenzotetraaza[14]annulene and its coordination chemistry toward the transition metal ions Mn(III), Fe(III), Co(II), Ni(II), Cu(II), and Pd(II).

Science.gov (United States)

Khaledi, Hamid; Olmstead, Marilyn M; Ali, Hapipah Mohd; Thomas, Noel F

2013-02-18

A new dibenzotetraaza[14]annulene bearing two 3,3-dimethylindolenine fragments at the meso positions (LH(2)), has been synthesized through a nontemplate method. X-ray crystallography shows that the whole molecule is planar. The basicity of the indolenine ring permits the macrocycle to be protonated external to the core and form LH(4)(2+)·2Cl(-). Yet another structural modification having strong C-H···π interactions was found in the chloroform solvate of LH(2). The latter two modifications are accompanied by a degree of nonplanar distortion. The antiaromatic core of the macrocycle can accommodate a number of metal ions, Mn(III), Fe(III), Co(II), Ni(II) and Cu(II), to form complexes of [Mn(L)Br], [Mn(L)Cl], [Fe(LH(2))Cl(2)](+)·Cl(-), [Co(L)], [Ni(L)], and [Cu(L)]. In addition, the reaction of LH(2) with the larger Pd(II) ion leads to the formation of [Pd(2)(LH(2))(2)(OAc)(4)] wherein the macrocycle acts as a semiflexible ditopic ligand to coordinate pairs of metal ions via its indolenine N atoms into dinuclear metallocycles. The compounds LH(2), [Co(L)], and [Ni(L)] are isostructural and feature close π-stacking as well as linear chain arrangements in the case of the metal complexes. Variable temperature magnetic susceptibility measurements showed thermally induced paramagnetism in [Ni(L)].

Adsorption of platinum(IV) and palladium(II) from aqueous solution by thiourea-modified chitosan microspheres

International Nuclear Information System (INIS)

Zhou Limin; Liu Jinhui; Liu Zhirong

2009-01-01

The chitosan microparticles were prepared using the inverse phase emulsion dispersion method and modified with thiourea (TCS). TCS was characterized by scanning electron microscope (SEM), the Fourier transform infrared (FT-IR) spectra, sulfur elemental analysis, specific surface area and pore diameter. The effects of various parameters, such as pH, contact time, initial concentration and temperature, on the adsorption of Pt(IV) and Pd(II) by TCS were investigated. The results showed that the maximum adsorption capacity was found at pH 2.0 for both Pt(IV) and Pd(II). TCS can selectively adsorb Pt(IV) and Pd(II) from binary mixtures with Cu(II), Pb(II), Cd(II), Zn(II), Ca(II), and Mg(II). The adsorption reaction followed the pseudo-second-order kinetics, indicating the main adsorption mechanism of chemical adsorption. The isotherm adsorption equilibrium was well described by Langmuir isotherms with the maximum adsorption capacity of 129.9 mg/g for Pt(IV) and 112.4 mg/g for Pd(II). The adsorption capacity of both Pt(IV) and Pd(II) decreased with temperature increasing. The negative values of enthalpy (ΔH o ) and Gibbs free energy (ΔG o ) indicate that the adsorption process is exothermic and spontaneous in nature. The adsorbent was stable without loss of the adsorption capacity up to at least 5 cycles and the desorption efficiencies were above 95% when 0.5 M EDTA-0.5 M H 2 SO 4 eluent was used. The results also showed that the preconcentration factor for Pt(IV) and Pd(II) was 196 and 172, respectively, and the recovery was found to be more than 97% for both precious metal ions.

Zn(II)- and Cu(II)-induced non-fibrillar aggregates of amyloid-beta (1-42) peptide are transformed to amyloid fibrils, both spontaneously and under the influence of metal chelators.

Science.gov (United States)

Tõugu, Vello; Karafin, Ann; Zovo, Kairit; Chung, Roger S; Howells, Claire; West, Adrian K; Palumaa, Peep

2009-09-01

Aggregation of amyloid-beta (Abeta) peptides is a central phenomenon in Alzheimer's disease. Zn(II) and Cu(II) have profound effects on Abeta aggregation; however, their impact on amyloidogenesis is unclear. Here we show that Zn(II) and Cu(II) inhibit Abeta(42) fibrillization and initiate formation of non-fibrillar Abeta(42) aggregates, and that the inhibitory effect of Zn(II) (IC(50) = 1.8 micromol/L) is three times stronger than that of Cu(II). Medium and high-affinity metal chelators including metallothioneins prevented metal-induced Abeta(42) aggregation. Moreover, their addition to preformed aggregates initiated fast Abeta(42) fibrillization. Upon prolonged incubation the metal-induced aggregates also transformed spontaneously into fibrils, that appear to represent the most stable state of Abeta(42). H13A and H14A mutations in Abeta(42) reduced the inhibitory effect of metal ions, whereas an H6A mutation had no significant impact. We suggest that metal binding by H13 and H14 prevents the formation of a cross-beta core structure within region 10-23 of the amyloid fibril. Cu(II)-Abeta(42) aggregates were neurotoxic to neurons in vitro only in the presence of ascorbate, whereas monomers and Zn(II)-Abeta(42) aggregates were non-toxic. Disturbed metal homeostasis in the vicinity of zinc-enriched neurons might pre-dispose formation of metal-induced Abeta aggregates, subsequent fibrillization of which can lead to amyloid formation. The molecular background underlying metal-chelating therapies for Alzheimer's disease is discussed in this light.

TUGAS DAN FUNGSI PDII-LIPI DARI MASA KE MASA

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Zultanawar Zultanawar

2011-12-01

Full Text Available PDII-LIPI telah berusia 25 tahun pada tanggal 1 Juni 1990 ini.Sudah saatnya perlu ditinjau kembali misi atau tugas dan fungsiPDII-LIPI dalam menunjang keqiatan pembangunan, khususnya kegiatan Iptek, pendidikan dan pengembangan industri. Perlu ditinjau kembali tujuan semula mendirilcan Pusat Dokumentasi Ilmiah Nasional yang sejak tanggal 13 Januari 1986 bernama Pusat Dokumentasi dan Informasi Ilmiah. Perlu dilihat apakah tujuan semula mendirikan PDII-LIPI itu telah tercnpai, apakah telah terjadi penyesuaian- penyesuaian dan apakah tujuan semula itu perlu diubah sesuai dengan perkembangan zaman.

Computer augumented modelling studies of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid in 1,2-propanediol–water mixtures

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MAHESWARA RAO VEGI

2008-12-01

Full Text Available Chemical speciation of Pb(II, Cd(II, Hg(II, Co(II, Ni(II, Cu(II and Zn(II complexes of L-glutamic acid was studied at 303 K in 0–60 vol. % 1,2-propanediol–water mixtures, whereby the ionic strength was maintained at 0.16 mol dm-3. The active forms of the ligand are LH3+, LH2 and LH–. The predominant detected species were ML, ML2, MLH, ML2H and ML2H2. The trend of the variation in the stability constants with changing dielectric constant of the medium is explained based on the cation stabilizing nature of the co-solvents, specific solvent–water interactions, charge dispersion and specific interactions of the co-solvent with the solute. The effect of systematic errors in the concentrations of the substances on the stability constants is in the order alkali > > acid > ligand > metal. The bioavailability and transportation of metals are explained based on distribution diagrams and stability constants.

Palladium and gold removal and recovery from precious metal solutions and electronic scrap leachates by Desulfovibrio desulfuricans.

Science.gov (United States)

Creamer, Neil J; Baxter-Plant, Victoria S; Henderson, John; Potter, M; Macaskie, Lynne E

2006-09-01

Biomass of Desulfovibrio desulfuricans was used to recover Au(III) as Au(0) from test solutions and from waste electronic scrap leachate. Au(0) was precipitated extracellularly by a different mechanism from the biodeposition of Pd(0). The presence of Cu(2+) ( approximately 2000 mg/l) in the leachate inhibited the hydrogenase-mediated removal of Pd(II) but pre-palladisation of the cells in the absence of added Cu(2+) facilitated removal of Pd(II) from the leachate and more than 95% of the Pd(II) was removed autocatalytically from a test solution supplemented with Cu(II) and Pd(II). Metal recovery was demonstrated in a gas-lift electrobioreactor with electrochemically generated hydrogen, followed by precipitation of recovered metal under gravity. A 3-stage bioseparation process for the recovery of Au(III), Pd(II) and Cu(II) is proposed.

Adsorption of copper and zinc by biochars produced from pyrolysis of hardwood and corn straw in aqueous solution.

Science.gov (United States)

Chen, Xincai; Chen, Guangcun; Chen, Linggui; Chen, Yingxu; Lehmann, Johannes; McBride, Murray B; Hay, Anthony G

2011-10-01

Biochars produced by pyrolysis of hardwood at 450 °C (HW450) and corn straw at 600 °C (CS600) were characterized and investigated as adsorbents for the removal of Cu(II) and Zn(II) from aqueous solution. The adsorption data were well described by a Langmuir isotherm, with maximum Cu(II) and Zn(II) adsorption capacities of 12.52 and 11.0 mg/g for CS600, 6.79 and 4.54 mg/g for HW450, respectively. Thermodynamic analysis suggested that the adsorption was an endothermic process and did not occur spontaneously. Although Cu(II) adsorption was only marginally affected by Zn(II), Cu(II) competed with Zn(II) for binding sites at Cu(II) and Zn(II) concentrations ≥ 1.0mM. Results from this study indicated that plant-residue or agricultural waste derived biochar can act as effective surface sorbent, but their ability to treat mixed waste streams needs to be carefully evaluated on an individual basis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Physicochemical properties of 3,4,5-trimethoxybenzoates of Mn(II, Co(II, Ni(II and Zn(II

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W. FERENC

2005-09-01

Full Text Available The complexes of Mn(II, Co(II, Ni(II, Cu(II and Zn(II with 3,4,5-trimethoxybenzoic acid anion of the formula: M(C10H11O52·nH2O, where n = 6 for Ni(II, n = 1 for Mn(II, Co(II, Cu(II, and n = 0 for Zn, have been synthesized and characterized by elemental analysis, IR spectroscopy, X–ray diffraction measurements, thermogravimetry and magnetic studies. They are crystalline compounds characterized by various symmetry. They decompose in various ways when heated in air to 1273 K. At first, they dehydrate in one step and form anhydrous salts. The final products of decomposition are oxides of the respective metals (Mn2O3, Co3O4, NiO, CuO, ZnO. The solubilities of the analysed complexes in water at 293 K are in the orders of 10-2 – 10-4 mol dm-3. The magnetic susceptibilities of the Mn(II, Co(II, Ni(II and Cu(II complexes were measured over the range of 76–303 K and the magnetic moments were calculated. The results show that the 3,4,5-trimethoxybenzoates of Mn(II, Co(II and Ni(II are high-spin complexes but that of Cu(II forms a dimer [Cu2(C10H11O54(H2O2]. The carboxylate groups bind as monodentate or bidentate chelating or bridging ligands.

Batch adsorptive removal of Fe(III, Cu(II and Zn(II ions in aqueous and aqueous organic–HCl media by Dowex HYRW2-Na Polisher resin as adsorbents

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Abdul-Aleem Soliman Aboul-Magd

2016-09-01

Full Text Available Of the metal ions in tap, Nile, waste and sea water samples and some ores were carried out. Removal of heavy metal ions such as Fe(III, Cd(II, Zn(II, Cu(II, Mn(II, Mg(II, and Pb(II from water and wastewater is obligatory in order to avoid water pollution. Batch shaking adsorption experiments to evaluate the performance of nitric and hydrochloric acid solutions in the removal of metal ions by cation exchange resin at the same conditions for both, such as the effect of initial metal ion concentration, different proportions of some organic solvents, H+-ion concentrations and reaction temperature on the partition coefficients. The metal adsorption for the cation exchanger was found to be significant in different media for both nitric and hydrochloric acids, i.e., the adsorption up take of metal ions presented in this work is very significant depending on the characteristics of ions and on the external concentrations of solute. The presence of low ionic strength or low concentration of acids does have a significant adsorption of metal ions on ion-exchange resin. The results show that the ion exchanger could be employed for the preconcentration, separation and the determination.

Desain Topologi Jaringan Kabel Nirkabel PDII-LIPI dengan Cisco Three-Layered Hierarchical menggunakan NDLC

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MUHAMMAD TEGUH KURNIAWAN

2016-02-01

Full Text Available ABSTRAK Saat ini Teknologi Informasi (TI merupakan salah satu hal yang penting dalam suatu perusahaan. Dalam penerapan TI diperlukan infrastruktur jaringan yang dapat mendukung pertukaran informasi baik melalui intranet mauapun internet yang diakses melalui kabel maupun nirkabel. Salah satu pendukung Infrastruktur jaringan adalah topologi jaringan yang handal.  PDII-LIPI (Pusat Dokumentasi dan Informasi Ilmiah - Lembaga Ilmu Pengetahuan Indonesia Jakarta merupakan lembaga di bawah LIPI yang berfokus pada tiga kegiatan yaitu  jasa  dokumentasi,  jasa  informasi, pembinaan dan pengembangan bidang dokumentasi informasi. Untuk mendukung proses bisnis berbasis TI di PDII-LIPI diperlukan infrastruktur jaringan yang memadai. Oleh karena itu, pada penelitian ini dilakukan perancangan infrastruktur jaringan kabel dan nirkabel di PDII-LIPI dengan menggunakan metode Network Development Life Cycle (NDLC. Metode ini berguna dalam mengembangkan infrastruktur jaringan kabel dan nirkabel dan dapat memantau kinerja jaringan. Dengan penelitian ini diharapkan dapat membantu PDII-LIPI dalam membangun, dan mengembangkan infrastruktur jaringan kabel dan nirkabel agar lebih optimal dalam mendukung proses bisnis yang ada. Kata Kunci: topologi jaringan, kabel, nirkabel, NDLC, PDII-LIPI. ABSTRACT Information Technology (IT has significant influence to a company. The robust network IT infrastructure should be installed earlier, supporting the information exchange through internet or intranet and it also should be easily accessible via wired or wireless network.  PDII-LIPI (Pusat Dokumentasi dan Informasi Ilmiah - Lembaga Ilmu Pengetahuan Indonesia Jakarta is an organization under LIPI which focuses on three processes for instance the documentation services, the  information services and the development of  documentation services. PDII-LIPI has already used IT to support those businesses so they must carefully choose the best network IT infrastructure. To

Desain Topologi Jaringan Kabel Nirkabel PDII-LIPI dengan Cisco Three-Layered Hierarchical menggunakan NDLC

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MUHAMMAD TEGUH KURNIAWAN

2016-01-01

Full Text Available ABSTRAK Saat ini Teknologi Informasi (TI merupakan salah satu hal yang penting dalam suatu perusahaan. Dalam penerapan TI diperlukan infrastruktur jaringan yang dapat mendukung pertukaran informasi baik melalui intranet mauapun internet yang diakses melalui kabel maupun nirkabel. Salah satu pendukung Infrastruktur jaringan adalah topologi jaringan yang handal.  PDII-LIPI (Pusat Dokumentasi dan Informasi Ilmiah - Lembaga Ilmu Pengetahuan Indonesia Jakarta merupakan lembaga di bawah LIPI yang berfokus pada tiga kegiatan yaitu  jasa  dokumentasi,  jasa  informasi, pembinaan dan pengembangan bidang dokumentasi informasi. Untuk mendukung proses bisnis berbasis TI di PDII-LIPI diperlukan infrastruktur jaringan yang memadai. Oleh karena itu, pada penelitian ini dilakukan perancangan infrastruktur jaringan kabel dan nirkabel di PDII-LIPI dengan menggunakan metode Network Development Life Cycle (NDLC. Metode ini berguna dalam mengembangkan infrastruktur jaringan kabel dan nirkabel dan dapat memantau kinerja jaringan. Dengan penelitian ini diharapkan dapat membantu PDII-LIPI dalam membangun, dan mengembangkan infrastruktur jaringan kabel dan nirkabel agar lebih optimal dalam mendukung proses bisnis yang ada. Kata Kunci: topologi jaringan, kabel, nirkabel, NDLC, PDII-LIPI.   ABSTRACT Information Technology (IT has significant influence to a company. The robust network IT infrastructure should be installed earlier, supporting the information exchange through internet or intranet and it also should be easily accessible via wired or wireless network.  PDII-LIPI (Pusat Dokumentasi dan Informasi Ilmiah - Lembaga Ilmu Pengetahuan Indonesia Jakarta is an organization under LIPI which focuses on three processes for instance the documentation services, the  information services and the development of  documentation services. PDII-LIPI has already used IT to support those businesses so they must carefully choose the best network IT infrastructure. To

ANALISIS TINGKAT KEMATANGAN PENYEDIAAN TATA KELOLA TEKNOLOGI INFORMASI DI PDII LIPI MENGGUNAKAN FRAMEWORK COBIT 4.1

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Rima Octavia

2014-12-01

Full Text Available Centre for Scientific Documentation and Information – Indonesian Institute of Science (PDII LIPI began to developbusiness objectives towards a digital library. To support this goal should be held IT governance while PDII LIPI hasno specific IT governance. This research aims to study the condition of the IT management and determine the levelof maturity of the provision of IT governance framework based on COBIT 4.1. COBIT is one of the internationalstandard for IT governance. COBIT is used in this study were able to measure the COBIT 4.1 for organizations thatdo not use IT governance. Analysis of the level of maturity of the provision of IT governance is based on aquestionnaire that is processed by the COBIT 4.1 framework and compared with the actual conditions in the ITmanagement in PDII LIPI. The results of the calculation of the maturity level of to provided IT governance in PDIILIPI based on framework COBIT 4.1 shows that PDII-LIPI already at level 3 (Defined Process. This is consistent withthe actual conditions in PDII-LIPI. COBIT 4.1 is considered quite capable, reliable and easy to implement in PDII LIPI. 

Neuroprotective Effects and Mechanisms of Curcumin-Cu(II) and -Zn(II) Complexes Systems and Their Pharmacological Implications.

Science.gov (United States)

Yan, Fa-Shun; Sun, Jian-Long; Xie, Wen-Hai; Shen, Liang; Ji, Hong-Fang

2017-12-28

Alzheimer's disease (AD) is the main form of dementia and has a steadily increasing prevalence. As both oxidative stress and metal homeostasis are involved in the pathogenesis of AD, it would be interesting to develop a dual function agent, targeting the two factors. Curcumin, a natural compound isolated from the rhizome of Curcuma longa , is an antioxidant and can also chelate metal ions. Whether the complexes of curcumin with metal ions possess neuroprotective effects has not been evaluated. Therefore, the present study was designed to investigate the protective effects of the complexes of curcumin with Cu(II) or Zn(II) on hydrogen peroxide (H₂O₂)-induced injury and the underlying molecular mechanisms. The use of rat pheochromocytoma (PC12) cells, a widely used neuronal cell model system, was adopted. It was revealed that curcumin-Cu(II) complexes systems possessed enhanced O₂ ·- -scavenging activities compared to unchelated curcumin. In comparison with unchelated curcumin, the protective effects of curcumin-Cu(II) complexes systems were stronger than curcumin-Zn(II) system. Curcumin-Cu(II) or -Zn(II) complexes systems significantly enhanced the superoxide dismutase, catalase, and glutathione peroxidase activities and attenuated the increase of malondialdehyde levels and caspase-3 and caspase-9 activities, in a dose-dependent manner. The curcumin-Cu(II) complex system with a 2:1 ratio exhibited the most significant effect. Further mechanistic study demonstrated that curcumin-Cu(II) or -Zn(II) complexes systems inhibited cell apoptosis via downregulating the nuclear factor κB (NF-κB) pathway and upregulating Bcl-2/Bax pathway. In summary, the present study found that curcumin-Cu(II) or -Zn(II) complexes systems, especially the former, possess significant neuroprotective effects, which indicates the potential advantage of curcumin as a promising agent against AD and deserves further study.

Highly selective solid-phase extraction of trace Pd(II) by murexide functionalized halloysite nanotubes

Energy Technology Data Exchange (ETDEWEB)

Li Ruijun; He Qun; Hu Zheng; Zhang Shengrui [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China); Zhang Lijun [Faculty of Science and Engineer, Curtin University, Perth, WA 6845 (Australia); Chang Xijun, E-mail: lirj2010@lzu.edu.cn [Department of Chemistry, Lanzhou University, Lanzhou 730000 (China); Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000 (China)

2012-02-03

Graphical abstract: Murexide functionalized halloysite nanotubes have been developed to separate and concentrate trace Pd(II) from aqueous samples. Parameters that affected the sorption and elution efficiency were studied in column mode, and the new adsorbent presented high selectivity and adsorption capacity for the solid phase extraction of trace Pd(II). Highlights: Black-Right-Pointing-Pointer Murexide modified halloysite nanotubes as adsorbent has been reported originally. Black-Right-Pointing-Pointer This adsorbent has a unique selectivity for Pd(II) at pH 1.0. Black-Right-Pointing-Pointer This adsorbent had high adsorption capacity for Pd(II). Black-Right-Pointing-Pointer The precision and accuracy of the method are satisfactory. - Abstract: The originality on the high efficiency of murexide modified halloysite nanotubes as a new adsorbent of solid phase extraction has been reported to preconcentrate and separate Pd(II) in solution samples. The new adsorbent was confirmed by Fourier transformed infrared spectra, X-ray diffraction, scanning electron microscope, transmission electron microscope and N{sub 2} adsorption-desorption isotherms. Effective preconcentration conditions of analyte were examined using column procedures prior to detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The effects of pH, the amount of adsorbent, the sample flow rate and volume, the elution condition and the interfering ions were optimized in detail. Under the optimized conditions, Pd(II) could be retained on the column at pH 1.0 and quantitatively eluted by 2.5 mL of 0.01 mol L{sup -1} HCl-3% thiourea solution at a flow rate of 2.0 mL min{sup -1}. The analysis time was 5 min. An enrichment factor of 120 was accomplished. Common interfering ions did not interfere in both separation and determination. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 42.86 mg g{sup -1} for Pd(II). The detection limit (3{sigma}) of

Highly selective solid-phase extraction of trace Pd(II) by murexide functionalized halloysite nanotubes

International Nuclear Information System (INIS)

Li Ruijun; He Qun; Hu Zheng; Zhang Shengrui; Zhang Lijun; Chang Xijun

2012-01-01

Graphical abstract: Murexide functionalized halloysite nanotubes have been developed to separate and concentrate trace Pd(II) from aqueous samples. Parameters that affected the sorption and elution efficiency were studied in column mode, and the new adsorbent presented high selectivity and adsorption capacity for the solid phase extraction of trace Pd(II). Highlights: ► Murexide modified halloysite nanotubes as adsorbent has been reported originally. ► This adsorbent has a unique selectivity for Pd(II) at pH 1.0. ► This adsorbent had high adsorption capacity for Pd(II). ► The precision and accuracy of the method are satisfactory. - Abstract: The originality on the high efficiency of murexide modified halloysite nanotubes as a new adsorbent of solid phase extraction has been reported to preconcentrate and separate Pd(II) in solution samples. The new adsorbent was confirmed by Fourier transformed infrared spectra, X-ray diffraction, scanning electron microscope, transmission electron microscope and N 2 adsorption–desorption isotherms. Effective preconcentration conditions of analyte were examined using column procedures prior to detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The effects of pH, the amount of adsorbent, the sample flow rate and volume, the elution condition and the interfering ions were optimized in detail. Under the optimized conditions, Pd(II) could be retained on the column at pH 1.0 and quantitatively eluted by 2.5 mL of 0.01 mol L −1 HCl–3% thiourea solution at a flow rate of 2.0 mL min −1 . The analysis time was 5 min. An enrichment factor of 120 was accomplished. Common interfering ions did not interfere in both separation and determination. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 42.86 mg g −1 for Pd(II). The detection limit (3σ) of the method was 0.29 ng mL −1 , and the relative standard deviation (RSD) was 3.1% (n = 11). The method was

Synthesis, spectral characterization, theoretical, antimicrobial, DNA interaction and in vitro anticancer studies of Cu(II and Zn(II complexes with pyrimidine-morpholine based Schiff base ligand

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M. Sankarganesh

2018-05-01

Full Text Available Novel Cu(II (1 and Zn(II (2 complexes with 4-(1-(4-morpholinophenylethylideneaminopyrimidine-5-carbonitrile (L have been synthesized and characterized by various spectroscopic and analytical techniques. DFT (density functional theory studies result confirms that, LMCT mechanism have been done between L and M(II ions. The antimicrobial studies indicate that the ligand L and complexes 1 & 2 exhibit higher activity against the E. coli bacteria and C. albicans fungi. The groove binding mode of ligand L and complexes 1 & 2 with CT-DNA have been confirmed by electronic absorption, competitive binding, viscometric and cyclic voltammetric studies. The electronic absorption titration of ligand L and complexes 1 & 2 with DNA have been carried out in different buffer solutions (pH 4.0, 7.0 & 10.0. The Kb values of ligand L and complexes 1 & 2 are higher in acidic buffer at pH 4.0 (Kb = 2.42 × 105, L; 2.8 × 105, 1; 2.65 × 105, 2 and the results revealed that, the interaction of synthesized compounds with DNA were higher in the acidic medium than basic and neutral medium. Furthermore, CT-DNA cleavage studies of ligand L and complexes 1 & 2 have been studied. The in vitro anticancer activities results show that complexes 1 & 2 have moderate cytotoxicity against cancer cell lines and low toxicity on normal cell line than ligand L. Keywords: Pyrimidine, Morpholine, DFT, Antimicrobial, DNA binding, Anticancer studies

Syntheses, spectroscopic and thermal analyses of cyanide bridged heteronuclear polymeric complexes: [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine or N-ethylethylenediamine; Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II))

Science.gov (United States)

Karaağaç, Dursun; Kürkçüoğlu, Güneş Süheyla

2016-02-01

Polymeric tetracyanonickelate(II) complexes of the type [M(L)2Ni(CN)4]n (Ldbnd N-methylethylenediamine (men) or N-ethylethylenediamine (neen); Mdbnd Ni(II), Cu(II), Zn(II) or Cd(II)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal and elemental analysis techniques. Additionally, FT-IR and Raman spectral analyses of men and neen have experimentally and theoretically investigated in the range of 4000-250 cm-1. The corresponding vibration assignments of men and neen are performed by using B3LYP density functional theory (DFT) method together with 6-31 G(d) basis set. The spectral features of the complexes suggest that the coordination environment of the M(II) ions are surrounded by the two symmetry related men and neen ligands and the two symmetry related N atom of cyanide groups, whereas the Ni(II) atoms are coordinated with a square-planar to four C atoms of the cyanide groups. Polymeric structures of the complexes consist of one dimensional alternative chains of [M(L)2]2+ and [Ni(CN)4]2- moieties. The thermal decompositions in the temperature range 30-700 °C of the complexes were investigated in the static air atmosphere.

Competition from Cu(II), Zn(II) and Cd(II) in Pb(II) binding to Suwannee River Fulvic Acid

NARCIS (Netherlands)

Chakraborty, P.; Chakrabarti, C.L.

2008-01-01

This is a study of trace metal competition in the complexation of Pb(II) by well-characterized humic substances, namely Suwannee River Fulvic Acid (SRFA) in model solutions. It was found that Cu(II) seems to compete with Pb(II) for strong binding sites of SRFA when present at the same concentration

Selective recovery of Pd(II) from extremely acidic solution using ion-imprinted chitosan fiber: Adsorption performance and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Lin, Shuo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wei, Wei [School of Chemical Engineering, Chonbuk National University, Jeonbuk 561-756 (Korea, Republic of); Wu, Xiaohui; Zhou, Tao [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Mao, Juan, E-mail: monicamao45@hust.edu.cn [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yun, Yeoung-Sang, E-mail: ysyun@jbnu.ac.kr [School of Chemical Engineering, Chonbuk National University, Jeonbuk 561-756 (Korea, Republic of)

2015-12-15

Highlights: • An acid-resisting chitosan fiber was prepared by ion-imprinting technique. • Pd(II) and ECH were as template and two-step crosslinking agent, respectively. • IIF showed a good adsorption and selectivity performance on Pd(II) solutions. • Selectivity was due to the electrostatic attraction between −NH{sub 3}{sup +} and [PdCl{sub 4}]{sup 2−}. • Stable sorption/desorption performance shows a potential in further application. - Abstract: A novel, selective and acid-resisting chitosan fiber adsorbent was prepared by the ion-imprinting technique using Pd(II) and epichlorohydrin as the template and two-step crosslinking agent, respectively. The resulting ion-imprinted chitosan fibers (IIF) were used to selectively adsorb Pd(II) under extremely acidic synthetic metal solutions. The adsorption and selectivity performances of IIF including kinetics, isotherms, pH effects, and regeneration were investigated. Pd(II) rapidly adsorbed on the IIF within 100 min, achieving the adsorption equilibrium. The isotherm results showed that the maximum Pd(II) uptake on the IIF was maintained as 324.6–326.4 mg g{sup −1} in solutions containing single and multiple metals, whereas the Pd(II) uptake on non-imprinted fibers (NIF) decreased from 313.7 to 235.3 mg g{sup −1} in solution containing multiple metals. Higher selectivity coefficients values were obtained from the adsorption on the IIF, indicating a better Pd(II) selectivity. The amine group, supposedly the predominant adsorption site for Pd(II), was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The pH value played a significant role on the mechanism of the selective adsorption in the extremely acidic conditions. Furthermore, the stabilized performance for three cycles of sorption/desorption shows a potential for further large-scale applications.

Selective recovery of Pd(II) from extremely acidic solution using ion-imprinted chitosan fiber: Adsorption performance and mechanisms

International Nuclear Information System (INIS)

Lin, Shuo; Wei, Wei; Wu, Xiaohui; Zhou, Tao; Mao, Juan; Yun, Yeoung-Sang

2015-01-01

Highlights: • An acid-resisting chitosan fiber was prepared by ion-imprinting technique. • Pd(II) and ECH were as template and two-step crosslinking agent, respectively. • IIF showed a good adsorption and selectivity performance on Pd(II) solutions. • Selectivity was due to the electrostatic attraction between −NH_3"+ and [PdCl_4]"2"−. • Stable sorption/desorption performance shows a potential in further application. - Abstract: A novel, selective and acid-resisting chitosan fiber adsorbent was prepared by the ion-imprinting technique using Pd(II) and epichlorohydrin as the template and two-step crosslinking agent, respectively. The resulting ion-imprinted chitosan fibers (IIF) were used to selectively adsorb Pd(II) under extremely acidic synthetic metal solutions. The adsorption and selectivity performances of IIF including kinetics, isotherms, pH effects, and regeneration were investigated. Pd(II) rapidly adsorbed on the IIF within 100 min, achieving the adsorption equilibrium. The isotherm results showed that the maximum Pd(II) uptake on the IIF was maintained as 324.6–326.4 mg g"−"1 in solutions containing single and multiple metals, whereas the Pd(II) uptake on non-imprinted fibers (NIF) decreased from 313.7 to 235.3 mg g"−"1 in solution containing multiple metals. Higher selectivity coefficients values were obtained from the adsorption on the IIF, indicating a better Pd(II) selectivity. The amine group, supposedly the predominant adsorption site for Pd(II), was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The pH value played a significant role on the mechanism of the selective adsorption in the extremely acidic conditions. Furthermore, the stabilized performance for three cycles of sorption/desorption shows a potential for further large-scale applications.

Cr(III,Mn(II,Fe(III,Co(II,Ni(II,Cu(II and Zn(II Complexes with Diisobutyldithiocarbamato Ligand

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Mohammad Tarique

2011-01-01

Full Text Available The synthesis of sulphur and nitrogen containing dithiocarbamato ligand derived from diisobutylamine as well as its coordination compounds with 3d series transition metals is presented. These synthesized compounds were characterized on the basis of elemental analysis, conductometric measurements and IR spectral studies. The analytical data showed the stoichiometry 1:2 and 1:3 for the compounds of the types ML2 {M=Mn(II, Co(II, Ni(II, Cu(II and Zn(II} and M'L3{M'=Cr(III and Fe(III} respectively. The conductometric measurements proved the non-electrolytic behaviour of all the compounds. The bidentate nature of dithiocarbamato moiety was confirmed on the basis of IR spectral data.

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

We report here the synthesis and characterization of a few phenolate-based ligands bearing tertamino substituent and their Zn(II) and Cu(II) metal complexes. Three mono/binuclear Zn(II) and Cu(II) complexes [Zn(L1)(H2O)].CH3OH.H2O (1) (H2 L1 = 6,6′-(((2-dimethylamino)ethylazanediyl)bis(methylene))bis(2, ...

The use of a polymer inclusion membrane in a paper-based sensor for the selective determination of Cu(II).

Science.gov (United States)

Jayawardane, B Manori; Coo, Lilibeth dlC; Cattrall, Robert W; Kolev, Spas D

2013-11-25

A disposable paper-based sensor (PBS) is described for the determination of Cu(II) in natural and waste waters at approximately 2 cents per measurement. The device makes use of a polymer inclusion membrane (PIM) to provide the selectivity for Cu(II). The PIM consists of 40 wt% di(2-ethlyhexyl) phosphoric acid (D2EHPA) as the carrier, 10 wt% dioctyl phthalate (DOP) as a plasticizer, 49.5 wt% poly(vinyl chloride) (PVC) as the base polymer and 0.5 wt% (mm(-1)) 1-(2'-pyridylazo)-2-naphthol (PAN) as the colourimetric reagent. High selectivity under mildly acidic conditions (HCl, pH 2.0) is achieved for Cu(II) in the presence of frequently encountered metal ions in natural and waste waters such as Fe(III), Al(III), Zn(II), Cd(II), Pb(II), Ca(II), Mg(II), and Ni(II). The laminated PBS consists of a PIM sensing disc (2mm in diameter) attached to the centre of a circular hydrophilic zone (7 mm in diameter) pretreated with 0.01 M HCl. This hydrophilic zone separates the sample port (a circular hole in the plastic cover) from the PIM sensing disc. After introducing 19.2 μL of a sample/standard solution to the sample port, Cu(II) diffuses across the hydrophilic zone and is extracted into the PIM disc as the Cu(II)-D2EHPA complex which subsequently reacts with PAN to produce the red-purple coloured Cu(II)-PAN complex. The colour intensity of the PIM disc is measured 15 min after sample/standard introduction by scanning using a flatbed scanner. Under optimal conditions the device is characterized by a limit of detection (LOD) and limit of quantitation (LOQ) of 0.06 and 0.21 mg L(-1) Cu(II), respectively, with two linear ranges together covering the Cu(II) concentration range from 0.1 to 30.0 mg L(-1). The PBS was successfully applied to the determination of Cu(II) in hot tap water and mine tailings water. Copyright © 2013 Elsevier B.V. All rights reserved.

KEMAS ULANG INFORMASI UNTUK PEMENUHAN KEBUTUHAN INFORMASI USAHA KECIL MENENGAH: TINJAUAN ANALISIS DI PDII-LIPI

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Tupan Tupan

2016-03-01

Full Text Available This purposed of study to determine: 1 the types of information packaging products; 2 the process of information repackaging; and 3 the complied effort to the user information needs of smart scale enterprises (UKM through PDII-LIPI information packs. Data of this study is a descriptive. Data collected by a discussion with the users or subscribers of information repackaging products of PDII-LIPI. The collected data are then be identified, analyzed, and interpreted the results and discussion chapter. The results of this study are known: 1 the types of information repackaging products of PDII-LIPI, namely: paket informasi teknologi, informasi kilat, pohon industri, panduan usaha, tinjauan literatur, fokus informasi indonesia, dan film animasi; 2 the process of making the package of information repackaging PDII-LIPI, namely the determination of topics, literature searching, analysis of the literature, making the design/template, duplication of information packing, and report generation; and 3 the efforts of institutions to complied the information needs of UKM through the product of information repackaging, namely: promotion, identification of needs, choosing the sources of information, product offerings, product evaluation utilization, and create innovative policies. In principle that the packaging of the information provided and created by PDII-LIPI had oriented by information needs of users, in particular to meet the UKM information needs.

A Method for Selective Depletion of Zn(II) Ions from Complex Biological Media and Evaluation of Cellular Consequences of Zn(II) Deficiency

Science.gov (United States)

Richardson, Christopher E. R.; Cunden, Lisa S.; Butty, Vincent L.; Nolan, Elizabeth M.; Lippard, Stephen J.; Shoulders, Matthew D.

2018-01-01

We describe the preparation, evaluation, and application of an S100A12 protein-conjugated solid support, hereafter the “A12-resin,” that can remove 99% of Zn(II) from complex biological solutions without significantly perturbing the concentrations of other metal ions. The A12-resin can be applied to selectively deplete Zn(II) from diverse tissue culture media and from other biological fluids, including human serum. To further demonstrate the utility of this approach, we investigated metabolic, transcriptomic, and metallomic responses of HEK293 cells cultured in medium depleted of Zn(II) using S100A12. The resulting data provide insight into how cells respond to acute Zn(II) deficiency. We expect that the A12-resin will facilitate interrogation of disrupted Zn(II) homeostasis in biological settings, uncovering novel roles for Zn(II) in biology. PMID:29334734

Extraction behaviour and mechanism of Pt(iv) and Pd(ii) by liquid-liquid extraction with an ionic liquid [HBBIm]Br.

Science.gov (United States)

Liu, Wenhui; Wang, Qi; Zheng, Yan; Wang, Shubin; Yan, Yan; Yang, Yanzhao

2017-06-06

In this study, a method of one-step separation and recycling of high purity Pd(ii) and Pt(iv) using an ionic liquid, 1-butyl-3-benzimidazolium bromate ([HBBIm]Br), was investigated. The effects of [HBBIm]Br concentration, initial metal concentration, and loading capacity of [HBBIm]Br were examined in detail. It was observed that [HBBIm]Br was a very effective extractant for selectively extracting Pd(ii) and precipitating Pt(iv). Through selectively extracting Pd(ii) and precipitating Pt(iv), each metal with high purity was separately obtained from mixed Pd(ii) and Pt(iv) multi-metal solution. The method of one-step separation of Pd(ii) and Pt(iv) is simple and convenient. The anion exchange mechanism between [HBBIm]Br and Pt(iv) was proven through Job's method and FTIR and 1 H NMR spectroscopies. The coordination mechanism between [HBBIm]Br and Pd(ii) was demonstrated via single X-ray diffraction and was found to be robust and distinct, as supported by the ab initio quantum-chemical studies. The crystals of the [PdBr 2 ·2BBIm] complex were formed first. Moreover, the influence of the concentrations of hydrochloric acid, sodium chloride, and sodium nitrate on the precipitation of Pt(iv) and extraction of Pd(ii) was studied herein. It was found that only the concentration of H + could inhibit the separation of Pt(iv) because H + could attract the anion PtCl 6 2- ; thus, the exchange (anion exchange mechanism) between the anions PtCl 6 2- and Br - was prevented. However, both the concentration of H + and Cl - can obviously inhibit the extraction of Pd(ii) because H + and Cl - are the reaction products and increasing their concentration can inhibit the progress of the reaction (coordination mechanism).

The use of new modified poly(acrylamide chelating resin with pendent benzothiazole groups containing donor atoms in the removal of heavy metal ions from aqueous solutions

Directory of Open Access Journals (Sweden)

Semmedu Selvaraj Kalaivani

2014-03-01

Full Text Available The adsorption studies of poly(6-(ethoxybenzothiazole acrylamide (PEBTA, for Cu(II and Zn(II metal ions removal from an aqueous solution have been investigated, as a function of solution pH, adsorbent dose, contact time, initial metal ion concentration and temperature. The chemical and structural characteristics of the adsorbent were determined by the FT-IR, 1H-NMR, TGA, SEM, and EDAX analysis. The maximum adsorption capacities of the adsorbent for Cu(II and Zn(II ions, as calculated from the Langmuir isotherm model, were 273.5 and 216.4 mg/g, respectively. The adsorption kinetic studies show that the adsorption of Cu(II and Zn(II ions onto PEBTA follows the pseudo second order kinetic model. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were also evaluated, and it has been found that the adsorption process is feasible, spontaneous and exothermic in nature. Desorption studies were carried out using 0.3 N HCl, and it revealed that the adsorbed Cu(II and Zn(II ions can be easily removed. The adsorption–desorption process is reversible, and this indicates that PEBTA is an effective adsorbent for the removal of heavy metal ions from an aqueous medium.

Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

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Tshabalala, M. A.

2007-02-01

Full Text Available Bark flour from ponderosa pine (Pinus ponderosa was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(II, Zn(II, Cd(II, and Ni(II under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(II and Zn(II showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(II data best fit the Freundlich isotherm, and the Ni(II data fitted both Freundlich and Langmuir isotherms equally. According to the Freundlich constant KF, adsorption capacity of pelletized bark for the metal ions in aqueous solution, pH 5.1 ± 0.2, followed the order Cd(II > Cu(II > Zn(II >> Ni(II; according to the Langmuir constant b, adsorption affinity followed the order Cd(II >> Cu(II ≈ Zn(II >> Ni(II. Although data from dynamic column adsorption experiments did not show a good fit to the Thomas kinetic adsorption model, estimates of sorption affinity series of the metal ions on pelletized bark derived from this model were not consistent with the series derived from the Langmuir or Freundlich isotherms and followed the order Cu(II > Zn(II ≈ Cd(II > Ni(II. According to the Thomas kinetic model, the theoretical maximum amounts of metal that can be sorbed on the pelletized bark in a column at influent concentration of ≈10 mg/L and flow rate = 5 mL/min were estimated to be 57, 53, 50, and 27 mg/g for copper, zinc, cadmium, and nickel, respectively. This study demonstrated the potential for converting low-cost bark residues to value-added sorbents using starting materials and chemicals derived from renewable resources. These sorbents can be applied in the removal of toxic heavy metals from waste streams with heavy metal ion concentrations of up to 100 mg/L in the case of Cu(II.

Radiochemical separation and their application to neutron activation analysis technique

International Nuclear Information System (INIS)

Turel, Z.R.

2013-01-01

The present paper discusses the development of some new, rapid and selective method for the radiochemical separation and estimation of elements such as, Co(II) 2-3 , Ir(III) 4 , Au(III) 5 , Pt(IV), Pd(II), Os(IV) 6 , Cu(II), Ag(I), Mo(VI), Ni(II), Zn(II), Cd(II), Hg(II), Cs(I), Sb(III), La(III), Sc(III) etc. using various reagents. Various parameters such as pH, time of equilibrium, effect of anions and cations, effect of reagent etc. has been determined employing tracers of the elements under consideration and will be discussed. The method is made highly selective by the use of appropriate masking agent. The stoichiometry of metal reagent is determined by the substoichiometric method. Some examples of multielemental radiochemical separation methods thus developed which have been applied in determining the elements by radiochemical thermal neutron activation analysis will be presented and discussed. The implications of the results on the reference system will also be accounted. Statistical evaluation with reference to accuracy, precision and sensitivity will also be presented

Removal of bisphenol A and some heavy metal ions by polydivinylbenzene magnetic latex particles.

Science.gov (United States)

Marzougui, Zied; Chaabouni, Amel; Elleuch, Boubaker; Elaissari, Abdelhamid

2016-08-01

In this study, magnetic polydivinylbenzene latex particles MPDVB with a core-shell structure were tested for the removal of bisphenol A (BPA), copper Cu(II), lead Pb(II), and zinc Zn(II) from aqueous solutions by a batch-adsorption technique. The effect of different parameters, such as initial concentration of pollutant, contact time, adsorbent dose, and initial pH solution on the adsorption of the different adsorbates considered was investigated. The adsorption of BPA, Cu(II), Pb(II), and Zn(II) was found to be fast, and the equilibrium was achieved within 30 min. The pH 5-5.5 was found to be the most suitable pH for metal removal. The presence of electrolytes and their increasing concentration reduced the metal adsorption capacity of the adsorbent. Whereas, the optimal pH for BPA adsorption was found 7, both hydrogen bonds and π-π interaction were thought responsible for the adsorption of BPA on MPDVB. The adsorption kinetics of BPA, Cu(II), Pb(II), and Zn(II) were found to follow a pseudo-second-order kinetic model. Equilibrium data for BPA, Cu(II), Pb(II), and Zn(II) adsorption were fitted well by the Langmuir isotherm model. Furthermore, the desorption and regeneration studies have proven that MPDVB can be employed repeatedly without impacting its adsorption capacity.

Cu(II), Zn(II)

African Journals Online (AJOL)

the kinetic parameters as order of decomposition reaction, activation energy and ..... Cu as anode material, K - alpha [Å] = 1.54060 and the generator settings 30 .... Calculated quantum chemical parameters for ligand and its metal complexes.

PENGUJIAN COGNITIVE WALKTHROUGH ANTARMUKA PERPUSTAKAAN DIGITAL (E-LIBRARY PUSAT DOKUMENTASI DAN INFORMASI ILMIAH – LIPI (PDII-LIPI

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Ira Maryati

2014-06-01

Full Text Available Interface design has a significant role towards the successful of digital librarys application use. Digital libraryservices developed by Centre for Scientific Documentation and Information - Indonesian Institute of Sciences (PDII-LIPI has yet to be evaluated. This research analyzed the design of the web interface of PDII-LIPI’s digitallibraries using the method of cognitive walkthrough (CW. The aim of the research is to identify user constraints inusing PDII-LIPI’s digital libraries. Object of this study are three menus in digital library web interface that is “KaryaIlmiah Indonesia”, “Buku Elektronik”, and “Jurnal Indonesia (ISJD”. CW testing parameters for PDII-LIPI’s digitallibrary interface consists of the successful completion of the task, and the effectiveness of the task. The successfulcompletion of the task was assessed by comparing the standard time with task completion time by respondents. Effectiveness accessed based on the processing time of each stage and the number of mistakes made by therespondent. The test results showed that all respondents successfully completed the task with the time that goesbeyond the standard set time. The analysis was conducted on all test results indicate that the obstacles faced byusers in general are finding menu of “E-Library”, specify the search facility is used, and searching the articles.

Chitosan/sporopollenin microcapsules: preparation, characterisation and application in heavy metal removal.

Science.gov (United States)

Sargın, İdris; Arslan, Gulsin

2015-04-01

Use of natural polymers as biosorbents for heavy metal removal is advantageous. This paper reports a study aiming to design a novel biosorbent from two biomacromolecules; chitosan, a versatile derivative of chitin, and sporopollenin, a biopolymer with excellent mechanical properties and great resistance to chemical and biological attack. Chitosan/sporopollenin microcapsules were prepared via cross-linking and characterised by employing scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. Sorption performance of the microcapsules and the plain chitosan beads were tested for Cu(II), Cd(II), Cr(III), Ni(II) and Zn(II) ions at different metal ion concentration, pH, amount of sorbent, temperature and sorption time. The adsorption pattern followed Langmuir isotherm model and the sorption capacity of the chitosan/sporopollenin microcapsules was found to be Cu(II): 1.34, Cd(II): 0.77, Cr(III): 0.99, Ni(II): 0.58 and Zn(II): 0.71 mmol g(-1). Plain chitosan beads showed higher affinity for the ions; Cu(II): 1.46, Cr(III): 1.16 and Ni(II): 0.81 mmol g(-1) but lower for Cd(II): 0.15 and Zn(II): 0.25 mmol g(-1). Sporopollenin enhanced Cd(II) and Zn(II) ions sorption capacity of the chitosan microcapsules. Chitosan/sporopollenin microcapsules can be used in Cd(II) and Zn(II) metal removal. Copyright © 2015 Elsevier B.V. All rights reserved.

Mercerized mesoporous date pit activated carbon-A novel adsorbent to sequester potentially toxic divalent heavy metals from water.

Science.gov (United States)

Aldawsari, Abdullah; Khan, Moonis Ali; Hameed, B H; Alqadami, Ayoub Abdullah; Siddiqui, Masoom Raza; Alothman, Zeid Abdullah; Ahmed, A Yacine Badjah Hadj

2017-01-01

A substantive approach converting waste date pits to mercerized mesoporous date pit activated carbon (DPAC) and utilizing it in the removal of Cd(II), Cu(II), Pb(II), and Zn(II) was reported. In general, rapid heavy metals adsorption kinetics for Co range: 25-100 mg/L was observed, accomplishing 77-97% adsorption within 15 min, finally, attaining equilibrium in 360 min. Linear and non-linear isotherm studies revealed Langmuir model applicability for Cd(II) and Pb(II) adsorption, while Freundlich model was fitted to Zn(II) and Cu(II) adsorption. Maximum monolayer adsorption capacities (qm) for Cd(II), Pb(II), Cu(II), and Zn(II) obtained by non-linear isotherm model at 298 K were 212.1, 133.5, 194.4, and 111 mg/g, respectively. Kinetics modeling parameters showed the applicability of pseudo-second-order model. The activation energy (Ea) magnitude revealed physical nature of adsorption. Maximum elution of Cu(II) (81.6%), Zn(II) (70.1%), Pb(II) (96%), and Cd(II) (78.2%) were observed with 0.1 M HCl. Thermogravimetric analysis of DPAC showed a total weight loss (in two-stages) of 28.3%. Infra-red spectral analysis showed the presence of carboxyl and hydroxyl groups over DPAC surface. The peaks at 820, 825, 845 and 885 cm-1 attributed to Zn-O, Pb-O, Cd-O, and Cu-O appeared on heavy metals saturated DPAC, confirmed their binding on DPAC during the adsorption.

Development of a surfactant liquid membrane extraction process for the cleansing of industrial aqueous effluents containing metallic cation traces

International Nuclear Information System (INIS)

Rapaumbya Akaye, Guy-Roland

1994-01-01

The purpose of this work was to develop a process of surfactant liquid membrane extraction to purify industrial waste solution containing Cu(II), Fe(III), and Zn(II) (about 0,1 g/L). The extractant is the ammonium salt of Cyanex 306 and Aliquat 336. The first part of this work deals with the study of the liquid-liquid extraction of the metals. The efficiency of the extractant has been shown for the extraction of each metal alone and for Cu(II) and Zn(II) in the case of a mixture of the three metals. During this study we have observed that Fe(III) is reduced to Fe(II) (which is not extracted by the salt of Cyanex 301) in presence of Cu(II) and the quaternary ammonium salt (Aliquat 336). The optimisation of the experimental conditions for the discontinuous surfactant liquid membrane process led us to choose the following composition of the emulsion: 1,5 % of Cyanex 301 salt, 2,5 % of ECA 4360, dodecan. The internal phase is an aqueous solution containing 3,5 mol/L of NaOH and 0,5 mol/L tri-ethanolamin The residual concentration of Cu(II) and Zn(II) in the external phase is very low. In the case of iron, only 60 % are extracted because of the reduction phenomenon (10 % in liquid-liquid extraction). The realisation of the continuous process in pulsed column, after optimisation of hydrodynamics conditions, leads to similar results. In stationary conditions, we obtain a raffinate containing less than 0,5 mg/L of Cu(II) and Zn(II) and 36 mg/L of iron. The internal phase contains about 2 g/L of Cu(II) an Zn(II). We tried and minimize the reduction of Fe(III) in surfactant liquid membrane process. Less than 16 % of iron cannot be reduced. This leads to a purification of only 84 % In the basis of these results, processes of purification have been proposed for effluents of various composition. They enable to purify the effluent and besides to concentrate the pollutants about twenty times. (author) [fr

Biosorption of Zn(II) by chemically modified biomass of corncob

International Nuclear Information System (INIS)

Zafar, H.; Nadeem, R.; Iqbal, T.; Ansari, T.M.

2011-01-01

In conducted research corncob powder was pretreated with inorganic acids and bases. The consequence of different parameters such as initial metal concentration, pH and contact time on Zn(II) bio sorption from aqueous solution was deliberated. The order of maximum Zn(II) uptake q/sub max/ (mgg/sup -1/) for different pretreated and raw corncob powder was Ba(OH)/sub 2/ (128.9)> H/sub 3/PO/sub 4/ (124.07)> NaOH (118.737)> H/sub 2/SO/sub 4/ (114.8)> HCl (93.41)> Al(OH)/sup 3/ (87.9)> Native (86.74). The percentage of Zn(II) removed on corncob biomass increased with increase in pH reaching a maximum at pH 5.5. Kinetics of Zn(II) bio sorption described that Zn(II) sorption rate was high in first 15-30 minutes and equilibrium was established after 120 minutes. The maximum adsorption data of native and pretreated biomass was investigated using Langmuir, Freundlich equilibrium and Pseudo first and second order kinetic models. It was accomplished that structural modifications onto corncob powder lead to the formation of novel bio masses with increased sorption efficiency and environmental stability for the abatement of Zn(II). Thus, optimization of bio sorption parameters, chemical pretreatments of bio sorbents and study of mechanisms are the main keys to transfer the bio sorption process from Lab to Industry. (author)

Kinetic Investigations on Pd(II) Catalyzed Oxidation of Some Amino ...

African Journals Online (AJOL)

Kinetic investigations on Pd(II) catalyzed oxidation of dl-serine and dl-threonine by acidic solution of potassium bromate in the presence of mercuric acetate, as a scavenger have been made in the temperature range of 30–45°C. The rate shows zero order kinetics in bromate [BrO3‾] and order of reaction is one with respect ...

Biosorption of heavy metals using a dead macro fungus schizophyllum commune fries: evaluation of equilibrium and kinetic models

International Nuclear Information System (INIS)

Javid, A.; Bajwa, R.; Javid, A.

2010-01-01

Biomass of a wood rotting fungus viz., Schizophyllum commune Fries was utilized for the treatment of electroplating wastewater that contained Cu(II), Ni(II), Zn(II) and Cr(VI) ions. Preliminary batch assays were conducted with synthetic pure metal-bearing solutions. Results obtained showed that among various parameters studied, solution pH between a range of 2.0-6.0 induced negligible uptake at pH < 3.5 and exhibited maximum at around 4.5-5.5 for Ni(II), Cu(II) and Zn(II) ions, while for Cr(VI) ion the highest was evidenced at pH 2.0-2.5. The kinetics of all metal ions was fast and biosorption equilibrium was established in 1 hour with appropriateness of pseudo-second-order. A temperature change in the range of 15 - 45 deg. C did not affect the biosorption capacity of the candidate fungus. The biosorption of metal ion increased on elevating initial metal ions concentrations (20-100 mg L/sup -1/) in the medium. The maximum biosorption capacity of fungus biomass was 9.0, 21.27, 4.83, 18.54 mg g/sup -1/ for Ni(II), Cu(II) and Zn(II) and Cr(VI), respectively. The experimental data was best adjusted by Langmuir, Freundlich and modified Langmuir models. Biosorption assays conducted with actual electroplating effluents under pre-optimized conditions revealed efficiency of 72.01, 53.16, 7.08 and 19.87% for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively by candidate biomass. (author)

Metallothionein Zn(2+)- and Cu(2+)-clusters from first-principles calculations

DEFF Research Database (Denmark)

Greisen, Per Junior; Jespersen, Jakob Berg; Kepp, Kasper Planeta

2012-01-01

Detailed electronic structures of Zn(ii) and Cu(ii) clusters from metallothioneins (MT) have been obtained using density functional theory (DFT), in order to investigate how oxidative stress-caused Cu(ii) intermediates affect Zn-binding to MT and cooperatively lead to Cu(i)MT. The inferred accura...

Structural and biological evaluation of some metal complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone

Science.gov (United States)

Yousef, T. A.; Abu El-Reash, G. M.; Al-Jahdali, M.; El-Rakhawy, El-Bastawesy R.

2013-12-01

The synthesis and characterization of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O2 complexes of vanillin-4N-(2-pyridyl) thiosemicarbazone (H2PVT) are reported. Theoretical calculations have been performed to obtain IR spectra of ligand and its complexes using AM1, Zindo/1, MM+ and PM3, methods. The Schiff base and its metal complexes have been screened for antibacterial Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Staphylococcus saprophyticus. H2VPT shows no apparent digestion effect on the egg albumin while Mn(II), Hg(II) and Cu(II) complexes exhibited a considerable digestion effect following the order Cu(II) > Mn(II) > Hg(II). Moreover, Ni(II) and Co(II) complexes revealed strong digestion effect. Fe(II), Mn(II), Cu(II), Zn(II) and Ni(II) acted as metal co- SOD enzyme factors, which are located in different compartments of the cell.

Selective separation, preconcentration and determination of Pd(II ions in environmental samples by coprecipitation with a 1,2,4-triazole derivative

Directory of Open Access Journals (Sweden)

D. Ozdes

2015-01-01

Full Text Available A simple, sensitive, facile and low cost methodology, combined with flame atomic absorption spectrometry (FAAS, was employed to evaluate the selective separation and preconcentration of Pd(II ions in environmental samples by using a triazole derivative as an organic coprecipitating agent without a carrier element. The developed method was systematically investigated in different set of experimental parameters that influence the quantitative recovery of Pd(II ions. The accuracy of the method was tested by analyzing certified reference material and spike tests. The developed coprecipitation procedure has been applied to road dust, anodic slime, industrial electronic waste materials and water samples to determine their Pd(II levels. DOI: http://dx.doi.org/10.4314/bcse.v29i1.1

Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls.

Science.gov (United States)

Rao, M Madhava; Ramana, D K; Seshaiah, K; Wang, M C; Chien, S W Chang

2009-07-30

Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g(-1) for Pb(II), 21.2 mg g(-1) for Zn(II), 19.5 mg g(-1) for Cu(II), and 15.7 mg g(-1) for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

Removal of some metal ions by activated carbon prepared from Phaseolus aureus hulls

International Nuclear Information System (INIS)

Rao, M. Madhava; Ramana, D.K.; Seshaiah, K.; Wang, M.C.; Chien, S.W. Chang

2009-01-01

Removal of lead [Pb(II)], zinc [Zn(II)], copper [Cu(II)], and cadmium [Cd(II)] from aqueous solutions using activated carbon prepared from Phaseolus aureus hulls (ACPAH), an agricultural waste was studied. The influence of various parameters such as effect of pH, contact time, adsorbent dose, and initial concentration of metal ions on the removal was evaluated by batch method. The removal of metal ions by ACPAH was pH dependent and the optimum pH values were 7.0, 8.0, 7.0 and 6.0 for Cu(II), Cd(II), Zn(II), and Pb(II), respectively. The sorption isotherms were studied using Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin isotherm models. The maximum adsorption capacity values of ACPAH for metal ions were 21.8 mg g -1 for Pb(II), 21.2 mg g -1 for Zn(II), 19.5 mg g -1 for Cu(II), and 15.7 mg g -1 for Cd(II). The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. Desorption experiments were carried out using HCl solution with a view to regenerate the spent adsorbent and to recover the adsorbed metal ions.

The sorption of metal ions on nanoscale zero-valent iron

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Suponik Tomasz

2017-01-01

Full Text Available The injection of the colloidal suspensions of nano-iron (nZVI into an aquifer is a novel method of removing metal ions from acidic water. In the batch tests, the equilibrium study of the sorption of metal ions, Cu(II and Zn(II, on Green Tea nanoscale Zero-Valent Ion (GT-nZVI was carried out. The sorption of metal ions on this reactive material was described using the Langmuir, Freundlich and Sips models. This last model described in a better way the sorption equilibrium in the tested range of concentrations and temperature. The value of determination coefficient (R2 for the Sips model, for copper and zinc, was 0.9735 to 0.9995, respectively. GT-nZVI has very good properties in removing Cu(II and Zn(II from acidic water. The high values of qmaxS, the maximum adsorption capacity in the Sips model, amounting to 348.0 and 267.3 mg/g for Cu(II and Zn(II, indicate the high adsorption capacity of GT-nZVI. The analyzed metals have good or very good affinity with GT-nZVI.

Biosorption of Cu(II) onto agricultural materials from tropical regions

KAUST Repository

Acheampong, Mike A.

2011-04-26

Background: In Ghana, the discharge of untreated gold mine wastewater contaminates the aquatic systems with heavy metals such as copper (Cu), threatening ecosystem and human health. The undesirable effects of these pollutants can be avoided by treatment of the mining wastewater prior to discharge. In this work, the sorption properties of agricultural materials, namely coconut shell, coconut husk, sawdust and Moringa oleifera seeds for Cu(II) were investigated. Results: The Freundlich isotherm model described the Cu(II) removal by coconut husk (R2 = 0.999) and sawdust (R2 = 0.993) very well and the Cu(II) removal by Moringa oleifera seeds (R2 = 0.960) well. The model only reasonably described the Cu(II) removal by coconut shell (R2 = 0.932). A maximum Cu(II) uptake of 53.9 mg g-1 was achieved using the coconut shell. The sorption of Cu(II) onto coconut shell followed pseudo-second-order kinetics (R2 = 0.997). FTIR spectroscopy indicated the presence of functional groups in the biosorbents, some of which were involved in the sorption process. SEM-EDX analysis confirmed an exchange of Mg(II) and K(I) for Cu(II) on Moringa oleifera seeds and K(I) for Cu(II) on coconut shell. Conclusion: This study shows that coconut shell can be an important low-cost biosorbent for Cu(II) removal. The results indicate that ion exchange, precipitation and electrostatic forces were involved in the Cu(II) removal by the biosorbents investigated. © 2011 Society of Chemical Industry.

Recognition of thymine in DNA bulges by a Zn(II) macrocyclic complex.

Science.gov (United States)

del Mundo, Imee Marie A; Fountain, Matthew A; Morrow, Janet R

2011-08-14

A Zn(II) macrocyclic complex with appended quinoline is a bifunctional recognition agent that uses both the Zn(II) center and the pendent aromatic group to bind to thymine in bulges with good selectivity over DNA containing G, C or A bulges. Spectroscopic studies show that the stem containing the bulge stays largely intact in a DNA hairpin with the Zn(II) complex bound to the thymine bulge. This journal is © The Royal Society of Chemistry 2011

Cu(II) promotes amyloid pore formation

International Nuclear Information System (INIS)

Zhang, Hangyu; Rochet, Jean-Christophe; Stanciu, Lia A.

2015-01-01

The aggregation of α-synuclein is associated with dopamine neuron death in Parkinson's disease. There is controversy in the field over the question of which species of the aggregates, fibrils or protofibrils, are toxic. Moreover, compelling evidence suggested the exposure to heavy metals to be a risk of PD. Nevertheless, the mechanism of metal ions in promoting PD remains unclear. In this research, we investigated the structural basis of Cu(II) induced aggregation of α-synuclein. Using transmission electron microscopy experiments, Cu(II) was found to promote in vitro aggregation of α-synuclein by facilitating annular protofibril formation rather than fibril formation. Furthermore, neuroprotective baicalein disaggregated annular protofibrils accompanied by considerable decrease of β-sheet content. These results strongly support the hypothesis that annular protofibrils are the toxic species, rather than fibrils, thereby inspiring us to search novel therapeutic strategies for the suppression of the toxic annular protofibril formation. - Highlights: • Cu(II) promoted the annular protofibril formation of α-synuclein in vitro. • Cu(II) postponed the in vitro fibrillization of α-synuclein. • Neuroprotective baicalein disaggregated annular protofibrils

Cu(II) promotes amyloid pore formation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Hangyu, E-mail: hangyuz@uw.edu [Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 (United States); Rochet, Jean-Christophe [Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907 (United States); Stanciu, Lia A. [Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 (United States); School of Materials Engineering, Purdue University, West Lafayette, IN 47907 (United States)

2015-08-14

The aggregation of α-synuclein is associated with dopamine neuron death in Parkinson's disease. There is controversy in the field over the question of which species of the aggregates, fibrils or protofibrils, are toxic. Moreover, compelling evidence suggested the exposure to heavy metals to be a risk of PD. Nevertheless, the mechanism of metal ions in promoting PD remains unclear. In this research, we investigated the structural basis of Cu(II) induced aggregation of α-synuclein. Using transmission electron microscopy experiments, Cu(II) was found to promote in vitro aggregation of α-synuclein by facilitating annular protofibril formation rather than fibril formation. Furthermore, neuroprotective baicalein disaggregated annular protofibrils accompanied by considerable decrease of β-sheet content. These results strongly support the hypothesis that annular protofibrils are the toxic species, rather than fibrils, thereby inspiring us to search novel therapeutic strategies for the suppression of the toxic annular protofibril formation. - Highlights: • Cu(II) promoted the annular protofibril formation of α-synuclein in vitro. • Cu(II) postponed the in vitro fibrillization of α-synuclein. • Neuroprotective baicalein disaggregated annular protofibrils.

Spectrophotometric Analysis of the Kinetic of Pd(II Chloride Complex Ions Sorption Process from Diluted Aqua Solutions Using Commercially Available Activated Carbon

Directory of Open Access Journals (Sweden)

Wojnicki M.

2017-12-01

Full Text Available In this paper, results of adsorption kinetic studies of Pd(II chloride complex ions on activated carbon Organosrob 10 CO are presented. Spectorphotometrical method was applied to investigate the process. Kinetic model was proposed, and fundamental thermodynamic parameters were determined. Proposed kinetic model describes well observed phenomenon in the studied range of concentration of Pd(II chloride complex ions as well, as concentration of activated carbon.

Nanoscale zero-valent iron for metal/metalloid removal from model hydraulic fracturing wastewater.

Science.gov (United States)

Sun, Yuqing; Lei, Cheng; Khan, Eakalak; Chen, Season S; Tsang, Daniel C W; Ok, Yong Sik; Lin, Daohui; Feng, Yujie; Li, Xiang-Dong

2017-06-01

Nanoscale zero-valent iron (nZVI) was tested for the removal of Cu(II), Zn(II), Cr(VI), and As(V) in model saline wastewaters from hydraulic fracturing. Increasing ionic strength (I) from 0.35 to 4.10 M (Day-1 to Day-90 wastewaters) increased Cu(II) removal (25.4-80.0%), inhibited Zn(II) removal (58.7-42.9%), slightly increased and then reduced Cr(VI) removal (65.7-44.1%), and almost unaffected As(V) removal (66.7-75.1%) by 8-h reaction with nZVI at 1-2 g L -1 . The removal kinetics conformed to pseudo-second-order model, and increasing I decreased the surface area-normalized rate coefficient (k sa ) of Cu(II) and Cr(VI), probably because agglomeration of nZVI in saline wastewaters restricted diffusion of metal(loid)s to active surface sites. Increasing I induced severe Fe dissolution from 0.37 to 0.77% in DIW to 4.87-13.0% in Day-90 wastewater; and Fe dissolution showed a significant positive correlation with Cu(II) removal. With surface stabilization by alginate and polyvinyl alcohol, the performance of entrapped nZVI in Day-90 wastewater was improved for Zn(II) and Cr(VI), and Fe dissolution was restrained (3.20-7.36%). The X-ray spectroscopic analysis and chemical speciation modelling demonstrated that the difference in removal trends from Day-1 to Day-90 wastewaters was attributed to: (i) distinctive removal mechanisms of Cu(II) and Cr(VI) (adsorption, (co-)precipitation, and reduction), compared to Zn(II) (adsorption) and As(V) (bidentate inner-sphere complexation); and (ii) changes in solution speciation (e.g., from Zn 2+ to ZnCl 3 - and ZnCl 4 2- ; from CrO 4 2- to CaCrO 4 complex). Bare nZVI was susceptible to variations in wastewater chemistry while entrapped nZVI was more stable and environmentally benign, which could be used to remove metals/metalloids before subsequent treatment for reuse/disposal. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intercalation of a Zn(II) complex containing ciprofloxacin drug between DNA base pairs.

Science.gov (United States)

Shahabadi, Nahid; Asadian, Ali Ashraf; Mahdavi, Mryam

2017-11-02

In this study, an attempt has been made to study the interaction of a Zn(II) complex containing an antibiotic drug, ciprofloxacin, with calf thymus DNA using spectroscopic methods. It was found that Zn(II) complex could bind with DNA via intercalation mode as evidenced by: hyperchromism in UV-Vis spectrum; these spectral characteristics suggest that the Zn(II) complex interacts with DNA most likely through a mode that involves a stacking interaction between the aromatic chromophore and the base pairs of DNA. DNA binding constant (K b = 1.4 × 10 4 M -1 ) from spectrophotometric studies of the interaction of Zn(II) complex with DNA is comparable to those of some DNA intercalative polypyridyl Ru(II) complexes 1.0 -4.8 × 10 4 M -1 . CD study showed stabilization of the right-handed B form of DNA in the presence of Zn(II) complex as observed for the classical intercalator methylene blue. Thermodynamic parameters (ΔH DNA-MB, indicating that it binds to DNA in strong competition with MB for the intercalation.

Pd-nanoparticles cause increased toxicity to kiwifruit pollen compared to soluble Pd(II)

International Nuclear Information System (INIS)

Speranza, Anna; Leopold, Kerstin; Maier, Marina; Taddei, Anna Rita; Scoccianti, Valeria

2010-01-01

In the present study, endpoints including in vitro pollen performance (i.e., germination and tube growth) and lethality were used as assessments of nanotoxicity. Pollen was treated with 5-10 nm-sized Pd particles, similar to those released into the environment by catalytic car exhaust converters. Results showed Pd-nanoparticles altered kiwifruit pollen morphology and entered the grains more rapidly and to a greater extent than soluble Pd(II). At particulate Pd concentrations well below those of soluble Pd(II), pollen grains experienced rapid losses in endogenous calcium and pollen plasma membrane damage was induced. This resulted in severe inhibition and subsequent cessation of pollen tube emergence and elongation at particulate Pd concentrations as low as 0.4 mg L -1 . Particulate Pd emissions related to automobile traffic have been increasing and are accumulating in the environment. This could seriously jeopardize in vivo pollen function, with impacts at an ecosystem level. - Nanoparticulate Pd - which resembles emissions from automobile catalysts - affects pollen to a higher extent than soluble Pd.

Pd-nanoparticles cause increased toxicity to kiwifruit pollen compared to soluble Pd(II)

Energy Technology Data Exchange (ETDEWEB)

Speranza, Anna, E-mail: anna.speranza@unibo.i [Dipartimento di Biologia, Universita di Bologna, via Irnerio 42, 40126 Bologna (Italy); Leopold, Kerstin, E-mail: kerstin.leopold@lrz.tu-muenchen.d [Arbeitsgruppe fuer Analytische Chemie, Technische Universitaet Muenchen, Garching (Germany); Maier, Marina, E-mail: marina.maier@ch.tum.d [Arbeitsgruppe fuer Analytische Chemie, Technische Universitaet Muenchen, Garching (Germany); Taddei, Anna Rita, E-mail: artaddei@unitus.i [CIME, Universita della Tuscia, Viterbo (Italy); Scoccianti, Valeria, E-mail: valeria.scoccianti@uniurb.i [Dipartimento di Scienze dell' Uomo, dell' Ambiente e della Natura, Universita di Urbino ' Carlo Bo' , Urbino (Italy)

2010-03-15

In the present study, endpoints including in vitro pollen performance (i.e., germination and tube growth) and lethality were used as assessments of nanotoxicity. Pollen was treated with 5-10 nm-sized Pd particles, similar to those released into the environment by catalytic car exhaust converters. Results showed Pd-nanoparticles altered kiwifruit pollen morphology and entered the grains more rapidly and to a greater extent than soluble Pd(II). At particulate Pd concentrations well below those of soluble Pd(II), pollen grains experienced rapid losses in endogenous calcium and pollen plasma membrane damage was induced. This resulted in severe inhibition and subsequent cessation of pollen tube emergence and elongation at particulate Pd concentrations as low as 0.4 mg L{sup -1}. Particulate Pd emissions related to automobile traffic have been increasing and are accumulating in the environment. This could seriously jeopardize in vivo pollen function, with impacts at an ecosystem level. - Nanoparticulate Pd - which resembles emissions from automobile catalysts - affects pollen to a higher extent than soluble Pd.

Biosorption of Cu(II) onto agricultural materials from tropical regions

KAUST Repository

Acheampong, Mike A.; Pereira, Joana P.C.; Meulepas, Roel J.W.; Lens, Piet N.L.

2011-01-01

model described the Cu(II) removal by coconut husk (R2 = 0.999) and sawdust (R2 = 0.993) very well and the Cu(II) removal by Moringa oleifera seeds (R2 = 0.960) well. The model only reasonably described the Cu(II) removal by coconut shell (R2 = 0.932). A

co-removal with nucleated Cu(II) precipitation in continuous-flow ...

African Journals Online (AJOL)

A compact nucleated precipitation technology using two fluidised sand columns in series was developed to pretreat model metal-plating wastewater containing high concentrations of Cu(II) and Cr(VI). Since either Cu(II) precipitation or Cr(VI) co-removal with Cu(II) precipitation was found to be highly pH dependent in batch ...

A novel polymer probe for Zn(II) detection with ratiometric fluorescence signal

Science.gov (United States)

Diao, Haipeng; Guo, Lixia; Liu, Wen; Feng, Liheng

2018-05-01

A conjugated polymer probe comprised of fluorene, quinolone and benzothiazole units was designed and synthesized by the Suzuki coupling reaction. Through the studies of photophysical and thermal properties, the polymer displays blue-emitting feature and good thermal stability. A ratiometric fluorescence signal of the probe for Zn(II) was observed in ethanol with a new emission peak at 555 nm. The probe possesses a high selectivity and sensitivity for Zn(II) during familiar metal ions in ethanol. The detection limit of the probe for Zn (II) is up to 10-8 mol/L. The electron distributions of the polymer before and after bonding with Zn (II) were investigated by the Gaussian 09 software, which agreed with the experimental results. Noticeably, based on the color property of the probe with Zn(II), a series of color test paper were developed for visual detecting Zn(II) ions. This work helps to provide a platform or pattern for the development of polymer fluorescence probe in the chemosensor field.

Studies on the Synthesis, Photophysical and Biological Evaluation of Some Unsymmetrical Meso-Tetrasubstituted Phenyl Porphyrins

Directory of Open Access Journals (Sweden)

Rica Boscencu

2017-10-01

Full Text Available Abstract: We designed three unsymmetrical meso-tetrasubstituted phenyl porphyrins for further development as theranostic agents for cancer photodynamic therapy (PDT: 5-(4-hydroxy-3-methoxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin (P2.2, Zn(II-5-(4-hydroxy-3-methoxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin (Zn(II2.2 and Cu(II-5-(4-hydroxy-3-methoxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin (Cu(II2.2. The porphyrinic compounds were synthesized and their structures were confirmed by elemental analysis, FT-IR, UV-Vis, EPR and NMR. The compounds had a good solubility in polar/nonpolar media. P2.2 and, to a lesser extent, Zn(II2.2 were fluorescent, albeit with low fluoresence quantum yields. P2.2 and Zn(II2.2 exhibited PDT-acceptable values of singlet oxygen generation. A “dark” cytotoxicity study was performed using cells that are relevant for the tumor niche (HT-29 colon carcinoma cells and L929 fibroblasts and for blood (peripheral mononuclear cells. Cellular uptake of fluorescent compounds, cell viability/proliferation and death were evaluated. P2.2 was highlighted as a promising theranostic agent for PDT in solid tumors considering that P2.2 generated PDT-acceptable singlet oxygen yields, accumulated into tumor cells and less in blood cells, exhibited good fluorescence within cells for imagistic detection, and had no significant cytotoxicity in vitro against tumor and normal cells. Complexing of P2.2 with Zn(II or Cu(II altered several of its PDT-relevant properties. These are consistent arguments for further developing P2.2 in animal models of solid tumors for in vivo PDT.

Intracellular Zn(II) Intoxication Leads to Dysregulation of the PerR Regulon Resulting in Heme Toxicity in Bacillus subtilis

Science.gov (United States)

2016-01-01

Transition metal ions (Zn(II), Cu(II)/(I), Fe(III)/(II), Mn(II)) are essential for life and participate in a wide range of biological functions. Cellular Zn(II) levels must be high enough to ensure that it can perform its essential roles. Yet, since Zn(II) binds to ligands with high avidity, excess Zn(II) can lead to protein mismetallation. The major targets of mismetallation, and the underlying causes of Zn(II) intoxication, are not well understood. Here, we use a forward genetic selection to identify targets of Zn(II) toxicity. In wild-type cells, in which Zn(II) efflux prevents intoxication of the cytoplasm, extracellular Zn(II) inhibits the electron transport chain due to the inactivation of the major aerobic cytochrome oxidase. This toxicity can be ameliorated by depression of an alternate oxidase or by mutations that restrict access of Zn(II) to the cell surface. Conversely, efflux deficient cells are sensitive to low levels of Zn(II) that do not inhibit the respiratory chain. Under these conditions, intracellular Zn(II) accumulates and leads to heme toxicity. Heme accumulation results from dysregulation of the regulon controlled by PerR, a metal-dependent repressor of peroxide stress genes. When metallated with Fe(II) or Mn(II), PerR represses both heme biosynthesis (hemAXCDBL operon) and the abundant heme protein catalase (katA). Metallation of PerR with Zn(II) disrupts this coordination, resulting in depression of heme biosynthesis but continued repression of catalase. Our results support a model in which excess heme partitions to the membrane and undergoes redox cycling catalyzed by reduced menaquinone thereby resulting in oxidative stress. PMID:27935957

Preparation and Evaluation of Acetabularia-Modified Carbon Paste Electrode in Anodic Stripping Voltammetry of Copper and Lead Ions

Directory of Open Access Journals (Sweden)

Muhammad Raziq Rahimi Kooh

2013-01-01

Full Text Available Seaweed is well known about for potential in chelating heavy metals. In this study, carbon paste electrodes were fabricated with siphonous seaweed Acetabularia acetabulum as the modifiers to sense lead (II and copper (II by square-wave anodic stripping voltammetry. Various scan rates and deposition potentials were measured to obtain the optimal peak current for Pb(II and Cu(II. Optimum conditions of Acetabularia-CPE for sensing Pb(II were at the scan rate of 75 mV/s and deposition potential of −800 mV, while for Cu(II sensing were at 100 mV/s and −300 mV, respectively. The electrodes were characterized by the duration of accumulation time, preconcentration over a range of standards, supporting electrolyte, and standard solutions of various pH values. Interference studies were carried out. Both Zn(II and Cu(II were found to interfere with Pb(II sensing, whereas only Zn(II causes interference with Cu(II sensing. The electrode was found to have good regeneration ability via electrochemical cleaning. Preliminary testing of complex samples such as NPK fertilisers, black soil, and sea salt samples was included.

Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

Directory of Open Access Journals (Sweden)

Monika Tyagi

2014-01-01

Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

Potentiation of radiation-induced cell kill by synthetic metalloporphyrins

International Nuclear Information System (INIS)

O'Hara, J.A.; Douple, E.B.; Abrams, M.J.; Picker, D.J.; Giandomenico, C.M.; Vollano, J.F.

1989-01-01

The effects of the combination of several meso-substituted, water soluble metalloporphyrins with ionizing radiation on hypoxic and oxic monolayers of Chinese hamster fibroblast (V79N) cells were studied. The metalloporphyrins tested included a series of cationic metalloporphyrins complexed with Co(III), Zn(II), Fe(III), Cu(II), Pd(II) or Mn(III) and a series of anionic porphyrins chelated with Co(III), Fe(III), Cu(II), Rh(III), Mn(III) or Sn(IV). Both cationic and anionic free porphyrins were also tested. Cationic ligands were tetrakis(4N-methylpyridyl)porphine [TMPyP], tetrakis(4N-trimethylamino phenyl)porphine [TMAP], tetrakis(4N-butylpyridyl)porphine [TBPyP] and tetrakis(3N-methylpyridyl)porphine [3TMPyP]. Anionic ligands tested were tetrakis(4-sulfonato phenyl)porphine [TPPS], tetrakis(biphenyl)porphine sulfonate [TBPS] and tetrakis(4-carboxyphenyl)porphine [TCPP]. SER calculated from survival curves and SFR from one radiation dose were used to assess the relative effectiveness of this class as non-cytotoxic hypoxic and oxic cell-kill potentiators. Comparisons were made at 100 microM, which was essentially non-toxic (greater than 70% survival) for all porphyrins tested except for Co[TMPyP] (approximately 50% survival after 1 hour at 37 degrees C under oxic conditions). The greatest effects on radiation-induced cell kill were achieved with Co[TPPS] and Co[TMPyP] with SER values of 2.3 and 2.4 respectively. Porphyrin analogs with no coordinated metal were found to be less active than the same compound with metal. The overall charge on the molecule did not systematically relate to the biological activity of the compounds tested

Electron spin resonance and electron spin echo modulation studies of Cu(II) ions in the aluminosilicate chabazite: A comparison of Cu(II) cation location and adsorbate interaction with isostructural silicoaluminophosphate-34

International Nuclear Information System (INIS)

Zamadics, M.; Kevan, L.

1992-01-01

This study focuses on Cu(II) ions exchanged in the aluminosilicate zeolite chabazite. The various Cu(II) species formed after dehydration, rehydration, and exposure to adsorbates are characterized by electron spin resonance and electron spin echo modulation spectroscopies. These results are interpreted in terms of Cu(II) ion location and adsorbate interaction. The results of this study are compared to the results found earlier for SAPO-34, chabazite's structural analog from the silicoaluminophosphate group. In a hydrated sample of chabazite the Cu(II) ions are found to be in a near octahedral environment coordinated to three nonequivalent water molecules and three framework oxygens. The most probable location of the Cu(II) ion in a hydrated sample is above the plane of the six-membered ring slightly displaced into the ellipsoidal cavity. A somewhat similar location and coordination is found for Cu(II) ions in H-SAPO-34. A feature common to both CuH-chabazite and CuH-SAPO-34 is the generation of two distinct Cu(II) species upon dehydration. It is found that Cu(II) cations in chabazite interact with the various adsorbate molecules in a similar manner as Cu(II) cation in H-chabazite and three molecules of ethanol and three propanol molecules. Only the Cu(II) ions located in the hexagonal rings after dehydration were found to complex with ethylene. The differences observed in the interaction of the Cu(II) in with water, propanol, and ehtylene between SAPO-34 and chabazite can be related to the differing cation densities of these two materials. 32 refs., 7 figs., 21 tabs

Synthesis, spectroscopic and DNA binding ability of CoII, NiII, CuII and ZnII complexes of Schiff base ligand (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol. X-ray crystal structure determination of cobalt (II) complex.

Science.gov (United States)

Yarkandi, Naeema H; El-Ghamry, Hoda A; Gaber, Mohamed

2017-06-01

A novel Schiff base ligand, (E)-1-(((1H-benzo[d]imidazol-2-yl)methylimino)methyl)naphthalen-2-ol (HL), has been designed and synthesized in addition to its metal chelates [Co(L) 2 ]·l2H 2 O, [Ni(L)Cl·(H 2 O) 2 ].5H 2 O, [Cu(L)Cl] and [Zn(L)(CH 3 COO)]. The structures of the isolated compounds have been confirmed and identified by means of different spectral and physicochemical techniques including CHN analysis, 1 H & 13 C NMR, mass spectral analysis, molar conductivity measurement, UV-Vis, infrared, magnetic moment in addition to TGA technique. The infrared spectral results ascertained that the ligand acts as monobasic tridentate binding to the metal centers via deprotonated hydroxyl oxygen, azomethine and imidazole nitrogen atoms. The UV-Vis, magnetic susceptibility and molar conductivity data implied octahedral geometry for Co(II) & Ni(II) complexes, tetrahedral for Zn(II) complex and square planar for Cu(II) complex. X-ray structural analysis of Co(II) complex 1 has been reported and discussed. Moreover, the type of interaction between the ligand & its complexes towards salmon sperm DNA (SS-DNA) has been examined by the measurement of absorption spectra and viscosity which confirmed that the ligand and its complexes interact with DNA via intercalation interaction as concluded from the values of binding constants (K b ). Copyright © 2017 Elsevier B.V. All rights reserved.

Reactions of green and black teas with Cu(II).

Science.gov (United States)

Goodman, B A; Ferreira Severino, J; Pirker, K F

2012-04-01

Electron paramagnetic resonance (EPR) measurements of the products of reactions between Cu(II) and samples of green and black teas showed spectral components from at least six different Cu(II) complexes with both tea types. Several of these complexes were common to both teas in spite of major differences in their polyphenol compositions. The pH range observed for complex formation, and the total signal intensity in the pH range 4-8, were greatly different from those for the reactions of Cu(II) with (-)-epigallocatechin gallate and gallic acid, the main polyphenols responsible for the free radical signals observed during oxidation of these beverages. Components with spectral parameters similar to those of Cu(II) complexes with theanine, the major amino acid in tea, may contribute to two of the spectra recorded under acidic conditions. However, the initial complexes formed at the lowest pH values investigated are still unidentified. EPR spectra with parameters consistent with Cu(II) polyphenol complexes were only observed under alkaline conditions, thus suggesting that components of tea other than polyphenols might be more important in reactions with copper, and possibly other transition metals, in solutions under physiological conditions. This journal is © The Royal Society of Chemistry 2012

Hydrothermal synthesis of silico-manganese nanohybrid for Cu(II) adsorption from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Zhu, Qiufeng, E-mail: zhuqiufeng@th.btbu.edu.cn; Wang, Liting; An, Zehuan; Ye, Hong; Feng, Xudong

2016-05-15

Highlights: • A novel silico-manganese nanohybrid adsorbent (SMNA) was synthesized by a hydrothermal method. • The adsorption capacities of the SMNA for Cu(II) are lower pH dependency. • As-adsorbents are very efficient at low metal concentration and substantial amounts of Cu(II) can be removed from aqueous solution. - Abstract: A novel silico-manganese nanohybrid adsorbent (SMNA) was synthesized by a facile hydrothermal method, and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption-desorption, Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurement. The adsorption of Cu(II) ions from aqueous solution on the SMNA was investigated with variations in contact time, pH and initial Cu(II) concentration. The results showed that hydrothermal method would generate nanowire/nanorod incomplete crystallite (δ-MnO{sub 2}) adsorbent. The adsorption of Cu(II) onto SMNA increased sharply within 25 min and reached equilibrium gradually. The maximum adsorption capacities of SMNA for Cu(II) were ∼40–88 mg g{sup −1}, which was lower than δ-MnO{sub 2} (92.42 mg g{sup −1}) but had a lower pH dependency. As compared with δ-MnO{sub 2}, higher adsorption capacities of SMNA (7.5–15 wt% of silica doping amount) for Cu(II) could be observed when pH of the aqueous solution was low (<4). The pseudo-second-order model was the best choice to describe the adsorption behavior of Cu(II) onto SMNA, suggesting that the removal of Cu(II) by the as-prepared adsorbents was dominated by migration of Cu(II). The possibility of Cu(II) recovery was also investigated and it revealed that SMNA was a promising recyclable adsorbent for removal of heavy metal ions in water and wastewater treatment.

Spectral, magnetic and biological studies of 1,4-dibenzoyl-3 ...

Indian Academy of Sciences (India)

Unknown

MS received 29 January 2001; revised 30 March 2001. Abstract. ... Room temperature ESR spectra of the Mn(II) and Cu(II) complexes yield ... H)Cl] (M = Cu(II), Ni(II) or Zn(II)) and [Mn(DBtsc)Cl2] were prepared by refluxing ... 5.1 In vitro DNA synthesis inhibition assay ..... 3⋅86 (s, 2H) 7⋅86 (t, 2H), 7⋅46 (d, 3H). DBtsc.

New hybrid materials as Zn(II) sorbents in water samples

International Nuclear Information System (INIS)

Perez-Quintanilla, Damian; Sanchez, Alfredo; Hierro, Isabel del; Fajardo, Mariano; Sierra, Isabel

2010-01-01

Mesoporous silicas have been chemically modified with 5-mercapto-1-methyltetrazole (MTTZ) obtaining hybrid materials denominated MTTZ-MSU-2 and MTTZ-HMS. These materials were employed as Zn(II) sorbents from aqueous media at room temperature. The effect of several variables (stirring time, pH, presence of other metals) has been studied using batch and column techniques. Flame atomic absorption spectrometry (FAAS) was used to determinate Zn(II) concentration in the filtrate or in the eluted solution after the adsorption process. The results indicate that under pH 8, the maximum adsorption value was 0.94 ± 0.01 and 0.72 ± 0.01 mmol Zn(II)/g for MTTZ-MSU-2 and MTTZ-HMS, respectively. In tap water samples, a preconcentration factor of 200 was obtained. On the basis of these results, it can be concluded that it is possible to modify chemically MSU-2 and HMS with 5-mercapto-1-methyltetrazole and to use the resulting modified mesoporous silica as an effective adsorbent for Zn(II) in aqueous media.

Adsorption of aqueous Zn(II) species on synthetic zeolites

International Nuclear Information System (INIS)

Badillo-Almaraz, Veronica; Trocellier, Patrick; Davila-Rangel, Ignacio

2003-01-01

To supply a good quality drinkable water tends to become a strategic task in both developed and under development countries in the world due to the number of potential contamination sources. One of the major problems is derived from the presence of heavy toxic metals like zinc or lead resulting from industrial activities. Zeolites are known as very efficient mineral substrates for fixing aqueous ionic species through their wide range of channels present in the crystalline structure and due to their strong surface reactivity. MicroPIXE coupled with microRBS (3.05 MeV 4 He + ions) have been used to quantify the incorporation of zinc within two commercial zeolites containing alkali elements (zeolite X and clinoptilolite) in the concentration range of: 0.0002-0.05 M at neutral pH. At the beginning of the interaction between zeolite and Zn(II) solution, the adsorption process exhibits a direct proportionality between the content of zinc fixed on the mineral substrate and the aqueous concentration up to 0.01 M. Beyond this point a saturation effect seems to occur, indicating the strong decrease of available adsorption sites. Sodium or potassium ions are probably exchanged with Zn(II) ions during this process. The compared behaviour of the two zeolites is then discussed in terms of kinetic effects based on ionic radius values. A co-adsorption test carried on with a 50-50% Zn(II) 0.001 M-Pb(II) 0.001 M solution shows that lead does not occupy the same sites as zinc because the content of zinc fixed on the zeolite sample exactly corresponds to the result obtained with a pure 0.001 M Zn(II) solution. All these data clearly showed that zeolite surface reactivity is greatly influenced by the mineral cage-like structure and particularly the presence of pockets, spaces and channels

Pb, Cu, and Zn distributions at humic acid-coated metal-oxide surfaces

Science.gov (United States)

Wang, Yingge; Michel, F. Marc; Choi, Yongseong; Eng, Peter J.; Levard, Clement; Siebner, Hagar; Gu, Baohua; Bargar, John R.; Brown, Gordon E.

2016-09-01

Mineral surfaces are often coated by natural organic matter (NOM), which has a major influence on metal-ion sorption and sequestration because of the abundance of binding sites in such coatings and the changes they cause in local nanoscale environments. The effects of NOM coatings on mineral surfaces are, however, still poorly understood at the molecular level due to the complexity of these systems. In this study, we have applied long-period X-ray standing wave-fluorescence yield (LP-XSW-FY) spectroscopy to measure the partitioning of naturally present Cu(II) (0.0226%), Zn(II) (0.009%), and Pb(II) (∼0.0004%) between Elliott Soil Humic Acid (ESHA) coatings and three model single-crystal metal-oxide substrates: α-Al2O3 (0 0 0 1), α-Al2O3 (1 -1 0 2), and α-Fe2O3 (0 0 0 1). The competitive sorption effects among these metal ions for binding sites in the ESHA coatings and on the metal-oxide surfaces were investigated as a function of reaction time, calcium content, and solution pH. Pb(II) ions present in the ESHA coatings were found to redistribute to reactive α-Al2O3 (1 -1 0 2) and α-Fe2O3 (0 0 0 1) surfaces after 3 h of reaction (pH = 6.0, [Ca(II)] = 2 mM). Pb(II) partitioning onto these reactive metal-oxide surfaces increased with increasing reaction time (up to 7 d). In addition, the partitioning of Cu(II) and Zn(II) from the ESHA coating to the α-Fe2O3 (0 0 0 1) substrate increased slightly with reaction time (2.4% and 3.7% for Cu(II) and Zn(II), respectively, after 3 h and 6.4% and 7.7% for Cu(II) and Zn(II), respectively, after 72 h of reaction time). However, no changes in the partitioning of Cu(II) and Zn(II) onto the α-Al2O3 (1 -1 0 2) surface were observed with increasing reaction time, suggesting that these ions strongly complex with functional groups in the ESHA coatings. Similar results were obtained for Cu(II) and Zn(II) on the ESHA-coated α-Al2O3 (1 -1 0 2) surfaces in samples without the addition of calcium. However, the amounts of Pb

Solvent extraction of noble metals by formazans

International Nuclear Information System (INIS)

Grote, M.; Hueppe, U.; Kettrup, A.

1984-01-01

The extraction properties of ion-pairs composed of quaternary ammonium cations and a sulphonated formazan were compared with those of an unsulphonated formazan, for various solvent media. In dichloromethane the combined system behaves as a 'coloured anion-exchanger', with displacement of the sulphonated formazan, whereas in toluene Pd(II) and Ag(I) are extracted as the metal formazan chelates from aqueous medium. The rates of extraction are remarkably higher than with the simple extractants. Because of the higher stability only the simple chelating extraction systems afford satisfactory separation of Pd(II) from excess of Pt(IV) and of Ag(I) from Cu(II). The extracted metals can be stripped and the extractant regenerated. (author)

Biosorption of Cd(II) and Zn(II) by nostoc commune: isotherm and kinetics studies

Energy Technology Data Exchange (ETDEWEB)

Morsy, Fatthy M. [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Hassan, Sedky H.A. [Department of Biological Environment, Kangwon National University, Kangwon-do (Korea, Republic of); Koutb, Mostafa [Faculty of Science, Botany Department, Assiut University, Assiut (Egypt); Umm Al-Qura University, Faculty of Applied Science, Biology Department, Mecca (Saudi Arabia)

2011-07-15

In this study, Nostoc commune (cyanobacterium) was used as an inexpensive and efficient biosorbent for Cd(II) and Zn(II) removal from aqueous solutions. The effect of various physicochemical factors on Cd(II) and Zn(II) biosorption such as pH 2.0-7.0, initial metal concentration 0.0-300 mg/L and contact time 0-120 min were studied. Optimum pH for removal of Cd(II) and Zn(II) was 6.0, while the contact time was 30 min at room temperature. The nature of biosorbent and metal ion interaction was evaluated by infrared (IR) technique. IR analysis of bacterial biomass revealed the presence of amino, carboxyl, hydroxyl, and carbonyl groups, which are responsible for biosorption of Cd(II) and Zn (II). The maximum biosorption capacities for Cd(II) and Zn(II) biosorption by N. commune calculated from Langmuir biosorption isotherm were 126.32 and 115.41 mg/g, respectively. The biosorption isotherm for two biosorbents fitted well with Freundlich isotherm than Langmuir model with correlation coefficient (r{sup 2} < 0.99). The biosorption kinetic data were fitted well with the pseudo-second-order kinetic model. Thus, this study indicated that the N. commune is an efficient biosorbent for the removal of Cd(II) and Zn(II) from aqueous solutions. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Zinc-sensitive MRI contrast agent detects differential release of Zn(II) ions from the healthy vs. malignant mouse prostate.

Science.gov (United States)

Clavijo Jordan, M Veronica; Lo, Su-Tang; Chen, Shiuhwei; Preihs, Christian; Chirayil, Sara; Zhang, Shanrong; Kapur, Payal; Li, Wen-Hong; De Leon-Rodriguez, Luis M; Lubag, Angelo J M; Rofsky, Neil M; Sherry, A Dean

2016-09-13

Many secretory tissues release Zn(II) ions along with other molecules in response to external stimuli. Here we demonstrate that secretion of Zn(II) ions from normal, healthy prostate tissue is stimulated by glucose in fasted mice and that release of Zn(II) can be monitored by MRI. An ∼50% increase in water proton signal enhancement is observed in T1-weighted images of the healthy mouse prostate after infusion of a Gd-based Zn(II) sensor and an i.p. bolus of glucose. Release of Zn(II) from intracellular stores was validated in human epithelial prostate cells in vitro and in surgically exposed prostate tissue in vivo using a Zn(II)-sensitive fluorescent probe known to bind to the extracellular surface of cells. Given the known differences in intracellular Zn(II) stores in healthy versus malignant prostate tissues, the Zn(II) sensor was then evaluated in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model in vivo. The agent proved successful in detecting small malignant lesions as early as 11 wk of age, making this noninvasive MR imaging method potentially useful for identifying prostate cancer in situations where it may be difficult to detect using current multiparametric MRI protocols.

Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis

International Nuclear Information System (INIS)

Tao, Hu-Chun; Lei, Tao; Shi, Gang; Sun, Xiao-Nan; Wei, Xue-Yan; Zhang, Li-Juan; Wu, Wei-Min

2014-01-01

Highlights: • Heavy metals removal from MSWI fly ash with BES and electrolysis was confirmed. • 98.5% of Cu(II), 95.4% of Zn(II) and 98.1% of Pb(II) removal were achieved in reactors. • BESs can remove some heavy metals in fly ash with energy saving. -- Abstract: Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10 h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors

Synthesis and Structural Studies on Transition Metal Complexes Derived from 4-Hydroxy-4-methyl–2-pentanone-1H-benzimidazol-2-yl-hydrazone

Directory of Open Access Journals (Sweden)

M. Neelamma

2011-01-01

Full Text Available Transition metal complexes of Cr(III, Fe(III, Mn(II, Co(II, Ni(II, Cu(II and Zn(II with a tridentate ligand, 4-hydroxy-4-methyl-2-pentanone-1H-benzimidazole-2yl-hydrazone (H-HPBH derived from the condensation of 2-hydrazinobenzimidazole and diacetone alcohol was synthesized. Characterization has been done on the basis of analytical, conductance, thermal and magnetic data, infrared, 1H NMR, electronic, mass and ESR spectral data. From analytical and thermal data, the stoichiometry of the complexes has been found to be 1:1 (metal: ligand. Divalent complexes have the general formula [M(HPBHCl(H2O2] in octahedral geometry, [M(HPBHCl] in tetrahedral and square planar stereochemistries and trivalent complexes [M(HPBHCl2(H2O] in octahedral disposition. Infrared spectral data suggest that the ligand HPBH behaves as a monobasic tridentate ligand with N: N: O donor sequence towards the metal ions. On the basis of the above physicochemical data, octahedral, tetrahedral and square planar geometries were assigned for the complexes. The ligand and metal complexes were screened for their physiological activities against E. coli and S. aureus. The order of physiological activity has been found to be Cu(II > Ni(II > Zn(II > Co(II > Cr(III > Mn(II > Fe (III > ligand against E.coli and Ni(II > Cu(II > Zn(II > Mn(II > Cr(III > Fe(III > Co(II > ligand against S. aureus.

AKSES JENIS DOKUMEN PADA BASIS DATA TERPADU: SUATU TINJAUAN TERHADAP OPAC DI PDII-LIPI

Directory of Open Access Journals (Sweden)

Ade Kohar

2012-07-01

Full Text Available Integrated data base is a data base records bibliographic data of several types of document like textbook, periodicals, proceedings, research report, thesis, and article. Purposes of this study were to investigate document type description and searching strategy in integrated data base of online public access catalogs (OPAC in PDII-LIPI, and to know user opinion about that data base existence. It used observation and interviews to 100 data base users to collect data. Result of this study stated that document type description in OPAC was not indexed, so users couldn't do information searching of special type of document directly in the data base. There was only one method could be used to search information of special type of document. User could select it from some information records on the computer screen as the result of document title, author name or subject searching in the data base. This information access method was not efficient. So document type description and indexing was an important factor and should be done in information retrieval system using integrated data base. But respondent majority (84% in PDII-LIPI stated that they liked using separated data base to search information of special type of document.

Adsorptive removal of Cu(II) from aqueous solutions using collagen-tannin resin

Energy Technology Data Exchange (ETDEWEB)

Sun Xia; Huang Xin [Department of Biomass Chemistry and Engineering, Sichuan University, Chengdu 610065 (China); Liao Xuepin, E-mail: xpliao@scu.edu.cn [Department of Biomass Chemistry and Engineering, Sichuan University, Chengdu 610065 (China); National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065 (China); Shi Bi, E-mail: shibi@scu.edu.cn [National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610065 (China)

2011-02-28

The collagen-tannin resin (CTR), as a novel adsorbent, was prepared via a reaction of collagen with black wattle tannin and aldehyde, and its adsorption properties to Cu(II) were systematically investigated, including pH effect, adsorption equilibrium, adsorption kinetics, and column adsorption. The adsorption capacity of Cu(II) on CTR was pH-dependent, and it increased with the increase of solution pH. The adsorption isotherms were well described by Langmuir isotherm model with correlating constant (R{sup 2}) higher than 0.99. The adsorption capacity determined at 303 K was high up to 0.26 mmol/g, which was close to the value (0.266 mmol/g) estimated from Langmuir equation. The adsorption capacity was increased with the increase of temperature, and thermodynamic calculations suggested that the adsorption of Cu(II) on CTR is an endothermic process. The adsorption kinetics were well fitted by the pseudo-second-order rate model. Further column studies suggested that CTR was effective for the removal of Cu(II) from solutions, and more than 99% of Cu(II) was desorbed from column using 0.1 mol/L HNO{sub 3} solution. The CTR column can be reused to adsorb Cu(II) without any loss of adsorption capacity.

From atactic to isotactic CO/p-methylstyrene copolymer by proper modification of Pd(II) catalysts bearing achiral alpha-diimines.

Science.gov (United States)

Binotti, Barbara; Carfagna, Carla; Zuccaccia, Cristiano; Macchioni, Alceo

2005-01-07

Cationic Pd(II) complexes modified with achiral C(2v)-symmetric alpha-diimine ligands allow preparation of atactic or isotactic stereoblock CO/p-methylstyrene copolymers; both catalyst activity and polyketone microstructure depend on the choice of alpha-diimine substituents and counterion.

Synthetic hydroxyapatites doped with Zn(II) studied by X-ray diffraction, infrared, Raman and thermal analysis

Science.gov (United States)

Guerra-López, José R.; Echeverría, Gustavo A.; Güida, Jorge A.; Viña, Raúl; Punte, Graciela

2015-06-01

Calcium hydroxyapatite (CaHap) formation when different amounts of Zn(II) are present in the mother solution has been investigated by atomic absorption, infrared and Raman spectroscopies, X-ray diffraction and thermal analysis (DTA and TG). The studied samples have been synthesized at T=95 °C and pH 9 in air. The analysis of the results have shown that the pure CaHap sample crystallizes in the monoclinic form P21/b. Concentrations up to 20% of Zn(II) in the mother solution, equivalent to smaller concentrations in solid (up to 9.1% in wt), favor the formation of the hexagonal apatite, P63/m, while Zn(II) concentrations higher than 20% in solution help an amorphous phase development where vibrational spectra indicated coexistence of two phases: an apatite and ZnNH4PO4·H2O. Infrared data of thermal treated samples endorse that HPO42- ion had not been incorporated in Zn(II) doped samples during the synthesis process. Present results also allow to conclude that Zn(II) cation exhibits a preference to occupy the Ca2 site of the apatite structure and induces water adsorption and a small quantity of CO32- cation incorporation, leading to formation of a less crystalline Ca deficient apatite.

COMPOSITIONS BASED ON PALLADIUM(II AND COPPER(II COMPOUNDS, HALIDE IONS, AND BENTONITE FOR OZONE DECOMPOSITION

Directory of Open Access Journals (Sweden)

T. L. Rakitskaya

2017-05-01

bromide ion. For Cu(II-KBr/N-Bent composition, kinetic and calculation data show that, in the presence of bromide ions, copper(II inhibits the ozone decomposition. For Pd(II-KBr/NBent composition, it has been found that the maximum activity is attained at СPd(II = 1.02·10-5 mol/g. For bimetallic Pd(II- Cu(II-KBr/N-Bent composition, changes in τ0, τ1/2, k1/2, and Q1/2 parameters depending on a Pd(II content are similar to those for monometallic Pd(II-KBr/NBent composition; however, values of the parameters are higher for the monometallic system. Thus, the inhibiting effect of Cu(II is observed even in the presence of palladium(II.

Artificial neural network (ANN) approach for modeling Zn(II) adsorption in batch process

Energy Technology Data Exchange (ETDEWEB)

Yildiz, Sayiter [Engineering Faculty, Cumhuriyet University, Sivas (Turkmenistan)

2017-09-15

Artificial neural networks (ANN) were applied to predict adsorption efficiency of peanut shells for the removal of Zn(II) ions from aqueous solutions. Effects of initial pH, Zn(II) concentrations, temperature, contact duration and adsorbent dosage were determined in batch experiments. The sorption capacities of the sorbents were predicted with the aid of equilibrium and kinetic models. The Zn(II) ions adsorption onto peanut shell was better defined by the pseudo-second-order kinetic model, for both initial pH, and temperature. The highest R{sup 2} value in isotherm studies was obtained from Freundlich isotherm for the inlet concentration and from Temkin isotherm for the sorbent amount. The high R{sup 2} values prove that modeling the adsorption process with ANN is a satisfactory approach. The experimental results and the predicted results by the model with the ANN were found to be highly compatible with each other.

Artificial neural network (ANN) approach for modeling Zn(II) adsorption in batch process

International Nuclear Information System (INIS)

Yildiz, Sayiter

2017-01-01

Artificial neural networks (ANN) were applied to predict adsorption efficiency of peanut shells for the removal of Zn(II) ions from aqueous solutions. Effects of initial pH, Zn(II) concentrations, temperature, contact duration and adsorbent dosage were determined in batch experiments. The sorption capacities of the sorbents were predicted with the aid of equilibrium and kinetic models. The Zn(II) ions adsorption onto peanut shell was better defined by the pseudo-second-order kinetic model, for both initial pH, and temperature. The highest R"2 value in isotherm studies was obtained from Freundlich isotherm for the inlet concentration and from Temkin isotherm for the sorbent amount. The high R"2 values prove that modeling the adsorption process with ANN is a satisfactory approach. The experimental results and the predicted results by the model with the ANN were found to be highly compatible with each other.

Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand

Energy Technology Data Exchange (ETDEWEB)

Mruthyunjayaswamy, B.H.M.; Ijare, Omkar B.; Jadegoud, Y. [Gulbarga University (India). Dept. of Chemistry]. E-mail: bhmmswamy53@rediffmail.com

2005-07-15

A phenol based novel macrocyclic binucleating compartmental ligand N,N-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. The complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of Cu(II), Ni(II), Co(II), Cd(II), Zn(II) and Hg(II) in methanol to get a series of dinuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, ESR, NMR and FAB mass spectral data. The dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, ESR and FAB mass spectral data. The ligand as well as Cu(II), Ni(II), Co(II) and Zn(II) complexes were tested for their antibacterial and antifungal properties against Escherichia coli, Staphyloccocus aureus, Aspergillus niger and Fusarium oxysporum. Magnetic susceptibility measurements of Cu(II), Ni(II) and Co(II) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. FAB mass spectrum of the Cu(II) complex gave a clear evidence for the dinuclear nature. The ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus Fusarium oxysporum. (author)

Studies on complexation of a tridentate ONS Schiff base with lighter and heavier metals ions, and investigation into their biological properties

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Ali, A.M.; Juan, W.D.; Crouse, K.A.; Silong, S.

1999-05-01

Several new complexes of a tridentate ONS Schiff base derived from the condensation of S-benzyldithiocarbazate with salicylaldehyde have been characterised by elemental analyses, molar conductivity measurements, infrared, and electronic spectral studies. The tridentate Schiff base (HONSH) behaves as a dinegatively charged ligand coordinating through the thiolo sulphur, the azomethine nitrogen atom and the hydroxyl oxygen atom. It forms mono-ligand complexes of the general formula, [M(ONS)X], [M = Ni(II), Cu(II), Cr(III), Sb(III), Zn(II), Zr(IV) or U(VI) and X = H 2 O, Cl]. The ligand produced bis-chelated complex with Th(IV) of composition, [Th(ONS) 2 ]. Square-planar structures were proposed for the Ni(II) and Cu(II) complexes. Antimicrobial tests indicated that the Schiff base and five of the metal complexes of Cu(II), Ni(II), U(VI), Zn(II) and Sb(III) were found to be strongly active against bacteria. Ni(II) and Sb(III) complexes were the most effective against Pseudomonas aeruginosa (gram negative) while the Cu(II) complex proved to be the best against Bacillus cereus (gram positive bacteria). Antifungal activities were also noted with the Schiff base and the U(VI) complex. These compounds have shown results against Candida albicans fungi. But none of these compounds were effective against Aspergillus ochraceous fungi. (author)

Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand

International Nuclear Information System (INIS)

Mruthyunjayaswamy, B.H.M.; Ijare, Omkar B.; Jadegoud, Y.

2005-01-01

A phenol based novel macrocyclic binucleating compartmental ligand N,N-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. The complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of Cu(II), Ni(II), Co(II), Cd(II), Zn(II) and Hg(II) in methanol to get a series of dinuclear complexes. The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, IR, UV-Vis, ESR, NMR and FAB mass spectral data. The dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, ESR and FAB mass spectral data. The ligand as well as Cu(II), Ni(II), Co(II) and Zn(II) complexes were tested for their antibacterial and antifungal properties against Escherichia coli, Staphyloccocus aureus, Aspergillus niger and Fusarium oxysporum. Magnetic susceptibility measurements of Cu(II), Ni(II) and Co(II) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. FAB mass spectrum of the Cu(II) complex gave a clear evidence for the dinuclear nature. The ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus Fusarium oxysporum. (author)

Adsorption of Zn(II) on the kaolinite(001) surfaces in aqueous environment: A combined DFT and molecular dynamics study

Energy Technology Data Exchange (ETDEWEB)

Wang, Qiang; Kong, Xiang-Ping; Zhang, Bao-Hua; Wang, Juan, E-mail: juaner80@163.com

2017-08-31

Highlights: • Zn(II) adsorption on two types of neutral kaolinite(001) surfaces is investigated. • Surface “Ou” is found the preferred site for mono- and bi-dentate complexes. • Both Zn(II) and surface oxygen accept electrons from aqua oxygens. • Coupling of O 2p with Zn sp{sup 3}d{sup 2} (or sp{sup 3}) hybridization states is the bonding nature. - Abstract: Adsorption of Zn(II) on two types of neutral (001) surfaces of kaolinite, tetrahedral Si(t) and octahedral Al(o), was studied by means of DFT calculations and classical molecular dynamics simulations. The position and structure for both outer-sphere and mono-/bi-dentate inner-sphere complexes of Zn(II) in aqueous environment were examined, with binding energy and radial distribution function calculated. Outer-sphere complex on the Si(t) surface, monodentate inner-sphere complex of “O{sub u}” (surface oxygen with “upright” hydrogen) site and bidentate complex of “O{sub u}-O{sub u}” site of neighboring Al centers on the Al(o) surface are considered to be the dominant adsorption species. The outer-sphere complex is found six-coordinated with distorted octahedral geometry, while both the inner-sphere complexes exhibit the tetrahedral structure with coordination number of four. Hydrogen bonding interactions between oxygen or hydrogen of the kaolinite(001) surfaces and the aqua ligands of Zn(II) act as the key role for the structure and stability of adsorption complexes. Upon the Mulliken population analysis and partial density of states, both Zn(II) and surface oxygen accept electrons from aqua oxygens, and coupling of O 2p with the sp{sup 3}d{sup 2} or sp{sup 3} hybridization states of Zn(II) is the primary bonding nature of Zn(II) with oxygen in outer- and inner-sphere complexes, respectively.

Equilibrium and spectral studies on ligational behaviour of N,N ...

Indian Academy of Sciences (India)

Unknown

The solid complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II),. Zn(II) and Pb(II) with DFH have been synthesized, and have been characterized by elemental analysis ... Magnetic susceptibilities of the metal chelates were measured at room ...

Synthesis, Spectroscopic and Pharmacological Studies of Bivalent ...

African Journals Online (AJOL)

NICO

A series of metal complexes of Cu(II), Zn(II) and Hg(II) having the general composition [M(L)2X2] [where L .... determined by carrageenan induced paw oedema model. The .... C–N deformation.21 In each complex, two thiourea ligands coor-.

Poly (furfural-acetone as New Adsorbent for Removal of Cu(II from Aqueous Solution: Equilibrium Study

Directory of Open Access Journals (Sweden)

Tariq S. Najim

2010-01-01

Full Text Available The batch removal of Cu(II from aqueous solution using poly (furfural-acetone, (PFA as adsorbent was investigated in this study. The influences of initial Cu(II ion concentration (10 to 120 ppm, pH (4-8 and contact time have been reported. Adsorption of Cu(II is highly pH-dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II from a solution of initial concentration 10 ppm. It was observed that an increase in initial concentration of Cu(II leads to decrease in percent removal of Cu(II and increase in amount of Cu(II adsorbed per unit mass of PFA. The adsorption process of Cu(II is tested with four isotherm models, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R. It was found that all models were applicable and the maximum adsorption capacity was found to be 13.66 mg/g. From the isotherm constants it was confirmed that, the sorption process was physisorption.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

International Nuclear Information System (INIS)

Xue Yongjie; Hou Haobo; Zhu Shujing

2009-01-01

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO 3 . In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH 50 (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

Energy Technology Data Exchange (ETDEWEB)

Xue Yongjie [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China); Wuhan Kaidi Electric Power Environmental Protection Co. Ltd., Hubei, Wuhan (China)], E-mail: xueyj@mail.whut.edu.cn; Hou Haobo; Zhu Shujing [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China)

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO{sub 3}. In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH{sub 50} (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag.

Science.gov (United States)

Xue, Yongjie; Hou, Haobo; Zhu, Shujing

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01M NaNO(3). In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84mM in the single element system and 0.21mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH(50) (the pH at which 50% adsorption occurs) was found to follow the sequence Zn>Cu>Pb>Cd in single-element systems, but Pb>Cu>Zn>Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

Accumulation of metal ions by pectinates

Science.gov (United States)

Deiana, S.; Deiana, L.; Palma, A.; Premoli, A.; Senette, C.

2009-04-01

The knowledge of the mechanisms which regulate the interactions of metal ions with partially methyl esterified linear polymers of α-1,4 linked D-galacturonic acid units (pectinates), well represented in the root inner and outer apoplasm, is of great relevance to understand the processes which control their accumulation at the soil-root interface as well as their mobilization by plant metabolites. Accumulation of a metal by pectinates can be affected by the presence of other metals so that competition or distribution could be expected depending on the similar or different affinity of the metal ions towards the binding sites, mainly represented by the carboxylate groups. In order to better understand the mechanism of accumulation in the apoplasm of several metal ions, the sorption of Cd(II), Zn(II), Cu(II), Pb(II) and Cr(III) by a Ca-polygalacturonate gel, used as model of the soil-root interface, with a degree of esterification of 18% (PGAE1) and 65% (PGAE2) was studied at pH 3.0, 4.0, 5.0 and 6.0 in the presence of CaCl2 2.5 mM.. The results show that sorption increases with increasing both the initial metal concentration and pH. A similar sorption trend was evidenced for Cu(II) and Pb(II) and for Zn(II) and Cd(II), indicating that the mechanism of sorption for these two ionic couples is quite different. As an example, at pH 6.0 and an initial metal concentration equal to 2.0 mM, the amount of Cu(II) and Pb(II) sorbed was about 1.98 mg-1 of PGAE1 while that of Cd(II) and Zn(II) was about 1.2 mg-1. Cr(III) showed a rather different sorption trend and a much higher amount (2.8 mg-1of PGAE1 at pH 6.0) was recorded. The higher affinity of Cr(III) for the polysaccharidic matrix is attributable to the formation of Cr(III) polynuclear species in solution, as shown by the distribution diagrams obtained through the MEDUSA software. On the basis of these findings, the following affinity towards the PGAE1 can be assessed: Cr(III) > Cu(II) ? Pb(II) > Zn (II) ? Cd

Removal of Cu(II) from acidic electroplating effluent by biochars generated from crop straws.

Science.gov (United States)

Tong, Xuejiao; Xu, Renkou

2013-04-01

The removal efficiency of copper (Cu(II)) from an actual acidic electroplating effluent by biochars generated from canola, rice, soybean and peanut straws was investigated. The biochars simultaneously removed Cu(II) from the effluent, mainly through the mechanisms of adsorption and precipitation, and neutralized its acidity. The removal efficiency of Cu(II) by the biochars followed the order: peanut straw char > soybean straw char > canola straw char > rice straw char > a commercial activated carbonaceous material, which is consistent with the alkalinity of the biochars. The pH of the effluent was a key factor determining the removal efficiency of Cu(II) by biochars. Raising the initial pH of the effluent enhanced the removal of Cu(II) from it. The optimum pyrolysis temperature was 400 degrees C for producing biochar from crop straws for acidic wastewater treatment, and the optimum reaction time was 8 hr.

Midrange affinity fluorescent Zn(II) sensors of the Zinpyr family: syntheses, characterization, and biological imaging applications.

Science.gov (United States)

Nolan, Elizabeth M; Jaworski, Jacek; Racine, Maryann E; Sheng, Morgan; Lippard, Stephen J

2006-11-27

The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as "midrange". They give approximately 12- (ZP9) and approximately 7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo.

Mononuclear Pd(II) complex as a new therapeutic agent: Synthesis, characterization, biological activity, spectral and DNA binding approaches

Science.gov (United States)

Saeidifar, Maryam; Mirzaei, Hamidreza; Ahmadi Nasab, Navid; Mansouri-Torshizi, Hassan

2017-11-01

The binding ability between a new water-soluble palladium(II) complex [Pd(bpy)(bez-dtc)]Cl (where bpy is 2,2‧-bipyridine and bez-dtc is benzyl dithiocarbamate), as an antitumor agent, and calf thymus DNA was evaluated using various physicochemical methods, such as UV-Vis absorption, Competitive fluorescence studies, viscosity measurement, zeta potential and circular dichroism (CD) spectroscopy. The Pd(II) complex was synthesized and characterized using elemental analysis, molar conductivity measurements, FT-IR, 1H NMR, 13C NMR and electronic spectra studies. The anticancer activity against HeLa cell lines demonstrated lower cytotoxicity than cisplatin. The binding constants and the thermodynamic parameters were determined at different temperatures (300 K, 310 K and 320 K) and shown that the complex can bind to DNA via electrostatic forces. Furthermore, this result was confirmed by the viscosity and zeta potential measurements. The CD spectral results demonstrated that the binding of Pd(II) complex to DNA induced conformational changes in DNA. We hope that these results will provide a basis for further studies and practical clinical use of anticancer drugs.

Investigation of solution chemistry effects on sorption behavior of radionuclide 64Cu(II) on illite

International Nuclear Information System (INIS)

Shitong Yang; Guodong Sheng; Zhiqiang Guo; Yubing Sun; Donglin Zhao

2011-01-01

In this work, a series of batch experiments were carried out to investigate the effect of various environmental factors such as contact time, pH, ionic strength, coexisting electrolyte ions, humic substances and temperature on the sorption behavior of illite towards 64 Cu(II). The results indicated that 64 Cu(II) sorption on illite achieved equilibrium quickly. The pH- and ionic strength-dependent sorption suggested that 64 Cu(II) sorption on illite was dominated by ion exchange or outer-sphere surface complexation at pH 7. A positive effect of humic substances on 64 Cu(II) sorption was found at pH 6.5. The Langmuir and Freundlich models were used to simulate the sorption isotherms of 64 Cu(II) at three different temperatures of 293, 313, and 333 K. The thermodynamic parameters (ΔH 0 , ΔS 0 , and ΔG 0 ) of 64 Cu(II) sorption on illite were calculated from the temperature dependent sorption isotherms, and the results indicated that the sorption of 64 Cu(II) on illite was endothermic and spontaneous. From the experimental results, it is possible to conclude that illite has good potentialities for cost-effective treatments of 64 Cu(II)-contaminated wastewaters. (author)

Characterization of sophorolipid biosurfactant produced by Cryptococcus sp. VITGBN2 and its application on Zn(II) removal from electroplating wastewater.

Science.gov (United States)

Basak, Geetanjali; Das, Nilanjana

2014-11-01

The present study aimed at elucidating the role of biosurfactant produced by yeast for the removal of Zn(II) ions from electroplating wastewater. The yeast species isolated from CETP, Vellore, Tamilnadu was identified as Cryptococcus sp.VITGBN2, based on molecular techniques, and was found to be potent producer of biosurfactant in mineral salt media containing vegetable oil as additional carbon source. Chemical structure of the purified biosurfactant was identified as acidic diacetate sophorolipid through GC-MS analysis. Interaction of Zn(II) ions with biosurfactant was monitored using FT-IR, SEM and EDS analysis. Zn (II) removal at 100 mg l(-1) concentration was 84.8% compared were other synthetic surfactants (Tween 80 and sodium dodecyl sulphate), yeast mediated biosurfactant showed enhanced Zn (II) removal in batch mode. The role of biosurfactant on Zn(II) removal was evaluated in column mode packed with biosurfactant entrapped in sodium alginate beads. At a flow rate of 1 ml min(-1) and bed height of 12 cm, immobilized biosurfactant showed 94.34% Zn(II) removal from electroplating wastewater. The present study confirmed that Zn(II) removal was biosurfactant mediated. This is the first report establishing the involvement of yeast mediated biosurfactant in Zn(II) removal from wastewater.

Adsorption of enrofloxacin in presence of Zn(II) on a calcareous soil.

Science.gov (United States)

Graouer-Bacart, Mareen; Sayen, Stéphanie; Guillon, Emmanuel

2015-12-01

As a result of their consumption, excretion, disposal and persistence, antibiotics enter the soil environment and may be transported to surface and ground waters. During their transfer through soils, retention processes play a key role in their mobility. Antibiotics often coexist with heavy metals in soils due to agricultural practices and other sources of inputs. In this context, this study deals with the co-adsorption of Zn(II) and enrofloxacin (ENR), a widely-used veterinary antibiotic, on a calcareous soil using batch retention experiments and X-ray Absorption Near Edge Structure (XANES) spectroscopy. To improve our understanding of the interaction of this emerging organic contaminant with metal cations at the water-soil interface, the ternary system containing ENR, Zn(II) and a selected calcareous soil was investigated over a pH range between 7 and 10, at different solid-solution contact times and ENR concentrations. The presence of Zn(II) slightly influenced the retention of the antibiotic, leading to an increase of the adsorbed ENR amounts. The distribution coefficient Kd value increased from 0.66 Lg(-1) for single ENR adsorption to 1.04 Lg(-1) in presence of Zn(II) at a 1/2 ENR/Zn(II) ratio. The combination of adsorption isotherm data, solution speciation diagrams and XANES spectra evidenced a small proportion of Zn(II)-ENR complexes at soil pH leading to the slight increase of ENR adsorption in presence of zinc. These results suggest that it is necessary to consider the interaction between ENR and metal cations when assessing the mobility of ENR in soils. Copyright © 2015 Elsevier Inc. All rights reserved.

SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A Zn(II COORDINATION POLYMER BASED ON 4,4’-BIPYRIDINE AND ACETATO

Directory of Open Access Journals (Sweden)

LI-HUA WANG

2015-05-01

Full Text Available A novel Zn(II coordination polymer, [Zn(bpy(acetato2]n (bpy = 4,4’-bipyridine, has been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The Zn(II coordination polymer is triclinic, space group P-1 with a = 8.046(3 Å, b = 9.161(3 Å, c = 10.663(3 Å, α = 109.769(4º, β = 99.966(5º, γ = 101.666(5º, V= 699.1(4 Å3, Z = 2, Dc = 1.614 mg·m-3, μ = 1.774 mm-1, F(000 = 348, and final R1 = 0.0541, ωR2 = 0.1605. X-ray diffraction analysis reveals that the Zn(II center is six-coordination with a N2O4 distorted octahedral coordination environment. The Zn(II complex forms 1D chain structure by the bridge of 4,4’-bipyridine and acetato.

Ni(II, Pd(II and Pt(II complexes with ligand containing thiosemicarbazone and semicarbazone moiety: synthesis, characterization and biological investigation

Directory of Open Access Journals (Sweden)

SULEKH CHANDRA

2008-07-01

Full Text Available The synthesis of nickel(II, palladium(II and platinum(II complexes with thiosemicarbazone and semicarbazone of p-tolualdehyde are reported. All the new compounds were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, 1H-NMR, IR and electronic spectral studies. Based on the molar conductance measurements in DMSO, the complexes may be formulated as [Ni(L2Cl2] and [M(L2]Cl2 (where M = Pd(II and Pt(II due to their non-electrolytic and 1:2 electrolytic nature, respectively. The spectral data are consistent with an octahedral geometry around Ni(II and a square planar geometry for Pd(II and Pt(II, in which the ligands act as bidentate chelating agents, coordinated through the nitrogen and sulphur/oxygen atoms. The ligands and their metal complexes were screened in vitro against fungal species Alternaria alternata, Aspergillus niger and Fusarium odum, using the food poison technique.

Transition metal complexes of a new 15-membered [N5] penta-azamacrocyclic ligand with their spectral and anticancer studies

Science.gov (United States)

El-Boraey, Hanaa A.; Serag El-Din, Azza A.

2014-11-01

Novel penta-azamacrocyclic 15-membered [N5] ligand [L] i.e. 1,5,8,12-tetetraaza-3,4: 9,10-dibenzo-6-ethyl-7-methyl-1,12-(2,6-pyrido)cyclopentadecan-5,7 diene-2,11-dione and its transition metal complexes with Co(II), Ni(II), Cu(II), Ru(III) and Pd(II) have been synthesized and structurally characterized by elemental analysis, spectral, thermal as well as magnetic and molar conductivity measurements. On basis of IR, MS, UV-Vis 1H NMR and EPR spectral studies an octahedral geometry has been proposed for all complexes except Co(II), Cu(II) nitrate complexes and Pd(II) chloride complex that adopt tetrahedral, square pyramidal and square planar geometries, respectively. The antitumor activity of the synthesized ligand and some complexes against human breast cancer cell lines (MCF-7) and human hepatocarcinoma cell lines (HepG2) has been studied. The complexes (IC50 = 2.04-9.7, 2.5-3.7 μg/mL) showed potent antitumor activity comparable with their ligand (IC50 = 11.7, 3.45 μg/mL) against the above mentioned cell lines, respectively. The results evidently show that the activity of the ligand becomes more pronounced and significant when coordinated to the metal ion.

14N nuclear quadrupole interaction in Cu(II) doped L-alanine

International Nuclear Information System (INIS)

Murgich, J.; Calvo, R.; Oseroff, S.B.; Instituto Venezolano de Investigaciones Cientificas, Caracas. Dept. de Quimica)

1980-01-01

The 14 N nuclear quadrupole interaction tensor Psub(N) measured by ENDOR in Cu(II) doped L-alanine is analyzed in terms of the Townes and Daily theory assuming a tetra-hedrally bonded N atom. The results of this analysis are compared with those for the 14 N in pure L-alanine and it is found that the principal directions of the Psub(N) tensor are drastically changed upon metal complexation as a consequence of the higher electron affinity of Cu(II) with respect to C and H. Comparison of the corresponding bond populations in pure and Cu(II) doped L-alanine indicates that the Cu draws 0.11 more electron from the N than the substituted H atom. (orig.)

Competitive metal sorption and desorption onto Kappaphycus alvarezii, seaweed waste biomass

International Nuclear Information System (INIS)

Lee, K.O.; Nazaruddin Ramli; Mamot Said; Musa Ahmad; Suhaimi Mohd Yasir; Arbakariya Ariff

2011-01-01

Competitive metal sorption and desorption onto Kappaphycus alvarezii waste biomass were investigated. Metal sorption capacities were 0.82 mg Cr (III)/ g, 0.73 mg Ni (II)/ g, 0.67 mg Cd (II)/ g, 0.65 mg Cu( II)/ g and 0.64 mg Zn (II)/ g in multi metal system. Whereas, desorption efficiencies were 66.08 %, 71.50 % and 80.44 % using 0.1 M HNO 3 , 0.1 M HCl and 0.1 M H 2 SO 4 , respectively. The metal sorption sequence were Cr(III) > Ni(II) > Cd(II) > Cu(II) > Zn(II), while metal desorption sequence were Cd(II) > Zn(II) > Cu(II) > Ni(II) > Cr(III). Fourier transformed infrared spectroscopy (FTIR) technique was used to characterize the seaweed waste biomass. FTIR analysis shown that carbonyl (-C-O) and nitrile (-C≡N) groups interact with the metal ions. The experiments result revealed that Kappaphycus alvarezii waste biomass represent an attractive candidate to remove multi metal ions. (author)

Structural characterization and antimicrobial activities of transition metal complexes of a hydrazone ligand

Science.gov (United States)

Bakale, Raghavendra P.; Naik, Ganesh N.; Machakanur, Shrinath S.; Mangannavar, Chandrashekhar V.; Muchchandi, Iranna S.; Gudasi, Kalagouda B.

2018-02-01

A hydrazone ligand has been synthesized by the condensation of 2-nitrobenzaldehyde and hydralazine, and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been reported. Structural characterization of the ligand and its metal complexes has been performed by various spectroscopic [IR, NMR, UV-Vis, Mass], thermal and other physicochemical methods. The structure of the ligand and its Ni(II) complex has been characterized by single crystal X-ray diffraction studies. All the synthesized compounds have been screened for in vitro antimicrobial activity. The antibacterial activity is tested against Gram-positive strains Enterococcus faecalis, Streptococcus mutans and Staphylococcus aureus and Gram-negative strains Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae using ciprofloxacin as the reference standard. Antifungal activity is tested against Candida albicans, Aspergillus fumigatus and Aspergillus niger using ketoconazole as the reference standard. The minimum inhibitory concentration (MIC) was determined for test compounds as well as for reference standard. Ligand, Cu(II) and Zn(II) complexes have shown excellent activity against Candida albicans.

Synthesis and Spectral Evaluation of Some Unsymmetrical Mesoporphyrinic Complexes

Directory of Open Access Journals (Sweden)

Rica Boscencu

2012-06-01

Full Text Available Synthesis and spectral evaluation of new zinc and copper unsymmetrical mesoporphyrinic complexes are reported. Zn(II-5-(4-acetoxy-3-methoxyphenyl-10,15,20-tris-(4-carboxymethylphenylporphyrin, Zn(II-5-[(3,4-methylenedioxyphenyl]-10,15,20-tris-(4-carboxymethylphenylporphyrin, Cu(II-5-(4-acetoxy-3-methoxyphenyl-10,15,20-tris-(4-carboxymethylphenylporphyrin and Cu(II-5-[(3,4-methylenedioxyphenyl]-10,15,20-tris-(4-carboxymethylphenylporphyrin were synthesized using microwave-assisted synthesis. The complexes were characterized by elemental analysis, FT-IR, UV-Vis, EPR and NMR spectroscopy, which fully confirmed their structure. The spectral absorption properties of the porphyrinic complexes were studied in solvents with different polarities. Fluorescence emission and singlet oxygen formation quantum yields were evaluated for the compounds under study, revealing high yields for the zinc derivatives. The copper complexes are not emissive and only display residual capacity for singlet oxygen formation.

Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

Energy Technology Data Exchange (ETDEWEB)

Ghaedi, Mehrorang [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Niknam, Khodabakhsh [Chemistry Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Shokrollahi, Ardeshir; Niknam, Ebrahim; Rajabi, Hamid Reza [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

2008-06-30

A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L{sup -1} nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples.

Competitive metal sorption and desorption onto Kappaphycus alvarezii, seaweed waste biomass

Energy Technology Data Exchange (ETDEWEB)

Lee, K O; Ramli, Nazaruddin; Said, Mamot; Ahmad, Musa [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), Bangi, selangor (Malaysia); Yasir, Suhaimi Mohd [School of Sciences and Technology, Universiti Malaysia Sabah (UMS), Sabah (Malaysia); Arbakariya Ariff, E-mail: naza@ukm.my [Faculty of Biotechnology and Biomolecular science, Universiti Putra Malaysia (UPM), Serdang, Selangor (Malaysia)

2011-07-15

Competitive metal sorption and desorption onto Kappaphycus alvarezii waste biomass were investigated. Metal sorption capacities were 0.82 mg Cr (III)/ g, 0.73 mg Ni (II)/ g, 0.67 mg Cd (II)/ g, 0.65 mg Cu( II)/ g and 0.64 mg Zn (II)/ g in multi metal system. Whereas, desorption efficiencies were 66.08 %, 71.50 % and 80.44 % using 0.1 M HNO{sub 3}, 0.1 M HCl and 0.1 M H{sub 2}SO{sub 4}, respectively. The metal sorption sequence were Cr(III) > Ni(II) > Cd(II) > Cu(II) > Zn(II), while metal desorption sequence were Cd(II) > Zn(II) > Cu(II) > Ni(II) > Cr(III). Fourier transformed infrared spectroscopy (FTIR) technique was used to characterize the seaweed waste biomass. FTIR analysis shown that carbonyl (-C-O) and nitrile (-C{identical_to}N) groups interact with the metal ions. The experiments result revealed that Kappaphycus alvarezii waste biomass represent an attractive candidate to remove multi metal ions. (author)

Removal of Cu(II) in water by polymer enhanced ultrafiltration: Influence of polymer nature and pH.

Science.gov (United States)

Kochkodan, Olga D; Kochkodan, Viktor M; Sharma, Virender K

2018-01-02

This study presents an efficient removal of Cu(II) in water using the polymer enhanced ultrafiltration (PEUF) method. Polymer of different molecular weight (MW) (polyethyleneimine (PEI), sodium lignosulfonates (SLS) and dextrans) were investigated to evaluate efficiency in removal of Cu(II) in water by the PEUF method. The decomposition of Cu(II)-polymer complex was also evaluated in order to reuse polymers. Cu(II) complexation depends on the MW of chelating polymer and the pH of feed solution. It was found that the Cu(II) rejection increased with the polymer dosage with high removal of Cu(II) when using PEI and SLS at a 10:20 (mg/mg) ratio ([Cu(II)]:[polymer]). It was found that the maximum chelating capacity was 15 mg of Cu(II) per 20 mg of PEI. The Cu(II)-PEI complex could be decomposed by acid addition and the polymer could be efficiently reused with multiple complexation-decomplexation cycles. A conceptual flow chart of the integrated process of efficient removal of Cu(II) by PEUF method is suggested.

Removal of Zn(II) from electroplating effluent using yeast biofilm formed on gravels: batch and column studies

Science.gov (United States)

2014-01-01

Background Present study deals with the removal of Zn(II) ions from effluent using yeast biofilm formed on gravels. Methods The biofilm forming ability of Candida rugosa and Cryptococcus laurentii was evaluated using XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) reduction assay and monitored by scanning electron microscopy (SEM), and Confocal laser scanning microscopy (CLSM). Copious amount of extracellular polymeric substances (EPS) produced by yeast species was quantified and characterized by Fourier transform infrared spectroscopy (FT-IR). Results Yeast biofilm formed on gravels by C. rugosa and C. laurentii showed 88% and 74.2% removal of Zn(II) ions respectively in batch mode. In column mode, removal of Zn(II) ions from real effluent was found to be 95.29% by C. rugosa biofilm formed on gravels. Conclusion The results of the present study showed that there is a scope to develop a cost effective method for the efficient removal of Zn(II) from effluent using gravels coated with yeast biofilm. PMID:24397917

Synthesis, spectral characterization, antimicrobial, DNA interactions ...

Indian Academy of Sciences (India)

KUNCHE SUDEEPA

2018-05-04

May 4, 2018 ... structural aspects of FMBC and its Cu(II), Ni(II) and. Zn(II) complexes ... of DNA was down- loaded from protein data bank24 (www.rcsb.org) pdb id: ... the reaction mixture was refluxed on water bath for 4–8 h maintaining the ...

Characterization of Schiff base derived from 2-hydroxo-1 ...

African Journals Online (AJOL)

MBI

2014-03-04

Mar 4, 2014 ... derived from 2, 2' bis(p-methoxylphenylamine) and salicylic ... containing Co(II), Ni(II), Cu(II) and Zn(II) synthesized from ..... pKa = 12.55. Ka = 2.81E-13 .... 20, no. 3, 297 – 300. Gaowen Y., Xiaping X. , Huan T. and Chenxue Z.

Template synthesis, characterization and antimicrobial activity of the complex combinations of some transitional metals with isonicotinoylhydrazone -2,4,6- trimethylbenzaldehyde

International Nuclear Information System (INIS)

Mitu, L.ITU; Imran, M.

2011-01-01

The complexes of Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) with isonicotinoyl-hydrazone -2,4,6-trimethylbenzaldehyde (INHTB) are reported. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility, thermal analysis and for the Cu(II) complex the ESR spectrum has been recorded. The anti-bacterial activity of these complexes were investigated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Shigella flexneri bacteria. The INHTB ligand is coordinated at the metallic ions by oxygen amide (O=C) and the azomethine nitrogen. (author)

Poly (furfural-acetone) as New Adsorbent for Removal of Cu(II) from Aqueous Solution: Equilibrium Study

OpenAIRE

Najim, Tariq S.

2010-01-01

The batch removal of Cu(II) from aqueous solution using poly (furfural-acetone), (PFA) as adsorbent was investigated in this study. The influences of initial Cu(II) ion concentration (10 to 120 ppm), pH (4-8) and contact time have been reported. Adsorption of Cu(II) is highly pH-dependent and the result indicate that the optimum pH for the removal was found to be 6. At this pH a small amount of PFA, 2 g/L, could remove as much as 97% of Cu(II) from a solution of initial concentration 10 ppm....

A convenient method for determination of quizalofop-p-ethyl based on the fluorescence quenching of eosin Y in the presence of Pd(II)

Science.gov (United States)

Wu, Huan; Zhao, Yanmei; Tan, Xuanping; Zeng, Xiaoqing; Guo, Yuan; Yang, Jidong

2017-03-01

A convenient fluorescence quenching method for determination of Quizalofop-p-ethyl(Qpe) was proposed in this paper. Eosin Y(EY) is a red dye with strong green fluorescence (λex/λem = 519/540 nm). The interaction between EY, Pd(II) and Qpe was investigated by fluorescence spectroscopy, resonance Rayleigh scattering(RRS) and UV-Vis absorption. Based on changes in spectrum, Pd(II) associated with Qpe giving a positively charged chelate firstly, then reacted with EY through electrostatic and hydrophobic interaction formed ternary chelate could be demonstrated. Under optimum conditions, the fluorescence intensity of EY could be quenched by Qpe in the presence of Pd(II) and the RRS intensity had a remarkable enhancement, which was directly proportional to the Qpe concentration within a certain concentration range, respectively. Based on the fluorescence quenching of EY-Pd(II) system by Qpe, a novel, convenient and specific method for Qpe determination was developed. To our knowledge, this is the first fluorescence method for determination of Qpe was reported. The detection limit for Qpe was 20.3 ng/mL and the quantitative determination range was 0.04-1.0 μg/mL. The method was highly sensitive and had larger detection range compared to other methods. The influence of coexisting substances was investigated with good anti-interference ability. The new analytical method has been applied to determine of Qpe in real samples with satisfactory results.

Synthesis, spectral, thermal and antimicrobial studies on cobalt(II), nickel(II), copper(II), zinc(II) and palladium(II) complexes containing thiosemicarbazone ligand

Science.gov (United States)

El-Sawaf, Ayman K.; El-Essawy, Farag; Nassar, Amal A.; El-Samanody, El-Sayed A.

2018-04-01

The coordination characteristic of new N4-morpholinyl isatin-3-thiosemicarbazone (HL) towards Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) has been studies. The structures of the complexes were described by elemental analyses, molar conductivity, magnetic, thermal and spectral (IR, UV-Vis, 1H and 13C NMR and ESR) studies. On the basis of analytical and spectral studies the ligand behaves as monobasic tridentate ONS donor forming two five membered rings towards cobalt, copper and palladium and afforded complexes of the kind [M(L)X], (Mdbnd Co, Cu or Pd; Xdbnd Cl, Br or OAc). Whereas the ligand bound to NiCl2 as neutral tridentate ONS donor and with ZnCl2 as neutral bidentate NS donor. The newly synthesized thiosemicarbazone ligand and some of its complexes were examined for antimicrobial activity against 2 gram negative bacterial strains (Escherichia coli Pseudomonas and aeruginosa), 2 gram positive bacterial strains (Streptococcus pneumoniae and Staphylococcus aureus)} and two Pathogenic fungi (Aspergillus fumigatus and Candida albicans). All metal complexes possess higher antimicrobial activity comparing with the free thiosemicarbazone ligand. The high potent activities of the complexes may arise from the coordination and chelation, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growing of the microorganisms. The antimicrobial results also show that copper bromide complex is better antimicrobial agent as compared to the Schiff base and its metal complexes.

Co-sequestration of Zn(II) and phosphate by γ-Al{sub 2}O{sub 3}: From macroscopic to microscopic investigation

Energy Technology Data Exchange (ETDEWEB)

Ren, Xuemei [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031, Hefei (China); Tan, Xiaoli [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, 230031, Hefei (China); Hayat, Tasawar [Department of Mathematics, Quaid-I-Azam University, Islamabad 44000 (Pakistan); NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Alsaedi, Ahmed [NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Wang, Xiangke, E-mail: xkwang@ipp.ac.cn [School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions (China)

2015-10-30

Highlights: • How the Zn and phosphate behave in each other’s presence is elucidated. • Surface speciation of Zn(II) is affected by the presence of phosphate. • Combining macroscopic study with EXAFS can determine the Zn(II) surface speciation. • The enhanced Zn(II) sorption is mainly due to ternary surface complexation at 0.19 mmol P/L and pH 6.5. • Phosphate ions prevent the formation of an Zn–Al LDH phase at pH 8.0. - Abstract: Little information is available concerning co-sorbing oxyanion and metal contaminants in the environment, yet in most metal-contaminated areas, co-contamination by phosphate is common. In this study, the mutual effects of phosphate and Zn(II) on their interaction with γ-Al{sub 2}O{sub 3} are investigated by batch experiments and X-ray absorption fine structure spectroscopy (XAFS) technique. The results show that the co-sorption of phosphate on γ-Al{sub 2}O{sub 3} modifies both the extent of Zn(II) sorption and the local atomic structures of sorbed Zn(II) ions. Multiple mechanisms are involved in Zn(II) retention in the presence of phosphate, including electrostatic interaction, binary and ternary surface complexation, and the formation of Zn(II)-phosphate polynuclear complexes. At pH 6.5, type III ternary surface complexation occurs concurrently with binary Zn-alumina surface complexation at low phosphate concentrations, whereas the formation of type III ternary surface complexes is promoted as the phosphate concentration increases. With further increasing phosphate concentration, Zn(II)-phosphate polynuclear complexes are formed. At pH 8.0, Zn dominantly forms type III ternary surface complexes in the presence of phosphate. The results of this study indicate the variability of Zn complexation on oxide surface and the importance of combining macroscopic observations with XAFS capable of determining metal complex formation mechanism for ternary system.

Magnetic Study of the Novel Polynuclear Compound [Cu(II)(6-Mercaptopurinolate 2-)] n

Science.gov (United States)

Acevedo-Chávez, Rodolfo; Costas, María. Eugenia; Escudero, Roberto

1997-08-01

Chemical reactions between Cu(II) and 6-mercaptopurine, both in aqueous and in methanolic media, yield the novel amorphous polynuclear compound [Cu(II)(6-mercaptopurinolate)2-]n, which is also obtained from diverse Cu(II)-heterocyclic ligand competitive reactions. The kinetic and thermodynamic stabilities associated with the formation of this compound are inferred as remarkable. The spectroscopic data let us suggest the involvement of the exocyclic S(6) donor site and the N atoms in the imidazolic moiety of the deprotonated heterocyclic ligand in the coordination to Cu(II) atoms, forming a distorted bidimensional metallic network. The magnetic studies show the existence of very weak antiferromagnetic coupling in the solid sample. This system represents the first example of a 1 : 1 metal : 6-mercaptopurinolate2-system with ad-type open shell metallic center. The magnetic study carried out also represents the first example of magnetic characterization for this type of polynuclear Cu(II) systems with the dianionic 6-mercaptopurine ligand.

Utilization of m-Phenylenediamine-Furfural Resin for Removal of Cu(II) from Aqueous Solution-A Thermodynamic Study

OpenAIRE

Najim, Tariq S.; Zainal, Israa G.; Ali, Dina A.

2010-01-01

m-Phenylenediamine was condensed with furfural in absence of catalyst at room temperature. The produced m-phenylenediamine-furfural resin was used for the removal of Cu(II) from aqueous solution. The pH for the optimum removal of Cu(II) was 6. The negative values of Gibbs free energy at low concentration of Cu(II) (20, 30 ppm) indicative of the spontaneous adsorption process, while, at higher Cu(II) concentration (40,50 ppm) the positive and weak values of ∆G° indicate that the process is fea...

Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies

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AYALOOR SUBRAMANIAN RAMASUBRAMANIAN

2011-01-01

Full Text Available Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II, Ni(II, Co(II and Pd(II, were synthesized and characterized by physico–chemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II and Ni(II complexes were assigned octahedral geometries, while the Cu (II and Pd(II complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2-methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO as co-oxidant. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.

Dendritic chelating agents. 1. Cu(II) binding to ethylene diamine core poly (amidoamine) denderimers in aqueous solutions

International Nuclear Information System (INIS)

Diallo, Mamadou S.; Christie, Simone; Swaminathan, Pirabalini; Balogh, Lajos; Shi, XIANGYANG; Um, Wooyong; Papelis, Charalambos; Goddard, William A.; Johnson, J. H.

2004-01-01

The overall results of the proton and metal ion binding measurements suggest that the uptake of Cu(II) by EDA core PAMAM dendrimers involves both the dendrimer tertiary amine and terminal groups. However, the extents of protonation of these groups control the ability of the dentrimers to bind Cu(II). Analysis of the EXAFS spectra suggests that Cu(II) forms octahedral complexes involving the tertiary amine groups of Gx-NH2 EDA core PAMAM dendrimers at pH 7.0. The central Cu(II) metal ion of each of these complexes appears to be coordinated to 2-4 dendrimer tertiary amine groups located in the equatorial plane and 2 axial water molecules. Finally, we combine the results of our experiments with literature data to formulate and evaluate a phenomenological model of Cu(II) uptake by Gx-NH2 PAMAM dendrimers in aqueous solutions. At low metal ion-dendrimer loadings, the model provides a good fit of the measured extent of binding of Cu(II) in aqueous solutions of G4-NH2 PAMAM dendrimers at pH 7.0

Adsorption of Cu(II) on Oxidized Multi-Walled Carbon Nanotubes in the Presence of Hydroxylated and Carboxylated Fullerenes

Science.gov (United States)

Wang, Jing; Li, Zhan; Li, Shicheng; Qi, Wei; Liu, Peng; Liu, Fuqiang; Ye, Yuanlv; Wu, Liansheng; Wang, Lei; Wu, Wangsuo

2013-01-01

The adsorption of Cu(II) on oxidized multi-walled carbon nanotubes (oMWCNTs) as a function of contact time, pH, ionic strength, temperature, and hydroxylated fullerene (C60(OH)n) and carboxylated fullerene (C60(C(COOH)2)n) were studied under ambient conditions using batch techniques. The results showed that the adsorption of Cu(II) had rapidly reached equilibrium and the kinetic process was well described by a pseudo-second-order rate model. Cu(II) adsorption on oMWCNTs was dependent on pH but independent of ionic strength. Compared with the Freundlich model, the Langmuir model was more suitable for analyzing the adsorption isotherms. The thermodynamic parameters calculated from temperature-dependent adsorption isotherms suggested that Cu(II) adsorption on oMWCNTs was spontaneous and endothermic. The effect of C60(OH)n on Cu(II) adsorption of oMWCNTs was not significant at low C60(OH)n concentration, whereas a negative effect was observed at higher concentration. The adsorption of Cu(II) on oMWCNTs was enhanced with increasing pH values at pH adsorption of Cu(II) onto oMWCNTs at pH 4–6. The double sorption site model was applied to simulate the adsorption isotherms of Cu(II) in the presence of C60(OH)n and fitted the experimental data well. PMID:24009683

Electrodialytic separation of Cu(II) and As(V) in acidic electrolytes; Separacion electrodialitica de Cu(II) y As(V) en electrolitos acidos

Energy Technology Data Exchange (ETDEWEB)

Ibanez, J. P.; Ipinza, J.; Cifuentes, L.

2007-07-01

The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. the effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II) transport rate was 0.75 mol/m''2/h and the As(V) transport rate was 0.002 mol/m''2/h. An efficient separation between Cu(II) and As(V) was achieved; Generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well. (Author) 23 refs.

Removal of Zn(II) and Hg(II) from aqueous solution on a carbonaceous sorbent chemically prepared from rice husk

International Nuclear Information System (INIS)

El-Shafey, E.I.

2010-01-01

A carbonaceous sorbent was prepared from rice husk via sulfuric acid treatment. Sorption of Zn(II) and Hg(II) from aqueous solution was studied varying time, pH, metal concentration, temperature and sorbent status (wet and dry). Zn(II) sorption was found fast reaching equilibrium within ∼2 h while Hg(II) sorption was slow reaching equilibrium within ∼120 h with better performance for the wet sorbent than for the dry. Kinetics data for both metals were found to follow pseudo-second order model. Sorption rate of both metals was enhanced with temperature rise. Activation energy, E a , for Zn(II) sorption, was ∼13.0 kJ/mol indicating a diffusion-controlled process ion exchange process, however, for Hg(II) sorption, E a was ∼54 kJ/mol indicating a chemically controlled process. Sorption of both metals was low at low pH and increased with pH increase. Sorption was much higher for Hg(II) than for Zn(II) with higher uptake for both metals by rising the temperature. Hg(II) was reduced to Hg(I) on the sorbent surface. This was confirmed from the identification of Hg 2 Cl 2 deposits on the sorbent surface by scanning electron microscopy and X-ray diffraction. However, no redox processes were observed in Zn(II) sorption. Sorption mechanism is discussed.

1D cyanide complexes with 2-pyridinemethanol: Synthesis, crystal structures and spectroscopic properties

Science.gov (United States)

Sayın, Elvan; Kürkçüoğlu, Güneş Süheyla; Yeşilel, Okan Zafer; Hökelek, Tuncer

2015-12-01

Two new one-dimensional coordination polymers, [Cu(hmpH)2Pd(μ-CN)2(CN)2]n (1) and [Cu(hmpH)2Pt(μ-CN)2(CN)2]n (2), (hmpH = 2-pyridinemethanol), have been synthesized and characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction, thermal and elemental analyses techniques. Single crystal X-ray diffraction analysis indicates that complexes 1 and 2 are isomorphous and isostructural, and crystallize in the triclinic system and P-1 space group. The Pd(II) or Pt(II) ions are four coordinated with four cyanide-carbon atoms in a square planar geometry. Cu(II) ion displays a distorted octahedral coordination by two N-atoms and two O-atoms of hmpH ligands, two bridging cyanide groups. In one dimensional structure of the complexes, [M(CN)4]2- (M = Pd(II) or Pt(II)) anions and [Cu(hmpH)2]2+ cations are linked via bridging cyanide ligands. In the complexes, the presence of intramolecular C-H⋯M (M = Pd(II) or Pt(II)) interactions with distance values of 3.00-2.95 Å are established, respectively.

Macroscopic and molecular approaches of enrofloxacin retention in soils in presence of Cu(II).

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Graouer-Bacart, Mareen; Sayen, Stéphanie; Guillon, Emmanuel

2013-10-15

The co-adsorption of copper and the fluoroquinolone antibiotic enrofloxacin (ENR) at the water-soil interface was studied by means of batch adsorption experiments, and extended X-ray absorption fine structure (EXAFS) spectroscopy. The system was investigated over a pH range between 6 and 10, at different contact times, ionic strengths, and ENR concentrations. Adsorption coefficient - Kd - was determined at relevant environmental concentrations and the value obtained in water at a ionic strength imposed by the soil and at soil natural pH was equal to 0.66Lg(-1). ENR adsorption onto the soil showed strong pH dependence illustrating the influence of the electrostatic interactions in the sorption processes. The simultaneous co-adsorption of ENR and Cu(II) on the soil was also investigated. The presence of Cu(II) strongly influenced the retention of the antibiotic, leading to an increase up to 35% of adsorbed ENR amount. The combined quantitative and spectroscopic results showed that Cu(II) and ENR directly interacted at the water-soil interface to form ternary surface complexes. Cu K-edge EXAFS data indicated a molecular structure where the carboxylate and carbonyl groups of ENR coordinate to Cu(II) to form a 6-membered chelate ring and where Cu(II) bridges between ENR and the soil surface sites. Cu(II) bonds bidentately to the surface in an inner-sphere mode. Thus, the spectroscopic data allowed us to propose the formation of ternary surface complexes with the molecular architecture soil-Cu(II)-ENR. Copyright © 2013 Elsevier Inc. All rights reserved.

Synthesis of 2,2-dimethyl-4-phenyl-[1,3]-dioxolane using zeolite ...

African Journals Online (AJOL)

Zeolite encapsulated Co(II), Cu(II) and Zn(II) complexes with 2-methyl benzimidazole (Mebzlh) have been used to catalyze the reaction of styrene oxide with acetone under reflux condition. The yield of the isolated product using various catalysts range from good to excellent and the efficiency of the recycled catalyst was ...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Synthesis, characterisation and electrochemical behaviour of Cu(II), Co(II), Ni(II) and Zn(II) complexes derived from acetylacetone and p-anisidine and their antimicrobial activity · N Raman V Muthuraj S Ravichandran A Kulandaisamy · More Details Abstract Fulltext PDF. Neutral tetradentate N2O2 type complexes of Cu(II), ...

Metal ion site engineering indicates a global toggle switch model for seven-transmembrane receptor activation

DEFF Research Database (Denmark)

Elling, Christian E; Frimurer, Thomas M; Gerlach, Lars-Ole

2006-01-01

for monoamine binding in TM-III, was used as the starting point to engineer activating metal ion sites between the extracellular segments of the beta2-adrenergic receptor. Cu(II) and Zn(II) alone and in complex with aromatic chelators acted as potent (EC50 decreased to 0.5 microm) and efficacious agonists...

Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Equilibrium and solution structural study of mixed-metal-mixed-ligand complexes of Cu(II), Ni(II) and Zn(II) with L-cysteine, L-threonine and imidazole are conducted in aqueous solution by potentiometry and spectrophotometry. Stability constants of the binary, ternary and quaternary complexes are determined at 25 ± 1 ° C ...

Optimizing Cu(II) removal from aqueous solution by magnetic nanoparticles immobilized on activated carbon using Taguchi method.

Science.gov (United States)

Ebrahimi Zarandi, Mohammad Javad; Sohrabi, Mahmoud Reza; Khosravi, Morteza; Mansouriieh, Nafiseh; Davallo, Mehran; Khosravan, Azita

2016-01-01

This study synthesized magnetic nanoparticles (Fe(3)O(4)) immobilized on activated carbon (AC) and used them as an effective adsorbent for Cu(II) removal from aqueous solution. The effect of three parameters, including the concentration of Cu(II), dosage of Fe(3)O(4)/AC magnetic nanocomposite and pH on the removal of Cu(II) using Fe(3)O(4)/AC nanocomposite were studied. In order to examine and describe the optimum condition for each of the mentioned parameters, Taguchi's optimization method was used in a batch system and L9 orthogonal array was used for the experimental design. The removal percentage (R%) of Cu(II) and uptake capacity (q) were transformed into an accurate signal-to-noise ratio (S/N) for a 'larger-the-better' response. Taguchi results, which were analyzed based on choosing the best run by examining the S/N, were statistically tested using analysis of variance; the tests showed that all the parameters' main effects were significant within a 95% confidence level. The best conditions for removal of Cu(II) were determined at pH of 7, nanocomposite dosage of 0.1 gL(-1) and initial Cu(II) concentration of 20 mg L(-1) at constant temperature of 25 °C. Generally, the results showed that the simple Taguchi's method is suitable to optimize the Cu(II) removal experiments.

Synthesis, spectroscopic characterization, electrochemistry and biological evaluation of some metal (II) complexes with ONO donor ligand containing benzo[b]thiophene and coumarin moieties

Science.gov (United States)

Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

2014-09-01

Schiff base ligand 3-chloro-N‧-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzo[b]thiophene-2-carbohydrazide and its Cu(II), Co(II), Ni(II) and Zn(II) complexes were synthesized, characterized by elemental analysis and various physico-chemical techniques like, IR, 1H NMR, ESI-mass, UV-Visible, thermogravimetry - differential thermal analysis, magnetic measurements and molar conductance. Spectral analysis indicates octahedral geometry for all the complexes. Cu(II) complex have 1:1 stoichiometry of the type [M(L)(Cl)(H2O)2], whereas Co(II), Ni(II) and Zn(II) complexes have 1:2 stoichiometric ratio of the type [M(L)2]. The bonding sites are the oxygen atom of amide carbonyl, nitrogen of azomethine function and phenolic oxygen of the Schiff base ligand via deprotonation. The thermogravimetry - differential thermal analysis studies gave evidence for the presence of coordinated water molecules in the composition of Cu(II) complex which was further supported by IR measurements. All the complexes were investigated for their electrochemical activity, but only the Cu(II) complex showed the redox property. In order to evaluate the effect of antimicrobial potency of metal ions upon chelation, ligand and its metal complexes along with their respective metal chlorides were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The results showed that the metal complexes were found to be more active than free ligand. Ligand and its complexes were screened for free radical scavenging activity by DPPH method and DNA cleavage activity using Calf-thymus DNA (Cat. No-105850).

Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

Science.gov (United States)

Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

2014-01-01

Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

Coeficientes de difusão de metais em materiais não convencionais (agarose e acetato de celulose usados na técnica de difusão em filmes finos por gradientes de concentração

Directory of Open Access Journals (Sweden)

Camila Destro Colaço

2012-01-01

Full Text Available The DGT technique allows one to measure quantitatively free and labile metal species in aquatic systems. Nevertheless, for this approach, knowledge is required of the diffusion coefficients of the analytes in a diffusive layer. In this study, the diffusion coefficients of Hg(II, As(III, Mn(II, Mg(II, Cu(II, Cd(II were determined in agarose gel and those of Ba(II, Cd(II, Cu(II, Mg(II, Mn(II e Zn(II in cellulose acetate membranes. These materials presented good performance and the reported results can be used as a data base for further DGT studies.

Structural and thermal characterization of ternary complexes of piroxicam and alanine with transition metals: Uranyl binary and ternary complexes of piroxicam. Spectroscopic characterization and properties of metal complexes

Science.gov (United States)

Mohamed, Gehad G.

2005-12-01

Ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO 2(II) complexes with piroxicam (Pir) drug (H 2L 1) and dl-alanine (Ala) (HL 2) and also the binary UO 2(II) complex with Pir were studied. The structures of the complexes were elucidated using elemental, IR, molar conductance, magnetic moment, diffused reflectance and thermal analyses. The UO 2(II) binary complex was isolated in 1:2 ratio with the formula [UO 2(H 2L) 2](NO 3) 2. The ternary complexes were isolated in 1:1:1 (M:H 2L 1:L 2) ratios. The solid complexes were isolated in the general formulae [M(H 2L)(L 2)(Cl) n(H 2O) m]· yH 2O (M = Fe(III) ( n = 2, m = 0, y = 1), Co(II) ( n = 1, m = 1, y = 2) and Ni(II) ( n = 1, m = 1, y = 0)); [M(H 2L)(L 2)](X) z· yH 2O (M = Cu(II) (X = AcO, z = 1, y = 0), Zn(II) (X = AcO, z = 1, y = 3) and UO 2(II) (X = NO 3, z = 1, y = 2)). Pir behaves as a neutral bidentate ligand coordinated to the metal ions via the pyridine-N and carbonyl-O groups, while Ala behaves as a uninegatively bidentate ligand coordinated to the metal ions via the deprotonated carboxylate-O and amino-N. The magnetic and reflectance spectral data show that the complexes have octahedral geometry except Cu(II) and Zn(II) complexes have tetrahedral structures. The thermal decomposition of the complexes was discussed in relation to structure, and the thermodynamic parameters of the decomposition stages were evaluated.

A breakthrough biosorbent in removing heavy metals: Equilibrium, kinetic, thermodynamic and mechanism analyses in a lab-scale study

Energy Technology Data Exchange (ETDEWEB)

Abdolali, Atefeh [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Ngo, Huu Hao, E-mail: h.ngo@uts.edu.au [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Guo, Wenshan [Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Lu, Shaoyong [Chinese Research Academy of Environmental Science, Beijing 100012 (China); Chen, Shiao-Shing; Nguyen, Nguyen Cong [Institute of Environmental Engineering and Management, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd, Taipei 106, Taiwan (China); Zhang, Xinbo [Department of Environmental and Municipal Engineering, Tianjin Key Laboratory of Aquatic Science and Technology, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384 (China); Wang, Jie; Wu, Yun [School of Environmental and Chemical Engineering, Tianjin Polytechnic University, Tianjin 300387 (China)

2016-01-15

A breakthrough biosorbent namely multi-metal binding biosorbent (MMBB) made from a combination of tea wastes, maple leaves and mandarin peels, was prepared to evaluate their biosorptive potential for removal of Cd(II), Cu(II), Pb(II) and Zn(II) from multi-metal aqueous solutions. FTIR and SEM were conducted, before and after biosorption, to explore the intensity and position of the available functional groups and changes in adsorbent surface morphology. Carboxylic, hydroxyl and amine groups were found to be the principal functional groups for the sorption of metals. MMBB exhibited best performance at pH 5.5 with maximum sorption capacities of 31.73, 41.06, 76.25 and 26.63 mg/g for Cd(II), Cu(II), Pb(II) and Zn(II), respectively. Pseudo-first and pseudo-second-order models represented the kinetic experimental data in different initial metal concentrations very well. Among two-parameter adsorption isotherm models, the Langmuir equation gave a better fit of the equilibrium data. For Cu(II) and Zn(II), the Khan isotherm describes better biosorption conditions while for Cd(II) and Pb(II), the Sips model was found to provide the best correlation of the biosorption equilibrium data. The calculated thermodynamic parameters indicated feasible, spontaneous and exothermic biosorption process. Overall, this novel MMBB can effectively be utilized as an adsorbent to remove heavy metal ions from aqueous solutions. - Highlights: • A novel multi-metal binding biosorbent (MMBB) was studied. • The biosorption of Cd{sup 2+}, Cu{sup 2+}, Pb{sup 2+} and Zn{sup 2+} on MMBB was evaluated. • Hydroxyl, carbonyl and amine groups are involved in metal binding of MMBB. • Equilibrium data were presented and the best fitting models were identified. • The obtained results recommend this MMBB as potentially low-cost biosorbent.

Synthesis, characterization and antimicrobial activity of mixed ...

African Journals Online (AJOL)

A new series of Mn(II), Fe(II), Co(II), Cu(II) and Zn(II) mixed ligands-metal complexes derived from salicylic acid (SA) and 1,10-phenanthroline (PHEN) have been synthesized and characterized by spectroscopic studies. The coordination of the two ligands towards central metal ions has been proposed in the light of ...

Kinetic and thermodynamic aspects of Cu(II) and Cr(III) removal from aqueous solutions using rose waste biomass

International Nuclear Information System (INIS)

Iftikhar, Abdur Rauf; Bhatti, Haq Nawaz; Hanif, Muhammad Asif; Nadeem, Razyia

2009-01-01

Distillation waste of rose petals was used to remove Cu(II) and Cr(III) from aqueous solutions. The results demonstrated the dependency of metal sorption on pH, sorbent dose, sorbent size, initial bulk concentration, time and temperature. A dosage of 1 g/L of rose waste biomass was found to be effective for maximum uptake of Cu(II) and Cr(III). Optimum sorption temperature and pH for Cu(II) and Cr(III) were 303 ± 1 K and 5, respectively. The Freundlich regression model and pseudo-second-order kinetic model were resulted in high correlation coefficients and described well the sorption of Cu(II) and Cr(III) on rose waste biomass. At equilibrium q max (mg/g) of Cu(II) and Cr(III) was 55.79 and 67.34, respectively. The free energy change (ΔG o ) for Cu(II) and Cr(III) sorption process was found to be -0.829 kJ/mol and -1.85 kJ/mol, respectively, which indicates the spontaneous nature of sorption process. Other thermodynamic parameters such as entropy change (ΔS o ), enthalpy (ΔH o )and activation energy (ΔE) were found to be 0.604 J mol -1 K -1 , -186.95 kJ/mol and 68.53 kJ/mol, respectively for Cu(II) and 0.397 J mol -1 K -1 , -119.79 kJ/mol and 114.45 kJ/mol, respectively for Cr(III). The main novelty of this work was the determination of shortest possible sorption time for Cu(II) and Cr(III) in comparison to earlier studies. Almost over 98% of Cu(II) and Cr(III) were removed in only first 20 min at an initial concentration of 100 mg/L

Electron Spin Resonance Studies of Carbonic Anhydrase: Transition Metal Ions and Spin-Labeled Sulfonamides*

Science.gov (United States)

Taylor, June S.; Mushak, Paul; Coleman, Joseph E.

1970-01-01

Electron spin resonance (esr) spectra of Cu(II) and Co(II) carbonic anhydrase, and a spin-labeled sulfonamide complex of the Zn(II) enzyme, are reported. The coordination geometry of Cu(II) bound in the enzyme appears to have approximately axial symmetry. Esr spectra of enzyme complexes with metal-binding anions also show axial symmetry and greater covalency, in the order ethoxzolamide cyanide complex suggests the presence of two, and probably three, equivalent nitrogen ligands from the protein. Esr spectra of the Co(II) enzyme and its complexes show two types of Co(II) environment, one typical of the native enzyme and the 1:1 CN- complex, and one typical of a 2:1 CN- complex. Co(II) in the 2:1 complex appears to be low-spin and probably has a coordination number of 5. Binding of a spin-labeled sulfonamide to the active center immobilizes the free radical. The similarity of the esr spectra of spin-labeled Zn(II) and Co(II) carbonic anhydrases suggests that the conformation at the active center is similar in the two metal derivatives. PMID:4320976

Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

Directory of Open Access Journals (Sweden)

Bipin Bihari Mahapatra

2013-01-01

Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal.

Science.gov (United States)

Sargın, İdris; Kaya, Murat; Arslan, Gulsin; Baran, Talat; Ceter, Talip

2015-02-01

Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g(-1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g(-1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Migration behavior of Cu and Zn in landfill with different operation modes

International Nuclear Information System (INIS)

Long Yuyang; Shen Dongsheng; Wang Hongtao; Lu Wenjing

2010-01-01

Cu and Zn were chosen to study the heavy metal migration behavior and mechanism in three simulated landfills with different operation modes, namely conventional landfill (CL), leachate directly recirculated landfill (RL) and leachate pre-treated bioreactor landfill (BL). It showed that Cu and Zn in refuse experienced periodic migration and retention gradually during decomposition, and the variation of Cu(II) and Zn(II) in leachate correspondingly reflected the releasing behavior of Cu and Zn in landfill refuse at different stabilization stages. Except for their accumulated leaching amounts, Cu(II) and Zn(II) concentrations in leachate from landfills with different operation modes had no significant difference. The accumulated leaching amounts of Cu and Zn from CL showed exponential increase, while those of RL and BL showed exponential decay. The operation of bioreactor landfill with leachate recirculation can obviously attenuate the heavy metal leaching than conventional operation. The introduction of methanogenic reactor (MR) in bioreactor landfill can further promote the immobilization of heavy metal in refuse than leachate recirculation directly.

Stability Constants of Mixed Ligand Complexes of Transition Metal(II Ions with Salicylidene-4-methoxyaniline as Primary Ligand and 5-Bromosalicylidene-4-nitroaniline as Secondary Ligand

Directory of Open Access Journals (Sweden)

N. G. Nadkarni

2011-01-01

Full Text Available Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II, Ni(II, Cu(II and Zn(II; X = salicylidene-4-methoxyaniline and Y=5-bromosalicylidene-4-nitroaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ= 0.1 M (KCl in 75 : 25(v/v 1,4-dioxne-water medium. The stability constants for binary (M-Y and ternary (M-X-Y systems were calculated. The relative stability (Δ log KT values of the ternary complexes with corresponding binary complexes for all the metal(II ions in the present study found to be negative indicating that ternary 1:1:1 (M-X-Y complexes are less stable than binary 1:1 (M-Y complexes. In the ternary system studied, the order of stability constants of mixed ligand complexes with respect to the metal ions was found to be Cu(II > NI(II > Mn(II > Zn(II; which is same as in the corresponding binary (M-Y systems.

Constituting fully integrated visual analysis system for Cu(II) on TiO₂/cellulose paper.

Science.gov (United States)

Li, Shun-Xing; Lin, Xiaofeng; Zheng, Feng-Ying; Liang, Wenjie; Zhong, Yanxue; Cai, Jiabai

2014-07-15

As a cheap and abundant porous material, cellulose filter paper was used to immobilize nano-TiO2 and denoted as TiO2/cellulose paper (TCP). With high adsorption capacity for Cu(II) (more than 1.65 mg), TCP was used as an adsorbent, photocatalyst, and colorimetric sensor at the same time. Under the optimum adsorption conditions, i.e., pH 6.5 and 25 °C, the adsorption ratio of Cu(II) was higher than 96.1%. Humic substances from the matrix could be enriched onto TCP but the interference of their colors on colorimetric detection could be eliminated by the photodegradation. In the presence of hydroxylamine, neocuproine, as a selective indicator, was added onto TCP, and a visual color change from white to orange was generated. The concentration of Cu(II) was quantified by the color intensity images using image processing software. This fully integrated visual analysis system was successfully applied for the detection of Cu(II) in 10.0 L of drinking water and seawater with a preconcentration factor of 10(4). The log-linear calibration curve for Cu(II) was in the range of 0.5-50.0 μg L(-1) with a determination coefficient (R(2)) of 0.985 and its detection limit was 0.073 μg L(-1).

Degradation of TCE by TEOS Coated nZVI in the Presence of Cu(II) for Groundwater Remediation

International Nuclear Information System (INIS)

Ramamurthy, A.S.; Eglal, M.M.

2014-01-01

The removal of TCE by nanofer zero valent iron (nanofer ZVI) coated with tetraethyl orthosilicate (TEOS) in the presence of Cu(II) at different environmental conditions was studied. The kinetics of TCE degradation by nanofer ZVI was determined. At a dosage of 10 mg of nanofer ZVI, almost 63% of TCE was removed, when Cu(II) and TCE were present. It contrasts with 42% degradation of TCE in the absence of Cu(II). SEM/EDS images indicated that Cu(II) is reduced to form Cu 0 and Cu 2 O. These formations are considered to be responsible for enhancing TCE degradation. Direct reduction involves hydrogenolysis and β-elimination in the transformation of TCE, while indirect reduction involves atomic hydrogen and no direct electron transfer from the metal to reactants. The reduction of activation energy was also noted indicating that the rate limiting step for TCE degradation in the presence of Cu(II) is surface chemical reaction rather than diffusion. Most of iron present in nanofer ZVI get dissolved causing the generation of localized positive charge regions and form metal chlorides. Local accumulation of hydrochloric acid inside the pits regenerates new reactive surfaces to serve as sources of continuous electron generation. No significant effect of TCE was noticed for Cu(II) sequestration.

Preparation and characterisation of tamarind 4-hydroxybenzoic acid ...

African Journals Online (AJOL)

The adsorption of heavy metal cations, Pb(II), Cd(II), Cu(II), Zn(II) and Fe(II) ... The distribution coefficients (Kd) and percentage adsorption of metal ions on ... initial metal ion concentration and flow rate, on the removal of metal ions was also studied. ... These results suggest that the cation exchange resin THBA holds great ...

Modulation in selectivity and allosteric properties of small-molecule ligands for CC-chemokine receptors

DEFF Research Database (Denmark)

Thiele, Stefanie; Malmgaard-Clausen, Mikkel; Engel-Andreasen, Jens

2012-01-01

Among 18 human chemokine receptors, CCR1, CCR4, CCR5, and CCR8 were activated by metal ion Zn(II) or Cu(II) in complex with 2,2'-bipyridine or 1,10-phenanthroline with similar potencies (EC(50) from 3.9 to 172 μM). Besides being agonists, they acted as selective allosteric enhancers of CCL3. Thes...

Quinonoid functionality redox properties Diiminic functionality Lewis ...

African Journals Online (AJOL)

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there is a 2:1 stoichiometry between ligand with studied metalic cations and ... biological chemistry [5], and in the synthesis of materials showing interesting optical or ... metallic cations [Cu(II), Ni(II), Co(II), Zn(II)] have been studied using UV–Vis ... where D is a matrix, the rows of which are formed by the absorption spectra ...

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African Journals Online (AJOL)

Model studies of the interaction of Zn(II) with amino acids and peptides have become significant in order to better understand the role of the metal ion in bioiogical systems [1]. N-protected amino acids and peptides are also of great biological importance [2]. Recently, the interaction of Cu(II) ion with. N-protected amino acids ...

Preparation and characterization of Schiff base Cu(II) complex and its applications on textile materials

Science.gov (United States)

Oylumluoglu, G.; Oner, J.

2017-10-01

Schiff base ligands are regarded as an important class of organic compounds on account of the fact that their complexation ability with transition metal ions. A new monomeric Schiff base Cu(II) complex, [Cu(HL)2], 1 [H2L = 2-((E)-(2-hydroxypropylimino)methyl)-4-nitrophenol] has been synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction and photoluminescence study. While the Schiff base ligand and its Cu(II) complex are excited at λex = 349 nm in UV region, the Schiff base ligand shows a blue emission band at λmax = 480 nm whereas its Cu(II) complex shows a strong green emission band at λmax = 520 nm in the solid state at room temperature. The luminescent properties showed that the Schiff base ligand and its Cu(II) complex can be used as novel potential candidates for applications in textile such as UV-protection, antimicrobial, laundry and functional bleaching treatments.

Direct Observation of Reduction of Cu(II) to Cu(I) by Terminal Alkynes

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guanghui; Yi, Hong; Zhang, Guoting; Deng, Yi; Bai, Ruopeng; Zhang, Heng; Miller, Jeffrey T.; Kropf, Arthur J.; Bunel, Emilio E.; Lei, Aiwen

2014-01-06

ABSTRACT: X-ray absorption spectroscopy and in situ electron paramagnetic resonance evidence were provided for the reduction of Cu(II) to Cu(I) species by alkynes in the presence of tetramethylethylenediamine (TMEDA), in which TMEDA plays dual roles as both ligand and base. The structures of the starting Cu(II) species and the obtained Cu(I) species were determined as (TMEDA)- CuCl2 and [(TMEDA)CuCl]2 dimer, respectively.

Sensitive and selective detection of Cu(II) ion: A new effective 1,8-naphthalimide-based fluorescence 'turn off' sensor.

Science.gov (United States)

Huang, Guozhen; Li, Chuang; Han, Xintong; Aderinto, Stephen Opeyemi; Shen, Kesheng; Mao, Shanshan; Wu, Huilu

2018-06-01

The present study reports the development of a new 1,8-naphthalimide-based fluorescent sensor V for monitoring Cu(II) ions. The sensor exhibited pH independence over a wide pH range 2.52-9.58, and indicated its possible use for monitoring Cu(II) ions in a competitive pH medium. The sensor also showed high selectivity and sensitivity towards the Cu(II) ions over other competitive metal ions in DMSO-HEPES buffer (v/v, 1:1; pH 7.4) with a fluorescence 'turn off' mode of 79.79% observed. A Job plot indicated the formation of a 1:1 binding mode of the sensor with Cu(II) ions. The association constant and detection limit were 1.14 × 10 6  M -1 and 4.67 × 10 -8 M, respectively. The fluorescence spectrum of the sensor was quenched due to the powerful paramagnetic nature of the Cu(II) ions. Potential application of this sensor was also demonstrated when determining Cu(II) ion levels in two different water samples. Copyright © 2018 John Wiley & Sons, Ltd.

Utilization of m-Phenylenediamine-Furfural Resin for Removal of Cu(II from Aqueous Solution-A Thermodynamic Study

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Tariq S. Najim

2010-01-01

Full Text Available m-Phenylenediamine was condensed with furfural in absence of catalyst at room temperature. The produced m-phenylenediamine-furfural resin was used for the removal of Cu(II from aqueous solution. The pH for the optimum removal of Cu(II was 6. The negative values of Gibbs free energy at low concentration of Cu(II (20, 30 ppm indicative of the spontaneous adsorption process, while, at higher Cu(II concentration (40,50 ppm the positive and weak values of ∆G° indicate that the process is feasible but non spontaneous. The values of ∆H° were positive indicating that the sorption process is endothermic. On the other hand, the values of activation energy (Ea were inconsistent with the values of ∆H° both are positive and lie in the range of physisorption. The entropy ∆S° of the process was positive indicative of the randomness of the Cu(II ions at the solid / liquid interface. The values of sticking probability S* were less than one which indicate a preferable adsorption process and the mechanism is physisorption.

Structural basis of Zn(II induced metal detoxification and antibiotic resistance by histidine kinase CzcS in Pseudomonas aeruginosa.

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Dan Wang

2017-07-01

Full Text Available Pseudomonas aeruginosa (P. aeruginosa is a major opportunistic human pathogen, causing serious nosocomial infections among immunocompromised patients by multi-determinant virulence and high antibiotic resistance. The CzcR-CzcS signal transduction system in P. aeruginosa is primarily involved in metal detoxification and antibiotic resistance through co-regulating cross-resistance between Zn(II and carbapenem antibiotics. Although the intracellular regulatory pathway is well-established, the mechanism by which extracellular sensor domain of histidine kinase (HK CzcS responds to Zn(II stimulus to trigger downstream signal transduction remains unclear. Here we determined the crystal structure of the CzcS sensor domain (CzcS SD in complex with Zn(II at 1.7 Å resolution. This is the first three-dimensional structural view of Zn(II-sensor domain of the two-component system (TCS. The CzcS SD is of α/β-fold in nature, and it senses the Zn(II stimulus at micromole level in a tetrahedral geometry through its symmetry-related residues (His55 and Asp60 on the dimer interface. Though the CzcS SD resembles the PhoQ-DcuS-CitA (PDC superfamily member, it interacts with the effector in a novel domain with the N-terminal α-helices rather than the conserved β-sheets pocket. The dimerization of the N-terminal H1 and H1' α-helices is of primary importance for the activity of HK CzcS. This study provides preliminary insight into the molecular mechanism of Zn(II sensing and signaling transduction by the HK CzcS, which will be beneficial to understand how the pathogen P. aeruginosa resists to high levels of heavy metals and antimicrobial agents.

Adsorption of As(III), As(V) and Cu(II) on zirconium oxide immobilized alginate beads in aqueous phase.

Science.gov (United States)

Kwon, Oh-Hun; Kim, Jong-Oh; Cho, Dong-Wan; Kumar, Rahul; Baek, Seung Han; Kurade, Mayur B; Jeon, Byong-Hun

2016-10-01

A composite adsorbent to remove arsenite [As(III)], arsenate [As(V)], and copper [Cu(II)] from aqueous phase was synthesized by immobilizing zirconium oxide on alginate beads (ZOAB). The composition (wt%) of ZOAB (Zr-34.0; O-32.7; C-21.3; Ca-1.0) was confirmed by energy dispersive X-ray (EDX) analysis. Sorption studies were conducted on single and binary sorbate systems, and the effects of contact time, initial adsorbate concentration, and pH on the adsorption performance of ZOAB (pHPZC = 4.3) were monitored. The sorption process for As(III)/As(V) and Cu(II) reached an equilibrium state within 240 h and 24 h, respectively, with maximum sorption capacities of 32.3, 28.5, and 69.9 mg g(-1), respectively. The addition of Cu(II) was favorable for As(V) sorption in contrast to As(III). In the presence of 48.6 mg L(-1) Cu(II), the sorption capacity of As(V) increased from 1.5 to 3.8 mg g(-1) after 240 h. The sorption data for As(III)/As(V) and Cu(II) conformed the Freundlich and Langmuir isotherm models, respectively. The adsorption of As(III), As(V), and Cu(II) followed pseudo second order kinetics. The effect of arsenic species on Cu(II) sorption was insignificant. The results of present study demonstrated that the synthesized sorbent could be useful for the simultaneous removal of both anionic and cationic contaminants from wastewaters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experiment, modeling and optimization of liquid phase adsorption of Cu(II) using dried and carbonized biomass of Lyngbya majuscula

Science.gov (United States)

Kushwaha, Deepika; Dutta, Susmita

2017-05-01

The present work aims at evaluation of the potential of cyanobacterial biomass to remove Cu(II) from simulated wastewater. Both dried and carbonized forms of Lyngbya majuscula, a cyanobacterial strain, have been used for such purpose. The influences of different experimental parameters viz., initial Cu(II) concentration, solution pH and adsorbent dose have been examined on sorption of Cu(II). Kinetic and equilibrium studies on Cu(II) removal from simulated wastewater have been done using both dried and carbonized biomass individually. Pseudo-second-order model and Langmuir isotherm have been found to fit most satisfactorily to the kinetic and equilibrium data, respectively. Maximum 87.99 and 99.15 % of Cu(II) removal have been achieved with initial Cu(II) concentration of 10 and 25 mg/L for dried and carbonized algae, respectively, at an adsorbent dose of 10 g/L for 20 min of contact time and optimum pH 6. To optimize the removal process, Response Surface Methodology has been employed using both the dried and carbonized biomass. Removal with initial Cu(II) concentration of 20 mg/L, with 0.25 g adsorbent dose in 50 mL solution at pH 6 has been found to be optimum with both the adsorbents. This is the first ever attempt to make a comparative study on Cu(II) removal using both dried algal biomass and its activated carbon. Furthermore, regeneration of matrix was attempted and more than 70% and 80% of the adsorbent has been regenerated successfully in the case of dried and carbonized biomass respectively upto the 3rd cycle of regeneration study.

Syntheses and characterizations of the cyanide-bridged ...

African Journals Online (AJOL)

The spectral features of the complexes suggest that the Ni(II) ion is four coordinate with four cyanide-carbon atoms in a square planar geometry, whereas the Cu(II) and the Zn(II) ions of the Cu–Ni–etim and the Zn–Ni–etim complexes are completed by nitrogen atoms of two cyano groups of [Ni(CN)4]2- coordinated to the ...

Synthesis and Characterization of Some Macrocylic Complexes Incorporating Indole and 2,2'-Bipyridine or 1,10-Phenanthroline

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Muhammad S. Khan

2015-06-01

Full Text Available Complexes of anionic pentadentate macrocyclic ligands by the template condensation of bis(hydrazino2,2'-bipyridine or 1,10-phenanthroline with an indoledialdehyde have been synthesized. The new Mn(II, Fe(II, Co(II, Ni(II, Cu(II and Zn(II macrocyclic complexes have been characterized by analytical and spectroscopic techniques and by conductivity and magnetic susceptibility measurements.

Differential Binding of Co(II) and Zn(II) to Metallo-beta-Lactamase Bla2 from Bacillus anthracis

Energy Technology Data Exchange (ETDEWEB)

Hawk, M.; Breece, R; Hajdin, C; Bender, K; Hu, Z; Costello, A; Bennett, B; Tierney, D; Crowder, M

2009-01-01

In an effort to probe the structure, mechanism, and biochemical properties of metallo-{beta}-lactamase Bla2 from Bacillus anthracis, the enzyme was overexpressed, purified, and characterized. Metal analyses demonstrated that recombinant Bla2 tightly binds 1 equiv of Zn(II). Steady-state kinetic studies showed that mono-Zn(II) Bla2 (1Zn-Bla2) is active, while di-Zn(II) Bla2 (ZnZn-Bla2) was unstable. Catalytically, 1Zn-Bla2 behaves like the related enzymes CcrA and L1. In contrast, di-Co(II) Bla2 (CoCo-Bla2) is substantially more active than the mono-Co(II) analogue. Rapid kinetics and UV-vis, 1H NMR, EPR, and EXAFS spectroscopic studies show that Co(II) binding to Bla2 is distributed, while EXAFS shows that Zn(II) binding is sequential. To our knowledge, this is the first documented example of a Zn enzyme that binds Co(II) and Zn(II) via distinct mechanisms, underscoring the need to demonstrate transferability when extrapolating results on Co(II)-substituted proteins to the native Zn(II)-containing forms.

Study on the adsorption of Cu(II) by folic acid functionalized magnetic graphene oxide

Energy Technology Data Exchange (ETDEWEB)

Wang, Cuicui [Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022 (China); School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Ge, Heyi, E-mail: geheyi@sina.com [Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022 (China); School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Zhao, Yueying [Shandong Xiaguang Industrial Co., Ltd., Jining 272000 (China); Liu, Shanshan; Zou, Yu; Zhang, Wenbo [Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022 (China); School of Material Science and Engineering, University of Jinan, Jinan 250022 (China)

2017-02-01

The folic acid functionalized magnetic graphene oxide (FA-mGO) as a new adsorbent has been synthesized in this work for the elimination of Cu(II) from waste water. The as-prepared FA-mGO was tested by SEM, TEM, particle size analyzer, FTIR, XRD, Roman spectrum, TGA and magnetic properties analyzer. Some factors, such as adsorbent dose, pH, contact time, initial concentration of adsorbate and temperature were explored. The results showed that the FA-mGO had the better adsorption performance than mGO. After 40 min, the adsorption equilibrium could be reached. Furthermore, the adsorption property obeyed the pseudo-second order kinetic model and the Temkin isotherms well. The maximum adsorption capacity was 283.29 mg/g for Cu(II) from Pseudo-second-order model at pH=5 and 318 K. The chelation action between FA and Cu(II) along with electrostatic incorporation between GO and Cu(II) determined the favourable adsorption property. Besides, thermodynamic studies results ∆G{sup 0}<0, ∆H{sup 0}>0, ∆S{sup 0}>0 suggested that the adsorption mechanism was an endothermic and spontaneous process essentially. Finally, desorption and reusability studies imply FA-mGO has an excellent reproducibility and is benefit to environmental protection and resource conservation. - Graphical abstract: Schematic illustration of preparing FA-mGO. - Highlights: • The FA-mGO was synthesized for the removal of Cu(II). • The chelation action and electrostatic incorporation determined the favourable adsorption property. • The adsorption property obeyed the pseudo-second-order and Temkin models well. • The adsorption mechanism was an endothermic and spontaneous process. • The FA-mGO has an excellent reproducibility.

Structural characterization and antioxidant properties of Cu(II) and Ni(II) complexes derived from dicyandiamide

Science.gov (United States)

Kertmen, Seda Nur; Gonul, Ilyas; Kose, Muhammet

2018-01-01

New Cu(II) and Ni(II) complexes derived from dicyandiamide were synthesized and characterised by spectroscopic and analytical methods. Molecular structures of the complexes were determined by single crystal X-ray diffraction studies. In the complexes, the Cu(II) or Ni(II) ions are four-coordinate with a slight distorted square planar geometry. The ligands (L-nPen and L-iPen) derived from dicyandiamide formed via nucleophilic addition of alcohol solvent molecule in the presence Cu(II) or Ni(II) ions. Complexes were stabilised by intricate array of hydrogen bonding interactions. Antioxidant activity of the complexes was evaluated by DPPH radical scavenging and CUPRAC methods. The complexes exhibit antioxidant activity, however, their activities were much lower than standard antioxidants (Vitamin C and trolox).

Sequestration of Cu(II), Ni(II), and Co(II) by ethyleneimine immobilized on silica

International Nuclear Information System (INIS)

Arakaki, Luiza N.H.; Alves, Ana Paula M.; Silva Filho, Edson C. da; Fonseca, Maria G.; Oliveira, Severino F.; Espinola, Jose Geraldo P.; Airoldi, Claudio

2007-01-01

Thermodynamic data on interaction of Cu(II), Ni(II), and Co(II) with silica modified with ethyleneimine are obtained by calorimetric titration. The amount of ethyleneimine anchored on silica surface was estimated to be 0.70 mmol g -1 . The enthalpies of binding Ni(II), Cu(II) and Co(II), are -3.59 ± 0.001, -4.88 ± 0.001, and -7.75 ± 0.003 kJ mol -1 , respectively

Synthesis, physico-chemical characterization and biological activity of 2-aminobenzimidazole complexes with different metal ions

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Podunavac-Kuzmanović Sanja O.

2004-01-01

Full Text Available Complexes of 2-aminobenzimidazole (L with nitrates of cobalt(II nickel(II, copper (II, zinc(II and silver(I were synthesized. The molar ratio metal:ligand in the reaction of the complex formation was 1:2. It should be noticed, that the reaction of all the metal salts yielded bis(ligand complexes of the general formula M(L2(NO32 × nH2O (M=Co, Ni Cu, Zn or Ag; n=0, 1, 2 or 6. The complexes were characterized by elemental analysis of the metal, molar conductivity, magnetic susceptibility measurements and IR spectra. Co(II, Ni(II and Cu(II complexes behave as non-electrolytes, whilst Zn(II and Ag(I are 1:1 electrolytes. Cu(II complex has a square-planar stereochemistry, Ag(I complex is linear, whilst the Co(II, Ni(II and Zn(II complexes have a tetrahedral configuration. In all the complexes ligand is coordinated by participation of the pyridine nitrogen of the benzimidazole ring. The antimicrobial activity of the ligand and its complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus and Saccharomyces cerevisiae was investigated. The effect of metal on the ligand antimicrobial activity is discussed.

Three novel metal-organic frameworks based on flexible porphyrin tetracarboxylic acids as highly effective catalysts

Energy Technology Data Exchange (ETDEWEB)

Zhang, Zengqi [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an, Shaanxi 710069 (China); Su, Xiaoqin [School of Materials and Chemical Engineering, Xi’an Technological University, Xi’an, Shaanxi 710021 (China); Yu, Fan; Li, Jun [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi’an, Shaanxi 710069 (China)

2016-06-15

Targeted synthesis of metalloporphyrinic frameworks (MPFs) with Cu(II) (1), Ni(II) (2, 3) 5, 10, 15, 20-tetrakis[4-(carboxymethyleneoxy)phenyl]porphyrin (Cu(TCMOPP) and Ni(TCMOPP)) as building blocks afforded three new extended coordination polymers inter-linked by Zn(II) (1) and K(I) (2, 3). 1 shows 2D frameworks while 2, 3 are 3D frameworks. The open channel are 7–17 Å wide and accessible to guest/solvent molecules. Besides, the thermogravimetric analyses (TGA) indicate that the framework structures of the three compounds are stable until 300 °C. In addition, the catalytic activities of 1–3 to the alkylbenzenes oxidation are examined, and the results indicate that 1 exhibit high catalytic activity to oxidation of ethylbenzene and 1,2,3,4-tetrahydronaphthalene with conversion of 64.1% and 80.3% respectively. - Graphical abstract: Three novel metalloporphyrinic frameworks (1, 2, 3) were synthesized based on tetracarboxylic Cu(II) (1), Ni(II) (2, 3) metalloporphyrin inter-linked by Zn(II) (1) , K(I) (2, 3), and 1 shows high catalytic activity to oxidation reaction of alkylbenzenes with conversion 80.3%. Display Omitted.

Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples

Energy Technology Data Exchange (ETDEWEB)

Baytak, Sitki [Department of Chemistry, Faculty of Science and Arts, Harran University, 63100 Sanliurfa (Turkey); Kenduezler, Erdal [Department of Primary Education, Faculty of Education, Ahi Evran University, 40100 Kirsehir (Turkey); Tuerker, Ali Rehber [Department of Chemistry, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey)], E-mail: aturker@gazi.edu.tr; Goek, Nuray [Department of Environmental Engineering, Faculty of Engineering, Harran University, 63000 Sanliurfa (Turkey)

2008-05-30

This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97 {+-} 2, 98 {+-} 2 and 98 {+-} 2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL{sup -1}, respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605)

Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples

International Nuclear Information System (INIS)

Baytak, Sitki; Kenduezler, Erdal; Tuerker, Ali Rehber; Goek, Nuray

2008-01-01

This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97 ± 2, 98 ± 2 and 98 ± 2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL -1 , respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605)

Removal of Cu (II and Zn (II from water with natural adsorbents from cassava agroindustry residues

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Daniel Schwantes

2015-07-01

Full Text Available Current study employs solid residues from the processing industry of the cassava (Manihot esculenta Crantz (bark, bagasse and bark + bagasse as natural adsorbents for the removal of metal ions Cu(II and Zn(II from contaminated water. The first stage comprised surface morphological characterization (SEM, determination of functional groups (IR, point of zero charge and the composition of naturally existent minerals in the biomass. Further, tests were carried out to evaluate the sorption process by kinetic, equilibrium and thermodynamic studies. The adsorbents showed a surface with favorable adsorption characteristics, with adsorption sites possibly derived from lignin, cellulose and hemicellulose. The dynamic equilibrium time for adsorption was 60 min. Results followed pseudo-second-order, Langmuir and Dubinin-Radushkevich models, suggesting a chemisorption monolayer. The thermodynamic parameters suggested that the biosorption process of Cu and Zn was endothermic, spontaneous or independent according to conditions. Results showed that the studied materials were potential biosorbents in the decontamination of water contaminated by Cu(II and Zn(II. Thus, the above practice complements the final stages of the cassava production chain of cassava, with a new disposal of solid residues from the cassava agroindustry activity.

Copper(II) and zinc(II) as metal-carboxylate coordination complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: Synthesis, crystal structure, spectroscopy, DFT calculations and antioxidant activity

Science.gov (United States)

Benhassine, Anfel; Boulebd, Houssem; Anak, Barkahem; Bouraiou, Abdelmalek; Bouacida, Sofiane; Bencharif, Mustapha; Belfaitah, Ali

2018-05-01

This work presents a combined experimental and theoretical study of two new metal-carboxylate coordination compounds. These complexes were prepared from (1-methyl-1H-benzimidazol-2-yl)methanol under mild conditions. The structures of the prepared compounds were characterized by single-crystal X-ray analysis, FTIR and UV-Vis spectroscopy. In the Cupper complex, the Cu(II) ion is coordinated by two ligands, which act as bidentate chelator through the non-substituted N and O atoms, and two carboxylicg oxygen atoms, displaying a hexa-coordinated compound in a distorted octahedral geometry, while in the Zinc complex the ligand is ligated to the Zn(II) ion in monodentate fashion through the N atom, and the metal ion is also bonded to carboxylic oxygen atoms. The tetra-coordinated compound displays a distorted tetrahedral shape. The density functional theory calculations are carried out for the determination of the optimized structures. The electronic transitions and fundamental vibrational wave numbers are calculated and are in good agreement with experimental. In addition, the ligand and its Cu(II) and Zn(II) complexes were screened and evaluated for their potential as DPPH radical scavenger.

Titania-Coated Silica Alone and Modified by Sodium Alginate as Sorbents for Heavy Metal Ions

Science.gov (United States)

Kołodyńska, D.; Gęca, M.; Skwarek, E.; Goncharuk, O.

2018-04-01

The novel organic-inorganic biohybrid composite adsorbent was synthesized based on nanosized silica-titania modified with alginate within the development of effective adsorbent for heavy metal ions. Effects of metal species Cu(II), Zn(II), Cd(II), and Pb(II); concentrations; pH; temperature; and adsorption onto titania-coated silica (ST20) initial or modified by sodium alginate (ST20-ALG) were studied. The equilibrium and kinetic data of metal ions adsorption were analyzed using Langmuir and Freundlich adsorption models and kinetic models: pseudo first order, pseudo second order, intraparticle kinetic model, and Elovich. The maximum sorption capacities observed were higher for the ST20-ALG composite compared to the initial ST20 oxide for all studied metal ions, namely their values for ST20-ALG were 22.44 mg g- 1 for Cu(II) adsorption, 19.95 mg g- 1 for Zn(II), 18.85 mg g- 1 for Cd(II), and 32.49 mg g- 1 for Pb(II). Structure and properties of initial silica-titania ST20 and modified by sodium alginate ST20-ALG adsorbents were analyzed using nitrogen adsorption/desorption isotherms, ATR-FTIR, SEM-EDS, and pHpzc techniques.

Antimicrobial and mutagenic activity of some carbono- and thiocarbonohydrazone ligands and their copper(II), iron(II) and zinc(II) complexes.

Science.gov (United States)

Bacchi, A; Carcelli, M; Pelagatti, P; Pelizzi, C; Pelizzi, G; Zani, F

1999-06-15

Several mono- and bis- carbono- and thiocarbonohydrazone ligands have been synthesised and characterised; the X-ray diffraction analysis of bis(phenyl 2-pyridyl ketone) thiocarbonohydrazone is reported. The coordinating properties of the ligands have been studied towards Cu(II), Fe(II), and Zn(II) salts. The ligands and the metal complexes were tested in vitro against Gram positive and Gram negative bacteria, yeasts and moulds. In general, the bisthiocarbonohydrazones possess the best antimicrobial properties and Gram positive bacteria are the most sensitive microorganisms. Bis(ethyl 2-pyridyl ketone) thiocarbonohydrazone, bis(butyl 2-pyridyl ketone)thiocarbonohydrazone and Cu(H2nft)Cl2 (H2nft, bis(5-nitrofuraldehyde)thiocarbonohydrazone) reveal a strong activity with minimum inhibitory concentrations of 0.7 microgram ml-1 against Bacillus subtilis and of 3 micrograms ml-1 against Staphylococcus aureus. Cu(II) complexes are more effective than Fe(II) and Zn(II) ones. All bisthiocarbono- and carbonohydrazones are devoid of mutagenic properties, with the exception of the compounds derived from 5-nitrofuraldehyde. On the contrary a weak mutagenicity, that disappears in the copper complexes, is exhibited by monosubstituted thiocarbonohydrazones.

Removal of Cu(II) ions from contaminated waters using a conducting microfiltration membrane.

Science.gov (United States)

Wang, Xueye; Wang, Zhiwei; Chen, Haiqin; Wu, Zhichao

2017-10-05

Efficient removal of toxic metals using low-pressure membrane processes from contaminated waters is an important but challenging task. In the present work, a conducting microfiltration membrane prepared by embedding a stainless steel mesh in the active layer of a polyvinylidene fluoride membrane is developed to remove Cu(II) ions from contaminated waters. Results showed that the conducting membrane had favorable electrochemical properties and stability as cathode. Batch tests showed that Cu(II) removal efficiency increased with the increase of voltages and leveled off with the further enhancement of electric field. The optimal voltages were determined to be 1.0V and 2.0V for the influent Cu(II) concentrations of 5mg/L and 30mg/L, respectively. X-ray photoelectron spectroscopy and X-ray diffraction results demonstrated the presence of Cu(0) and Cu(OH) 2 on the membrane surface. The removal mechanisms involved the intrinsic adsorption of membrane, electrosorption of membrane, adsorption of deposited layer, chemical precipitation of Cu(OH) 2 and deposition of Cu(0) which were aided by electrophoresis and electrochemical oxidation-reduction. Long-term tests showed that the major contributors for Cu(II) removal were the deposition of Cu(0) by electrochemical reduction-oxidation (47.3%±8.5%) and chemical precipitation (41.1%±0.2%), followed by electrosorption, adsorption by the fouling layer and membrane intrinsic sorption. Copyright © 2017 Elsevier B.V. All rights reserved.

Responses of the alga Pseudokirchneriella subcapitata to long-term exposure to metal stress

Energy Technology Data Exchange (ETDEWEB)

Machado, Manuela D. [Bioengineering Laboratory, Chemical Engineering Department, ISEP-School of Engineering of Polytechnic Institute of Porto, Porto (Portugal); CEB-Centre of Biological Engineering, University of Minho, Braga (Portugal); Lopes, Ana R. [LEPABE, Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto (Portugal); Soares, Eduardo V., E-mail: evs@isep.ipp.pt [Bioengineering Laboratory, Chemical Engineering Department, ISEP-School of Engineering of Polytechnic Institute of Porto, Porto (Portugal); CEB-Centre of Biological Engineering, University of Minho, Braga (Portugal)

2015-10-15

Highlights: • Heavy metals provoke a perturbation of the physiological status of Pseudokirchneriella subcapitata. • Cd(II), Cr(VI) and Cu(II), at high concentrations, cause the loss of membrane integrity. • Cd(II), Cr(VI), Cu(II) and Zn(II) inhibit esterase activity in a dose dependent manner. • Heavy metals affect mitochondrial function and photosynthetic activity. • Fluorescent probes are a useful tool in the identification of toxicity targets of the heavy metals. - Abstract: The green alga Pseudokirchneriella subcapitata has been widely used in ecological risk assessment, usually based on the impact of the toxicants in the alga growth. However, the physiological causes that lead algal growth inhibition are not completely understood. This work aimed to evaluate the biochemical and structural modifications in P. subcapitata after exposure, for 72 h, to three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II), corresponding approximately to 72 h-EC{sub 10} and 72 h-EC{sub 50} values and a high concentration (above 72 h-EC{sub 90} values). The incubation of algal cells with the highest concentration of Cd(II), Cr(VI) or Cu(II) resulted in a loss of membrane integrity of ~16, 38 and 55%, respectively. For all metals tested, an inhibition of esterase activity, in a dose-dependent manner, was observed. Reduction of chlorophyll a content, decrease of maximum quantum yield of photosystem II and modification of mitochondrial membrane potential was also verified. In conclusion, the exposure of P. subcapitata to metals resulted in a perturbation of the cell physiological status. Principal component analysis revealed that the impairment of esterase activity combined with the reduction of chlorophyll a content were related with the inhibition of growth caused by a prolonged exposure to the heavy metals.

Responses of the alga Pseudokirchneriella subcapitata to long-term exposure to metal stress

International Nuclear Information System (INIS)

Machado, Manuela D.; Lopes, Ana R.; Soares, Eduardo V.

2015-01-01

Highlights: • Heavy metals provoke a perturbation of the physiological status of Pseudokirchneriella subcapitata. • Cd(II), Cr(VI) and Cu(II), at high concentrations, cause the loss of membrane integrity. • Cd(II), Cr(VI), Cu(II) and Zn(II) inhibit esterase activity in a dose dependent manner. • Heavy metals affect mitochondrial function and photosynthetic activity. • Fluorescent probes are a useful tool in the identification of toxicity targets of the heavy metals. - Abstract: The green alga Pseudokirchneriella subcapitata has been widely used in ecological risk assessment, usually based on the impact of the toxicants in the alga growth. However, the physiological causes that lead algal growth inhibition are not completely understood. This work aimed to evaluate the biochemical and structural modifications in P. subcapitata after exposure, for 72 h, to three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II), corresponding approximately to 72 h-EC 10 and 72 h-EC 50 values and a high concentration (above 72 h-EC 90 values). The incubation of algal cells with the highest concentration of Cd(II), Cr(VI) or Cu(II) resulted in a loss of membrane integrity of ~16, 38 and 55%, respectively. For all metals tested, an inhibition of esterase activity, in a dose-dependent manner, was observed. Reduction of chlorophyll a content, decrease of maximum quantum yield of photosystem II and modification of mitochondrial membrane potential was also verified. In conclusion, the exposure of P. subcapitata to metals resulted in a perturbation of the cell physiological status. Principal component analysis revealed that the impairment of esterase activity combined with the reduction of chlorophyll a content were related with the inhibition of growth caused by a prolonged exposure to the heavy metals

Complexos metálicos com o herbicida glifosato: revisão

OpenAIRE

Coutinho,Cláudia F. B.; Mazo,Luiz Henrique

2005-01-01

We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature.

Metallic complexes with glyphosate: a review

OpenAIRE

Coutinho, Cláudia F. B.; Mazo, Luiz Henrique

2005-01-01

We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature.

Application of proton induced x-ray emission (PIXE) in estimation of trace metals entrapped in silica matrix

International Nuclear Information System (INIS)

Jal, P.K.; Patel, Sabita; Mishra, B.K.; Sudarshan, M.; Saha, A.

2005-01-01

Proton induced x-ray emission technique is used for multielemental analysis of metal ions adsorbed on nanosilica surface. At pH 3.5, silica traps uranium selectively from a mixture of solutions of 13 different metal ions viz., K(I), Ca(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II). Ba(II), Hg(II) and UO 2 (VI). (author)

SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ...

African Journals Online (AJOL)

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The synthesized chelating agent and metal(II) complexes were screened for ... Coordination compounds, Antimicrobial study ... The biological activity of Zn(II), Cu(II), Co(II) and Ni(II) with imidazole derivative (DIPO) ... product in 86% yield. .... [Ni(DIPO)Br2]. 2.0. 2.5. 2.5. 3.0. 3.0. 3.0. 9. Maxipime. 10.6. D iam eter o f in h ib itio.

Ni(II) ion-imprinted solid-phase extraction and preconcentration in aqueous solutions by packed-bed columns

International Nuclear Information System (INIS)

Ersoez, Arzu; Say, Ridvan; Denizli, Adil

2004-01-01

Solid-phase extraction (SPE) columns packed with materials based on molecularly imprinted polymers (MIPs) were used to develop selective separation and preconcentration for Ni(II) ion from aqueous solutions. SPE is more rapid, simple and economical method than the traditional liquid-liquid extraction. MIPs were used as column sorbent to increase the grade of selectivity in SPE columns. In this study, we have developed a polymer obtained by imprinting with Ni(II) ion as a ion-imprinted SPE sorbent. For this purpose, NI(II)-methacryloylhistidinedihydrate (MAH/Ni(II)) complex monomer was synthesized and polymerized with cross-linking ethyleneglycoldimethacrylate to obtain [poly(EGDMA-MAH/Ni(II))]. Then, Ni(II) ions were removed from the polymer getting Ni(II) ion-imprinted sorbent. The MIP-SPE preconcentration procedure showed a linear calibration curve within concentration range from 0.3 to 25 ng/ml and the detection limit was 0.3 ng/ml (3 s) for flame atomic absorption spectrometry (FAAS). Ni(II) ion-imprinted microbeads can be used several times without considerable loss of adsorption capacity. When the adsorption capacity of nickel imprinted microbeads were compared with non-imprinted microbeads, nickel imprinted microbeads have higher adsorption capacity. The K d (distribution coefficient) values for the Ni(II)-imprinted microbeads show increase in K d for Ni(II) with respect to both K d values of Zn(II), Cu(II) and Co(II) ions and non-imprinted polymer. During that time K d decreases for Zn(II), Cu(II) and Co(II) ions and the k' (relative selectivity coefficient) values which are greater than 1 for imprinted microbeads of Ni(II)/Cu(II), Ni(II)/Zn(II) and Ni(II)/Co(II) are 57.3, 53.9, and 17.3, respectively. Determination of Ni(II) ion in sea water showed that the interfering matrix had been almost removed during preconcentration. The column was good enough for Ni determination in matrixes containing similar ionic radii ions such as Cu(II), Zn(II) and Co(II)

Spectral, optical and cytotoxicity studies on 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide(H3L) and some of its metal complexes

Science.gov (United States)

Hosny, Nasser M.; Hassan, Nader Y.; Mahmoud, Heba M.; Abdel-Rhman, Mohamed H.

2018-03-01

The ligand 2-isonicotinoyl-N-phenylhydrazine-1-carboxamide (H3L) and its metal complexes with Co(II), Ni(II), Cu(II) and Zn(II) acetates have been synthesized. The isolated compounds have been characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR, ESR, mass, electronic spectra, electrical conductivity, effective magnetic moments and thermal analyses. The free organic ligand exists in the keto form, but in the metal complexes, it coordinates in the enol form. Four coordinated species were suggested for all the isolated metal complexes. The measured optical band gap values confirmed the presence of direct electronic transition and the semi-conductivity of the compounds. The ligand and its Zn(II) complex were examined as cytotoxic agent against HCT-116 and HePG-2. The ligand showed very strong cytotoxic effect against HePG-2, but moderate cytotoxicity against HCT-116. Zn(II) complex showed weak cytotoxicity against the two cell lines.

Photophysical studies of the interactions of poly(amidoamine) generation zero (PAMAM G0) with copper and zinc ions

Energy Technology Data Exchange (ETDEWEB)

López-Cabaña, Z.E. [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Valdés, O. [Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile); Vergara, C.E. [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Camarada, M.B. [Universidad Andrés Bello, Facultad de Biología, Center for Bioinformatics and Integrative Biology (CBIB), República 239, Santiago (Chile); Fundación Fraunhofer Chile Research, M. Sánchez Fontecilla 310 piso 14, Las Condes (Chile); Nachtigall, F.M. [Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile); González-Nilo, F.D. [Universidad Andrés Bello, Facultad de Biología, Center for Bioinformatics and Integrative Biology (CBIB), República 239, Santiago (Chile); Fundación Fraunhofer Chile Research, M. Sánchez Fontecilla 310 piso 14, Las Condes (Chile); Santos, Leonardo S., E-mail: lssantos@utalca.cl [Laboratory of Asymmetric Synthesis, Chemistry Institute of Natural Resources, University of Talca (Chile); Nanobiotechnology Division at University of Talca, Fraunhofer Chile Research Foundation – Center for Systems Biotechnology, FCR-CSB, P.O. Box 747 Talca (Chile)

2015-08-15

This study reports the photophysical behavior of poly(amidoamine) generation zero (PAMAM G0) in the presence of Cu(II) and Zn(II) ions in aqueous solutions using absorption and fluorescence spectroscopy. Theoretical and experimental results confirmed the presence of a strong covalent metal–ligand interaction between PAMAM G0 and copper ion that favored the formation of a ligand–metal charge transfer band coordination complex. In the case of Zn(II), no complex formation with PAMAM G0 was registered. Structure analysis identified the presence of aggregate like PAMAM G0–Zn moieties that generated an enhancement in the fluorescence emission of PAMAM G0. - Highlights: • Photophysical behavior of PAMAM G0 dendrimer with Cu and Zn ions was studied. • Strong covalent metal–ligand interaction was confirmed between PAMAM G0–Cu(II). • No complex formation with PAMAM G0 was registered in the case of Zn(II). • Dendrimer aggregate generated an enhancement in fluorescence emission.

Photophysical studies of the interactions of poly(amidoamine) generation zero (PAMAM G0) with copper and zinc ions

International Nuclear Information System (INIS)

López-Cabaña, Z.E.; Valdés, O.; Vergara, C.E.; Camarada, M.B.; Nachtigall, F.M.; González-Nilo, F.D.; Santos, Leonardo S.

2015-01-01

This study reports the photophysical behavior of poly(amidoamine) generation zero (PAMAM G0) in the presence of Cu(II) and Zn(II) ions in aqueous solutions using absorption and fluorescence spectroscopy. Theoretical and experimental results confirmed the presence of a strong covalent metal–ligand interaction between PAMAM G0 and copper ion that favored the formation of a ligand–metal charge transfer band coordination complex. In the case of Zn(II), no complex formation with PAMAM G0 was registered. Structure analysis identified the presence of aggregate like PAMAM G0–Zn moieties that generated an enhancement in the fluorescence emission of PAMAM G0. - Highlights: • Photophysical behavior of PAMAM G0 dendrimer with Cu and Zn ions was studied. • Strong covalent metal–ligand interaction was confirmed between PAMAM G0–Cu(II). • No complex formation with PAMAM G0 was registered in the case of Zn(II). • Dendrimer aggregate generated an enhancement in fluorescence emission

Effect of HCl Concentration on the Oxidation of LIX 63 and the Subsequent Separation of Pd(II), Pt(IV), Ir(IV) and Rh(III) by Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Thi Hong; Lee, Man Seung [Mokpo National University, Jeollanamdo (Korea, Republic of)

2016-10-15

During the selective extraction of Pd(II) by LIX 63 from 6 M HCl solutions containing platinum group metals, an oxidation-reduction reaction occurs between the LIX 63 and Ir(IV). Since the reduced Ir(III) cannot be extracted by solvating and amine extractants, the oxidation-reduction reaction has a significant effect on the separation of Pt(IV), Ir(IV) and Rh(III). Therefore, the effect of HCl concentration on the reduction of Ir(IV) during the extraction with LIX 63 was investigated at 3 and 6 M HCl solutions. The extraction behavior of Iridium by Aliquat 336 from the Pd(II) free raffinate showed that the percentage of iridium extraction rapidly decreased when HCl concentration was increased from 3 to 6 M, indicating that more Ir(IV) was reduced to Ir(III). Extraction schemes for the separation of Pt(IV), iridium and Rh(III) by Aliquat 336 from 3 and 6 M HCl solutions were investigated.

Cu(II) recognition materials: Fluorophores grafted on mesoporous silica supports

International Nuclear Information System (INIS)

Kledzik, Krzysztof; Orlowska, Maja; Patralska, Dorota; Gwiazda, Marcin; Jezierska, Julia; Pikus, Stanislaw; Ostaszewski, Ryszard; Klonkowski, Andrzej M.

2007-01-01

There were designed and synthesized naphthalene and pyrene derivatives consisting of fluorophore group and of receptor fragment with donor N and O atoms. These fluorosensors were covalently attached by grafting carboxyl group to surfaces of silica xerogel or mesoporous silicas (MCM-41 and MCM-48) functionalized either with 3-aminopropyl or 3-glycidoxypropyl groups. The pyrene derivatives 2 and 3 covalently grafted on MCM-48 silica functionalized with 3-aminopropyl groups are potential recognition elements of a fluorescence chemical sensor. Fluorescence emission of the prepared recognition materials is quenched specifically owing to photoinduced electron transfer (PET) effect after coordination reactions with Cu(II) ions. Moreover, both the materials exhibit selectivity for Cu(II) ions in aqueous solutions in presence of such metal ions as: alkali, alkaline earth and transition. During UV irradiation the studied recognition elements undergo slowly photochemical degradation

Functionalization of mesoporous silica membrane with a Schiff base fluorophore for Cu(II) ion sensing

Energy Technology Data Exchange (ETDEWEB)

Chen Xiaotong [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Department of Chemistry, Tsinghua University, Beijing 100084 (China); Yamaguchi, Akira [College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Tokai, Ibaraki 319-1106 (Japan); Namekawa, Manato [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Kamijo, Toshio [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Tsuruoka National College of Technology, Aza-Sawada, Tsuruoka 997-8511 (Japan); Teramae, Norio, E-mail: teramae@m.tohoku.ac.jp [Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku 980-8578, Sendai, Miyagi Prefecture (Japan); Tong, Aijun, E-mail: tongaj@mail.tsinghua.edu.cn [Department of Chemistry, Tsinghua University, Beijing 100084 (China)

2011-06-24

Graphical abstract: Highlights: > A hybrid mesoporous membrane (SB-HMM) functionalized by Schiff base fluorophores was fabricated. > SB-HMM showed strong fluorescence with aggregation-induced emission enhancement properties. > SB-HMM was applicable for the detection of Cu(II) in an aqueous solution with good reversibility and reproducibility. - Abstract: A Schiff base (SB) immobilized hybrid mesoporous silica membrane (SB-HMM) was prepared by immobilizing a Schiff base onto the pore surface of mesoporous silica (pore size = 3.1 nm) embedded in the pores of a porous anodic alumina membrane. In contrast to the non-fluorescent analogous SB molecule in homogeneous solutions, SB-HMM exhibited intense fluorescence due to emission enhancement caused by aggregation of SB groups on the pore surface. The high quantum efficiency of the surface SB groups allows SB-HMM to function as a fluorescent sensor for Cu(II) ions in an aqueous solution with good sensitivity, selectivity and reproducibility. Under the optimal conditions described, the linear ranges of fluorescence intensity for Cu(II) are 1.2-13.8 (M (R{sup 2} = 0.993) and 19.4-60 (R{sup 2} = 0.992) (M. The limit of detection for Cu(II) is 0.8 {mu}M on basis of the definition by IUPAC (C{sub LOD} = 3.3S{sub b}/m).

Solid phase selective separation and preconcentration of Cu(II) by Cu(II)-imprinted polymethacrylic microbeads.

Science.gov (United States)

Dakova, Ivanka; Karadjova, Irina; Ivanov, Ivo; Georgieva, Ventsislava; Evtimova, Bisera; Georgiev, George

2007-02-12

Ion-imprinted polymer (IIP) particles are prepared by copolymerization of methacrylic acid as monomer, trimethylolpropane trimethacrylate as crosslinking agent and 2,2'-azo-bis-isobutyronitrile as initiator in the presence of Cu(II), a Cu(II)-4-(2-pyridylazo)resorcinol (Cu(II)-PAR) complex, and PAR only. A batch procedure is used for the determination of the characteristics of the Cu(II) solid phase extraction from the IIP produced. The results obtained show that the Cu(II)-PAR IIP has the greatest adsorption capacity (37.4 micromol g(-1) of dry copolymer) among the IIPs investigated. The optimal pH value for the quantitative preconcentration is 7, and full desorption is achieved by 1 M HNO(3). The selectivity coefficients (S(Cu/Me)) for Me=Ni(II), Co(II) are 45.0 and 38.5, respectively. It is established that Cu(II)-PAR IIPs can be used repeatedly without a considerable adsorption capacity loss. The determination of Cu(II) ions in seawater shows that the interfering matrix does not influence the preconcentration and selectivity values of the Cu(II)-PAR IIPs. The detection and quantification limits are 0.001 micromol L(-1) (3sigma) and 0.003 micromol L(-1) (6sigma), respectively.

Functionalization of Magnetic Chitosan Particles for the Sorption of U(VI, Cu(II and Zn(II—Hydrazide Derivative of Glycine-Grafted Chitosan

Directory of Open Access Journals (Sweden)

Mohammed F. Hamza

2017-05-01

Full Text Available A new magnetic functionalized derivative of chitosan is synthesized and characterized for the sorption of metal ions (environmental applications and metal valorization. The chemical modification of the glycine derivative of chitosan consists of: activation of the magnetic support with epichlorohydrin, followed by reaction with either glycine to produce the reference material (i.e., Gly sorbent or glycine ester hydrochloride, followed by hydrazinolysis to synthesize the hydrazide functionalized sorbent (i.e., HGly sorbent. The materials are characterized by titration, elemental analysis, FTIR analysis (Fourrier-transform infrared spectrometry, TGA analysis (thermogravimetric analysis and with SEM-EDX (scanning electron microscopy coupled to energy dispersive X-ray analysis. The sorption performances for U(VI, Cu(II, and Zn(II are tested in batch systems. The sorption performances are compared for Gly and HGly taking into account the effect of pH, the uptake kinetics (fitted by the pseudo-second order rate equation, and the sorption isotherms (described by the Langmuir and the Sips equations. The sorption capacities of the modified sorbent reach up to 1.14 mmol U g−1, 1.69 mmol Cu g−1, and 0.85 mmol Zn g−1. In multi-metal solutions of equimolar concentration, the chemical modification changes the preferences for given metal ions. Metal ions are desorbed using 0.2 M HCl solutions and the sorbents are re-used for five cycles of sorption/desorption without significant loss in performances.

Modelling Zn(II) sorption onto clayey sediments using a multi-site ion-exchange model

International Nuclear Information System (INIS)

Tertre, E.; Beaucaire, C.; Coreau, N.; Juery, A.

2009-01-01

In environmental studies, it is necessary to be able to predict the behaviour of contaminants in more or less complex physico-chemical contexts. The improvement of this prediction partly depends on establishing thermodynamic models that can describe the behaviour of these contaminants and, in particular, the sorption reactions on mineral surfaces. In this way, based on the mass action law, it is possible to use surface complexation models and ion exchange models. Therefore, the aim of this study is (i) to develop an ion-exchange model able to describe the sorption of transition metal onto pure clay minerals and (ii) to test the ability of this approach to predict the sorption of these elements onto natural materials containing clay minerals (i.e. soils/sediments) under various chemical conditions. This study is focused on the behaviour of Zn(II) in the presence of clayey sediments. Considering that clay minerals are cation exchangers containing multiple sorption sites, it is possible to interpret the sorption of Zn(II), as well as competitor cations, by ion-exchange equilibria with the clay minerals. This approach is applied with success to interpret the experimental data obtained previously in the Zn(II)-H + -Na + -montmorillonite system. The authors' research team has already studied the behaviour of Na + , K + , Ca 2+ and Mg 2+ versus pH in terms of ion exchange onto pure montmorillonite, leading to the development of a thermodynamic database including the exchange site concentrations associated with montmorillonite and the selectivity coefficients of Na + , K + , Ca 2+ , Mg 2+ , and Zn 2+ versus H + . In the present study, experimental isotherms of Zn(II) on two different sediments in batch reactors at different pH and ionic strengths, using NaCl and CaSO 4 as electrolytes are reported. Assuming clay minerals are the main ion-exchanging phases, it is possible to predict Zn(II) sorption onto sediments under different experimental conditions, using the previously

Combined cation-exchange and solid phase extraction for the selective separation and preconcentration of zinc, copper, cadmium, mercury and cobalt among others using azo-dye functionalized resin.

Science.gov (United States)

Chatterjee, Mousumi; Srivastava, Bhavya; Barman, Milan K; Mandal, Bhabatosh

2016-04-01

A facile synthesis of an ion exchange material (FSG-PAN) has been achieved by functionalizing silica gel with an azo-dye. Its composition and structure are well assessed by systematic analysis. Extractor possesses high BET surface area (617.794m(2)g(-1)), exchange capacity and break-through capacity (BTC) (Q0 Zn(II): 225; Cd(II): 918; Hg(II): 384, Cu(II): 269 and Co(II): 388μMg(-1)). The sorption process was endothermic (+ΔH), entropy-gaining (+ΔS) and spontaneous (-ΔG) in nature. Preconcentration factor has been optimized at 172(Zn(II)); 157.2(Cd(II)); 193.6(Hg(II)); 176(Cu(II)); 172.4(Co(II)). Density functional theory calculation has been performed to analyze the sorption pathway. BTC (μMg(-1)) of FSG-PAN was found to be the product of its frontier orbitals and state of sorbed metal ion species, x (at x=1, mononuclear and x>1, a polynuclear species; i.e., BTC=[amount of HOMO]×x). FSG-PAN is used for the selective separation and preconcentration of Zn(II), Cd(II), Hg(II), Cu(II),Co(II) from large volume sample (800mL) of low concentration (0.017-0.40mML(-1)) in presence of foreign ions (50-300mML(-1)) at optimum conditions (pH: 7.0±1.5, flow rate: 2.5mLmin(-1), temperature: 27°C, equilibration-time: 5min). The method was found to be effective for real samples also. Copyright © 2016 Elsevier B.V. All rights reserved.

Removal of Cu(II) from aqueous solution by agricultural by-product: Peanut hull

Energy Technology Data Exchange (ETDEWEB)

Zhu Chunshui, E-mail: silk588@126.com [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China) and School of Chemical Engineering, Huai-hai institute of Technology, Lian Yungang, Jiangsu 222005 (China); Wang Liping [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China); Chen Wenbin [School of Environment Science and Spatial Informatics, China university of Mining and technology, Xuzhou, Jiangsu 221008 (China); School of Chemical Engineering, Huai-hai institute of Technology, Lian Yungang, Jiangsu 222005 (China)

2009-09-15

Peanut hull, an agricultural by-product abundant in China, was used as adsorbent for the removal of Cu(II) from aqueous solutions. The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration and reaction temperature. The Cu(II) removal was pH-dependent, reaching a maximum at pH 5.5. The biosorption process followed pseudo-second-order kinetics and equilibrium was attained at 2 h. The rate constant increased with the increase of temperature indicates endothermic nature of biosorption. The activation energy (E{sub a}) of Cu(II) biosorption was determined at 17.02 kJ/mol according to Arrhenius equation which shows that biosorption may be an activated chemical biosorption. Other activation parameters such as {Delta}H{sup numbersign}, {Delta}S{sup numbersign}, and {Delta}G{sup numbersign} were also determined from Eyring equation. The equilibrium data were analyzed using the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models depending on temperature. The equilibrium biosorption capacity of Cu(II) determined from the Langmuir equation was 21.25 mg/g at 30 deg. C. The mean free energy E (kJ/mol) got from the D-R isotherm also indicated a chemical ion-exchange mechanism. The thermodynamic parameters such as changes in Gibbs free energy ({Delta}G{sup 0}), enthalpy ({Delta}H{sup 0}) and entropy ({Delta}S{sup 0}) were used to predict the nature of biosorption process. The negative {Delta}G{sup 0} values at various temperatures confirm the biosorption processes are spontaneous.

One-Pot Synthesis of Cu(II Complex with Partially Oxidized TTF Moieties

Directory of Open Access Journals (Sweden)

Hiroki Oshio

2012-07-01

Full Text Available The one-pot synthesis of a Cu(II complex with partially oxidized tetrathiafulvalene (TTF moieties in its capping MT-Hsae-TTF ligands, [CuII(MT-sae-TTF2] [CuICl2] was realized by the simultaneous occurrence of Cu(II complexation and CuIICl2 mediated oxidation of TTF moieties. The crystal structure was composed of one-dimensional columns formed by partially oxidized TTF moieties and thus the cation radical salt showed relatively high electrical conductivity. Tight binding band structure calculations indicated the existence of a Peierls gap due to the tetramerization of the TTF moieties in the one-dimensional stacking column at room temperature, which is consistent with the semiconducting behavior of this salt.

Spectroscopic, electrochemical and photovoltaic properties of Pt(ii) and Pd(ii) complexes of a chelating 1,10-phenanthroline appended perylene diimide.

Science.gov (United States)

Işık Büyükekşi, Sebile; Şengül, Abdurrahman; Erdönmez, Seda; Altındal, Ahmet; Orman, Efe Baturhan; Özkaya, Ali Rıza

2018-02-20

In this study, a bis-chelating bridging perylene diimide ditopic ligand, namely N,N'-di(1,10-phenanthroline)-1,6,7,12-tetrakis-(4-methoxyphenoxy)perylene tetracarboxylic acid diimide (1), was synthesized and characterized. Further reactions of 1 with d 8 metal ions such as Pt(ii) and Pd(ii) having preferential square-planar geometry afforded the novel triads [(Cl 2 )M(ii)-(1)-M(ii)(Cl 2 )] where M(ii) = Pt(ii) (2), and Pd(ii) (3), respectively. The isolated triads and the key precursor were fully characterized by FT-IR, 1D-NMR ( 1 H NMR and 13 C DEPT NMR), 2D-NMR ( 1 H- 1 H COSY, 1 H- 13 C HSQC, 1 H- 13 C HMBC), MALDI-TOF mass and UV/Vis spectroscopy. The electrochemical properties of 1, 2 and 3 were investigated by cyclic voltammetry as well as in situ spectroelectrochemistry and also in situ electrocolorimetric measurements. These compounds were shown to exhibit net colour changes suitable for electrochromic applications. The compounds exhibited remarkably narrow HOMO-LUMO gaps, leading to their ease of reduction at low negative potentials. More importantly, dye-sensitized solar cells (DSSCs) were also fabricated using 1-3 to clarify the potential use of these complexes as a sensitizer. Analysis of the experimental data indicated that 2 has good potential as a sensitizer material for DSSCs.

A saponification-triggered gelation of ester-based Zn(II) complex through conformational transformations.

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Kumar, Ashish; Dubey, Mrigendra; Kumar, Amit; Pandey, Daya Shankar

2014-09-11

Novel saponification-triggered gelation in an ester-based bis-salen Zn(II) complex (1) is described. Strategic structural modifications induced by NaOH in 1 tune the dipolar-/π-interactions leading to J-aggregation and the creation of an inorganic gel material (IGM), which has been established by photophysical, DFT and rheological studies.

Removal of Cu(II) metal ions from aqueous solution by amine functionalized magnetic nanoparticles

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Kothavale, V. P.; Karade, V. C.; Waifalkar, P. P.; Sahoo, Subasa C.; Patil, P. S.; Patil, P. B.

2018-04-01

The adsorption behavior of Cu(II) metal cations was investigated on the amine functionalized magnetic nanoparticles (MNPs). TheMNPs were synthesized by thesolvothermal method and functionalized with (3-Aminopropyl)triethoxysilane (APTES). MNPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM). The MNPs have pure magnetite phase with particle size around 10-12 nm. MNPs exhibits superparamagnetic behavior with asaturation magnetization of 68 emu/g. The maximum 38 % removal efficiency was obtained for Cu(II) metal ions from the aqueous solution.

Metallic complexes with glyphosate: a review; Complexos metalicos com o herbicida glifosato: revisao

Energy Technology Data Exchange (ETDEWEB)

Coutinho, Claudia F.B.; Mazo, Luiz Henrique [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Quimica]. E-mail: claudiabreda@iqsc.usp.br

2005-11-15

We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature. (author)

Metallic complexes with glyphosate: a review

International Nuclear Information System (INIS)

Coutinho, Claudia F.B.; Mazo, Luiz Henrique

2005-01-01

We present studies involving metallic ions and the herbicide glyphosate. The metallic complexes of Cu(II), Zn(II), Mn(II), Ni(II), Cd(II), Pb(II), Cr(III), Fe(III), Co(III), ammonium, sodium, Ag(I), alkaline earth metals and of some lanthanides ions are described. The complexes are discussed in terms of their synthesis, identification, stability and structural properties, based on data from the current literature. (author)

Adsorption of Pb, Cd, Zn, Cu and Hg ions on Formaldehyde and ...

African Journals Online (AJOL)

Adsorption of Pb(II), Cd(II), Zn(II), Cu(II) and Hg(II) ions on formaldehyde and Pyridine modified bean husks were determined. The adsorption capacity of formaldehyde modified bean husks (mg/g) was: Pb2+, 5.01; Cd2+, 3.63; Zn2+, 2.18; Hg2+, 1.82; Cu2+, 1.58 and that of pyridine modified bean husk was: Hg2+, 6.92; Cd2+ ...

Spectroscopic characterization of some Cu(II) complexes

International Nuclear Information System (INIS)

Singh, Puja; Sharma, S.

2014-01-01

3-hydroxy-4-methoxy benzaldehyde semicarbazone (HMBS) is a biologically active compound which has several potential donor sites. This compound has been used for complexation with Cu(II) ions to synthesize complexes of general formula [Cu(HMBS) 2 X 2 ] where X is Cl − , NO 3 − and CH 3 COO − . Cu(II) is a d 9 system for which 2 D term is generated. Under O h symmetry, this term splits into 2 E g and 2 T 2g . the ground term 2 Eg is doubly degenerate and hence suffers strong Jahn-Teller effect and accordingly the further splitting of terms occur to lower the symmetry from perfect O h . Here, the ligand occupies four planar positions while the two axial positions have been varied by using different ions like Cl − , NO 3 − and CH 3 COO − . These variations on the axial positions also add to the distortion in O h symmetry. Under strong distortion, the electronic spectral band splits into multiplets exhibiting tetragonal distortion in complexes. The extent of distortion has been derived by the derivation of the two radial parameters D s and D t from electronic spectral bands. The ESR spectra of complexes reveal the real position of the only unpaired electron of the d 9 system in complexes

Ultraviolet spectroscopy and metal ions detection

International Nuclear Information System (INIS)

Chaudry, M.A.

1995-01-01

The spectrochemical analysis is based on the interaction of radiation with the chemical species and depends on their nature, having pi, sigma or electrons, or d and f electrons, UV. Visible spectrophotometry has been used extensively in the detection and determination of both organics and inorganics. In UV detection the sensitivity is proportional to the bath length and the excitation coefficient of the given sample. It may be insensitive to many species unless these are converted to UV, absorbing derivatives. The technique has been applied for the monitoring of the effluents from HPLC, as chlorides or other complexes of various elements in this article the utility of HCl as reagent for the spectrophotometric determination of the metal ions like Al(III), As(III,IV), Ba(II), Cd(II), Ca(II) Ce(III), Cs(i), Cr(III,VI), Co(II), Cu(II), Dy(III), Eu(III), Gd(III), Au(III), Hf(IV), Ho(III), In(III), Fe(III), La(III), Pb(II), Lu (III), Mg(II), Mn(II), Hg(II), Mo(VI), Ni(II), Pd(II), Pt(IV), K(I), Pr(III), Re(VII), Ru(IV), Sm(III), Sc(III), Ag(I), Sr(II) Te(III), Th(IV), Sn(II,IV), Ti(III,IV), W(VI), U(VI), V(IV,V), Yb(III), Zn(II) AND Zr(IV) Ions i.e. for meta ions from d of the most of these metal ions has been found sufficient permit their detection in HPLC. Their molar absorptive have also been reported. Reference has also been provided to post column derivatization of some metal ions from d and f block elements for their detection in HPLC. (author) 12 figs.; 6 tabs.; 27 refs

The facile synthesis of a chitosan Cu(II) complex by solution plasma process and evaluation of their antioxidant activities.

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Ma, Fengming; Li, Pu; Zhang, Baiqing; Wang, Zhenyu

2017-10-01

Synthesis of chitosan-Cu(II) complex by solution plasma process (SPP) irradiation was investigated. The effects of the distance between the electrodes, initial Cu(II) concentration, and initial pH on the Cu(II) adsorption capacity were evaluated. The results showed that narrower distance between the electrodes, higher initial Cu(II) concentration and higher initial pH (at pHchitosan-Cu(II) complex by ultraviolet-visible (UV-vis), fourier transform infrared (FT-IR) and electron spin resonance (ESR) spectroscopy revealed that the main structure of chitosan was not changed after irradiation. Thermogravimetry (TG) analysis indicated that Cu(II) ions were well incorporated into the chitosan. The antioxidant activity of the chitosan-Cu(II) complex was evaluated by DPPH, ABTS, and reducing power assays. The chitosan-Cu(II) complex exhibited greater antioxidant activity than the original chitosan. Thus, SPP could be used for preparation of chitosan-Cu(II) complexes. Copyright © 2017. Published by Elsevier B.V.

Study of the relationship between chemical structure and antimicrobial activity in a series of hydrazine-based coordination compounds.

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Dobrova, B N; Dimoglo, A S; Chumakov, Y M

2000-08-01

The dependence of antimicrobial activity on the structure of compounds is studied in a series of compounds based on hydrazine coordinated with ions of Cu(II), Ni(II) and Pd(II). The study has been carried out by means of the original electron-topological method developed earlier. A molecular fragment has been found that is only characteristic of biologically active compounds. Its spatial and electron parameters have been used for the quantitative assessment of the activity in view. The results obtained can be used for the antimicrobial activity prediction in a series of compounds with similar structures.

Potentiometric and spectroscopic study of the interaction of 3d transition metal ions with inositol hexakisphosphate

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Veiga, Nicolás; Macho, Israel; Gómez, Kerman; González, Gabriel; Kremer, Carlos; Torres, Julia

2015-10-01

Among myo-inositol phosphates, the most abundant in nature is the myo-inositol hexakisphosphate, InsP6. Although it is known to be vital to cell functioning, the biochemical research into its metabolism needs chemical and structural analysis of all the protonation, complexation and precipitation processes that it undergoes in the biological media. In view of its high negative charge at physiological level, our group has been leading a thorough research into the InsP6 chemical and structural behavior in the presence of the alkali and alkaline earth metal ions essential for life. The aim of this article is to extend these studies, dealing with the chemical and structural features of the InsP6 interaction with biologically relevant 3d transition metal ions (Fe(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)), in a non-interacting medium and under simulated physiological conditions. The metal-complex stability constants were determined by potentiometry, showing under ligand-excess conditions the formation of mononuclear species in different protonation states. Under metal ion excess, polymetallic species were detected for Fe(II), Fe(III), Zn(II) and Cu(II). Additionally, the 31P NMR and UV-vis spectroscopic studies provided interesting structural aspects of the strong metal ion-InsP6 interaction.

Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III Oxide

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Zuzana Koudelkova

2017-08-01

Full Text Available In this study, the preparation and electrochemical application of a chromium(III oxide modified carbon paste electrode (Cr-CPE and a screen printed electrode (SPE, made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L−1 for Zn(II, 3 and 10 µg·L−1 for Cd(II, 3 and 10 µg·L−1 for Pb(II, 3 and 10 µg·L−1 for Cu(II, and 3 and 10 µg·L−1 for Ag(I, respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L−1 for Zn(II, 25 µg·L−1 for Cd(II, 3 µg·L−1 for Pb(II and 3 µg·L−1 for Cu(II. Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

Electrochemical and spectroscopic studies of the complexed species of models of nitrohumic acids derived from phthalic acid

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Mercê Ana Lucia Ramalho

1998-01-01

Full Text Available The study of model compounds is necessary in order to obtain information about complex organic substances as in the case of humic substances (HS. These substances are potential organic fertilizers and have other important functions in soils, natural waters and organic sediments. The main chemical properties of the complexes formed from 3-nitrophthalic and 4-nitrophthalic acids and the metal ions Fe(III and Zn(II were studied using potentiometric titrations, ultraviolet-visible spectroscopy (UV-Vis and cyclic voltammetry (CV. A trial potentiometric titration was done with a mixture of the models for nitrohumic acids and Cu(II. Equilibrium constants for the systems were calculated and UV-Vis and CV were employed to monitor the formation of the species. Comparative studies involving chelating centres of nitrosalicylic acids and nitrocatechols with Fe(III, Zn(II and Cu(II are presented. The initial studies involving the nitrohumic substances (NHS, a laboratory artifact of HS have been made and good evidence was found for the further use of NHS as a potential organic fertilizer as well as HS. In this present work one of the observed advantages of NHS over HS was that some aromatic nitro- centres can bind some metal ions at p[H] values of normal soils, near 7.0 to 7.5.

Structural, theoretical and corrosion inhibition studies on some transition metal complexes derived from heterocyclic system

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Gupta, Shraddha Rani; Mourya, Punita; Singh, M. M.; Singh, Vinod P.

2017-06-01

A Schiff base, (E)-N‧-((1H-indol-3-yl)methylene)-2-aminobenzohydrazide (Iabh) and its Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. These compounds have been characterized by different physico-chemical and spectroscopic tools (UV-Vis, IR, NMR and ESI-Mass). The molecular structure of Iabh is determined by single crystal X-ray diffraction technique. The ligand Iabh displays E-configuration about the >Cdbnd N- bond. The structure of ligand is stabilized by intra-molecular H-bonding. In all the metal complexes the ligand coordinates through azomethine-N and carbonyl-O resulting a distorted octahedral geometry for Mn(II), Co(II) and Cu(II) complexes in which chloride ions occupy axial positions. Ni(II) and Zn(II) complexes, however, form 4-coordinate distorted square planer and tetrahedral geometry around metal ion, respectively. The structures of the complexes have been satisfactorily modeled by calculations based on density functional theory (DFT) and time dependent-DFT (TD-DFT). The corrosion inhibition study of the compounds have been performed against mild steel in 0.5 M H2SO4 solution at 298 K by using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). They show appreciable corrosion inhibition property.

Determination of Zinc, Cadmium, Lead, Copper and Silver Using a Carbon Paste Electrode and a Screen Printed Electrode Modified with Chromium(III) Oxide.

Science.gov (United States)

Koudelkova, Zuzana; Syrovy, Tomas; Ambrozova, Pavlina; Moravec, Zdenek; Kubac, Lubomir; Hynek, David; Richtera, Lukas; Adam, Vojtech

2017-08-09

In this study, the preparation and electrochemical application of a chromium(III) oxide modified carbon paste electrode (Cr-CPE) and a screen printed electrode (SPE), made from the same material and optimized for the simple, cheap and sensitive simultaneous determination of zinc, cadmium, lead, copper and the detection of silver ions, is described. The limits of detection and quantification were 25 and 80 µg·L -1 for Zn(II), 3 and 10 µg·L -1 for Cd(II), 3 and 10 µg·L -1 for Pb(II), 3 and 10 µg·L -1 for Cu(II), and 3 and 10 µg·L -1 for Ag(I), respectively. Furthermore, this promising modification was transferred to the screen-printed electrode. The limits of detection for the simultaneous determination of zinc, cadmium, copper and lead on the screen printed electrodes were found to be 350 µg·L -1 for Zn(II), 25 µg·L -1 for Cd(II), 3 µg·L -1 for Pb(II) and 3 µg·L -1 for Cu(II). Practical usability for the simultaneous detection of these heavy metal ions by the Cr-CPE was also demonstrated in the analyses of wastewaters.

Solvent extraction of Zn(II) from aqueous sulphate media by di(2-ethylhexyl) phosphoric acid in kerosene

International Nuclear Information System (INIS)

Begum, D.A.; Alauddin, M.; Rahman, M.S.

2009-01-01

The extraction equilibrium studies of Zn(II) from sulphate medium by di(2-ethylhexyl) phosphoric acid (D2EHPA, H/sub 2/A/sub 2/) in kerosene revealed that the distribution ratio (D) decreased with the increase of initial (Zn(A(II) in the aqueous phase and increased with the increase of equilibrium pH and extractant concentration. The equilibration is reached within 2 min. The species extracted into the organic phase is thought to be ZnA2, HA. The pH and extractant dependencies were about 2 and 1.67, respectively. The distribution ratio decreased with the increase in sulphate ion concentration in the aqueous phase. The extraction equilibrium reaction is suggested as Zn/sup 2+/ /sub aq/ +1.5 (H/sub 2/A/sub 2/)org - (ZnA/sub 2/, HA)org +2H/sup +/ /sub aq/. The extraction equilibrium constant (kex) for the above reaction was calculated to be 10-2.26. The extraction process was endothermic in nature having positive DH value of 16.27 kJ/mol. The loading of D2EHPA by Zn(II) is about 4.50 g of Zn(II) by 0.10 M D2EHPA. Possible reaction mechanism has been suggested based on distribution data, extractant concentration and equilibrium pH of the aqueous phase. (author)

Bioassay studies of metal(II complexes of 2,2'-(ethane-1,2-diyldiiminodiacetic acid

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Saeed-ur-Rehman

2011-08-01

Full Text Available Ni(II, Cu(II and Zn(II coordination compounds with modified diammine 2,2'-(ethane-1,2-diyldiiminodiacetic acid (EDDA were prepared and characterized. Coordination complexes of the EDDA were characterized by physical measurements including elemental analysis, IR, UV-Visible, magnetic susceptibilities and conductance measurements. The complexes were screened against four pathogenic bacteria like Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus and their concentrations for maximum inhibition zones were obtained.

Voltammetric determination of zirconium using azo compounds

International Nuclear Information System (INIS)

Orshulyak, O.O.; Levitskaya, G.D.

2008-01-01

The optimum conditions for zirconium complexation with azo compounds are found. The applicability of Eriochrome Red B, Calcon, and Calcion to the voltammetric determination of zirconium, total Zr(IV) and Hf(IV), and Zr(IV) in the presence of Zn(II), Cu(II), Cd(II), Ni(II), or Ti(IV) is demonstrated. The developed procedures are used to determine zirconium in a terbium alloy and in an alloy for airplane wheel drums [ru

Determination of Proton Relaxivities of Mn(II, Cu(II and Cr(III added to Solutions of Serum Proteins

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Ali Yilmaz

2009-04-01

Full Text Available Relaxometric studies are still of scientific interest due to their use in medicine and biology. In this study, proton T1 and T2 relaxivities of Mn(II, Cu(II and Cr(III in water were determined in the presence and absence of various proteins (albumin, α-globulin, γ-globulin, lysozyme, fibrinogen. The 1/T1 and 1/T2 in all solutions are linearly proportional to the concentration of the paramagnetic ions. Mn(II has the great influence to alter relaxations in all protein solutions, while Cu(II and Cr(III have a poor influence on the relaxations. In addition, Mn(II and Cu(II are bound to each protein, but Cr(III is not bound to any protein.

Sorption of Cu(II) Ions on Chitosan-Zeolite X Composites: Impact of Gelling and Drying Conditions.

Science.gov (United States)

Djelad, Amal; Morsli, Amine; Robitzer, Mike; Bengueddach, Abdelkader; di Renzo, Francesco; Quignard, Françoise

2016-01-19

Chitosan-zeolite Na-X composite beads with open porosity and different zeolite contents were prepared by an encapsulation method. Preparation conditions had to be optimised in order to stabilize the zeolite network during the polysaccharide gelling process. Composites and pure reference components were characterized using X-ray diffraction (XRD); scanning electron microscopy (SEM); N₂ adsorption-desorption; and thermogravimetric analysis (TG). Cu(II) sorption was investigated at pH 6. The choice of drying method used for the storage of the adsorbent severely affects the textural properties of the composite and the copper sorption effectiveness. The copper sorption capacity of chitosan hydrogel is about 190 mg·g(-1). More than 70% of this capacity is retained when the polysaccharide is stored as an aerogel after supercrititcal CO₂ drying, but nearly 90% of the capacity is lost after evaporative drying to a xerogel. Textural data and Cu(II) sorption data indicate that the properties of the zeolite-polysaccharide composites are not just the sum of the properties of the individual components. Whereas a chitosan coating impairs the accessibility of the microporosity of the zeolite; the presence of the zeolite improves the stability of the dispersion of chitosan upon supercritical drying and increases the affinity of the composites for Cu(II) cations. Chitosan-zeolite aerogels present Cu(II) sorption properties.

Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines

Science.gov (United States)

Anbarasu, G.; Malathy, M.; Karthikeyan, P.; Rajavel, R.

2017-09-01

Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.

Coordination Chemistry of Linear Oligopyrrolic Fragments Inspired by Heme Metabolites

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Gautam, Ritika

Linear oligopyrroles are degradation products of heme, which is converted in the presence of heme oxygenase to bile pigments, such as biliverdin and bilirubin. These tetrapyrrolic oligopyrroles are ubiquitously present in biological systems and find applications in the fields of catalysis and sensing. These linear tetrapyrrolic scaffolds are further degraded into linear tripyrrolic and dipyrrolic fragments. Although these lower oligopyrroles are abundantly present, their coordination chemistry requires further characterization. This dissertation focuses mainly on two classes of bioinspired linear oligopyrroles, propentdyopent and tripyrrindione, and their transition metal complexes, which present a rich ligand-based redox chemistry. Chapter 1 offers an overview of heme degradation to different classes of linear oligopyrroles and properties of their transition metal complexes. Chapter 2 is focused on the tripyrrin-1,14-dione scaffold of the urinary pigment uroerythrin, which coordinates divalent transition metals palladium and copper with square planar geometry. Specifically, the tripyrrin-1, 14-dione ligand binds Cu(II) and Pd(II) as a dianionic organic radical under ambient conditions. The electrochemical study confirms the presence of ligand based redox chemistry, and one electron oxidation or reduction reactions do not alter the planar geometry around the metal center. The X-Ray analysis and the electron paramagnetic resonance (EPR) studies of the complexes in the solid and solution phase reveals intermolecular interactions between the ligand based unpaired electrons and therefore formation of neutral pi-pi dimers. In Chapter 3, the antioxidant activity and the fluorescence sensor properties of the tripyrrin-1,14-dione ligand in the presence of superoxide are described. We found that the tripyrrindione ligand undergoes one-electron reduction in the presence of the superoxide radical anion (O2•- ) to form highly fluorescent H3TD1•- radical anion, which emits

Antiferromagnetic Coupling in the Polynuclear Compound [Cu(II) (Allopurinolate) (OH-)] n

Science.gov (United States)

Acevedo-Chávez, Rodolfo; Costas, María. Eugenia; Escudero-Derat, Roberto

1994-11-01

Synthetic, spectral, and magnetic studies of the Cu(II) polynuclear coordination compound [Cu(HL(OH-)]n with bridging OH- and HL (allopurinolate; C5H3N4O-) ligands are reported. The compound is obtained from aqueous media (at several pH values and from CI-, Br-, NO-3, SO2-4, ClO-4, and CH3CO-2 Cu(II) salts), from DMSO at ca. 70°C using several of the above salts, and under refluxing methanol employing Cu(SO4) or Cu(CH3CO2)2. The results suggest that the compound [Cu(HL)(OH-)]n has a polynuclear form in which the bridging allopurinolate is coordinated through the N(1) and N(2) atoms of the pyrazolic moiety. All attempts to grow crystals suitable for X-ray studies were unsuccessful, and an amorphous compound was always obtained. Magnetic studies show the existence of a strong antiferromagnetic coupling, which may be associated with a favorable structural arrangement between the metallic centers and the bridging ligands. This magnetic behavior is remarkable for a Cu(II) polynuclear coordination compound. Spectral and magnetic results together with the coordination modes of the bridging groups let us postulate as a possible arrangement a cyclic polynuclear structure presenting the allopurinolate and OH- bridging ligands in a mutually trans configuration. This work is the first EPR spectral and magnetic study reported for a coordination compound with the allopurinol heterocycle as a ligand and, thus for the first example of a polynuclear coordination compound combining allopurinolate and OH- as bridging groups.

Cu(II) salen complex with propylene linkage: An efficient catalyst in the formation of Csbnd X bonds (X = N, O, S) and biological investigations

Science.gov (United States)

Azam, Mohammad; Dwivedi, Sourabh; Al-Resayes, Saud I.; Adil, S. F.; Islam, Mohammad Shahidul; Trzesowska-Kruszynska, Agata; Kruszynski, Rafal; Lee, Dong-Ung

2017-02-01

The catalytic property of a mononuclear Cu(II) salen complex in Chan-Lam coupling reaction with phenyl boronic acid at room temperature is reported. The studied complex is found to be potential catalyst in the preparation of carbon-heteroatom bonds with excellent yields. The studied Cu(II) salen complex is monoclinic with cell parameters, a = 9.6807(5) (α 90°), (b = 17.2504(8) (β 112.429 (2), c = 11.1403 (6) (γ = 90°), and has distorted square planar environment around Cu(II) ion. Furthermore, there is no π⋯π interactions in the reported complex due to large distance between the centroid of aromatic rings. In addition, DNA binding study of Cu(II) salen complex by fluorescence and absorption spectroscopy is also reported. Moreover, the reported Cu(II) salen complex exhibits significant anticancer activity against MCF-7 cancer cell lines, and displays potential antimicrobial biofilm activity against P. aeruginosa, suggesting antimicrobial biofilm an important tool for suppression of resistant infections caused by P. aeruginosa.

Synthesis, spectroscopic properties, molecular docking, anti-colon cancer and anti-microbial studies of some novel metal complexes for 2-amino-4-phenylthiazole derivative

Science.gov (United States)

Al-Harbi, Sami A.; Bashandy, Mahmoud S.; Al-Saidi, Hammed M.; Emara, Adel A. A.; Mousa, Tarek A. A.

2015-06-01

This article describes the synthesis of novel bidentate Schiff base (H2L) from condensation of 2-amino-4-phenylthiazole (APT) with 4,6-diacetylresorcinol (DAR) in the molar ratio 2:1. We studied interaction of ligand (H2L) with transition metal ions such as Cr(III), Fe(III), Cu(II), Zn(II) and Cd(II). The ligand (H2L) has two bidentate sets of (N-O) units which can coordinate with two metal ions to afford novel binuclear metal complexes. The directions of coordinate bonds are from nitrogen atoms of azomethine groups and oxygen atoms of the phenolic groups. Structures of the newly synthesized complexes were confirmed by elemental analysis, IR, UV, 1H NMR, ESR, TGA and mass spectral data. All of the newly synthesized complexes were evaluated for their antibacterial and anti-fungal activities. They were also evaluated for their in vitro anticancer activity against human colon carcinoma cells (HCT-116) and mammalian cells of African green monkey kidney (VERO). The Cu(II) complex with selectivity index (S.I.) = 21.26 exhibited better activity than methotrexate (MTX) as a reference drug with S.I. value = 13.30, while Zn(II) complex with S.I. value = 10.24 was found to be nearly as active as MTX. Molecular docking studies further helped in understanding the mode of action of the compounds through their various interactions with active sites of dihydrofolate reductase (DHFR) enzyme. The observed activity of Fe(III) and Cu(II) complexes gave rise to the conclusion that they might exert their action through inhibition of the DHFR enzyme.

Artificial neural networks study of the catalytic reduction of resazurin: stopped-flow injection kinetic-spectrophotometric determination of Cu(II) and Ni(II)

International Nuclear Information System (INIS)

Magni, Diana M.; Olivieri, Alejandro C.; Bonivardi, Adrian L.

2005-01-01

An artificial neural network (ANN) procedure was used in the development of a catalytic spectrophotometric method for the determination of Cu(II) and Ni(II) employing a stopped-flow injection system. The method is based on the catalytic action of these ions on the reduction of resazurin by sulfide. ANNs trained by back-propagation of errors allowed us to model the systems in a concentration range of 0.5-6 and 1-15 mg l -1 for Cu(II) and Ni(II), respectively, with a low relative error of prediction (REP) for each cation: REP Cu(II) = 0.85% and REP Ni(II) = 0.79%. The standard deviations of the repeatability (s r ) and of the within-laboratory reproducibility (s w ) were measured using standard solutions of Cu(II) and Ni(II) equal to 2.75 and 3.5 mg l -1 , respectively: s r [Cu(II)] = 0.039 mg l -1 , s r [Ni(II)] = 0.044 mg l -1 , s w [Ni(II)] = 0.045 mg l -1 and s w [Ni(II)] = 0.050 mg l -1 . The ANNs-kinetic method has been applied to the determination of Cu(II) and Ni(II) in electroplating solutions and provided satisfactory results as compared with flame atomic absorption spectrophotometry method. The effect of resazurin, NaOH and Na 2 S concentrations and the reaction temperature on the analytical sensitivity is discussed

Determination of gold by substoichiometric extraction with N-thioacetyl benzamide

International Nuclear Information System (INIS)

Madhumita Bag; Pabitra Chattopadhyay; Sukalyan Basu

2011-01-01

Estimation of gold has been successfully carried out by substoichiometric radiochemical solvent extraction method using a newly designed organic moiety, N-thioacetyl benzamide as extractant and chloroform as solvent at aqueous pH 4. The interference effects of different closely related diverse ions like Fe(III), Cu(II), Co(II), Zn(II), Ni(II) etc. were also critically studied. The validity of this method has been verified by the study of recovery of gold in mud samples. (author)

Emission solvatochromic behavior of a pentacoordinated Zn(II) complex: A viable tool for studying the metallodrug–protein interaction

Energy Technology Data Exchange (ETDEWEB)

Ricciardi, Loredana, E-mail: loredana.ricciardi@unical.it [Department of Chemistry and Chemical Technology, University of Calabria, I-87036 Rende (CS) (Italy); Centre of Excellence “Functional Nanostructured Materials” CEMIF.CAL, LASCAMM and CR INSTM, INSTM Calabria Unit, and CNR-IPCF-UOS Cosenza - Licryl Laboratory, I-87036 Rende (CS) (Italy); Pucci, Daniela; Pirillo, Sante; La Deda, Massimo [Department of Chemistry and Chemical Technology, University of Calabria, I-87036 Rende (CS) (Italy); Centre of Excellence “Functional Nanostructured Materials” CEMIF.CAL, LASCAMM and CR INSTM, INSTM Calabria Unit, and CNR-IPCF-UOS Cosenza - Licryl Laboratory, I-87036 Rende (CS) (Italy)

2014-07-01

A metal complex with antitumoral activity, Zn(Curcumin)(bypiridine)Cl, was characterized from a photophysical point of view, showing a green emission and a positive solvatochromism. These characteristics can be conveniently used to study its interaction with Human Serum Albumin (HSA), a protein carrier of many non-aqueous biologically-active compounds in the blood stream. The intrinsic fluorescence of HSA was quenched by Fluorescence Resonance Energy Transfer toward the Zn(II) complex, and the Stern–Volmer equation was applied to determine the bimolecular quenching rate constant of the interaction. - Highlights: • Albumin binding information is a key characteristic of drug pharmacology. • Fluorescence spectroscopy offers a simple method for revealing drug–protein interaction. • The fluorescence of the Zn(II) complex and its solvatochromisms has allowed studying the binding from a dual perspective.

Cu(II) Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

OpenAIRE

Ramadevi, Pulipaka; Singh, Rinky; Prajapati, Akhilesh; Gupta, Sarita; Chakraborty, Debjani

2014-01-01

A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II). The ligands are coordinated to Cu(II) ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds...

Adsorption of Zn(II) and Cd(II) ions in batch system by using the Eichhornia crassipes.

Science.gov (United States)

Módenes, A N; Espinoza-Quiñones, F R; Borba, C E; Trigueros, D E G; Lavarda, F L; Abugderah, M M; Kroumov, A D

2011-01-01

In this work, the displacement effects on the sorption capacities of zinc and cadmium ions of the Eichornia crassipes-type biosorbent in batch binary system has been studied. Preliminary single metal sorption experiments were carried out. An improvement on the Zn(II) and Cd(II) ions removal was achieved by working at 30 °C temperature and with non-uniform biosorbent grain sizes. A 60 min equilibrium time was achieved for both Zn(II) and Cd(II) ions. Furthermore, it was found that the overall kinetic data were best described by the pseudo second-order kinetic model. Classical multi-component adsorption isotherms have been tested as well as a modified extended Langmuir isotherm model, showing good agreement with the equilibrium binary data. Around 0.65 mequiv./g maximum metal uptake associated with the E. crassipes biosorbent was attained and the E. crassipes biosorbent has shown higher adsorption affinity for the zinc ions than for the cadmium ones in the binary system.

Study of new rubber to steel adhesive systems based on Co(II and Cu(II sulphides coats

Directory of Open Access Journals (Sweden)

Labaj Ivan

2018-01-01

Full Text Available The presented paper deals with the preparation of new rubber to steel adhesive systems using the steel surface treatment with deposition of adhesive coats based on Co(II and Cu(II sulphides. Efficiency of new prepared adhesive systems containing Co(II and Cu(II sulphides has been compared with the efficiency of double layer adhesive system commonly used in industry. The chemical composition of prepared adhesive systems was determined using the EDX analysis. Scanning Electron Microscopy (SEM was used for study of topography and microstructure of prepared rubber to steel adhesive systems (Co(II, Cu(II sulphide, double layer adhesive system. For determination of adhesion strength between rubber blends and metal pieces with various adhesive systems deposited on these pieces, the test according to ASTM D429 standard relating to Rubber to metal adhesion, method A was used. For all test samples, the same type of rubber blend and the same curing conditions have been used.

Synthesis, characterization and biological assay of Salicylaldehyde Schiff base Cu(II) complexes and their precursors

Science.gov (United States)

Iftikhar, Bushra; Javed, Kanwal; Khan, Muhammad Saif Ullah; Akhter, Zareen; Mirza, Bushra; Mckee, Vickie

2018-03-01

Three new Schiff base ligands were synthesized by the reaction of Salicylaldehyde with semi-aromatic diamines, prepared by the reduction of corresponding dinitro-compounds, and were further used for the formation of complexes with Cu(II) metal ion. The structural features of the synthesized compounds were confirmed by their physical properties and infrared, electronic and NMR spectroscopic techniques. The studies revealed that the synthesized Schiff bases existed as tetradentate ligands and bonded to the metal ion through the phenolic oxygen and azomethine nitrogen. One of the dinitro precursors was also analyzed by single crystal X-ray crystallography, which showed that it crystallizes in monoclinic system with space group P2/n. The thermal behavior of the Cu(II) complexes was determined by thermogravimetric analysis (TGA) and kinetic parameters were evaluated from the data. Schiff base ligands, their precursors and metal complexes were also screened for antibacterial, antifungal, antitumor, Brine shrimp lethality, DPPH free radical scavenging and DNA damage assays. The results of these analyses indicated the substantial potential of the synthesized Schiff bases, their precursors and Cu(II) complexes in biological field as future drugs.

Synthesis of poly(aminopropyl/methyl)silsesquioxane particles as effective Cu(II) and Pb(II) adsorbents.

Science.gov (United States)

Lu, Xin; Yin, Qiangfeng; Xin, Zhong; Li, Yang; Han, Ting

2011-11-30

Poly(aminopropyl/methyl)silsesquioxane (PAMSQ) particles have been synthesized by a one-step hydrolytic co-condensation process using 3-aminopropyltriethoxysilane (APTES) and methyltrimethoxysilane (MTMS) as precursors in the presence of base catalyst in aqueous medium. The amino functionalities of the particles could be controlled by adjusting the organosilanes feed ratio. The compositions of the amino-functionalized polysilsesquioxanes were confirmed by FT-IR spectroscopy, solid-state (29)Si NMR spectroscopy, and elemental analysis. The strong adsorbability of Cu(II) and Pb(II) ions onto PAMSQ particles was systematically examined. The effect of adsorption time, initial metal ions concentration and pH of solutions was studied to optimize the metal ions adsorbability of PAMSQ particles. The kinetic studies indicated that the adsorption process well fits the pseudo-second-order kinetics. Adsorption phenomena appeared to follow Langmuir isotherm. The PAMSQ particles demonstrate the highest Cu(II) and Pb(II) adsorption capacity of 2.29 mmol/g and 1.31 mmol/g at an initial metal ions concentration of 20mM, respectively. The PAMSQ particles demonstrate a promising application in the removal of Cu(II) and Pb(II) ions from aqueous solutions. Copyright © 2011 Elsevier B.V. All rights reserved.

Coordination structure of adsorbed Zn(II) at Water-TiO2 interfaces

Energy Technology Data Exchange (ETDEWEB)

He, G.; Pan, G.; Zhang, M.; Waychunas, G.A.

2011-01-15

The local structure of aqueous metal ions on solid surfaces is central to understanding many chemical and biological processes in soil and aquatic environments. Here, the local coordination structure of hydrated Zn(II) at water-TiO{sub 2} interfaces was identified by extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) spectroscopy combined with density functional theory (DFT) calculations. A nonintegral coordination number of average {approx}4.5 O atoms around a central Zn atom was obtained by EXAFS analysis. DFT calculations indicated that this coordination structure was consistent with the mixture of 4-coordinated bidentate binuclear (BB) and 5-coordinated bidentate mononuclear (BM) metastable equilibrium adsorption (MEA) states. The BB complex has 4-coordinated Zn, while the monodentate mononuclear (MM) complex has 6-coordinated Zn, and a 5-coordinated adsorbed Zn was found in the BM adsorption mode. DFT calculated energies showed that the lower-coordinated BB and BM modes were thermodynamically more favorable than the higher-coordinated MM MEA state. The experimentally observed XANES fingerprinting provided additional direct spectral evidence of 4- and 5-coordinated Zn-O modes. The overall spectral and computational evidence indicated that Zn(II) can occur in 4-, 5-, and 6-oxygen coordinated sites in different MEA states due to steric hindrance effects, and the coexistence of different MEA states formed the multiple coordination environments.

Catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid under an irradiation of simulated solar light.

Science.gov (United States)

Li, Ying; Chen, Cheng; Zhang, Jing; Lan, Yeqing

2015-05-01

The catalytic role of Cu(II) in the reduction of Cr(VI) by citric acid with simulated solar light was investigated. The results demonstrated that Cu(II) could significantly accelerate Cr(VI) reduction and the reaction obeyed to pseudo zero-order kinetics with respect to Cr(VI). The removal of Cr(VI) was related to the initial concentrations of Cu(II), citric acid, and the types of organic acids. The optimal removal of Cr(VI) was achieved at pH 4, and the rates of Cu(II) photocatalytic reduction of Cr(VI) by organic acids were in the order: tartaric acid (two α-OH groups, two -COOH groups)>citric acid (one α-OH group, three -COOH groups)>malic acid (one α-OH group, two -COOH groups)>lactic acid (one α-OH group, one -COOH group)≫succinic acid (two -COOH groups), suggesting that the number of α-OH was the key factor for the reaction, followed by the number of -COOH. The formation of Cu(II)-citric acid complex could generate Cu(I) and radicals through a pathway of metal-ligand-electron transfer, promoting the reduction of Cr(VI). This study is helpful to fully understanding the conversion of Cr(VI) in the existence of both organic acids and Cu(II) with solar light in aquatic environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Methodology to obtain exchange properties of the calcite surface-Application to major and trace elements: Ca(II), HCO3-, and Zn(II)

International Nuclear Information System (INIS)

Tertre, E.; Beaucaire, C.; Juery, A.; Ly, J.; Tertre, E.; Beaucaire, C.; Juery, A.; Ly, J.

2010-01-01

Sorption of inorganic elements onto carbonate minerals has been intensively described in the literature by two reaction steps: (1) a first one rapid and completed within a few hours and (2) a second one slower, eventually irreversible, and occurring at a constant rate. The first step is often attributed to an ion-exchange process, but its reversibility is rarely investigated. Consequently, discrimination of the global sorption phenomenon into two different mechanisms is not always justified. In this study, we investigated, by batch experiments, both sorption and desorption of Ca(II), HCO 3 - , and Zn(II), radiolabeled with isotopes 45 Ca(II), H 14 CO 3 - , and 65 Zn(II), respectively, onto synthetic pure calcite. Solutions were pre-equilibrated with atmospheric p(CO 2 ) and saturated with respect to calcite. Therefore, our purpose was to: (1) obtain experimental distribution coefficients of major elements (Ca(II) and HCO 3 - ) and a trace element (Zn(II)) onto calcite from sorption and desorption experiments, (2) test the validity of a first-occurring ion-exchange process generally noted in the literature, by calculating distribution coefficients for the 'sole' exchange process, and (3) quantify the amounts of Ca(II), HCO 3 - , and Zn(II) sorbed on the calcite surface by the sole 'exchange process' and compare them with surface crystallochemical data. Ca(II) or HCO 3 - sorption experimental data suggest that a significant fraction of these two elements was sorbed irreversibly onto or in the calcite. By using a method based on isotopic ratios, the Ca(II) or HCO 3 - concentrations, which are reversibly adsorbed on the calcite, have been quantified. These concentrations are respectively estimated at 4. 0 ± 2. 0 * 10 -4 and 7. 0 ± 1. 5 * 10 -4 mol/kg. The obtained Ca(II) surface concentration value is one order of magnitude lower than the one obtained from isotopic measurement by former authors [Geochim. Cosmochim. Acta 55 (1991) 1549; Geochim. Cosmochim. Acta 51

Synthesis, characterization, antimicrobial and anthelmentic activities of some metal complexes with a new Schiff base 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one

International Nuclear Information System (INIS)

Reddy, K. R. K; Mahendra, K.N.

2008-01-01

The complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), dioxouranium(VI), and Th(IV) with a new Schiff base, 3-[(Z)-5-amino-1,3,3-trimethyl cyclohexylmethylimino]-1,3-dihydroindol-2-one formed by the condensation of isatin (Indole-2.3-dione) with isophoronediamine(5-amino-1,3,3-trimethyl-cyclohexane methylamine) were synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 1 H NMR, TGA, and magnetic susceptibility measurements. All the complexes exhibit 1: 1 metal to ligand ratio except for the dioxouranium(VI) and thorium(IV) complexes, where the metal: ligand stoichiometry is 1: 2. The spectral data revealed that the ligand acts as monobasic bidentate, coordinating to the metal ion through the azomethine nitrogen and carbonyl oxygen of the isatin moiety. Tetrahedral geometry for Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes, square planar geometry for Cu(II) complexes, and the coordination numbers 6 and 8 for UO 2 (VI) and Th(IV) complexes, respectively, are proposed. Both the ligand and the metal complexes were screened for their antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa, and the complexes are more potent bactericides than the ligand. The anthelmintic activity of the ligand and its complexes against earthworms was also investigated [ru

Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

International Nuclear Information System (INIS)

Syamal, A.; Singh, M.M.

1998-01-01

A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH) 2 . DMF, PS L MoO 2 and PS-LUO 2 (where PS-LH 2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO 2 and PS-LUO 2 have octahedral structure, PS L Zn and PS-LCd are tetrahedral and PS-LZr(OH) 2 .DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

Pb(II), Cd(II) and Zn(II) adsorption on low grade manganese ore ...

African Journals Online (AJOL)

Low grade manganese ore (LMO) of Orissa containing 58.37% SiO2, 25.05% MnO2, 8.8% Al2O3, and 5.03% Fe2O3 as the main constituents was taken to study its adsorption behaviour for Pb(II), Cd(II) and Zn(II) from aqueous solutions. The XRD studies showed the crystalline phases to be quartz, ß-MnO2, d-MnO2 and ...

A fluorescent chemosensor for Zn(II). Exciplex formation in solution and the solid state.

Science.gov (United States)

Bencini, Andrea; Berni, Emanuela; Bianchi, Antonio; Fornasari, Patrizia; Giorgi, Claudia; Lima, Joao C; Lodeiro, Carlos; Melo, Maria J; de Melo, J Seixas; Parola, Antonio Jorge; Pina, Fernando; Pina, Joao; Valtancoli, Barbara

2004-07-21

The macrocyclic phenanthrolinophane 2,9-[2,5,8-triaza-5-(N-anthracene-9-methylamino)ethyl]-[9]-1,10-phenanthrolinophane (L) bearing a pendant arm containing a coordinating amine and an anthracene group forms stable complexes with Zn(II), Cd(II) and Hg(II) in solution. Stability constants of these complexes were determined in 0.10 mol dm(-3) NMe(4)Cl H(2)O-MeCN (1:1, v/v) solution at 298.1 +/- 0.1 K by means of potentiometric (pH metric) titration. The fluorescence emission properties of these complexes were studied in this solvent. For the Zn(II) complex, steady-state and time-resolved fluorescence studies were performed in ethanol solution and in the solid state. In solution, intramolecular pi-stacking interaction between phenanthroline and anthracene in the ground state and exciplex emission in the excited state were observed. From the temperature dependence of the photostationary ratio (I(Exc)/I(M)), the activation energy for the exciplex formation (E(a)) and the binding energy of the exciplex (-DeltaH) were determined. The crystal structure of the [ZnLBr](ClO(4)).H(2)O compound was resolved, showing that in the solid state both intra- and inter-molecular pi-stacking interactions are present. Such interactions were also evidenced by UV-vis absorption and emission spectra in the solid state. The absorption spectrum of a thin film of the solid complex is red-shifted compared with the solution spectra, whereas its emission spectrum reveals the unique featureless exciplex band, blue shifted compared with the solution. In conjunction with X-ray data the solid-state data was interpreted as being due to a new exciplex where no pi-stacking (full overlap of the pi-electron cloud of the two chromophores - anthracene and phenanthroline) is observed. L is a fluorescent chemosensor able to signal Zn(II) in presence of Cd(II) and Hg(II), since the last two metal ions do not give rise either to the formation of pi-stacking complexes or to exciplex emission in solution.

Adsorption characteristics of Pb(II) and Cu(II) ions by domestic clays

International Nuclear Information System (INIS)

Kwon, Ee Yol; Noh, Hea Ran

1990-01-01

This investigation was carried out to study the adsorption characteristics of Pb(II) and Cu(II) ions in aqueous solution by using clays of Gampo 35, Bentonite (chulwon) and Mangwoon 95 which were dug in the country. As the results, the adsorption of metal ions clays were reached equilibrium by shaking for about 40-60 minutes. In acidic solution, the adsorptivity of clays was increased as pH increased, however, Gampo 35 showed the high adsorptivity over 90% even at pH2-3. Pb(II) ion showed better removal efficiency than Cu(II) ion. The adsorptivities of adsorbents showed following order: Gampo 35>Bentonite> Mangwoon 95. The adsorption isotherms of Pb(II) ion on clays were well fitted in Freundlich's equation. Freundlich constantstion isotherms of Pb(II) ion on clays were well fitted in Freundlich's equation. Freundlich constants (1/n) of Gampo 35, Bentonite and Mangwoon 95 were 0.195, 0.271 and 0.314, respectively.(Author)

Thermodynamics of the Cu(II) adsorption on thin vanillin-modified chitosan membranes

International Nuclear Information System (INIS)

Cestari, Antonio R.; Vieira, Eunice F.S.; Mattos, Charlene R.S.

2006-01-01

In this work, low-density vanillin-modified thin chitosan membranes were synthesized and characterized. The membranes were utilized as adsorbent for the removal of Cu(II) from aqueous solutions. The experimental data obtained in batch experiments at different temperatures were fitted to the Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. The adsorption equilibrium data fitted well with the Langmuir model (average R 2 > 0.99). Interactions thermodynamic parameters (Δ int H, Δ int G, and Δ int S), as well as the interaction thermal effects (Q int ) were determined from T = (298 to 333) K. The thermodynamic parameters, the Dubinin-Radushkevick equation and the comparative values of Δ int H for some Cu(II)-adsorbent interactions suggested that the adsorption of Cu(II) ions to vanillin-chitosan membranes show average results for both the diffusional (endothermic) and chemical bonding (exothermic) processes in relation to the temperature range studied

Structurally related hydrazone-based metal complexes with different antitumor activities variably induce apoptotic cell death.

Science.gov (United States)

Megger, Dominik A; Rosowski, Kristin; Radunsky, Christian; Kösters, Jutta; Sitek, Barbara; Müller, Jens

2017-04-05

Three new complexes bearing the tridentate hydrazone-based ligand 2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)pyridine (L) were synthesized and structurally characterized. Biological tests indicate that the Zn(ii) complex [ZnCl 2 (L)] is of low cytotoxicity against the hepatocellular carcinoma cell line HepG2. In contrast, the Cu(ii) and Mn(ii) complexes [CuCl 2 (L)] and [MnCl 2 (L)] are highly cytotoxic with EC 50 values of 1.25 ± 0.01 μM and 20 ± 1 μM, respectively. A quantitative proteome analysis reveals that treatment of the cells with the Cu(ii) complex leads to a significantly altered abundance of 102 apoptosis-related proteins, whereas 38 proteins were up- or down-regulated by the Mn(ii) complex. A closer inspection of those proteins regulated only by the Cu(ii) complex suggests that the superior cytotoxic activity of this complex is likely to be related to an initiation of the caspase-independent cell death (CICD). In addition, an increased generation of reactive oxygen species (ROS) and a strong up-regulation of proteins responsive to oxidative stress suggest that alterations of the cellular redox metabolism likely contribute to the cytotoxicity of the Cu(ii) complex.

Nuevos receptores heteroditópicos derivados de urea con potencial aplicación en el reconocimiento selectivo de aniones y metabolitos fosfatados

OpenAIRE

Carreira Barral, Israel

2016-01-01

[Resumen]En la presente Tesis Doctoral se han desarrollado nuevas plataformas estructurales basadas en complejos de metales del bloque d (CoII, NiII, CuII y ZnII) con potencial aplicación en el reconocimiento selectivo de aniones y metabolitos con actividad biológica. Los sistemas diseñados se pueden clasificar como receptores heteroditópicos que incorporan, por un lado, una zona de reconocimiento catiónico [1,7-dioxa-4,10-diazaciclododecano, 1,4,7,10-tetraazaciclododecano (...

Wastewater treatment by adsorption onto micro-particles of dried Withania frutescens Plant as new adsorbent

International Nuclear Information System (INIS)

Chiban, M.; Soudani, A.; Sinan, F.; Persin, M.

2009-01-01

Several industrial wastewater streams may contain heavy metals such as Cd(II), Cr(III), Cr(VI), Cu(II), Pb(II), Zn(II), etc. including the waste liquids generated by metal finishing or the mineral processing industries. The toxic metals must be effectively treated/removed from the wastewaters. If the wastewaters were discharged directly into natural waters, it will constitute a great risk for the aquatic ecosystem, whilst the direct discharge into the sewerage system may affect negatively the subsequent biological wastewater treatment. (Author)

PENGEMBANGAN SISTEM TEMU KEMBALI INFORMASI DIGITAL FULLTEXT ARTIKEL JURNAL DI PDII – LIPI

Directory of Open Access Journals (Sweden)

Sjaeful Afandi

2016-03-01

Full Text Available One of the tasks in Center for Scientific Documentation and Information – Indonesian Institutes of Sciences (PDII - LIPI is to disseminate the results of existing research in Indonesia. The research result can be either books or journal articles. Currently, activity of retrieval system on a journal article have still using a traditional retrieve systems regardless of the relevance of data search results. The order of search results based only on the order of data entry that need to be developed information retrieval of digital full text articles as data retrieval alternative. Development of information retrieval system that uses Sphinx Search software. The data used are the result of the conversion from Portable Digital Format (PDF into XML as much as 1000 file. Data of conversion result, then are processed through “tokenisasi” and indexing techniques using Sphinx Search software. Retrieval system tested with a query that has been determined. Retrieval results calculated using standard recalls eleven that in mind the relevance and accuracy. Data retrieval system produces search results that are relevant and accurate with average presicion (AVP value is of 79%.

Investigation of irradiated rats DNA in the presence of Cu(II) chelates of amino acids Schiff bases.

Science.gov (United States)

Karapetyan, N H; Torosyan, A L; Malakyan, M; Bajinyan, S A; Haroutiunian, S G

2016-01-01

The new synthesized Cu(II) chelates of amino acids Schiff bases were studied as a potential radioprotectors. Male albino rats of Wistar strain were exposed to X-ray whole-body irradiation at 4.8 Gy. This dose caused 30% mortality of the animals (LD30). The survival of animals exposed to radiation after preliminary administration of 10 mg/kg Cu(II)(Nicotinyl-L-Tyrosinate)2 or Cu(II)(Nicotinyl-L-Tryptophanate)2 prior to irradiation was registered about 80 and 100% correspondingly. Using spectrophotometric melting and agarose gel electrophoresis methods, the differences between the DNA isolated from irradiated rats and rats pretreated with Cu(II) chelates were studied. The fragments of DNA with different breaks were revealed in DNA samples isolated from irradiated animals. While, the repair of the DNA structure was observed for animals pretreated with the Cu(II) chelates. The results suggested that pretreatment of the irradiated rats with Cu(II)(Nicotinyl-L-Tyrosinate)2 and Cu(II)(Nicotinyl-L-Tryptophanate)2 compounds improves the liver DNA characteristics.

Fabrication, characterization and sensing properties of Cu(II) ion imprinted sol–gel thin film on QCM

International Nuclear Information System (INIS)

Su, Pi-Guey; Hung, Fang-Chieh; Lin, Po-Hung

2012-01-01

Cu(II)-molecularly imprinted sol–gel films (Cu(II)-MISGF), coated on a quartz crystal microbalance (QCM) chip, were fabricated using a sol–gel procedure. Co-hydrolysis and co-condensation of Cu(II) (templates), 3-aminopropyltrimethoxysilane (APTS, functional monomer) and tetraethoxysilane (TEOS, cross-linking agent) were performed with acid and base catalysis. The properties of the Cu(II)-MISGF were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and the electrochemical methods of cyclic voltammetry (CV). Microstructural observations revealed that the acid-catalyzed system yielded more mechanically stable thin films. A combined Cu(II)-MISGF-QCM with flow injection analysis (FIA) method was utilized to investigate the sensing performance of the Cu(II)-MISGF, with special emphasis on the most important properties of sensitivity, selectivity and response time. The Cu(II)-MISGF-QCM sensor, at a TEOS/APTS molar ratio of 10, exhibited excellent selectivity and rapidly responded to Cu(II) ions. - Highlights: ► A Cu(II)-molecularly imprinted sol–gel thin film on chip was fabricated. ► The thin film had mechanical stability using acidic catalyst. ► The thin film had good selectivity and response time for Cu(II) ions.

Synthesis and characterization of chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), cadmium(II) and dioxouranium(VI) complexes of 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone

International Nuclear Information System (INIS)

Abu El-Reash, G.M.; Ibrahim, M.M.; Kenawy; El-Ayaan, Usama; Khattab, M.A.

1994-01-01

A few complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and dioxouranium(VI) with 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone have been synthesised and characterized on the basis of elemental analysis, IR, electronic NMR, and magnetic moment data. An octahedral structure is proposed for the Cr(III), Fe(III), Co(II) and Ni(H 3 PBT) 2 Cl 2 .2H 2 O complexes; a tetrahedral structure for the Mn(II) and Ni 2 (PBT)OAc.H 2 0 complexes and a square planar structure for the Cu(II) complexes. The antimicrobial and antifungal activities of H 3 PBT and of its metal(II) complexes are investigated. The results reveal that H 3 PBT exhibits greater antimicrobial activities than its complexes. (author). 34 refs., 4 figs., 2 tabs

EPR interpretation, magnetism and biological study of a Cu(II) dinuclear complex assisted by a schiff base precursor.

Science.gov (United States)

Das, Kuheli; Patra, Chiranjit; Sen, Chandana; Datta, Amitabha; Massera, Chiara; Garribba, Eugenio; El Fallah, Mohamed Salah; Beyene, Belete B; Hung, Chen-Hsiung; Sinha, Chittaranjan; Askun, Tulin; Celikboyun, Pinar; Escudero, Daniel; Frontera, Antonio

2017-06-01

A new Cu(II) dinuclear complex, Cu 2 L 2 (1) was afforded employing the potentially pentatentate Schiff base precursor H 2 L, a refluxed product of o-vanillin and diethylenetriamine in methanol. Complex 1 was systematically characterized by FTIR, UV-Vis, emission and EPR spectrometry. The single crystal X-ray diffraction analysis of 1 reveals that the copper atom exhibits a distorted square planar geometry, comprising two pairs of phenolato-O and imine-N donors from two different H 2 L ligands. The temperature dependent magnetic interpretation agrees with the existence of weak antiferromagnetic interactions between the bridging dinuclear Cu(II) ions. A considerable body of experimental evidence has been accumulated to elucidate the magneto-structural relationship in this dinuclear Cu(II) complex by DFT computation. Both the ligand and complex 1 exhibit anti-mycobacterial activity and considerable efficacy on M. tuberculosis H 37 Ra (ATCC 25177) and M. tuberculosis H 37 Rv (ATCC 25618) strains. The practical applicability of the ligand and complex 1 has been examined in living cells (African Monkey Vero Cells). The MTT assay proves the non-toxicity of the probe up to 100 mg mL -1 . A new homometallic dinuclear Cu(II) complex is afforded with a tetradentate Schiff base precursor. EPR interpretation and temperature dependent magnetic studies show that complex 1 has weak antiferromagnetic coupling and DFT computation is governed to explain the magneto-structural correlation.

H2S Sensing by Hybrids Based on Nanocrystalline SnO2 Functionalized with Cu(II Organometallic Complexes: The Role of the Ligand Platform

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Marina Rumyantseva

2017-11-01

Full Text Available This paper deals with the functionalization of nanocrystalline SnO2 with Cu(II complexes with organic ligands, aimed at the improvement of sensor selectivity towards gas molecules. For the synthesis of metalorganic/SnO2 hybrid material complexes of Cu(II with phthalocyanine, porphyrinines, bipyridine and azadithiacrown etherwere used. The analysis of gas sensor properties showed the possibility of increasing the sensitivity and selectivity of hybrid materials in H2S detection due to the electron transfer from SnO2 to an adsorbed organic molecule, which changes during the interaction between H2S and Cu(II ions.

Separación electrodialítica de Cu(II y As(V en electrolitos ácidos

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Ibáñez, J. P.

2007-02-01

Full Text Available The separation of copper and arsenic from acidic electrolytes by electrodialysis was investigated at room temperature. The effect of current density and pH was studied in a batch cell during 3 hours. The kinetic parameters showed that Cu(II transport rate was 0.75 mol/m²/h and the As(V transport rate was 0.002 mol/m²/h. An efficient separation between Cu(II and As(V was achieved; generating a concentrated solution of copper with no arsenic, which was obtained independently of the electrolyte acidity and current density used. The effect of the arsenic speciation with pH is discussed as well.

Se investigó el uso de la electrodiálisis para separar cobre y arsénico desde soluciones ácidas a temperatura ambiente. Se estudió el efecto de la densidad de corriente y grado de
acidez del electrolito en la separación a través de experimentos en celda batch de 5 compartimientos durante 3 h. Los parámetros cinéticos indican que la velocidad de transporte de Cu(II fue de 0,75 mol/h/m² y de As(V fue de 0,002 mol/h/m2 a una densidad de corriente de 225 A/m². Se logró obtener una eficiente separación de Cu(II y As(V, con la generación de una solución concentrada de cobre sin presencia de arsénico, lo cual fue independiente del grado de acidez de la operación y de la densidad de corriente. El efecto de la distribución de las especies iónicas de As(V con el pH también se discute.

Novel adsorptive ultrafiltration membranes derived from polyvinyltetrazole-co-polyacrylonitrile for Cu(II) ions removal

KAUST Repository

Kumar, Mahendra; Shevate, Rahul; Hilke, Roland; Peinemann, Klaus-Viktor

2016-01-01

Novel adsorptive ultrafiltration membranes were manufactured from synthesized polyvinyltetrazole−co−polyacrylonitrile (PVT−co−PAN) by nonsolvent induced phase separation (NIPS). PVT−co−PAN with various degree of functionalization (DF) was synthesized via a [3+2] cycloaddition reaction at 60°C using a commercial PAN. PVT−co−PAN with varied DF was then explored to prepare adsorptive membranes. The membranes were characterized by surface zeta potential and static water contact angle measurements, scanning electron microscopy as well as atomic force microscopy (AFM) techniques. It was shown that PVT segments contributed to alter the pore size, charge and hydrophilic behavior of the membranes. The membranes became more negatively charged and hydrophilic after addition of PVT segments. The PVT segments in the membranes served as the major binding sites for adsorption of Cu(II) ions from aqueous solution. The maximum adsorption of Cu(II) ions by the membranes in static condition and in a continuous ultrafiltration of 10 ppm solution was attained at pH = 5. The adsorption data suggest that the Freundlich isotherm model describes well Cu(II) ions adsorption on the membranes from aqueous solution. The adsorption capacity obtained from the Freundlich isotherm model was 44.3 mg g−1; this value is higher than other membrane adsorption data reported in the literature. Overall, the membranes fabricated from PVT−co−PAN are attractive for efficient removal of heavy metal ions under the optimized conditions.

Novel adsorptive ultrafiltration membranes derived from polyvinyltetrazole-co-polyacrylonitrile for Cu(II) ions removal

KAUST Repository

Kumar, Mahendra

2016-05-04

Novel adsorptive ultrafiltration membranes were manufactured from synthesized polyvinyltetrazole−co−polyacrylonitrile (PVT−co−PAN) by nonsolvent induced phase separation (NIPS). PVT−co−PAN with various degree of functionalization (DF) was synthesized via a [3+2] cycloaddition reaction at 60°C using a commercial PAN. PVT−co−PAN with varied DF was then explored to prepare adsorptive membranes. The membranes were characterized by surface zeta potential and static water contact angle measurements, scanning electron microscopy as well as atomic force microscopy (AFM) techniques. It was shown that PVT segments contributed to alter the pore size, charge and hydrophilic behavior of the membranes. The membranes became more negatively charged and hydrophilic after addition of PVT segments. The PVT segments in the membranes served as the major binding sites for adsorption of Cu(II) ions from aqueous solution. The maximum adsorption of Cu(II) ions by the membranes in static condition and in a continuous ultrafiltration of 10 ppm solution was attained at pH = 5. The adsorption data suggest that the Freundlich isotherm model describes well Cu(II) ions adsorption on the membranes from aqueous solution. The adsorption capacity obtained from the Freundlich isotherm model was 44.3 mg g−1; this value is higher than other membrane adsorption data reported in the literature. Overall, the membranes fabricated from PVT−co−PAN are attractive for efficient removal of heavy metal ions under the optimized conditions.

A novel Schiff-base as a Cu(II) ion fluorescent sensor in aqueous solution

Science.gov (United States)

Gündüz, Z. Yurtman; Gündüz, C.; Özpınar, C.; Urucu, O. Aydın

2015-02-01

A new fluorescent Cu(II) sensor (L) obtained from the Schiff base of 5,5‧-methylene-bis-salicylaldehyde with amidol (2,4-diaminophenol) was synthesized and characterized by FT-IR, MS, 1H NMR, 13C NMR techniques. In the presence of pH 6.5 (KHPO4-Na2HPO4) buffer solutions, copper reacted with L to form a stable 2:1 complex. Fluorescence spectroscopic study showed that Schiff base is highly sensitive towards Cu(II) over other metal ions (K+, Na+, Al3+, Ni2+, Co2+, Fe3+, Zn2+, Pb2+) in DMSO/H2O (30%, v/v). The sensor L was successfully applied to the determination of copper in standard reference material. The structural properties and molecular orbitals of the complex formed between L and Cu2+ ions were also investigated using quantum chemical computations.

Stability Studies of Transition Metal Chelates of 5-Bromosalicylidene-4-methoxyaniline andSalicylidene-2,3-dimethylaniline as Ligands

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N. G. Nadkarni

2011-01-01

Full Text Available Binary and ternary complexes of the type M-Y and M-X-Y [M = Mn(II, Ni(II, Cu(II and Zn(II; X = 5-bromosalicylidene-4-methoxyaniline and Y = salicylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5 °C and at constant ionic strength, μ = 0.1 M (KCl in 75 : 25(v/v 1,4-dioxne-water medium. The stability constants for binary (M-Y and ternary (M-X-Y systems were calculated.

Synthesis and spectral studies of manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and mercury(II) complexes of 4-oxo-4H-1-benzopyran-3-carboxaldehyde hydrazone derivatives

International Nuclear Information System (INIS)

Nawar, N.; Khattab, M.A.; Bekheit, M.M.; El-Kaddah, A.H.

1996-01-01

A few complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with 4-oxo-4H-1-benzopyran-3-(carboxaldehyde-4-chlorobenzylhydrazone) (BCBH) and 4-oxo-4H-1-benzopyran-3-(carboxaldehyde-4-methylbenzylhydrazone) (BMBH) have been synthesised and characterized by elemental analysis, molar conductivities, magnetic measurements and infrared (IR) and visible spectral studies. The IR spectra show that BCBH and BMBH behave as bidentate ligands either in the keto or enol form. (author). 24 refs., 2 tabs

Radiative parameters for some transitions in Cu(II) and Ag(II) spectrum

International Nuclear Information System (INIS)

Biemont, E.; Blagoev, K.; Campos, J.; Mayo, R.; Malcheva, G.; Ortiz, M.; Quinet, P.

2005-01-01

Radiative parameters for transitions depopulating the levels belonging to the 3d 8 4s 2 configuration of Cu(II) and 4d 9 6s and 4d 9 5d configurations of Ag(II) have been obtained both theoretically and experimentally. On the experimental side, a laser-produced plasma was used as a source of Cu(II) and Ag(II) spectra. The light emitted by the plasma was focused on the input slit of a grating monochromator coupled with a time-resolved optical multichannel analyzer system. Spectral response calibration of the experimental system was made using a deuterium lamp in the wavelength range extending from 200 to 400-bar nm, and a standard tungsten lamp in the range from 350 to 600-bar nm. The transition probabilities were obtained using measured branching fractions and available radiative lifetimes of the corresponding states. On the theoretical side, a relativistic Hartree-Fock (HFR) approach, including core-polarization effects, has been used for the calculations. A reasonable agreement theory-experiment has been observed

Sorption of Pb(II and Cu(II by low-cost magnetic eggshells-Fe3O4 powder

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Ren Jianwei

2012-01-01

Full Text Available This study explored the feasibility of using magnetic eggshell-Fe3O4 powder as adsorbent for the removal of Pb(II and Cu(II ions from aqueous solution. The metal ionsadsorption media interaction was characterized using XRD and FTIR. The effects of contact time, initial concentrations, temperature, solution pH and reusability of the adsorption media were investigated. The metal ions adsorption was fast and the amount of metal ions adsorbed increased with an increase in temperature, suggesting an endothermic adsorption. The kinetic data showed that the adsorption process followed the pseudo-second-order kinetic model. The optimal adsorption pH value was around 5.5 at which condition the equilibrium capacity was 263.2 mg/g for Pb(II and 250.0 for Cu(II. The adsorption equilibrium data fitted very well to the Langmuir and Freundlich adsorption isotherm models. The thermodynamics of Pb(II and Cu(II adsorption onto the magnetic eggshell-Fe3O4 powder indicated that the adsorption was spontaneous. The reusability study has proven that magnetic eggshell-Fe3O4 powder can be employed as a low-cost and easy to separate adsorbent.

Synthesis, spectral and theoretical studies of Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline.

Science.gov (United States)

Gaber, Mohamed; El-Ghamry, Hoda; Atlam, Faten; Fathalla, Shaimaa

2015-02-25

Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2'-hydroxynaphthaline have been isolated and characterized by elemental analysis, IR, (1)H NMR, EI-mass, UV-vis, molar conductance, magnetic moment measurements and thermogravimetric analysis. The molar conductance values indicated that the complexes are non-electrolytes. The magnetic moment values of the complexes displayed diamagnetic behavior for Pd(II) and Pt(II) complexes and tetrahedral geometrical structure for Ni(II) complex. From the bioinorganic applications point of view, the interaction of the ligand and its metal complexes with CT-DNA was investigated using absorption and viscosity titration techniques. The Schiff-base ligand and its metal complexes have also been screened for their antimicrobial and antitumor activities. Also, theoretical investigation of molecular and electronic structures of the studied ligand and its metal complexes has been carried out. Molecular orbital calculations were performed using DFT (density functional theory) at B3LYP level with standard 6-31G(d,p) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), Mulliken atomic charges, reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), chemical potential and Mulliken electronegativity (χ). Copyright © 2014 Elsevier B.V. All rights reserved.

The Cu(II) affinity of the N-terminus of human copper transporter CTR1: Comparison of human and mouse sequences.

Science.gov (United States)

Bossak, Karolina; Drew, Simon C; Stefaniak, Ewelina; Płonka, Dawid; Bonna, Arkadiusz; Bal, Wojciech

2018-05-01

Copper Transporter 1 (CTR1) is a homotrimeric membrane protein providing the main route of copper transport into eukaryotic cells from the extracellular milieu. Its N-terminal extracellular domain, rich in His and Met residues, is considered responsible for directing copper into the transmembrane channel. Most of vertebrate CTR1 proteins contain the His residue in position three from N-terminus, creating a well-known Amino Terminal Cu(II)- and Ni(II)-Binding (ATCUN) site. CTR1 from humans, primates and many other species contains the Met-Asp-His (MDH) sequence, while some rodents including mouse have the Met-Asn-His (MNH) N-terminal sequence. CTR1 is thought to collect Cu(II) ions from blood copper transport proteins, including albumin, but previous reports indicated that the affinity of N-terminal peptide/domain of CTR1 is significantly lower than that of albumin, casting serious doubt on this aspect of CTR1 function. Using potentiometry and spectroscopic techniques we demonstrated that MDH-amide, a tripeptide model of human CTR1 N-terminus, binds Cu(II) with K of 1.3 × 10 13  M -1 at pH 7.4, ~13 times stronger than Human Serum Albumin (HSA), and MNH-amide is even stronger, K of 3.2 × 10 14  M -1 at pH 7.4. These results indicate that the N-terminus of CTR1 may serve as intermediate binding site during Cu(II) transfer from blood copper carriers to the transporter. MDH-amide, but not MNH-amide also forms a low abundance complex with non-ATCUN coordination involving the Met amine, His imidazole and Asp carboxylate. This species might assist Cu(II) relay down the peptide chain or its reduction to Cu(I), both steps necessary for the CTR1 function. Copyright © 2018 Elsevier Inc. All rights reserved.

Combined cation-exchange and extraction chromatographic method of pre-concentration and concomitant separation of Cu(II) with high molecular mass liquid cation exchanger after its online detection.

Science.gov (United States)

Mandal, B; Roy, U S; Datta, D; Ghosh, N

2011-08-19

A selective method has been developed for the extraction chromatographic trace level separation of Cu(II) with Versatic 10 (liquid cation exchanger) coated on silanised silica gel (SSG-V10). Cu(II) has been extracted from 0.1M acetate buffer at the range of pH 4.0-5.5. The effects of foreign ions, pH, flow-rate, stripping agents on extraction and elution have been investigated. Exchange capacity of the prepared exchanger at different temperatures with respect to Cu(II) has been determined. The extraction equilibrium constant (K(ex)) and different standard thermodynamic parameters have also been calculated by temperature variation method. Positive value of ΔH (7.98 kJ mol⁻¹) and ΔS (0.1916 kJ mol⁻¹) and negative value of ΔG (-49.16 kJ mol⁻¹) indicated that the process was endothermic, entropy gaining and spontaneous. Preconcentration factor was optimized at 74.7 ± 0.2 and the desorption constants K(desorption)¹(1.4 × 10⁻²) and K(desorption)²(9.8 × 10⁻²) were determined. The effect of pH on R(f) values in ion exchange paper chromatography has been investigated. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. Cu(II) has been separated from synthetic binary and multi-component mixtures containing various metal ions associated with it in ores and alloy samples. The method effectively permits sequential separation of Cu(II) from synthetic quaternary mixture containing its congeners Bi(III), Sn(II), Hg(II) and Cu(II), Cd(II), Pb(II) of same analytical group. The method was found effective for the selective detection, removal and recovery of Cu(II) from industrial waste and standard alloy samples following its preconcentration on the column. A plausible mechanism for the extraction of Cu(II) has been suggested. Copyright © 2011 Elsevier B.V. All rights reserved.

Impregnation of chelating agent 3,3-bis-N,N bis-(carboxymethylaminomethyl-o-cresolsulfonephthalein in biopolymer chitosan: adsorption equilibrium of Cu(II in aqueous medium

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Luciano Vitali

2006-06-01

Full Text Available The aim of this study was to impregnate the chelating agent 3,3-bis-N,N,bis-(carboxymethylaminomethyl-o-cresolsulfonephthalein in chitosan and to investigate the adsorption of Cu(II ions. The chemical modification was confirmed by FTIR spectrometry, thermogravimetric analysis (TGA and energy dispersive x-ray spectroscopy (EDX. The adsorption studies were carried out with Cu(II ions in a batch process and were shown to be dependent on pH. The adsorption kinetics was tested using three models: pseudo first-order, pseudo second order and intraparticle diffusion. The experimental kinetics data were best fitted with the pseudo second-order model (R² = 0.999, which provided a rate constant, k2, of 1.21 x 10-3 g mg-1 min-1. The adsorption rate depended on the concentration of Cu(II ions on the adsorbent surface and on the quantity of Cu(II ions adsorbed at equilibrium. The Langmuir isotherm model provided the best fit for the equilibrium data in the concentration range investigated, with the maximum adsorption capacity being 81.0 mg of Cu(II per gram of adsorbent, as obtained from the linear equation of the isotherm. Desorption tests revealed that around 90% of the adsorbed metal was removed, using EDTA solution as the eluent. This result suggests that the polymeric matrix can be reused.

Synthesis, Structural Characterization and Catalytic Activity of A Cu(II Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine

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Wang Li-Hua

2017-04-01

Full Text Available In order to study the catalytic activity of Cu(II coordination polymer material, a novel 1D chained Cu(II coordination polymer material, [CuL(bipy(H2O5]n (A1 (H2L = 1,4-phenylenediacetic acid, bipy = 2,2’-bipyridine, has been prepared by the reaction of 1,4-phenylenediacetic acid, 2,2’-bipyridine, Cu(CH3COO2·H2O and NaOH. The composition of A1 was determined by elemental analysis, IR spectra and single crystal X-ray diffraction. The results of characterization show that each Cu(II atom adopts six-coordination and forms a distorted octahedral configuration. The catalytic activity and reusability of A1 catalyst for A3 coupling reaction of benzaldehyde, piperidine, and phenylacetylene have been investigated. And the results show that the Cu(II complex catalyst has good catalytic activity with a maximum yield of 54.3% and stability. Copyright © 2017 BCREC GROUP. All rights reserved Received: 21st October 2016; Revised: 17th November 2016; Accepted: 22nd November 2016 How to Cite: Li-Hua, W., Lei, L., Xin, W. (2017. Synthesis, Structural Characterization and Catalytic Activity of A Cu(II Coordination Polymer Constructed from 1,4-Phenylenediacetic Acid and 2,2’-Bipyridine. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 113-118 (doi:10.9767/bcrec.12.1.735.113-118 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.735.113-118

Highly selective determination of methylmercury with methylmercury-imprinted polymers

Energy Technology Data Exchange (ETDEWEB)

Liu Yongwen [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)]. E-mail: dtlyw@263.net; Zai Yunhui [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Chang Xijun [School of Chemistry and Chemical Engineering of Lanzhou University, Lanzhou 730000 (China); Guo Yong [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Meng Shuangming [Department of Chemistry, Shanxi Datong University, Datong 037009 (China); Feng Feng [Department of Chemistry, Shanxi Datong University, Datong 037009 (China)

2006-08-11

Methylmercury-imprinted and non-imprinted polymers were prepared by formation monomer complex of methylmercury with (4-ethenylphenyl)-4-formate-6-phenyl-2,2'-bipyridine and thermally polymerizing with divinylbenzene (crosslinker) in the presence of 2,2'-azobisisobutyronitrile as initiator and subsequently leached with the acidic thiourea solution (1.0 mol L{sup -1} of thiourea and 4.0 mol L{sup -1} of HCl). In the same way, non-imprinted copolymers were prepared without methylmercury chloride added. The separation and preconcentration characteristics of the polymers for methylmercury were investigated by batch and column procedures. The results demonstrated that the methylmercury-imprinted polymers had higher adsorption capacity (170 {mu}mol g{sup -1} of dry microbeads) and good selectivity for methylmercury compared to non-imprinted polymers. The distribution ratio (D) values of the methylmercury-imprinted polymers increased for methylmercury with respect to both D values of Hg(II), Cu(II), Zn(II), Cd(II) and non-imprinted polymers. The relatively selective factor ({alpha} {sub r}) values of CH{sub 3}Hg{sup +}/Hg(II), CH{sub 3}Hg{sup +}/Cu(II), CH{sub 3}Hg{sup +}/Zn(II), and CH{sub 3}Hg{sup +}/Cd(II) are 24.0, 46.7, 50.7, and 40.2, which are greater than 1. The methylmercury-imprinted polymers can be used at least twenty times with recoveries no less than 95%. Based on the packed columns with methylmercury-imprinted polymers, a highly selective solid-phase extraction (SPE) and preconcentration method for methylmercury was developed. The metal ion imprinted polymer solid-phase extraction (MIIP-SPE) preconcentration procedure showed a linear calibration curve within concentration range from 0.093 to 22 {mu}g L{sup -1}. The detection limit and quantification limit were 0.041 and 0.093 {mu}g L{sup -1} (3{sigma}) for cold vapor atomic absorption spectrometry (CVAAS). The relative standard deviation of the 10 replicate determinations was 3.5% for the

Complexes of Cu(II), Ni(II), Co(II), oxovanadium(IV) and dioxouranium(VI) with N,N'-ethylenebis (2-hydroxy-4-methylpropiophenoneimine)

International Nuclear Information System (INIS)

Patel, M.M.; Patel, M.R.; Patel, M.N.; Patel, R.P.

1982-01-01

Complexes of Cu(II), Ni(II), Co(II), oxovanadium(IV) and dioxouranium(VI) with the schiff base, N,N'-ethylenebis(2-hydroxy-4-methylpropiophenoneimine)(4-MeOHPEN), have been synthesised and characterised on the basis of elemental analyses, conductivity, magnetic moment, electronic and infrared spectral data. Square-planar structures are suggested for Cu(II), Ni(II) and Co(II) complexes while a distorted square-pyramidal structure is suggested for the oxovanadium(IV) complex. (author)

Assessment of heavy metal tolerance and hexavalent chromium reducing potential of Corynebacterium paurometabolum SKPD 1204 isolated from chromite mine seepage

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Amal Kanti Paul

2016-07-01

Full Text Available Corynebacterium paurometabolum SKPD 1204 (MTCC 8730, a heavy metal tolerant and chromate reducing bacterium isolated from chromite mine seepage of Odisha, India has been evaluated for chromate reduction under batch culture. The isolate was found to tolerate metals like Co(II, Cu(II, Ni(II, Mn(II, Zn(II, Fe(III and Hg(II along with Cr(VI and was resistant to different antibiotics as evaluated by disc-diffusion method. The isolate, SKPD 1204 was found to reduce 62.5% of 2 mM Cr(VI in Vogel Bonner broth within 8 days of incubation. Chromate reduction capability of SKPD 1204 decreased with increase in Cr(VI concentration, but increased with increase in cell density and attained its maximum at 1010 cells/mL. Chromate reducing efficiency of SKPD 1204 was promoted in the presence of glycerol and glucose, while the highest reduction was recorded at pH 7.0 and 35 °C. The reduction process was inhibited by divalent cations Zn(II, Cd(II, Cu(II, and Ni(II, but not by Mn(II. Anions like nitrate, phosphate, sulphate and sulphite was found to be inhibitory to the process of Cr(VI reduction. Similarly, sodium fluoride, carbonyl cyanide m-chlorophenylhydrazone, sodium azide and N, N,-Di cyclohexyl carboiimide were inhibitory to chromate reduction, while 2,4-dinitrophenol appeared to be neither promotive nor inhibitory to the process.

Cu(II) Binding to the Peptide Ala-His-His, a Chimera of the Canonical Cu(II)-Binding Motifs Xxx-His and Xxx-Zzz-His.

Science.gov (United States)

Gonzalez, Paulina; Vileno, Bertrand; Bossak, Karolina; El Khoury, Youssef; Hellwig, Petra; Bal, Wojciech; Hureau, Christelle; Faller, Peter

2017-12-18

Peptides and proteins with the N-terminal motifs NH 2 -Xxx-His and NH 2 -Xxx-Zzz-His form well-established Cu(II) complexes. The canonical peptides are Gly-His-Lys and Asp-Ala-His-Lys (from the wound healing factor and human serum albumin, respectively). Cu(II) is bound to NH 2 -Xxx-His via three nitrogens from the peptide and an external ligand in the equatorial plane (called 3N form here). In contrast, Cu(II) is bound to NH 2 -Xxx-Zzz-His via four nitrogens from the peptide in the equatorial plane (called 4N form here). These two motifs are not mutually exclusive, as the peptides with the sequence NH 2 -Xxx-His-His contain both of them. However, this chimera has never been fully explored. In this work, we use a multispectroscopic approach to analyze the Cu(II) binding to the chimeric peptide Ala-His-His (AHH). AHH is capable of forming the 3N- and 4N-type complexes in a pH dependent manner. The 3N form predominates at pH ∼ 4-6.5 and the 4N form at ∼ pH 6.5-10. NMR experiments showed that at pH 8.5, where Cu(II) is almost exclusively bound in the 4N form, the Cu(II)-exchange between AHH or the amidated AHH-NH 2 is fast, in comparison to the nonchimeric 4N form (AAH). Together, the results show that the chimeric AHH can access both Cu(II) coordination types, that minor changes in the second (or further) coordination sphere can impact considerably the equilibrium between the forms, and that Cu kinetic exchange is fast even when Cu-AHH is mainly in the 4N form.

A treatise on benzimidazole based Schiff base metal(II) complexes accentuating their biological efficacy: Spectroscopic evaluation of DNA interactions, DNA cleavage and antimicrobial screening

Energy Technology Data Exchange (ETDEWEB)

Kumaravel, Ganesan; Raman, Natarajan, E-mail: ramchem1964@gmail.com

2017-01-01

Two novel imidazole derived Schiff bases, (Z)-1-(1H-benzo[d]imidazol-2-yl)-N-benzylidenemethanamine (L{sup 1}) and 1-(1H-benzo[d]imidazol-2-yl)-N-(4-nitrobenzylidene) methanamine, and a series of their transition metal complexes of the types [M(L{sup 1}){sub 2}]Cl{sub 2} and [M(L{sup 2}){sub 2}]Cl{sub 2} where, M = Cu(II), Ni(II), Co(II) and Zn(II) have been designed and synthesized. These compounds were characterized by various spectral and physicochemical data. UV–Vis, magnetic susceptibility and molar conductivity data indicate that all the complexes adopt square planar geometry. The EPR spectral data of the Cu(II) complexes have provided supportive evidence to the conclusion derived on the basis of electronic absorption and magnetic moment values. Moreover, the interaction of complexes with DNA via intercalation has been explored by absorption, fluorescence spectroscopy, cyclic voltammetry, viscosity and circular dichroism. Agarose gel electrophoresis technique reveals that the complexes are good metallonucleases. All the compounds have relatively high antibacterial and antifungal potencies. Among the metal complexes, Cu(II) complexes exhibit higher efficacy against all the pathogens. - Highlights: • Synthesis of new and efficient benzimidazole based DNA targeting complexes • Synthesis of efficient metallointercalators • Excellent DNA exploiting ability of Cu(II) complexes • Efficient antimicrobial agents against various pathogens.

Synthesis, spectral and theoretical studies of Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2‧-hydroxynaphyhaline

Science.gov (United States)

Gaber, Mohamed; El-Ghamry, Hoda; Atlam, Faten; Fathalla, Shaimaa

2015-02-01

Ni(II), Pd(II) and Pt(II) complexes of 5-mercapto-1,2,4-triazole-3-imine-2‧-hydroxynaphthaline have been isolated and characterized by elemental analysis, IR, 1H NMR, EI-mass, UV-vis, molar conductance, magnetic moment measurements and thermogravimetric analysis. The molar conductance values indicated that the complexes are non-electrolytes. The magnetic moment values of the complexes displayed diamagnetic behavior for Pd(II) and Pt(II) complexes and tetrahedral geometrical structure for Ni(II) complex. From the bioinorganic applications point of view, the interaction of the ligand and its metal complexes with CT-DNA was investigated using absorption and viscosity titration techniques. The Schiff-base ligand and its metal complexes have also been screened for their antimicrobial and antitumor activities. Also, theoretical investigation of molecular and electronic structures of the studied ligand and its metal complexes has been carried out. Molecular orbital calculations were performed using DFT (density functional theory) at B3LYP level with standard 6-31G(d,p) and LANL2DZ basis sets to access reliable results to the experimental values. The calculations were performed to obtain the optimized molecular geometry, charge density distribution, extent of distortion from regular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), Mulliken atomic charges, reactivity index (ΔE), dipole moment (D), global hardness (η), softness (σ), electrophilicity index (ω), chemical potential and Mulliken electronegativity (χ).

Synthesis and spectral studies of Pd(II) complexes with 2, 3-disubstituted quinazolin-(3H)-4-ones

International Nuclear Information System (INIS)

Prabhakar, B.; Lingaiah, P.; Laxima Reddy, K.

1991-01-01

A number of palladium(II) complexes of bidentate O-O and O-N donors, 2,3-disubstituted quinazoline-(3H)-4-ones, have been synthesized and characterized based on analytical, conductivity, magnetic, thermal, IR, electronic and PMR spectral data. The complexes of Pd(II) with ligands such as 2-(R)-3-(X)-substituted quinazoline-(3H)-4-ones, where R=methyl/phenyl and X=2'-hydroxybenzalimino (MHBQ/PHBQ), carboxymethyl (MCMQ/PCMQ), furfuralimino (MFQ/PFQ), acetamino (MAQ/PAQ), uramino (MUQ/PUQ) and thiouramino (MTUQ/PTUQ), yielded the complexes of the type [Pd(O-N) 2 ]Cl 2 and [Pd(O-O) 2 ]. The IR and PMR spectral data of the metal complexes indicate that MHQB, PHQB, MCMQ, and PCMQ act as uninegative bidentate ligands whereas MFQ, PFQ, MAQ, PAQ, MUQ, PUQ, MTUQ and PTUQ act as neutral bidentate ligands. The electronic spectral studies of these complexes indicate that they were square-planar geometry. (author). 23 refs., 2 tabs

Screen-printed carbon-containing electrode modified with formazan for determining copper, lead, cadmium, and zinc

International Nuclear Information System (INIS)

Stozhko, N.Yu.; Aleshina, L.V.; Brajnina, Kh.Z.; Lipunova, G.N.; Maslakova, T.I.

2004-01-01

The electrochemical behavior of some hetarylated formazans introduced into the bulk of carbon-containing inks of screen-printed electrodes was studied. The compositions of complexes formed at the electrode surface were found, and their stability constants were estimated. It was shown that the modification of carbon-containing screen-printed electrode with 1-(o-chlorophenyl-3-phenyl-5-(6-methyl-4-oxo-pyrimidinyl-2)formazan improves its sensitivity, lowers detection limits for Pb(II), Cu(II), Cd(II), and Zn(II), and ensures high precision of the results of voltammetric analysis [ru

Nickel removal from exhausted electroplatting baths by using vegetable wastes

OpenAIRE

Martínez Martínez, María del Rosario; Villaescusa Gil, Isabel; Fiol Santalo, Núria; Miralles Esteban, Núria; Florido Pérez, Antonio

2014-01-01

During the last years our research group has been studying the use of industrial vegetable wastes as grape stalks and exhausted coffee to remove metals ions such as Ni(II), Cu(II), Pb(II), Zn(II), Cd(II) or Cr(VI) and Cr(III) in aqueous solution from the point of view to use these wastes as biosorbents in a low cost alternative to activated carbon for wastewater treatment. The optimal experimental conditions for the removal of each of these metal ions in synthetic solutions by using both bio...

Sorption of Co2+ on modified inorganic materials

International Nuclear Information System (INIS)

Hanzel, R.; Rajec, P.

1999-01-01

The aim of this study was preparation and characterization of sorbents on the base a silica-gel matrix with immobilized functional group (imidazole or crown-ether). Sorption of cobalt from aqueous solutions on prepared sorbents in static conditions (by 'batch' method) in the dependence of concentration, pH value,, as well as kinetics of sorption were studied. The influence of heavy or toxic metals [Hg(II), Cd(II), Mn(II), Zn(II), Cu(II), Fe(III), Cr(III), Al(III), Na and K] on sorption of cobalt was studied, too

Stability Constants of Mixed Ligand Complexes of Transition Metal(II Ions with N-(2-Hydroxy-1-naphthylidene-2,6-diisopropylaniline as Primary Ligand and N-(2-Hydroxybenzylidene-2,3-dimethylaniline as Secondary Ligand

Directory of Open Access Journals (Sweden)

A. K. Mapari

2011-01-01

Full Text Available Binary and ternary complexes of the type M-Y and M-X-Y [M = Co(II, Ni(II, Cu(II and Zn(II; X = N-(2-hydroxy-1-naphthylidene-2,6-diisopropylaniline and Y = N-(2-hydroxybenzylidene-2,3-dimethylaniline] have been examined pH-metrically at 27±0.5 °C and µ = 0.1 M in 75: 25% (v/v 1,4-dioxne-water medium. The logarithms of the values of stability constants for binary (M-Y and for ternary (M-X-Y systems were calculated.

Evaluation of the in vitro stability of gadolinium (III) polyoxometalates

International Nuclear Information System (INIS)

Crooks, William J.; Choppin, Gregory R.; Rogers, Buck E.; Welch, Michael

1997-01-01

The gadolinium chelates of lacunary polyoxometalates were evaluated for in vitro stability against rat serum, diethylenetriaminepentaacetic acid (DTPA), endogenous metal cations, and DTPA-doped rat serum. The chelates dissociated rapidly in rat serum. Challenges by DTPA gave relatively slower dissociation rates, whereas challenges by endogenous metal cations (Fe(III), Zn(II), and Cu(II)) occurred at a rate comparable to the serum challenge, suggesting the instability in serum is due to a transmetalation mechanism. Challenges by DTPA-doped serum gave slower rates of dissociation than in native serum, verifying the transmetalation mechanism

Ni(II) and Cu(II) binding with a 14-aminoacid sequence of Cap43 protein, TRSRSHTSEGTRSR.

Science.gov (United States)

Zoroddu, M A; Kowalik-Jankowska, T; Kozlowski, H; Salnikow, K; Costa, M

2001-03-01

The tetradecapeptide containing the 10 aminoacid repeated sequence on the C-terminus of the Ni(II)-induced Cap43 protein, was analyzed for Ni(II) and Cu(II) binding. A combined pH-metric and spectroscopic UV-VIS, EPR, CD and NMR study of Ni(II) and Cu(II) binding to the blocked CH3CO-Thr-Arg-Ser-Arg-Ser-His-Thr-Ser-Glu-Gly-Thr-Arg-Ser-Arg-NH2 (Ac-TRSRSHTSEGTRSR-Am) peptide, modeling a part of the C-terminal sequence of the Cap43 protein, revealed the formation of octahedral complexes involving imidazole nitrogen of histidine, at pH 5.5 and pH 7 for Cu(II) and Ni(II), respectively; a major square planar 4N-Ni(II) complex (about 100% at pH 9, log K* = -28.16) involving imidazole nitrogen of histidine and three deprotonated amide nitrogens of the backbone of the peptide was revealed; a 3N-Cu(II) complex (maximum about 70% at pH 7, log K*=-13.91) and a series of 4N-Cu(II) complexes starting at pH 5.5 (maximum about 90% at pH 8.7, log K* = -21.39 for CuH(-3)L), were revealed. This work supports the existence of a metal binding site at the COOH-terminal part of the Cap43 peptide.

Cu(II Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

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Pulipaka Ramadevi

2014-01-01

Full Text Available A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II. The ligands are coordinated to Cu(II ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic.

Cu(II complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

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Saha Sanjoy

2015-01-01

Full Text Available Two Cu(II complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II salts. The synthesized Cu(II complexes were tested for biological activity.

Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

Science.gov (United States)

El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

2017-08-01

New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

Electron paramagnetic resonance of Cu(II) and vibrational spectrum of chalcanthite

International Nuclear Information System (INIS)

Reddy, B.J.; Sreeramulu, P.; Ramesh, K.; Reddy, Y.P.; Botto, I.L.

1988-01-01

The EPR spectrum of Cu(II) in Chalcanthite has the characteristic features of D 4h symmetry. Optical and EPR results are correlated. The parameters g parallel, g perpendicular, k parallel and k perpendicular are evaluated. The nature of the bonding between the metal ion and the ligand environment is analized. On the other hand, the vibrational spectrum confirms the information about the site symmetry of the SO 4 group in the lattice. (Author) [es

Low-cost route for synthesis of mesoporous silica materials with high silanol groups and their application for Cu(II) removal

International Nuclear Information System (INIS)

Wang Yangang; Huang Sujun; Kang Shifei; Zhang Chengli; Li Xi

2012-01-01

Graphical abstract: A simple and low-cost route to synthesize mesoporous silica materials with high silanol groups has been demonstrated by means of a sol–gel process using citric acid as the template and acid catalyst, further studies on the adsorption of Cu(II) onto the representative amine-functionalized mesoporous silica showed that it had a high Cu(II) removal efficiency. Highlights: ► A low-cost route to synthesize mesoporous silica with high silanol groups was demonstrated. ► Citric acid as the template and acid catalyst for the reaction of tetraethylorthosilicate. ► Water extraction method was an effective technique to remove template which can be recycled. ► The mesoporous silica with high silanol groups was easily modified by functional groups. ► A high Cu(II) removal efficiency on the amine-functionalized mesoporous silica. - Abstract: We report a simple and low-cost route for the synthesis of mesoporous silica materials with high silanol groups by means of a sol–gel process using citric acid as the template, tetraethylorthosilicate (TEOS) as the silica source under aqueous solution system. The citric acid can directly work as an acid catalyst for the hydrolysis of TEOS besides the function as a pore-forming agent in the synthesis. It was found that by using a water extraction method the citric acid template in as-prepared mesoporous silica composite can be easily removed and a high degree of silanol groups were retained in the mesopores, moreover, the citric acid template in the filtrate can be recycled after being dried. The structural properties of the obtained mesoporous silica materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and nitrogen adsorption–desorption analysis. Furthermore, an adsorption of Cu(II) from aqueous solution on the representative amine-functionalized mesoporous silica was investigated

Synthesis and characterization of Ni(II, Cu(II and Co(III complexes with polyamine-containing macrocycles bearing an aminoethyl pendant arm

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K. S. SIDDIQI

2004-09-01

Full Text Available Reaction of [M(ppn2]X2 (where M = Cu(II, Ni(II, Co(II and ppn = 1,3-diaminopropane with formaldehyde and ethylenediamine in methanol results in the ready formation of a 16-membered macrocyclic complex. The complexes were characterized by elemental anlysis, IR, EPR, electronic spectral data, magnetic moments and conductance measurements. The Cu(II, Ni(II and Co(III complexes are coordinated axially with both pendant groups of the hexadentate macrocycle. These pendant donors are attached to the macrocycle by a carbon chain. The electrical conductivities of the Cu(II and Ni(II chelates indicated them to be 1:2 electrolytes whilst those of Co(III is a 1:3 electrolyte in DMSO. The EPR spectrum of the copper complex exhibited G at 3.66, which indicates a considerable exchange interaction in the complex. Spectroscopic evidence suggests that in all of the complexes the metal ion is in an octahedral environment.

EPR of Cu(II) in sarcosine cadmium chloride: probe into dopant site - symmetry and copper-sarcosine interaction

CERN Document Server

Pathinettam-Padiyan, D; Murugesan, R

2000-01-01

The electron paramagnetic resonance spectra of Cu(II) doped sarcosine cadmium chloride single crystals have been investigated at room temperature. Experimental results reveal that the Cu(II) ion enters the lattice interstitially. The observed superhyperfine lines indicate the superposition of two sets of quintet structure with interaction of nitrogen atoms and the two isotopes of copper. The spin Hamiltonian parameters are evaluated by Schonland method and the electric field symmetry around the copper ion is rhombic. An admixture of d sub z sup 2 orbital with the d sub x sub sup 2 sub - sub y sub sup 2 ground state is observed. Evaluation of MO coefficients reveals that the in-plane interaction between copper and nitrogen is strong in this lattice.

Quantum-chemical, NMR, FT IR, and ESI MS studies of complexes of colchicine with Zn(II).

Science.gov (United States)

Jankowski, Wojciech; Kurek, Joanna; Barczyński, Piotr; Hoffmann, Marcin

2017-04-01

Colchicine is a tropolone alkaloid from Colchicinum autumnale. It shows antifibrotic, antimitotic, and anti-inflammatory activities, and is used to treat gout and Mediterranean fever. In this work, complexes of colchicine with zinc(II) nitrate were synthesized and investigated using DFT, 1 H and 13 C NMR, FT IR, and ESI MS. The counterpoise-corrected and uncorrected interaction energies of these complexes were calculated. We also calculated their 1 H, 13 C NMR, and IR spectra and compared them with the corresponding experimentally obtained data. According to the ESI MS mass spectra, colchicine forms stable complexes with zinc(II) nitrate that have various stoichiometries: 2:1, 1:1:1, and 2:1:1 with respect to colchichine, Zn(II), and nitrate ion. All of the complexes were investigated using the quantum theory of atoms in molecules (QTAIM). The calculated and the measured spectra showed differences before and after the complexation process. Calculated electron densities and bond critical points indicated the presence of bonds between the ligands and the central cation in the investigated complexes that satisfied the quantum theory of atoms in molecules. Graphical Abstract DFT, NMR, FT IR, ESI MS, QTAIM and puckering studies of complexes of colchicine with Zn(II).

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms

Energy Technology Data Exchange (ETDEWEB)

Wang, Jingjing [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China); Li, Zhengkui, E-mail: zhkuili@nju.edu.cn [State Key Laboratory of Pollutant Control and Resource Reuse, Nanjing 210023 (China); School of the Environment, Nanjing University, Nanjing 210023 (China)

2015-12-30

Highlights: • A novel ion-imprinted poly(polyethylenimine/hydroxyethyl acrylate) hydrogel was synthesized. • The prepared hydrogel enhanced the selectivity of Cu(II) removal. • The material had high adsorption capacity and excellent regeneration property for copper. • The adsorption mechanism was the chelate interaction between functional groups and Cu(II) ions. - Abstract: A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by {sup 60}Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption–desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater.

Fe3O4@SiO2@CS-TETA functionalized graphene oxide for the adsorption of methylene blue (MB) and Cu(II)

Science.gov (United States)

Wang, Fan; Zhang, Lijuan; Wang, Yeying; Liu, Xijian; Rohani, Sohrab; Lu, Jie

2017-10-01

The graphene oxide (GO) functionalized by Fe3O4@SiO2@CS-TETA nanoparticles, Fe3O4@SiO2@CS-TETA-GO, was firstly fabricated in a mild way as a novel adsorbent for the removal of Cu(II) ions and methylene blue (MB) from aqueous solutions. The magnetic composites showed a good dispersity in water and can be conveniently collected for reuse through magnetic separation due to its excellent magnetism. When the Fe3O4@SiO2@CS- TETA-GO was used as an absorbent for the absorption of MB and Cu(II), the adsorption kinetics and isotherms data well fitted the pseudo-second-order model and the Langmuir model, respectively. Under the optimized pH and initial concentration, the maximum adsorption capacity was about 529.1 mg g-1 for MB in 20 min and 324.7 mg g-1 for Cu(II) in 16 min, respectively, exhibiting a better adsorption performance than other GO-based adsorbents reported recently. More importantly, the synthesized adsorbent could be effectively regenerated and repeatedly utilized without significant capacity loss after six times cycles. All the results demonstrated that Fe3O4@SiO2@CS-TETA-GO could be used as an excellent adsorbent for the adsorption of Cu(II) and MB in many fields.

Synthesis, characterization and crystal structure determination of a new Zn(II Schiff base complex derived from condensation of a new asymmetrical tripodal amine, 3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol and 2-hydroxy-3-methoxybenzaldehyde

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Majid Rezaeivala

2017-05-01

Full Text Available A new tripodal amine, 3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol (HL has been prepared. This has been used to synthesize a new Schiff base complex by template condensation with 2-hydroxy-3-methoxybenzaldehyde in the presence of Zn(II metal ion in methanol. The complex has been characterized using spectroscopic methods and the crystal structure of [ZnL]BF4, L:3-((4-aminobutyl(pyridin-2-ylmethylaminopropan-1-ol was confirmed by single crystal X-ray diffraction studies. Single crystal X-ray structure analysis showed that in the mononuclear Zn(II complex, [ZnL]BF4 the Zn(II ion is in a distorted square pyramidal environment.

Quantum chemical calculations and experimental investigations on 2-aminobenzoic acid-cyclodiphosph(V)azane derivative and its homo-binuclear Cu(II) complex

Science.gov (United States)

El-Gogary, Tarek M.; Alaghaz, Abdel-Nasser M. A.; Ammar, Reda A. A.

2012-03-01

A novel 2-aminobenzoic acid-cyclodiphosph(V)azane ligand H4L and its homo-binuclear Cu(II) complex of the type [Cu2L(H2O)2].2.5 H2O in which L is 1,3-di(-o-pyridyl)-2,4-(dioxo)-2',4'-bis-(2-iminobenzoic acid) cyclodiphosph(V)azane, were synthesized and characterized by different physical techniques. Infrared spectra of the complex indicate deprotonation and coordination of the imine NH and carboxyl COOH groups. It also confirms that nitrogen atom of the pyridine ring contribute to the complexation. Electronic spectra and magnetic susceptibility measurements reveal square-planar geometry for the Cu(II) complex. The elemental analyses and thermogravimetric results have justified the [Cu2L(H2O)2]·2.5H2O composition of the complex. Quantum chemical calculations were utilized to explore the electronic structure and stability of the H4L as well as the binuclear Cu(II) complex. Computational studies have been carried out at the DFT-B3LYP/6-31G(d) level of theory on the structural and spectroscopic properties of H4L and its binuclear Cu(II) complex. Different tautomers and geometrical isomers of the ligand were optimized at the ab initio DFT level. Simulated IR frequencies were scaled and compared with that experimentally measured. TD-DFT method was used to compute the UV-VIS spectra which show good agreement with measured electronic spectra.

Adsorption of Cd(II) and Cu(II) from aqueous solution by carbonate hydroxylapatite derived from eggshell waste

International Nuclear Information System (INIS)

Zheng Wei; Li Xiaoming; Yang Qi; Zeng Guangming; Shen Xiangxin; Zhang Ying; Liu Jingjin

2007-01-01

Carbonate hydroxylapatite (CHAP) synthesized by using eggshell waste as raw material has been investigated as metal adsorption for Cd(II) and Cu(II) from aqueous solutions. The effect of various parameters on adsorption process such as contact time, solution pH, amount of CHAP and initial concentration of metal ions was studied at room temperature to optimize the conditions for maximum adsorption. The results showed that the removal efficiency of Cd(II) and Cu(II) by CHAP could reach 94 and 93.17%, respectively, when the initial Cd(II) concentration 80 mg/L and Cu(II) 60 mg/L and the liquid/solid ratio was 2.5 g/L. The equilibrium sorption data for single metal systems at room temperature could be described by the Langmuir and Freundlich isotherm models. The highest value of Langmuir maximum uptake, (b), was found for cadmium (111.1 mg/g) and copper (142.86 mg/g). Similar Freundlich empirical constants, K, were obtained for cadmium (2.224) and copper (7.925). Ion exchange and surface adsorption might be involved in the adsorption process of cadmium and copper. Desorption experiments showed that CaCl 2 , NaCl, acetic acid and ultrasonic were not efficient enough to desorb substantial amount of metal ions from the CHAP. The results obtained show that CHAP has a high affinity to cadmium and copper

In Silico Analysis for Transcription Factors With Zn(II2C6 Binuclear Cluster DNA-Binding Domains in Candida albicans

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Sergi Maicas

2005-01-01

presence of the CysX2CysX6CysX5-16CysX2CysX6-8Cys motif and a putative nuclear localization signal. Using this approach, 70 putative Zn(II2C6 transcription factors have been found in the genome of C. albicans.

Removal of Industrial Pollutants From Wastewater's By Graft Copolymers

International Nuclear Information System (INIS)

Hegazy El-Sayed, A.; El-Nagar Abdel-Wahab, M.; Senna Magdy, M.; Zahran Abdel-Hamid, H.

1999-01-01

Graft copolymers that obtained by radiation grafting of acrylic acid and acrylamide onto LDPE film were converted to N-hydroxy ethyl amide and hydroxamic acid derivatives respectively. The possible application for the different prepared chemical derivatives of LDPE graft copolymers in metal adsorption from solutions containing a single cation or simulated medium active waste has been investigated. The results showed that the adsorption of Cu(II) metal by different chemical derivatives was greatly affected by different factors such as graft yield, ph value, concentration of metal in the feed solution, immersion time and treatment temperature. The affinity of N-hydroxy ethyl amide derivative toward the different metals was found to be in the order of; Cu(II) >Pd(II) > Cd(II)> Co(II). However, for hydroxamic acid derivative , the affinity order was: Cd(II) > Cu(II) > Co(II). The ESR and IR analysis revealed that the metal ions are chelated through the lone pair of electrons on the -OH and -NH- groups forming a ring structure. The measured metal ion uptake from simulated medium active waste mixture by N-hydroxy ethyl amide derivative was found to follow the following order: Fe> U> Ni> Zr> Zn> Cr. On the other hand, the measured metal uptake by hydroxamic acid derivative was found to follow: Fe>U> Zr> Ca. It is concluded that the prepared grafted copolymers are of interest for metal chelation and could be applied in the field of waste treatment

(Benzoato-κOchlorido[(–-sparteine-κ2N,N′]zinc(II

Directory of Open Access Journals (Sweden)

José Luis Alcántara-Flores

2009-09-01

Full Text Available The title complex, [Zn(C7H5O2Cl(C15H26N2], used for the magnetic dilution of the analogous CuII complex, was synthesized through a direct synthesis route. The coordination geometry around ZnII is best described as distorted tetrahedral, the largest deviation arising from the (–-sparteine ligand, as is invariably found in complexes containing this rather rigid molecule. The benzoate anion behaves as a monodentate ligand, with a non-coordinating Zn...O separation of 2.969 (5 Å. Molecules are packed in the crystal without significant intermolecular interactions. The shortest Zn...Zn separation [6.8186 (7 Å] is observed between molecules related through the 21 screw axis. This is an important feature for the magnetic behaviour of the CuII analogue, which is intended for modeling isolated metal centers in the active site of type 1 blue copper proteins.

Utilization of poplar wood sawdust for heavy metals removal from model solutions

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Demcak Stefan

2017-06-01

Full Text Available Some kinds of natural organic materials have a potential for removal of heavy metal ions from wastewater. It is well known that cellulosic waste materials or by-products can be used as cheap adsorbents in chemical treatment process. In this paper, poplar wood sawdust were used for removal of Cu(II, Zn(II and Fe(II ions from model solutions with using the static and dynamic adsorption experiments. Infrared spectrometry of poplar wood sawdust confirmed the presence of the functional groups which correspond with hemicelluloses, cellulose and lignin. At static adsorption was achieved approximately of 80 % efficiency for all treated model solutions. Similar efficiency of the adsorption processes was reached after 5 min at dynamic condition. The highest efficiency of Cu(II removal (98 % was observed after 30 min of dynamic adsorption. Changes of pH values confirmed a mechanism of ion exchange on the beginning of the adsorption process.

A study on adsorption of Pb(II), Cr(Ш) and Cu(II) from aqueous ...

African Journals Online (AJOL)

Peanut husk has been used in this work for removing Pb(II), Cr(Ш) and Cu(II) from aqueous solution. Batch adsorption studies were carried out under different pH, initial concentration of metal ions, interfering metal ions, time and temperature. Adsorption was poor in strongly acidic solution but was improved in alkaline ...

Straightforward grafting approach for cyclam-functionalized screen-printed electrodes for selective Cu(II) determination

International Nuclear Information System (INIS)

Jasmin, Jean-Philippe; Ouhenia-Ouadahi, Karima; Miserque, Frédéric; Dumas, Eddy; Cannizzo, Caroline; Chaussé, Annie

2016-01-01

We report in this paper an original way to covalently bind the macrocyclic ligand, 1,4,8,11-tetraazacyclotetradecane (cyclam), through diazonium salt chemistry, on the surface of carbon screen-printed electrodes (SPEs). The in situ synthesis of the diazonium salt obtained from the amine precursor derived from the cyclam and its electrografting are described. X-ray Photoelectron Spectroscopy was used to characterize this functionalized surface. Owing to the strong cyclam–Cu(II) affinity, the so called SPE-cyclam can be used as electrochemical sensors for Cu(II) determination at trace levels. The influence of electroanalysis parameters such as the accumulation time and the pH of the medium were investigated. An interference study was carried out with numerous metallic cations and few interference was found for Cu(II) quantification. The described method provided a limit of detection and a limit of quantification of 1.3 × 10"−"8 M and 4.0 × 10"−"8 M, respectively. Interference study and performances show that SPE-cyclam could be considered as efficient sensors for environmental analysis.

Role of the Ca-pectates on the accumulation of heavy metals in the root apoplasm.

Science.gov (United States)

Castaldi, Paola; Lauro, Giampaolo; Senette, Caterina; Deiana, Salvatore

2010-12-01

In order to better understand the processes that regulate the accumulation in the apoplasm of heavy metals and their mobilization by the plant metabolites it is essential to study the mechanisms that regulate the interactions between metal ions and pectins. In such a context, the sorption of Cd(II), Zn(II), Cu(II) and Pb(II) from single and multi-metal solutions, by a Ca-polygalacturonate gel with a degree of esterification of 18.0 (PGAM(1)) and 65.5% (PGAM(2)) was studied in the 3.0-6.0 pH range in the presence of CaCl(2) 2.5mM. The sorption of Cr(III) from single metal solution was also considered. The results show that the amount of each metal ion sorbed increases with increasing the initial metal ion concentration and pH. The data from the single metal solution tests show that at pH 6.0 the affinity of the metal ions towards the PGAM(1) matrix follows the order: Cr(III)>Cu(II)≅Pb(II)≫Zn(II)≅Cd(II). The simultaneous sorption of the bivalent metal ions by the PGAM(1) gels indicates that Pb(II) is selectively sorbed. The FT-IR spectra show that the carboxylate groups are mainly responsible for the metal ion coordination. The ability of PGAM(2) to accumulate Cr(III), Cu(II), and Pb(II) was lower than that found in the PGAM(1) systems whereas the sorption of Zn(II) and Cd(II) was negligible. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Determination of the characteristics of a Schottky barrier formed by latent finger mark corrosion of brass

International Nuclear Information System (INIS)

Bond, J W

2009-01-01

The ideality factor (η) and barrier height (φ B ) for a metal-copper(I) oxide rectifying contact formed by the latent finger mark corrosion of α phase brass have been determined from forward bias I/V characteristics in the range 0.4 V ≤ V ≤ 0.55 V. Rectifying contacts formed from the finger mark deposits of different people gave η = 1.5-1.6 ± 0.1 and φ B = 0.49-0.52 ± 0.04 V. A Mott-Schottky plot of capacitance-voltage measurements in reverse bias gave the built in potential ψ bi = 0.4 ± 0.1 V, the gradient of the plot confirming the conductivity of the finger mark corrosion as p type. X-ray photoelectron spectroscopy spectra of the corrosion showed that Cu(I), Cu(II) and Zn(II) can co-exist on the surface, the Cu(I) : Cu(II) and Zn : Cu ratios determining whether a rectifying contact is formed. Initial findings suggest that when the concentration of Cu(I) dominates the Cu(I) : Cu(II) ratio (approximately 6 : 1), or when Cu(II) is absent, a rectifying contact can be formed subject to the Zn : Cu ratio being approximately 1 : 3. As the surface concentration of zinc increases, the rectifying contact is degraded until the concentration of zinc approaches that of copper when no evidence of a Schottky barrier is observed and the contact appears ohmic.

IR, UV-Vis, magnetic and thermal characterization of chelates of some catecholamines and 4-aminoantipyrine with Fe(III) and Cu(II)

Science.gov (United States)

Mohamed, Gehad G.; Zayed, M. A.; El-Dien, F. A. Nour; El-Nahas, Reham G.

2004-07-01

The dopamine derivatives participate in the regulation of wide variety of physiological functions in the human body and in medication life. Increase and/or decrease in the concentration of dopamine in human body reflect an indication for diseases such as Schizophrenia and/or Parkinson diseases. α-Methyldopa (α-MD) in tablets is used in medication of hypertension. The Fe(III) and Cu(II) chelates with coupled products of adrenaline hydrogen tartarate (AHT), levodopa (LD), α-MD and carbidopa (CD) with 4-aminoantipyrine (4-AAP) are prepared and characterized. Different physico-chemical methods like IR, magnetic and UV-Vis spectra are used to investigate the structure of these chelates. Fe(III) form 1:2 (M:catecholamines) chelates while Cu(II) form 1:1 chelates. Catecholamines behave as a bidentate mono- or dibasic ligands in binding to the metal ions. IR spectra show that the catecholamines are coordinated to the metal ions in a bidentate manner with O,O donor sites of the phenolic - OH. Magnetic moment measurements reveal the presence of Fe(III) chelates in octahedral geometry while the Cu(II) chelates are square planar. The thermal decomposition of Fe(III) and Cu(II) complexes is studied using thermogravimetric (TGA) and differential thermal analysis (DTA) techniques. The water molecules are removed in the first step followed immediately by decomposition of the ligand molecules. The activation thermodynamic parameters, such as, energy of activation, enthalpy, entropy and free energy change of the complexes are evaluated and the relative thermal stability of the complexes are discussed.

Synthesis, structural studies and antituberculosis evaluation of new hydrazone derivatives of quinoline and their Zn(II complexes

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Mustapha C. Mandewale

2018-02-01

Full Text Available The quinoline hydrazone ligands were synthesized through multi-step reactions. The 2-hydroxy-3-formylquinoline derivatives (1a–1c were prepared from acetanilide derivatives as starting materials using Vilsmeier–Haack reaction. Then the condensation of 2-hydroxy-3-formylquinoline derivatives with hydrazide derivatives (2a–2c yielded quinoline hydrazone ligands (3a–3i. The synthesis of a new series of Zn(II complexes carried out by refluxing with these quinoline hydrazone ligands (3a–3i is reported. The molecular structures of the ligands (3a–3i and the Zn complexes were characterized by elemental analysis and spectral studies like FT-IR, 1H and 13C NMR, MS, UV–Visible and fluorescence. The preliminary results of antituberculosis study showed that most of the Zn(II complexes 4a–4i demonstrated very good antituberculosis activity while the ligands 3a–3i showed moderate activity. Among the tested compounds 4e and 4g were found to be most active with minimum inhibitory concentration (MIC of 8.00μM and 7.42 μM respectively against Mycobacterium tuberculosis (H37 RV strain ATCC No-27294 which is comparable to “first and second line” drugs used to treat tuberculosis.

Complexation of 1,3-dimorpholinopropane with Hg(II) and Zn(II) salts: Synthese, crystal structures and antibacterial studies

Czech Academy of Sciences Publication Activity Database

Goudarziafshar, H.; Yousefi, S.; Abbasityula, Y.; Dušek, Michal; Eigner, Václav; Rezaeivala, M.; Özbek, N.

2015-01-01

Roč. 31, č. 6 (2015), s. 1076-1084 ISSN 1001-4861 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : crystal structure * 1,3-dimorpholinopropane * antibacterial activity * Hg(II) complex * Zn(II) complex Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.488, year: 2015

Adsorption of tetracycline on soil and sediment: Effects of pH and the presence of Cu(II)

International Nuclear Information System (INIS)

Zhang Zheyun; Sun Ke; Gao Bo; Zhang Guixiang; Liu Xitao; Zhao Ye

2011-01-01

Tetracycline (TC) is frequently detected in the environment, however, knowledge on the environmental fate and transport of TC is still limited. Batch adsorption experiments of TC by soil and sediment samples were conducted. The distribution of charge and electrostatic potential of individual atoms of various TC species in the aqueous solution were determined using MOPAC version 0.034 W program in ChemBio3D Ultra software. Most of the adsorption isotherms on the soil, river and marine sediments were well fitted with the Freundlich and Polanyi-Manes (PMM) models. The single point organic carbon (OC)-normalized adsorption distribution coefficients (K OC ) and PMM saturated adsorption capacity (Q OC 0 ) values of TC were associated with the mesopore volume and clay content to a greater extent, indicating the mesopore volume of the soil and sediments and their clay content possibly influenced the fate and transport of TC in the natural environment. The adsorption of TC on soil and sediments strongly depended on the pH and presence of Cu(II). The presence of Cu(II) facilitated TC adsorption on soil and sediments at low pH (pH < 5), possibly due to the metallic complexation and surface-bridging mechanism by Cu(II) adsorption on soil and sediments. The cation exchange interaction, metallic complexation and Coulombic interaction of mechanisms for adsorption of TC to soils and sediments were further supported by quantum chemical calculation of various TC species in different pH.

Synthesis and Spectral Investigations of Manganese(II, Cobalt(II, Nickel(II, Copper(II and Zinc(II Complexes of New Polydentate Ligands Containing a 1,8-Naphthyridine Moiety

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Sunkari Jyothi

2006-12-01

Full Text Available 2-(o-Hydroxyphenyl-1,8-naphthyridine (HN, 2-(4-hydroxy-6-methylpyran-2-one-3-yl-1,8-naphthyridine (HMPN and 2-(benzimidazol-2-yl-1,8-naphthyridine(BN react with acetates of Mn(II, Co(II, Ni(II, Cu(II and Zn(II to yield metal ioncomplexes of definite composition. These compounds were characterized by elementalanalyses, molar conductivity, magnetic susceptibility measurements, thermal studies, IR,UV-visible, NMR and mass spectral investigations. The complexes are found to have theformulae [M(HN2(H2O2], [M(HMPN2(H2O2] and [M(BN2(OAc2], respectively.

Metal chelates of some transition and non-transition metal ions with Schiff base derived from isatin with o-phenylenediamine

International Nuclear Information System (INIS)

Hassaan, A.M.A.; Khalifa, M.A.

1993-01-01

New Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) chelates of the Schiff base derived from isatin with o-phenylenediamine have been synthesized and characterized on the basis of elemental analyses, electronic, IR and 1 H NMR spectra, and also by aid of molar conductivity and magnetic moment measurements. It has been found that the Schiff base behaves as ONNO tetradentate dibasic ligand forming chelates with 1:1 (metal:ligand) stoichiometry. Square planar environment is suggested for nickel(II) chelate. All the metal chelates show non-electrolytic behaviour

Tailoring the Synergistic Bronsted-Lewis acidic effects in Heteropolyacid catalysts: Applied in Esterification and Transesterification Reactions

OpenAIRE

Tao, Meilin; Xue, Lifang; Sun, Zhong; Wang, Shengtian; Wang, Xiaohong; Shi, Junyou

2015-01-01

In order to investigate the influences of Lewis metals on acidic properties and catalytic activities, a series of Keggin heteropolyacid (HPA) catalysts, HnPW11MO39 (M = TiIV, CuII, AlIII, SnIV, FeIII, CrIII, ZrIV and ZnII; for Ti and Zr, the number of oxygen is 40), were prepared and applied in the esterification and transesterification reactions. Only those cations with moderate Lewis acidity had a higher impact. Ti Substituted HPA, H5PW11TiO40, posse lower acid content compared with TixH3−4...

Effects of toxic metals and chemicals on biofilm and biocorrosion.

Science.gov (United States)

Fang, Herbert H P; Xu, Li-Chong; Chan, Kwong-Yu

2002-11-01

Microbes in marine biofilms aggregated into clusters and increased the production of extracellular polymeric substances (EPS), by over 100% in some cases, when the seawater media containing toxic metals and chemicals, such as Cd(II), Cu(II), Pb(II), Zn(II), AI(III), Cr(III), glutaraldehyde, and phenol. The formation of microbial cluster and the increased production of EPS, which contained 84-92% proteins and 8-16% polysaccharides, accelerated the corrosion of the mild steel. However, there was no quantitative relationship between the degree of increased corrosion and the toxicity of metals/chemicals towards sulfate-reducing bacteria, or the increased EPS production.

Volatile hexafluoroacetylacetonates for the isolation and gas-chromatographic determination of trace metals. Pt. 1

International Nuclear Information System (INIS)

Hellmuth, K.H.; Mirzai, H.

1985-01-01

The optimization of the extraction of metal cations [Sc(III), Cr(III), Mn(II), Fe(III), Co(II), Cu(II), Zn(II), Y(III), Ag(I), Cd(II), La(IIII), Ce(III), Eu(III), Yb(III), Hg(II), Pb(II), Th(IV), U(IV, VI) and Am(III)] in the form of mixed-ligand complexes with hexafluoroacetylacetone and neutral donators with nitrogen atoms or P=O-groups is described. The thermal and gas-chromatographic characteristics of the extracted volatile compounds are reported. Optimal results were achieved using tri-n-butyl-phosphine oxide as donator. (orig.) [de

DNA binding and biological activity of mixed ligand complexes of Cu(II, Ni(II and Co(II with quinolones and N donor ligand

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S.M M Akram

2015-10-01

Full Text Available  AbstractMixed ligand complexes of  Cu(II, Ni(II and Co(II have been synthesized by using levofloxacin and bipyridyl and characterized using spectral and analytical techniques. The binding behavior of the Ni(II and Cu(II complexes with herring sperm DNA(Hs-DNA were determined using electronic absorption titration, viscometric measurements and cyclic voltammetry measurements. The binding constant calculated  for Cu(II and Ni(II complexes are 2.0 x 104 and 4.0 x 104 M-1 respectively. Detailed analysis reveals that these metal complexes interact with DNA through intercalative binding mode. The nuclease activity of  Cu(II and Ni(II complexes with ct-DNA was carried out using agarose gel electrophoresis technique. The antioxidant activities for the synthesized complexes have been tested and the antibacterial activity for Ni(II complex was also checked.Key words: Intercalation, hypochromism, red shift and  peak potential.

Determination of copper binding in Pseudomonas putida CZ1 by chemical modifications and X-ray absorption spectroscopy.

Science.gov (United States)

Chen, XinCai; Shi, JiYan; Chen, YingXu; Xu, XiangHua; Chen, LiTao; Wang, Hui; Hu, TianDou

2007-03-01

Previously performed studies have shown that Pseudomonas putida CZ1 biomass can bind an appreciable amount of Cu(II) and Zn(II) ions from aqueous solutions. The mechanisms of Cu- and Zn-binding by P. putida CZ1 were ascertained by chemical modifications of the biomass followed by Fourier transform infrared and X-ray absorption spectroscopic analyses of the living or nonliving cells. A dramatic decrease in Cu(II)- and Zn(II)-binding resulted after acidic methanol esterification of the nonliving cells, indicating that carboxyl functional groups play an important role in the binding of metal to the biomaterial. X-ray absorption spectroscopy was used to determine the speciation of Cu ions bound by living and nonliving cells, as well as to elucidate which functional groups were involved in binding of the Cu ions. The X-ray absorption near-edge structure spectra analysis showed that the majority of the Cu was bound in both samples as Cu(II). The fitting results of Cu K-edge extended X-ray absorption fine structure spectra showed that N/O ligands dominated in living and nonliving cells. Therefore, by combining different techniques, our results indicate that carboxyl functional groups are the major ligands responsible for the metal binding in P. putida CZ1.

Preparation and characterization of trihydroxamic acid functionalized carbon materials for the removal of Cu(II) ions from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Godino-Salido, M. Luz, E-mail: mlgodino@ujaen.es [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Santiago-Medina, Antonio; López-Garzón, Rafael; Gutiérrez-Valero, María D.; Arranz-Mascarós, Paloma; López de la Torre, M. Dolores [Departamento de Química Inorgánica y Orgánica, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071, Jaén (Spain); Domingo-García, María; López-Garzón, F. Javier [Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada (Spain)

2016-11-30

Highlights: • Hybrid materials made by irreversible adsorption of a deferoxamine derivative on ACs. • The surface trihydroxamate groups are the active functions of the hybrid materials. • Great adsorption capacity for Cu(II) of novel trihydroxamic acid functionalized ACs. • Desorption of Cu(II) from the loaded hybrid materials regenerates the parent hybrids. - Abstract: The main objective of this study is to prepare and characterize two functionalizated carbon materials with enhanced adsorptive properties for Cu(II). Thus, two novel hybrid materials have been prepared by a non-covalent functionalization method based on the adsorption of a pyrimidine-desferrioxamine-B conjugate compound (H{sub 4}L) on two activated carbons, ACs (labelled Merck and F). The adsorption of H{sub 4}L on the ACs is pH-dependent and highly irreversible. This is due to strong π-π interactions between the arene centers of the ACs and the pyrimidine moiety of H{sub 4}L. The textural characterization of the AC/H{sub 4}L hybrids shows large decreases of their surface areas. Thus the values of Merck and F are 1031 and 1426 m{sup 2}/g respectively, while these of Merck/H{sub 4}L and F/H{sub 4}L hybrids are 200 and 322 m{sup 2}/g. An important decrease in the micropore volumes is also found, due to the blockage of narrow porosity produced by the adsorption of H{sub 4}L molecules. The ACs/H{sub 4}L hybrids show larger adsorption capacities for Cu(II) (0.105(4) and 0.13(2) mmol/g, at pH 2.0, and 0.20(3) and 0.242(9) mmol/g, at pH 5.5, for Merck/H{sub 4}L and F/H{sub 4}L, respectively) than those of the ACs (0.024(6) and 0.096(9) mmol/g, at pH 2.0, and 0.10(2) and 0.177(8) mmol/g, at pH 5.5, for Merck and F respectively), which is explained on the basis of the complexing ability of the trihydroxamic acid functions. The desorption of Cu(II) from the ACs/H{sub 4}L/Cu(II) materials in acid solution allows the regeneration of most active sites (78.5% in the case of Merck/H{sub 4}L/Cu(II) and 83

Contact angle study on the activation mechanisms of sphalerite with Cu(II) and Pb(II); Estudio de los mecanismos de activacion de la esfalerita con Cu(II) y Pb(II)

Energy Technology Data Exchange (ETDEWEB)

Davila Pulido, G. I.; Uribe Salas, A.

2011-07-01

This article presents results of an experimental study on the sphalerite activation with Cu(II) and Pb(II), whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate) is characterized making use of the contact angle technique. The results show that Cu(II) replaces the Zn of the external layers of the mineral, promoting the sulfide (S{sup 2}-) oxidation to produce a mixture of CuS, Cu{sub 2}S and S{sup o}, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II) activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX{sub 2}). It is also observed that the hydrophobicity of sphalerite activated with Pb(II) is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation. (Author) 11 refs.

Removal of Pb(II), Cu(II) and Cd(II) from aqueous solution by some fungi and natural adsorbents in single and multiple metal systems

International Nuclear Information System (INIS)

Shoaib, A.; Badar, T.; Aslam, N.

2011-01-01

Six fungal and 10 natural biosorbents were analyzed for their Cu(II), Cd(II) and Pb(II) uptake capacity from single, binary and ternary metal ion system. Preliminary screening biosorption of assays revealed 2 fungi (Aspergillus niger and Cunninghamella echinulata) and three natural [Cicer arietinum husk, Moringa oleifera flower and soil (clay)] adsorbents hold considerable high adsorption efficiency and capacity for 3 meta l ions amongst the adsorbents. Further biosorption trials with five elected adsorbents showed a considerable reduction in metal uptake capability of adsorbents in binary- and ternary systems as compared to singly metal system. Cd(II) manifested the highest inhibitory effect on the biosorption of other metal ions, followed by Pb(II) and Cu(II). On account of metal preference, the selectivity order for metal ion towards the studied biomass matrices was Pb(II) (40-90%) > Cd(II) (2-53%) > Cu(II) (2-30%). (author)

New complexes of Co(II, Ni(II, Cu(II with Schiff base N,N’-bis-(3-methoxy-saliciliden-3,3’-dimethylbenzidine

Directory of Open Access Journals (Sweden)

Alan Ionela

2013-01-01

Full Text Available The new N,N’-bis-(3-methoxy-saliciliden-3,3’-dimetilbenzidine (H2L Schiff base and complexes with Co(II, Ni(II and Cu(II of type [M(HLCl(H2O] (M=Co(II, Cu(II [M2L(H2O4]X2 (M=Co(II, X=ClO4 and M=Cu(II, X=NO3 and [M2L(CH3COO2] (M=Co(II, Ni(II, Cu(II were synthesised. The ligand and complexes were characterized by elemental analysis, conductibility measurements, magnetic moments at room temperature, IR, NMR, UV-VIS-NIR, EPR spectra and thermogravimetric analysis. A molar ratio of 1:1 or 1:2 between ligand and metal was determined from the elemental analysis. Except for perchlorate complex that behave as electrolyte, the rest of complexes are non-electrolytes. The spectral data suggest a tetrahedral, pseudo-tetrahedral or square-planar stereochemistry respectively, data confirmed by magnetic behaviour of complexes. The antimicrobial tests indicate a fungicide effect both for ligand and complexes.

Pecan nutshell as biosorbent to remove Cu(II), Mn(II) and Pb(II) from aqueous solutions.

Science.gov (United States)

Vaghetti, Julio C P; Lima, Eder C; Royer, Betina; da Cunha, Bruna M; Cardoso, Natali F; Brasil, Jorge L; Dias, Silvio L P

2009-02-15

In the present study we reported for the first time the feasibility of pecan nutshell (PNS, Carya illinoensis) as an alternative biosorbent to remove Cu(II), Mn(II) and Pb(II) metallic ions from aqueous solutions. The ability of PNS to remove the metallic ions was investigated by using batch biosorption procedure. The effects such as, pH, biosorbent dosage on the adsorption capacities of PNS were studied. Four kinetic models were tested, being the adsorption kinetics better fitted to fractionary-order kinetic model. Besides that, the kinetic data were also fitted to intra-particle diffusion model, presenting three linear regions, indicating that the kinetics of adsorption should follow multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips and Redlich-Peterson isotherm models. Taking into account a statistical error function, the data were best fitted to Sips isotherm model. The maximum biosorption capacities of PNS were 1.35, 1.78 and 0.946mmolg(-1) for Cu(II), Mn(II) and Pb(II), respectively.

Highly luminescent colloidal Eu(3)+-doped KZnF(3) nanoparticles for the selective and sensitive detection of Cu(II) ions.

Science.gov (United States)

Sarkar, Shyam; Chatti, Manjunath; Mahalingam, Venkataramanan

2014-03-17

This article describes a green synthetic approach to prepare water dispersible perovskite-type Eu3+-doped KZnF3 nanoparticles, carried out using environmentally friendly microwave irradiation at low temperature (85 8C) with water as a solvent. Incorporation of Eu3+ ions into the KZnF3 matrix is confirmed by strong red emission upon ultraviolet (UV) excitation of the nanoparticles. The nanoparticles are coated with poly(acrylic acid) (PAA), which enhances the dispersibility of the nanoparticles in hydrophilic solvents. The strong red emission from Eu3+ ions is selectively quenched upon addition of CuII ions, thus making the nanoparticles a potential CuII sensing material. This sensing ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA), with recovery of almost 90% of the luminescence. If the nanoparticles are strongly attached to a positively charged surface, dipping the surface in a CuII solution leads to the quenching of Eu3+ luminescence, which can be recovered after dipping in an EDTA solution. This process can be repeated for more than five cycles with only a slight decrease in the sensing ability. In addition to sensing, the strong luminescence from Eu3+-doped KZnF3 nanoparticles could be used as a tool for bioimaging.

Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

Science.gov (United States)

Gao, Ru; Hu, Zheng; Chang, Xijun; He, Qun; Zhang, Lijun; Tu, Zhifeng; Shi, Jianping

2009-12-15

A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.20, 67.80 and 48.56 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 3.0 mL of 2% CS(NH2)2 and 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation. According to the definition of IUPAC, the detection limits (3sigma) of this method for Cu(II), Hg(II) and Pb(II) were 0.20, 0.12 and 0.45 ng mL(-1), respectively. The relative standard deviation under optimum conditions is less than 4.0% (n=8). The prepared sorbent was applied for the preconcentration of trace Cu(II), Hg(II) and Pb(II) in certified and water samples with satisfactory results.

Removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution using rice husk-based activated carbon

Energy Technology Data Exchange (ETDEWEB)

Taha, Mohd F., E-mail: faisalt@petronas.com.my; Shaharun, Maizatul S. [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia); Shuib, Anis Suhaila, E-mail: anisuha@petronas.com.my; Borhan, Azry [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750, Perak Darul Ridzuan (Malaysia)

2014-10-24

An attempt was made to investigate the potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Rice husk-based activated carbon was prepared via treatment of rice husk with NaOH followed by the carbonization process at 400°C for 2 hours. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). These samples were also analyzed for their carbon, hydrogen, nitrogen, oxygen and silica contents using CHN elemental analyzer and FESEM/EDX. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were 255 m{sup 2}/g and 0.17 cm{sup 2}/g, respectively. The adsorption studies for the removal of Ni(II), Zn(II) and Pb(II) ions from single metal aqueous solution were carried out at a fixed initial concentration of metal ion (150 ppm) with variation amount of adsorbent (rice husk-based activated carbon) as a function of varied contact time at room temperature. The concentration of each metal ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Ni(II), Zn(II) and Pb(II) ions from single aqueous solution. Isotherm and kinetic model analyses suggested that the experimental data of adsorption studies fitted well with Langmuir, Freundlich and second-order kinetic models.

Two new Zn(II) and Cd(II) coordinastion polymers based on amino-tetrazole and phenylcarboxylate: Syntheses, topological structures and photoluminescent properties

International Nuclear Information System (INIS)

Liu, Dong-Sheng; Sui, Yan; Chen, Weng-Tong; Huang, Jian-Gen; Chen, Jian-Zhong; Huang, Chang-Cang

2012-01-01

Two Zn(II) and Cd(II) compounds with the in-situ generated ligand of 5-amino-tetrazolate (atz − ) were prepared from the hydrothermal reactions of the corresponding Cd or Zn(II) salts with phenylcarboxylate, and characterized by elemental analysis, IR spectroscopy, and TGA. The results of X-ray crystallographic analysis reveal that compound [Zn 2 (BZA)(atz) 2 (OH)] n (1) (BZA=benzoic acid) presents a two-dimensional (2D) “hcb” topological network constructed from the ZnN 2 O 2 tetrahedra. In compound [Cd 6 (atz) 6 (PTA) 3 ] n (2) (PTA=terephthalic acid), the identical [Cd 3 (atz) 3 )] 3+ n clusters are connected by atz ligands to generate a 2D cationic layer, and the neighboring cationic layers are pillared by PTA giving birth to 3D network. After simplifying, the complicated 3D network of 2 can be presented as an unprecedented (4, 4, 10)-connected trinodal topology. The formations of the structures show a good example that using the combination of the in-situ generated ligand and other coligand synthetic strategy can construct interesting topological structures. The thermal stabilities and fluorescent properties of the complexes have also been studied. - Graphical abstract: Two d 10 metal complexes have been synthesized by employing mixed-ligand synthetic approach. Complex 1 presents a 2D “hcb” topological network. Complex 2 shows an unprecedented (4, 4, 10)-connected trinodal topology. Highlights: ► Coligand synthetic strategy was applied to obtain new MOFs with useful properties. ► Two new Zn(II) and Cd(II) complexes were constructed from the mixed-ligand. ► Topologically, compound 2 presented an unprecedented (4, 4, 10)-connected trinodal topology. ► The two compounds may be excellent candidates for potential photoactive material.

Cu(II) and Co(II) complexes of benzimidazole derivative: Structures, catecholase like activities and interaction studies with hydrogen peroxide

Science.gov (United States)

Kumari, Babli; Adhikari, Sangita; Matalobos, Jesús Sanmartín; Das, Debasis

2018-01-01

Present study describes the synthesis and single crystal X-ray structures of two metal complexes of benzimidazole derivative (PBI), viz. the Cu(II) complex, [Cu(PBI)2(NCS)]ClO4 (1) and a Co(II) complex, [Co(PBI)2(NCS)1.75Cl0.25] (2). The Cu(II) complex (1) shows catecholase like activity having Kcat = 1.84 × 104 h-1. Moreover, interactions of the complexes with hydrogen peroxide have been investigated using fluorescence spectroscopy. The interaction constant of 1 and 2 for H2O2 are 6.67 × 102 M-1 and 1.049 × 103 M-1 while their detection limits for H2O2 are 3.37 × 10-7 M and 2.46 × 10-7 M respectively.

Time-Resolved Transient Optical Absorption Study of Bis(terpyridyl)oligothiophenes and Their Metallo-Supramolecular Polymers with Zn(II) Ion Couplers.

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Rais, David; Menšík, Miroslav; Štenclová-Bláhová, Pavla; Svoboda, Jan; Vohlídal, Jiří; Pfleger, Jiří

2015-06-18

α,ω-Bis(terpyridyl)oligothiophenes spontaneously assemble with Zn(II) ions giving conjugated constitutional dynamic polymers (dynamers) of the metallo-supramolecular class, which potentially might be utilized in optoelectronics. Their photophysical properties, which are of great importance in this field of application, are strongly influenced by the dynamic morphology. It was assessed in this study by using ultrafast pump-probe optical absorption spectroscopy. We identified and characterized relaxation processes running in photoexcited molecules of these oligomers and dynamers and show impacts of disturbed coplanarity of adjacent rings (twisting the thiophene-thiophene and thiophene-terpyridyl bonds by attached hexyl side groups) and Zn(II) ion couplers on these processes. Major effects are seen in the time constants of rotational relaxation, intersystem crossing, and de-excitation lifetimes. The photoexcited states formed on different repeating units within the same dynamer chain do not interact with each other even at very high excitation density. The method is presented that allows determining the equilibrium fraction of unbound oligothiophene species in a dynamer solution, from which otherwise hardly accessible values of the average degree of polymerization of constitutionally dynamic chains in solution can be estimated.

Spectral studies, thermal investigation and biological activity of some metal complexes derived from (E)-N‧-(1-(4-aminophenyl)ethylidene)morpholine-4-carbothiohydrazide

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El-Samanody, El-Sayed A.; Polis, Magdy W.; Emara, Esam M.

2017-09-01

A new series of biologically active Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes derived from the novel thiosemicarbazone ligand; (E)-N‧-(1-(4-aminophenyl)ethylidene)morpholine-4-carbothiohydrazide (HL) were synthesized. The mode of bonding of the ligand and the geometrical structures of its metal complexes were achieved by different analytical and spectral methods. The ligand coordinated with metal ions in a neutral bidentate fashion through the thione sulfur and azomethine nitrogen atoms. All metal complexes adopted octahedral geometry, except Cu(II) complexes (3, 6, 7) which have a square planar structure. The general thermal decomposition pathways of the ligand along with its metal complexes were explained. The thermal stability of the complexes is controlled by the number of outer and inner sphere water molecules, ionic radii and the steric hindrance. The activation thermodynamic parameters; (activation energy (E*), enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*)) along with order of reaction (n) were estimated from DTG curves. The ESR spectra of Cu(II) complexes indicated that (dx2-y2)1 is the ground state with covalence character of metal-ligand bonds. The molluscicidal and biochemical effects of the ligand and its Ni(II); Cu(II) complexes (2; 3, 5, 7) along with their combinations with metaldehyde were screened in vitro on the mucous gland of Eobania vermiculata. The tested compounds exhibited a significant toxicity against the tested animals and have almost the same toxic effect of metaldehyde which increases the mucous secretion of the snails and leads to death.

Facile and green preparation of novel adsorption materials by combining sol-gel with ion imprinting technology for selective removal of Cu(II) ions from aqueous solution

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Ren, Zhongqi; Zhu, Xinyan; Du, Jian; Kong, Delong; Wang, Nian; Wang, Zhuo; Wang, Qi; Liu, Wei; Li, Qunsheng; Zhou, Zhiyong

2018-03-01

A novel green adsorption polymer was prepared by ion imprinted technology in conjunction with sol-gel process under mild conditions for the selective removal of Cu(II) ions from aqueous solution. Effects of preparation conditions on adsorption performance of prepared polymers were studied. The ion-imprinted polymer was prepared using Cu(II) ion as template, N-[3-(2-aminoethylamino) propyl] trimethoxysilane (AAPTMS) as functional monomer and tetraethyl orthosilicate (TEOS) as cross-linker. Water was used as solvent in the whole preparation process. The imprinted and non-imprinted polymers were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM), Brunauer, Emmett and Teller (BET) and zeta potential. Three-dimensional network structure was formed and functional monomer was successfully cross-linked into the network structure of polymers. Effects of adsorption conditions on adsorption performance of prepared polymers were studied too. The pH value is of great influence on adsorption behavior. Adsorption by ion-imprinted polymer was fast (adsorption equilibrium was reached within 60 min). The adsorption capacity of Cu(II) ion-imprinted polymer was always larger than that of non-imprinted polymer. Pseudo-second-order kinetics model and Freundlich isotherm model fitted well with adsorption data. The maximum adsorption capacity of Cu(II) ion-imprinted polymer was 39.82 mg·g-1. However, the preparation conditions used in this work are much milder than those reported in literatures. The Cu(II) ion-imprinted polymer showed high selectivity and relative selectivity coefficients for Pb(II), Ni(II), Cd(II) and Co(II). In addition, the prepared ion-imprinted polymer could be reused several times without significant loss of adsorption capacity.

Synthesis, Physical Characterization and Biological Activity of Some Schiff Base Complexes

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R. Rajavel

2008-01-01

Full Text Available Structural modification of organic molecule has considerable biological relevance. Further, coordination of a biomolecules to the metal ions significantly alters the effectiveness of the biomolecules. In view of the antimicrobial activity ligand [bis-(2-aminobenzaldehyde] malonoyl dihydrazone], metal complexes with Cu(II, Ni(II, Zn(II and oxovanadium(IV have been synthesized and found to be potential antimicrobial agents. An attempt is also made to correlate the biological activities with geometry of the complexes. The complexes have been characterized by elemental analysis, molar conductance, spectra and cyclicvoltammetric measurements. The structural assessment of the complexes has been carried out based on electronic, infrared and molar conductivity values.

Determinação voltamétrica de metais em águas e fluidos biológicos empregando mineralização de amostras com radiação ultravioleta Voltammetric determination of metals in waters and biological fluids using sample mineralization with ultraviolet radiation

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Leandro M. de Carvalho

2008-01-01

Full Text Available This work describes the optimization of pretreatment steps for the destruction of organic matter in samples of waters and biological fluids, by using an UV irradiation system with a high power UV radiation source (400 W. The efficiency of the system constructed for the photo-decomposition of samples of model waters, natural waters and biological fluids was investigated by performing recovery experiments of the metallic species Zn(II, Cd(II, Pb(II, Cu(II, Al(III and Fe(III. The use of UV irradiation allowed the liberation of metals bound to the organic matrix and the determination of the total content of elements in the samples.

Synthesis, characterization, X-ray crystal structure and conductometry studying of a number of new Schiff base complexes; a new example of binuclear square pyramidal geometry of Cu(II) complex bridged with an oxo group

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Golbedaghi, Reza; Alavipour, Ehsan

2015-11-01

Three new binuclear Cu(II), Mn(II), Co(II) complexes [Cu2(L) (ClO4)](ClO4)2 (1), [Mn2(L) (ClO4)](ClO4)2 (2), and [Co2(L) (ClO4)](ClO4)2 (3), {L = 1,3-bis(2-((Z)-(2-aminopropylimino)methyl)phenoxy)propan-2-ol} have been synthesized. Single crystal X-ray structure analysis of complex 1 showed that the complex is binuclear and all nitrogen and oxygen atoms of ligand (N4O3) are coordinated to two Cu(II) center ions. In addition, the crystal structure studying shows, a perchlorate ion has been bridged to the Cu(II) metal centers. However, two distorted square pyramidal Cu(II) ions are bridged asymmetrically by a perchlorate ion and oxygen of hydroxyl group of Schiff base ligand. In addition, the conductometry behaviors of all complexes were studied in acetonitrile solution.

Synthesis and Characterization of a New Coordinative Compound of Cu(II with 1-(3 Bromo, 2 Hydroxy, 4 Methylphenyl- 2-(4 Bromo-Phenyl-Sulphanyl- Etanone

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Antighin Simona

2015-07-01

Full Text Available Continuing the research in the field of complex compounds, the authors present in this paper the synthesis and characterization of a new compound of Cu(II with the ligand 1-(3 bromo, 2 hydroxy, 4 methyl-phenyl-2-(4 bromophenyl- sulphanyl-etanone. Different methods were used, such as chemical elemental analysis, thermal-gravimetry, infrared absorption spectroscopy and electronic spin resonance (ESR. From chemical analysis resulted that the combination ratio ligand-central atom is 2:1. The new compound can also be used for gravimetric determination of Cu(II.

Equilibrium and kinetic studies of Pb(II, Cd(II and Zn(II sorption by Lagenaria vulgaris shell

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Mitić-Stojanović Dragana-Linda

2012-01-01

Full Text Available The sorption of lead, cadmium and zinc ions from aqueous solution by Lagenaria vulgaris shell biosorbent (LVB in batch system was investigated. The effect of relevant parameters such as contact time, biosorbent dosage and initial metal ions concentration was evaluated. The Pb(II, Cd(II and Zn(II sorption equilibrium (when 98% of initial metal ions were sorbed was attained within 15, 20 and 25 min, respectively. The pseudo first, pseudo-second order, Chrastil’s and intra-particle diffusion models were used to describe the kinetic data. The experimental data fitted the pseudo-second order kinetic model and intra-particle diffusion model. Removal efficiency of lead(II, cadmium(II and zinc(II ions rapidly increased with increasing biosorbent dose from 0.5 to 8.0 g dm-3. Optimal biosorbent dose was set to 4.0 g dm-3. An increase in the initial metal concentration increases the sorption capacity. The sorption data of investigated metal ions are fitted to Langmuir, Freundlich and Temkin isotherm models. Langmuir model best fitted the equilibrium data (r2 > 0.99. Maximal sorption capacities of LVB for Pb(II, Cd(II and Zn(II at 25.0±0.5°C were 0.130, 0.103 and 0.098 mM g-1, respectively. The desorption experiments showed that the LVB could be reused for six cycles with a minimum loss of the initial sorption capacity.

Synthesis, Characterization and Biological Evaluation of Transition Metal Complexes Derived from N, S Bidentate Ligands

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Enis Nadia Md Yusof

2015-05-01

Full Text Available Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC with 2-methoxybenzaldehyde (2MB and 3-methoxybenzaldehyde (3MB. The ligands were reacted separately with acetates of Cu(II, Ni(II and Zn(II yielding 1:2 (metal:ligand complexes. The metal complexes formed were expected to have a general formula of [M(NS2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1 and S2M3MBH (2 were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7 and estrogen receptor-negative (MDA-MB-231 breast cancer cell lines. Only the Cu(II complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II complexes have a strong DNA binding affinity.

Experimental and theoretical investigations on Pd(II) host-guest compound: Deciphering the structural and electronic features of a potential bioactive complex

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Sreejith, S. S.; Mohan, Nithya; Prathapachandra Kurup, M. R.

2017-10-01

A Pd(II) complex from N,N‧-bis(2-hydroxy-3-ethoxybenzylidene)butane-1,4-diamine salen-type ligand has been synthesized and characterised using single crystal XRD analysis, elemental analysis, IR and UV-Vis spectroscopic methods. Thermal profile of the compound is investigated using TG-DTG-DSC method. The quantification of intermolecular interactions and surface morphology has been done using Hirshfeld surface study mapped using various functions like dnorm, shape index and curvedness. ESP analysis is done to visualize the electrophilic and nucleophilic regions in the complex. Geometry optimization of the structure is done using DFT at B3LYP/def2-TZVP level of theory. Frontier orbital analysis reveals the kinetical stability and chemical inertness of the complex. A detailed charge distribution analysis is done using different analytical methods like Mulliken, Löwdin, NPA and AIM methods. Further bond order analysis and topological analysis are also done. Finally the bioactivity of the titled complex is checked using molecular docking method on both DNA and protein.

Comparative energies of Zn(II) cation localization as a function of the distance between two forming cation position aluminium ions in high-silica zeolites

NARCIS (Netherlands)

Kachurovskaya, N.A.; Zhidomirov, G.M.; van Santen, R.A.

2004-01-01

Periodical calcns. of Zn(II) metal cation stabilization in cationic positions with distantly placed aluminum ions has been performed for high-silica ferrierite. It was found that decrease of the stabilization energy at large distances between Al ions (more than 10 .ANG.) is about of 2 eV in

Cassava root husks powder as green adsorbent for the removal of Cu(II) from natural river water

Energy Technology Data Exchange (ETDEWEB)

Jorgetto, A.O.; Silva, R.I.V.; Saeki, M.J.; Barbosa, R.C. [IB-UNESP, Dept. Química e Bioquímica, C.P. 510, 18618-000 Botucatu, SP (Brazil); Martines, M.A.U. [UFMS – Dept. Química, 79074-460 Campo Grande, MS (Brazil); Jorge, S.M.A.; Silva, A.C.P. [IB-UNESP, Dept. Química e Bioquímica, C.P. 510, 18618-000 Botucatu, SP (Brazil); Schneider, J.F. [USP – Instituto de Física de São Carlos, 13566-590 São Carlos, SP (Brazil); Castro, G.R., E-mail: castrogr@ibb.unesp.br [IB-UNESP, Dept. Química e Bioquímica, C.P. 510, 18618-000 Botucatu, SP (Brazil)

2014-01-01

Through a series of simple processes, cassava root husks were turned into a fine powder of controlled particle size (63–75 μm). FTIR spectrum demonstrated the existence of alcohol, amine and carboxylic groups; and elemental analysis confirmed the presence of elements of interest such as sulphur, nitrogen and oxygen. Cross-polarized {"1H}-{sup 13}C NMR technique indicated the existence of methionine and thiamine through the signals observed at 55 ppm and 54 ppm, respectively, and the point of zero charge (pH{sub pzc}) was achieved at pH 5.2. The material was applied in solid-phase extraction of Cu(II) via batch experiments. Optimum adsorption pH was found to be in range of 3–6 and in the kinetic experiment the equilibrium was attained in 1 min. The highest adsorption capacity was 0.14 mmol g{sup −1}. The adsorption data were fit to the modified Langmuir equation, and the maximum amount of metal species extracted from the solution, N{sub s}, was determined to be ∼0.14 mmol g{sup −1}, which is an indicative that the main adsorption mechanism is through chemisorption. Under optimized conditions, the material was utilized in preconcentration experiments, which culminated in an enrichment factor of 41.3-fold. With the aid of the enrichment factor, experiments were carried out to determine the Cu(II) content in tap water and natural water. Preconcentration method was also applied to a certified reference material (1643e) and the concentration found was 23.03 ± 0.79 μg L{sup −1}, whereas the specified Cu(II) concentration was 22.7 ± 0.31 μg L{sup −1}.

Crystal structures and thermodynamics/kinetics of Zn(II) coordination polymers with helical chains

Energy Technology Data Exchange (ETDEWEB)

He, Tian [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Yue, Ke-Fen, E-mail: ykflyy@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Zhao, Yi-xing; Chen, San-Ping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Zhou, Chun-sheng, E-mail: slzhoucs@126.com.cn [Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources, College of Chemical Engineering and Modern Materials, Shangluo University, Shangluo 726000 (China); Yan, Ni [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China)

2016-07-15

Solvothermal reactions of Zn(II) acetates and four V-shaped carboxylates ligands in the presence of 1,4-Bis(2-methyl-imidazol-1-yl)butane afforded four interesting Zn(II) coordination polymers with helical chains, namely, {[Zn(bib)(atibdc)]·2H_2O}{sub n} (1), {[Zn(bib)(atbip)]·H_2O}{sub n} (2), {[Zn(bib)(2,2′-tda)]}{sub n} (3) and {[Zn(bib)(5-tbipa)]·EtOH}{sub n} (4), (H{sub 2}atibdc=5-amino-2,4,6-triiodoisophthalic acid, H{sub 2}atbip=5-amino-2,4,6-tribromoisophthalic acid, 2,2′-H{sub 2}tad=2,2′-thiodiacetic acid, 5-H{sub 2}tbipa=5-tert-butyl-isophthalic acid). 1 reveals a 3D chiral framework with three kinds of helical chains along a, b and c axis. 2 shows a 2D step-type chiral framework with right-handed helical chains. 3 displays a wavelike 2D layer network possessing alternate left- and right-handed helical chains. 4 presents a four-connected 3D framework with zigzag and meso-helical chains. The different spacers and substituent group of carboxylic acid ligands may lead to the diverse network structures of 1–4. The fluorescent properties of complexes 1−4 were studied. In addition, the thermal decompositions properties of 1–4 were investigated by simultaneous TG/DTG–DSC technique. The apparent activation energy E and the pre-exponential factor (A) of skeleton collapse for the complexes 1–4 are calculated by the integral Kissinger's method and Ozawa–Doyle's method. The activation energy E (E{sub 1}=209.658 kJ·mol{sup −1}, E{sub 2}=250.037 kJ mol{sup −1}, E{sub 3}=225.300 kJ mol{sup −1}, E{sub 4}=186.529 kJ·mol{sup −1}) demonstrates that the reaction rate of the melting decomposition is slow. The thermodynamic parameters (ΔH{sup ‡}, ΔG{sup ‡} and ΔS{sup ‡}) at the peak temperatures of the DTG curves were also calculated. ΔG{sup ‡}>0 indicates that the skeleton collapse is not spontaneous. ΔH{sub d}>0 suggests that the skeleton collapse is endothermic, corresponding to the intense endothermic peak of the DSC

Studies on some VO(IV, Ni(II and Cu(II complexes of non-symmetrical tetradentate Schiff-bases

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Aderoju A. Osowole

2008-08-01

Full Text Available The coordination chemistry of VO(IV, Ni(II and Cu(II with unsymmetrical Schiff base ligands, [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(C6H5OH], H2L and [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(CH3OH], H2L1 (derived from condensation of 1-phenyl-1,3-butanedione/2,4-pentanedione, ethylenediamine and 5-methoxy-2-hydroxy acetophenone is discussed. The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral measurements. They are magnetically dilute, non-electrolytes in nitromethane. The ligands are tetradentately coordinating via the imine N and enolic O atoms, resulting in 5-coordinate square-pyramidal geometry for the VO(IV complexes and 4-coordinate square-planar geometry for the Ni(II and Cu(II complexes. The assignment of geometry is supported by magnetic and spectral measurements.

Characterization of a meso-chiral isomer of a hexanuclear Cu(II) cage from racemization of the L-alanine Schiff base.

Science.gov (United States)

Rajesh, Chinnaiyan Mahalingam; Ray, Manabendra

2014-09-14

We are reporting structural characterization of two new hexanuclear cages (H3O)2[Cu3(μ3-OH)(μ3-NH3)(0.5)(L)3]2·8H2O (1) and (H3O)2[Cu3(μ3-OH)(μ3-H2O)(0.5)(L)3]2·8H2O (1a) where L(2-) is the dianionic form of the Schiff base of L-alanine and salicylaldehyde. The complex 1 has two C3 symmetric hydroxo bridged trinuclear halves joined by an ammonia or water molecule at the center through H-bonding. Each of the trinuclear halves is enantiopure but of opposite chirality to the other half, making the hexanuclear unit a meso isomer. Temperature dependent magnetic measurements showed the presence of ferromagnetic interactions among trinuclear Cu(II) units, a rare occurrence among trinuclear Cu(II) complexes. Characterization of the LiHL showed it to be enantiopure. Addition of a base, monitored using optical rotation, showed that racemization occurs as a result of base addition. The racemization depends on the base as well as the temperature. Base or Cu(II) induced racemization of amino acid derivatives has been indicated in a number of cases in the past but structural characterization of the products or formation of this type of chiral hexanuclear architecture was never reported. Structures of the complex and the ligand have a number of interesting H-bonding situations.

A novel adsorbent TEMPO-mediated oxidized cellulose nanofibrils modified with PEI: Preparation, characterization, and application for Cu(II) removal

Energy Technology Data Exchange (ETDEWEB)

Zhang, Nan; Zang, Guo-Long; Shi, Chen; Yu, Han-Qing; Sheng, Guo-Ping, E-mail: gpsheng@ustc.edu.cn

2016-10-05

Highlights: • A cellulose nanofibril based adsorbent with abundant carboxyl/amino was prepared. • After modification by PEI, the Cu adsorption capacity of nanofibril increased. • TOCN-PEI has good Cu(II) removal ability and its maximum capacity was 52.32 mg g{sup −1}. • Results show Cu adsorption on TOCN-PEI is an exothermic and enthalpy-driven process. • Sorption-desorption tests reveal that TOCN-PEI has good stability for Cu removal. - Abstract: This study describes the preparation of a novel adsorbent based on cellulose nanofibrils by first TEMPO mediated oxidation and then PEI grafting (TOCN-PEI) for heavy metal removal. FTIR results demonstrated the successful introduction of the adsorption functional groups (carboxyl and amino groups), and the elemental analysis and acid base titration were used to quantify the contents of these introduced groups. The kinetics curve suited the pseudo-second-order model better and the equilibrium data well fitted the Langmuir model, with the maximum Cu(II) uptake of 52.32 mg g{sup −1}. Kinetic study showed that the PEI grafting increased the initial adsorption rate of the TOCN-PEI compared with the adsorbents without PEI. Thermodynamic study was carried out through isothermal titration calorimetry (ITC) measurement and the binding reaction was found to be exothermic and driven by enthalpy change. The adsorption process by TOCN-PEI was pH dependent, and decreasing pH would lead to desorption of Cu(II) ions, thus make the reuse of the absorbent more convenient through adsorption-desorption cycles.

A novel sensitive Cu(II) and Cd(II) nanosensor platform: Graphene oxide terminated p-aminophenyl modified glassy carbon surface

International Nuclear Information System (INIS)

Gupta, Vinod Kumar; Yola, Mehmet Lütfi; Atar, Necip; Ustundag, Zafer; Solak, Ali Osman

2013-01-01

Graphical abstract: - Highlights: • We electrochemically prepared sensor based on graphene oxide. • The prepared electrode was characterized by using various techniques. • The proposed nanosensor showed good stability, selectivity and high sensitivity. • The proposed nanosensor electrode was used for the analysis of Cd(II) and Cu(II). - Abstract: Graphene oxide (GO) based glassy carbon (GC) electrode has been prepared. Firstly, p-nitrophenyl (NP) modified GC (NP/GC) electrode was prepared via the electrochemical reduction of its tetraflouroborate diazonium salt. After the formation of NP/GC electrode, the negative potential was applied to NP/GC electrode to reduce the nitro groups to amine. p-Aminophenyl (AP) modified GC (AP/GC) electrode was immersed into a graphene oxide solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide. Hence, we constructed GO terminated AP modified GC (GO/AP/GC) electrode. NP/GC, AP/GC and GO/AP/GC electrodes were characterized sequentially using cyclic voltammetry (CV) in the presence of 1.0 mM of potassium ferricyanide in 0.1 M KCl. In addition, GO and GO/AP/GC surfaces were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The GO/AP/GC electrode was used for the analysis of Cd(II) and Cu(II) ions by adsorptive stripping voltammetry. The linearity range and the detection limit of Cd(II) and Cu(II) ions were 1.0 × 10 −11 –5.0 × 10 −10 M and 3.3 × 10 −12 M (S/N = 3), respectively

Synthesis and Spectroscopic Studies of Mixed Ligand Complexes of Pt(II and Pd(II with Ethyl-α-Isonitrosoacetoacetate and Dienes

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Anita Krishankant Taksande

2015-12-01

Full Text Available The mixed ligand complexes of the kind [M(L1 (L2] where M= Pt(II, Pd(II.L1 = primary ligand ethyl-α-isonitrosoacetoacetate derived from reaction between ethyl acetoacetate, acetic acid and sodium nitrite and L2=secondary ligand para-phenyldiamine (PPD are synthesized. All the prepared complexes were identified and confirmed by elemental analysis, molar conductance measurements, and infrared electronic absorption. Their complexes has been made based on elemental analysis, molar conductivity, UV-Vis, FT-IR and 1HNMR spectroscopy and magnetic moment measurements as well as thermal analysis (TGA and DTA. The elemental analysis information recommends that the stoichiometry of the complexes to be 1:2:1. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral information showed the coordination sites of the free ligand with the central metal particle. The electronic absorption spectral information disclosed the existence of an octahedral geometry for Pt(II and Pd(II complexes. DOI: http://dx.doi.org/10.17807/orbital.v7i4.633 

Column dynamic studies and breakthrough curve analysis for Cd(II) and Cu(II) ions adsorption onto palm oil boiler mill fly ash (POFA).

Science.gov (United States)

Aziz, Abdul Shukor Abdul; Manaf, Latifah Abd; Man, Hasfalina Che; Kumar, Nadavala Siva

2014-01-01

This paper investigates the adsorption characteristics of palm oil boiler mill fly ash (POFA) derived from an agricultural waste material in removing Cd(II) and Cu(II) from aqueous solution via column studies. The performance of the study is described through the breakthrough curves concept under relevant operating conditions such as column bed depths (1, 1.5, and 2 cm) and influent metal concentrations (5, 10, and 20 mg/L). The Cd(II) and Cu(II) uptake mechanism is particularly bed depth- and concentration-dependant, favoring higher bed depth and lower influent metal concentration. The highest bed capacity of 34.91 mg Cd(II)/g and 21.93 mg Cu(II)/g of POFA was achieved at 20 mg/L of influent metal concentrations, column bed depth of 2 cm, and flow rate of 5 mL/min. The whole breakthrough curve simulation for both metal ions were best described using the Thomas and Yoon–Nelson models, but it is apparent that the initial region of the breakthrough for Cd(II) was better described using the BDST model. The results illustrate that POFA could be utilized effectively for the removal of Cd(II) and Cu(II) ions from aqueous solution in a fixed-bed column system.

Studies on the competitive sorption of divalent metal ions to natural soil samples using a multitracer technique

International Nuclear Information System (INIS)

Fujiyoshi, R.; Hirashima, H.; Sawamura, S.

1997-01-01

Speciation of minor or trace amount of pollutants, such as heavy metals and radionuclides released from atmospheric precipitation and water streams have been studied in order to elucidate their fates in the environment through 'in situ' observations or laboratory experiments. The authors have investigated sorption of heavy metals on various natural samples radiometrically ( 65 Zn as a tracer). A sequential extraction technique was found to be very effective to elucidate possible scavengers (minerals) of heavy metals in some cases. A sediment with low CEC does not sorb Zn (ii) ions to a great extent. It is thus considered that the zinc sorption occurs competitively with protons present in the aqueous media. Divalent copper and cadmium ions also behaved similarly to Zn(II), which was obtained electrochemically with the ion selective electrodes of Cu(II) and Cd(II). This time the authors investigated the competitive sorption of Mn(ii) and Zn(II) to natural soils using a radiotracer technique, which was considered to be useful to evaluate relative importance of the sorption of each metal ion without serious matrix effects. Quite different properties appeared among those metal ions used independently or simultaneously as a tracer. Proton exchange process may be important for the Zn(II) sorption, whereas a solid-solution partition is supposed to control the Mn(ii) uptake, when each of them was examined independently as a sorbate. In contrast, simultaneous use of those tracers to a soil suspension had great effects on the result; the maximum sorption (A m ) of Zn(II) increased, and Mn(II) behaved like a sorbate which tends to occupy specific sites of the soil surfaces. Those results indicate that the sorption of minor and/or trace elements to natural soils would not be evaluated through a series of experiments with a single sorbate

Synthesis, spectroscopic characterization, biological studies and DFT calculations on some transition metal complexes of NO donor ligand

Science.gov (United States)

Zordok, W. A.; Sadeek, S. A.

2018-04-01

Seven new complexes of2-oxo-4,6-diphenyl-1,2-dihyropyridine-3-carbonitrile (L) with Fe(III), Co(II), Cu(II), Zn(II), Y(III), Zr(IV) and La(III) were synthesized. The isolated solid compounds were elucidated from micro analytical, IR, electronic, mass, 1H NMR, magnetic susceptibility measurements and TG/DTG, DTA analyses. The intensity of ν(Ctbnd N) was changed to strong and shifted to around 2200 cm-1. Also, the ν(Cdbnd O) was shifted to higher frequency value (1644 cm-1). The spectra of the complexes indicate that the free ligand is coordinated to the metal ions via nitrogen of carbonitrile group and oxygen of keto group. From DFT calculations the Cu(II) and Fe(III) complexes behave as regular octahedral, while other complexes are distorted octahedral. The value of energy gap of the free ligand (ΔE = 0.3343 eV) is greater than all new complexes, so they are more reactive than free ligand, also the Fe(III) complex (ΔE = 0.0985 eV) is the most reactive complex, while Cu(II) complex (ΔE = 0.3219 eV) is the least reactive complex. The LMCT in case of Zr(IV) complex was resulted from transitions from HOMO-2 (62%), HOMO-1 (16%)and HOMO (25%), while the d-d transition in Fe(III) complex was resulted from HOMO-1(30%), HOMO-2(62%) and HOMO(30%). Also, the metal complexes exhibit antibacterial activity for Gram-positive and Gram-negative and antifungal activity. The Y(III) and Cu(II) complexes are highly significant for Escherichia coli and salmonella typhimurium.

Interaction of Zn(II) with hematite nanoparticles and microparticles: Part 2. ATR-FTIR and EXAFS study of the aqueous Zn(II)/oxalate/hematite ternary system.

Science.gov (United States)

Ha, Juyoung; Trainor, Thomas P; Farges, François; Brown, Gordon E

2009-05-19

Sorption of Zn(II) to hematite nanoparticles (HN) (av diam=10.5 nm) and microparticles (HM) (av diam=550 nm) was studied in the presence of oxalate anions (Ox2-(aq)) in aqueous solutions as a function of total Zn(II)(aq) to total Ox2-(aq) concentration ratio (R=[Zn(II)(aq)]tot/[Ox2-(aq)]tot) at pH 5.5. Zn(II) uptake is similar in extent for both the Zn(II)/Ox/HN and Zn(II)/Ox/HM ternary systems and the Zn(II)/HN binary system at [Zn(II)(aq)](tot)system than for the Zn(II)/Ox/HM ternary and the Zn(II)/HN and Zn(II)/HM binary systems at [Zn(II)(aq)]tot>4 mM. In contrast, Zn(II) uptake for the Zn(II)/HM binary system is a factor of 2 greater than that for the Zn(II)/Ox/HM and Zn(II)/Ox/HN ternary systems and the Zn(II)/HN binary system at [Zn(II)(aq)]totternary system at both R values examined (0.16 and 0.68), attenuated total reflectance Fourier transform infrared (ATR-FTIR) results are consistent with the presence of inner-sphere oxalate complexes and outer-sphere ZnOx(aq) complexes, and/or type A ternary complexes. In addition, extended X-ray absorption fine structure (EXAFS) spectroscopic results suggest that type A ternary surface complexes (i.e., >O2-Zn-Ox) are present. In the Zn(II)/Ox/HN ternary system at R=0.15, ATR-FTIR results indicate the presence of inner-sphere oxalate and outer-sphere ZnOx(aq) complexes; the EXAFS results provide no evidence for inner-sphere Zn(II) complexes or type A ternary complexes. In contrast, ATR-FTIR results for the Zn/Ox/HN sample with R = 0.68 are consistent with a ZnOx(s)-like surface precipitate and possibly type B ternary surface complexes (i.e., >O2-Ox-Zn). EXAFS results are also consistent with the presence of ZnOx(s)-like precipitates. We ascribe the observed increase of Zn(II)(aq) uptake in the Zn(II)/Ox/HN ternary system at [Zn(II)(aq)]tot>or=4 mM relative to the Zn(II)/Ox/HM ternary system to formation of a ZnOx(s)-like precipitate at the hematite nanoparticle/water interface.

Solid Phase Extraction of Trace Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) Ions in Beverages on Functionalized Polymer Microspheres Prior to Flame Atomic Absorption Spectrometric Determinations.

Science.gov (United States)

Berber, Hale; Alpdogan, Güzin

2017-01-01

In this study, poly(glycidyl methacrylate-methyl methacrylate-divinylbenzene) was synthesized in the form of microspheres, and then functionalized by 2-aminobenzothiazole ligand. The sorption properties of these functionalized microspheres were investigated for separation, preconcentration and determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions using flame atomic absorption spectrometry. The optimum pH values for quantitative sorption were 2 - 4, 5 - 8, 6 - 8, 4 - 6, 2 - 6 and 2 - 3 for Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II), respectively, and also the highest sorption capacity of the functionalized microspheres was found to be for Cu(II) with the value of 1.87 mmol g -1 . The detection limits (3σ; N = 6) obtained for the studied metals in the optimal conditions were observed in the range of 0.26 - 2.20 μg L -1 . The proposed method was successfully applied to different beverage samples for the determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions, with the relative standard deviation of <3.7%.

Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

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Bitmez, Şirin; Sayin, Koray; Avar, Bariş; Köse, Muhammet; Kayraldız, Ahmet; Kurtoğlu, Mükerrem

2014-11-01

A new tridentate azo-azomethine ligand, N‧-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H2O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)2]·4H2O (2), [Ni(sb)2]·H2O (3), [Cu(sb)2]·4H2O (4), [Zn(sb)2]·H2O (5) and [Cd(sb)2]·H2O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the Cdbnd Nsbnd group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

Application of EDTA-functionalized bamboo activated carbon (BAC) for Pb(II) and Cu(II) removal from aqueous solutions

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Lv, Dan; Liu, Yu; Zhou, Jiasheng; Yang, Kunlun; Lou, Zimo; Baig, Shams Ali; Xu, Xinhua

2018-01-01

In this study, a novel bamboo activated carbon (BAC) with ethylene diamine tetraacetic acid (EDTA) functionality was prepared by direct grafting in the presence of tetraethyl orthosilicate (TEOS) as a crosslinking agent. The BAC@SiO2-EDTA was characterized by SEM, TEM, TGA, FTIR, XPS and its adsorption property for removal of Pb(II) and Cu(II) under various experimental conditions was also investigated. The characterization results reflected that EDTA was successfully assembled on the surface of the BAC and average pore size increased from 4.10 to 4.83 nm as BAC grafted with EDTA. Adsorption data fitted very well in Langmuir isotherm model and pseudo-second-order kinetic model. As compared with the raw BAC, the maximum adsorption capacities of BAC@SiO2-EDTA for the Pb(II) and Cu(II) increased from 45.45 to 123.45 mg g-1 and from 6.85 to 42.19 mg g-1, since the existence of EDTA on modified BAC promoted the formation of chemical complex. The removal of heavy metal ions mainly depended on the complexation with EDTA and the electrostatic attractions with negatively charged surface of BAC@SiO2-EDTA. The adsorption of Pb(II)/Cu(II) on the BAC@SiO2-EDTA was pH dependent and pH 5-6 was considered an optimum. However, lower temperature favored the adsorption and the maximum adsorption was recorded at 20 °C. In addition, BAC@SiO2-EDTA had an excellent reusability with about 40% decline in the adsorption capacity for Pb(II) after fifth reuse. Insignificant influences of co-existing cations and natural organic matter (NOM) were found on the adsorption of Pb(II) and Cu(II). All the results demonstrate that BAC@SiO2-EDTA is a potential adsorbent for metal ions in wastewater.

Can Cu(II) ions be doped into the crystal structure of potassium hydrogen tartrate?

OpenAIRE

Srinivasan, Bikshandarkoil R.; Remesh, H.

2015-01-01

The differing binding preferences of the hydrogen tartrate ligand (HC4H4O6)- namely {\\mu}7-octadentate mode for potassium ion and bidentate mode for cupric ion rules out the doping (incorporation) of any Cu(II) ion into the crystal structure of potassium hydrogen tartrate. Hence, the claim of growth of copper doped potassium hydrogen tartrate viz. K0.96Cu0.04C4H5O6 by Mathivanan and Haris, Indian J Pure App Phys 51 (2013) 851-859 is untenable.

New Mononuclear Cu(II Complexes and 1D Chains with 4-Amino-4H-1,2,4-triazole

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Marinela M. Dîrtu

2013-12-01

Full Text Available The crystal structures of two mononuclear Cu(II NH2trz complexes [Cu(NH2trz4(H2O](AsF62 (I and [Cu(NH2trz4(H2O](PF62 (II as well as two coordination polymers [Cu(μ2-NH2trz2Cl]Cl∙H2O (III and [Cu(μ2-NH2trz2Cl] (SiF60.5∙1.5H2O (IV are presented. Cationic 1D chains with bridging bis-monodentate μ2-coordinated NH2trz and bridging μ2-coordinated chloride ligands are present in III and IV. In these coordination polymers, the Cu(II ions are strongly antiferromagnetically coupled with J = −128.4 cm−1 for III and J = −143 cm−1 for IV (H = −JΣSiSi+1, due to the nature of the bridges between spin centers. Inter-chain interactions present in the crystal structures were taken into consideration, as well as g factors, which were determined experimentally, for the quantitative modeling of their magnetic properties.

1D Cu(II) coordination polymer derived from 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonate chelator and pyrazine spacer

Science.gov (United States)

Mahmudov, Kamran T.; Haukka, Matti; Sutradhar, Manas; Mizar, Archana; Kopylovich, Maximilian N.; Pombeiro, Armando J. L.

2013-02-01

Reaction of 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzenesulfonic acid (H2L) with copper(II) nitrate hydrate in the presence of pyrazine (pz) in methanol affords the coordination polymer [Cu2(μ-L)2(H2O)2(μ-pz)]n (1), where the bidentate pz molecule links two Cu(II) centres of two different dimeric units, giving rise to a one-dimensional chain. The dimeric unit [Cu2(μ-L)2(H2O)2] consists of two distorted octahedral Cu(II) centres connected via oxygen atoms of the sulfo group of the bridging L2- ligand. The extensive hydrogen bonding between the coordinated water and pz molecules leads to the formation of a supramolecular 3D associate. Compound 1 has been characterized by elemental analysis, ESI-MS, IR spectroscopy and single-crystal X-ray diffraction analysis.

Functionalisation of mesoporous silica gel with 2-[(phosphonomethyl)-amino]acetic acid functional groups. Characterisation and application

Energy Technology Data Exchange (ETDEWEB)

Caldarola, Dario [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Australian Centre for Research on Separation Sciences (ACROSS), University of Tasmania, Hobart, Tasmania 7001 (Australia); Mitev, Dimitar P. [Australian Centre for Research on Separation Sciences (ACROSS), University of Tasmania, Hobart, Tasmania 7001 (Australia); Marlin, Lucile [Ecole Nationale Superieure des Ingenieurs en Arts Chimiques et Technologiquesm, Toulouse (France); Irish Separation Science Cluster, Dublin City University, Dublin (Ireland); Nesterenko, Ekaterina P. [Irish Separation Science Cluster, Dublin City University, Dublin (Ireland); Paull, Brett [Australian Centre for Research on Separation Sciences (ACROSS), University of Tasmania, Hobart, Tasmania 7001 (Australia); Onida, Barbara [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); CR-INSTM for Materials with Controlled Porosity (Italy); Bruzzoniti, Maria Concetta; Carlo, Rosa Maria De; Sarzanini, Corrado [Analytical Chemistry Department, University of Torino, Via P. Giuria 5, 10125 Torino (Italy); Nesterenko, Pavel N., E-mail: Pavel.Nesterenko@utas.edu.au [Australian Centre for Research on Separation Sciences (ACROSS), University of Tasmania, Hobart, Tasmania 7001 (Australia)

2014-01-01

A new complexing adsorbent was prepared by chemical modification of mesoporous silica Kieselgel 60 (d{sub p} = 37–63 μm, average pore size 6 nm, specific surface area 425 m{sup 2} g{sup −1}) with 3-glycidoxypropyltrimethoxysilane and 2-[(phosphonomethyl)amino]acetic acid (PMA), commonly known as glyphosate. The prepared adsorbent was fully characterised using elemental analysis, thermal gravimetric analysis (TGA), acid–base potentiometric titration, Fourier Transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption isotherms at 77 K (BET), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The concentration of bonded PMA groups calculated from the nitrogen content was 0.38 mmol per gram. The adsorption of transition metal ions on PMA functionalised silica (HEPMAS) was studied from aqueous solutions having different pH and the following selectivity was established, Zn(II) < Co(II) < Cd(II) < Mn(II) < Ni(II) < Cu(II). The calculated values of distribution coefficients D for the adsorption of ecotoxic metal ions on HEPMAS are 5.0 × 10{sup 4}, 4.9 × 10{sup 5} and 2.6 × 10{sup 4} for Zn(II), Pb(II) and Cd(II), respectively.

Functionalisation of mesoporous silica gel with 2-[(phosphonomethyl)-amino]acetic acid functional groups. Characterisation and application

Science.gov (United States)

Caldarola, Dario; Mitev, Dimitar P.; Marlin, Lucile; Nesterenko, Ekaterina P.; Paull, Brett; Onida, Barbara; Bruzzoniti, Maria Concetta; Carlo, Rosa Maria De; Sarzanini, Corrado; Nesterenko, Pavel N.

2014-01-01

A new complexing adsorbent was prepared by chemical modification of mesoporous silica Kieselgel 60 (dp = 37-63 μm, average pore size 6 nm, specific surface area 425 m2 g-1) with 3-glycidoxypropyltrimethoxysilane and 2-[(phosphonomethyl)amino]acetic acid (PMA), commonly known as glyphosate. The prepared adsorbent was fully characterised using elemental analysis, thermal gravimetric analysis (TGA), acid-base potentiometric titration, Fourier Transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption isotherms at 77 K (BET), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). The concentration of bonded PMA groups calculated from the nitrogen content was 0.38 mmol per gram. The adsorption of transition metal ions on PMA functionalised silica (HEPMAS) was studied from aqueous solutions having different pH and the following selectivity was established, Zn(II) < Co(II) < Cd(II) < Mn(II) < Ni(II) < Cu(II). The calculated values of distribution coefficients D for the adsorption of ecotoxic metal ions on HEPMAS are 5.0 × 104, 4.9 × 105 and 2.6 × 104 for Zn(II), Pb(II) and Cd(II), respectively.

Preparation Characterization and Antibacterial Studies of Chelates of Schiff Base Derived from4-Aminoantipyrine, Furfural and o-phenylenediamine

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M. S. Suresh

2011-01-01

Full Text Available A new series of transition metal complexes of Mn(II, Co(II, Ni(II, Cu(II and Zn(II were synthesized from the Schiff base ligand derived from 4-aminoantipyrine, furfural and o-phenylenediamine. The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, NMR spectroscopy, thermal gravimetric analyses, ESR spectral analyses and conductivity measurements. The data of the complexes suggested square planar geometry for the metals with primary valency two. Antimicrobial screening tests were performed against bacteria. The comparative study of the MIC values of the Schiff base and its metal complexes indicate that the metal complexes exhibit greater antibacterial activity than the free ligand.

Effectively simultaneous naked-eye detection of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin extracted from red cabbage as chelating agent

Science.gov (United States)

Khaodee, Warangkhana; Aeungmaitrepirom, Wanlapa; Tuntulani, Thawatchai

Simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) using cyanidin as a chelating agent was investigated in terms of both quantitative and qualitative detections. Cyanidin was extracted and purified from red cabbage which is a local plant in Thailand. The selectivity of this method was examined by regulating the pH of cyanidin solution operated together with masking agents. It was found that Cu(II), Pb(II), Al(III) and Fe(III) simultaneously responded with the color change at pH 7, pH 6, pH 5 and pH 4, respectively. KF, DMG and the mixture of KF and DMG were used as masking agents for the determination of Fe(III), Al(III) and Pb(II), respectively. Results from naked-eye detection were evaluated by comparing with those of inductively coupled plasma (ICP), and there was no significant difference noticed. Cyanidin using as a multianalyte reagent could be employed for simultaneous determination of Cu(II), Pb(II), Al(III) and Fe(III) at the lowest concentration at 50, 80, 50 and 200 μM, respectively, by slightly varying pHs. Moreover, the proposed method could be potentially applied for real water samples with simplicity, rapidity, low cost and environmental safety.

Four Mixed-Ligand Zn(II Three-Dimensional Metal-Organic Frameworks: Synthesis, Structural Diversity, and Photoluminescent Property

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Chih-Chieh Wang

2017-11-01

Full Text Available Assemblies of four three-dimensional (3D mixed-ligand coordination polymers (CPs having formulas, {[Zn2(bdc2(4-bpdh]·C2H5OH·2H2O}n (1, [Zn(bdc(4-bpdh]n (2, {[Zn2(bdc2(4-bpdh2]·(4-bpdh}n (3, and {[Zn(bdc(4-bpdh]·C2H5OH}n (4 (bdc2− = dianion of 1,4-benzenedicarboxylic acid, 4-bpdh = 2,5-bis(4-pyridyl-3,4-diaza-2,4-hexadiene have been synthesized and structurally characterized by single-crystal X-ray diffraction method. Structural determination reveals that the coordination numbers (geometry of Zn(II ions in 1, 2, 3, and 4 are five (distorted square-pyramidal (SP, six (distorted octahedral (Oh, five (trigonal-bipyramidal (TBP, and four (tetrahedral (Td, respectively, and are bridged by 4-bpdh with bis-monodentate coordination mode and bdc2− ligands with bis-bidentate in 1, chelating/bidentate in 2, bis-monodentate and bis-bidentate in 3, and bis-monodentate in 4, to generate two-fold interpenetrating 3D cube-like metal-organic framework (MOF with pcu topology, non-interpenetrating 3D MOF, two-fold interpenetrating 3D rectangular-box-like MOF with pcu topology and five-fold interpenetrating diamondoid-like MOF with dia topology, respectively. These different intriguing architectures indicate that the coordination numbers and geometries of Zn(II ions, coordination modes of bdc2− ligand, and guest molecules play important roles in the construction of MOFs and the formation of the structural topologies and interpenetrations. Thermal stabilities, and photoluminescence study of 1–4 were also studied in detail. The complexes exhibit ligands based photoluminescence properties at room temperature.

Reaction of Pb(II) and Zn(II) with Ethyl Linoleate To Form Structured Hybrid Inorganic–Organic Complexes: A Model for Degradation in Historic Paint Films

Energy Technology Data Exchange (ETDEWEB)

MacDonald, Margaret G.; Palmer, Michael R.; Suchomel, Matthew R.; Berrie, Barbara H. (NGA); (Bordeaux)

2016-09-23

To investigate soap formation in drying oils in historic paints, the reaction between metal acetates (K⁺, Zn²⁺, Pb²⁺) and ethyl linoleate (EL) was studied using optical microscopy, X-ray powder diffraction, and electron microscopy. Pb(II) and Zn(II) react rapidly with EL to form highly structured, spherulitic, luminescent crystallites that aggregate. Evidence from Fourier transform infrared (FTIR) and scanning electron microscopy/energy dispersive X-ray analysis and high-resolution synchrotron powder X-ray diffraction indicates that these are organic–inorganic hybrid complexes or coordination polymers. FTIR absorbance peaks at ca. 1540 cm^–1 for Pb(II) and ca. 1580 cm^–1 for Zn(II) are consistent with the formation of carboxylate complexes. The complexes formed offer insight into the degradation processes observed in oil paint films, suggesting that soap formation is rapid when metal ions are solubilized and can occur with unsaturated fatty acids that are present in fresh oils. These complexes may account for the atypical luminescence observed in lead-containing cured oil paint films.

Electrospray ionization mass spectrometric investigations of the complexation behavior of macrocyclic thiacrown ethers with bivalent transitional metals (Cu, Co, Ni and Zn).

Science.gov (United States)

Tsybizova, Alexandra; Tarábek, Ján; Buchta, Michal; Holý, Petr; Schröder, Detlef

2012-10-15

Heavy metals are both a problem for the environment and an important resource for industry. Their selective extraction by means of organic ligands therefore is an attractive topic. The coordination of three thiacrown ethers to late 3d-metal ions was investigated by a combination of electrospray ionization mass spectrometry (ESI-MS) and electron paramagnetic resonance (EPR). The mass spectrometric experiments were carried out in an ion trap mass spectrometer with an ESI source. Absolute binding constants were estimated by comparison with data for 18-crown-6/Na(+). EPR spectroscopy was used as a complementary method for investigating the Cu(I) /Cu(II) redox couple. The study found that thiacrown ethers preferentially bind traces of copper even at an excess of other metal ions (Co(II), Ni(II), and Zn(II)). The absolute association constants of the Cu(I) complexes were about 10(8) M(-1), and about two orders of magnitude lower for the other 3d-metal cations. The EPR spectra demonstrated that the reduction from Cu(II) to Cu(I) upon formation of the [(thiacrown)Cu](+) species takes place in solution. ESI-MS demonstrated that the three thiacrown ligands examined had high binding constants as well as good selectivities for copper(I) at low concentrations, and in the presence of other metal ions. By a combination of ESI-MS and EPR spectrometry it was shown that the reduction from Cu(II) to Cu(I) occurred in solution. Copyright © 2012 John Wiley & Sons, Ltd.

Synthesis, Characterization and Antimicrobial Activity of Cu(II, Co(II and Ni(II Complexes with O, N, and S Donor Ligands

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Vidyavati Reddy

2008-01-01

Full Text Available The complexes of the type ML2 [where M = Cu(II, Co(II, and Ni(II] L = 1-phenyl-1-ene-3-(2-hydroxyphenyl-prop-2-ene with 3- substituted-5-mercapto-4-amino-1,2,4-triazoles. Schiff base ligands have been prepared by reacting 3-(2-hydroxyphenyl-1-phenylprop-2-en-1-one and 3-phenyl/pyridyl-4-amino-5-mercapto-1,2,4-triazoles in an alcoholic medium. The complexes are non-electrolytes in DMF. The resulting complexes were characterized by elemental analysis, magnetic measurements, conductivity measurements and spectral studies. The Schiff base acts as a tridentate dibasic and coordinating through the deprotonated oxygen, thioenolic sulphur and azomethine nitrogen atoms. It is found that Cu(II, Co(II, and Ni(II complexes exhibited octahedral geometry. The antimicrobial activities of ligands and its complexes were screened by cup plate method.

Efficient simultaneous removal of U(VI) and Cu(II) from aqueous solution using core-shell nZVI@SA/CMC-Ca beads

International Nuclear Information System (INIS)

Shuhong Hu; Xiaoyan Lin; Wenhui Zhao; Ministry of Education, Sichuan; Xuegang Luo

2018-01-01

Core-shell nanoscale zero-valent iron@alginate/carboxymethyl cellulose sodium composite loaded with calcium (nZVI@SA/CMC-Ca) beads were synthesized in this study using coaxial electronic injection method. The adsorbent structure was characterized via FT-IR, SEM, EDX and XPS. The adsorption behavior of U(VI) and Cu(II) on core-shell nZVI@SA/CMC-Ca beads was studied under various experimental parameters like pH, contact time and temperature. The isotherm and the kinetic data, pertaining to the adsorption of U(VI) and Cu(II) by core-shell nZVI@SA/CMC-Ca beads obeyed both the Langmuir and Freundlich isotherms model and the pseudo-second-order kinetics model, respectively. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption. The experiment of regeneration and reusability suggested core-shell nZVI@SA/CMC-Ca bead was a regenerated material. (author)

Development of a Novel Cu(II Complex Modified Electrode and a Portable Electrochemical Analyzer for the Determination of Dissolved Oxygen (DO in Water

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Salvatore Gianluca Leonardi

2016-04-01

Full Text Available The development of an electrochemical dissolved oxygen (DO sensor based on a novel Cu(II complex-modified screen printed carbon electrode is reported. The voltammetric behavior of the modified electrode was investigated at different scan rates and oxygen concentrations in PBS (pH = 7. An increase of cathodic current (at about −0.4 vs. Ag/AgCl with the addition of oxygen was observed. The modified Cu(II complex electrode was demonstrated for the determination of DO in water using chronoamperometry. A small size and low power consumption home-made portable electrochemical analyzer based on custom electronics for sensor interfacing and operating in voltammetry and amperometry modes has been also designed and fabricated. Its performances in the monitoring of DO in water were compared with a commercial one.

Adsorption of heavy metal ions on molybdenum and molybdenum trioxide from dilute aqueous solution

International Nuclear Information System (INIS)

Utsunomiya, Taizo; Hoshino, Yoshio; Sakabe, Ken-ichi

1984-01-01

The adsorption of heavy metal ions such as Co(II), Cu(II) and Pb(II) on molybdenum powder has been investigated by the batch technique as a function of soaking time, concentration of heavy metal ions and coexisting salts, pH etc. Molybdenum trioxide was also used as an adsorbent for a comparison to discuss the adsorption mechanism. The amount of these heavy metal ions adsorbed was highly pH and coexisting salts dependent. These adsorbents have features of selective adsorption for Pb(II) and large adsorption rate. The adsorption of heavy metal ions on these adsorbents proceeds independently or concurrently by following complex mechanism; (1) cation exchange reaction by hydroxyl radical on the surface of Mo and MoO 3 is predominant for most of heavy metal ions except Pb(II) [Co(II), Mn(II), Fe(III), Ni(II), Zn(II), Cd(II) and Sr(II)], (2) reduction (electron exchange reaction) to low ionic or metallic state after cation exchange reaction [Cu(II) and Ag(I) on Mo] and (3) formation of a compound [Pb(II) on both Mo and MoO 3 ]. (author)

New sample preparation method based on task-specific ionic liquids for extraction and determination of copper in urine and wastewater.

Science.gov (United States)

Trtić-Petrović, Tatjana; Dimitrijević, Aleksandra; Zdolšek, Nikola; Đorđević, Jelena; Tot, Aleksandar; Vraneš, Milan; Gadžurić, Slobodan

2018-01-01

In this study, four hydrophilic ionic liquids (ILs) containing 1-alkyl-3-methylimidazolim cation and either salicylate or chloride anions were synthetized and studied as new task-specific ionic liquids (TSILs) suitable for aqueous biphasic system (ABS) formation and selective one-step extraction of copper(II). TSILs are designed so that the anion is responsible for forming the complex with metal(II) and preventing hydrolysis of metal cations at very strong alkaline pH, whereas the cation is responsible for selective extraction of metal(II)-salicylate complexes. It was found that 1-butyl-3-methylimidazolium salicylate could be used for selective extraction of Cu(II) in the presence of Zn(II), Cd(II), and Pb(II) at very alkaline solution without metal hydroxide formation. It was assumed that formation of metal(II)-salicylate complexes prevents the hydrolysis of the metal ions in alkaline solutions. The determined stability constants for Cu(II)-salicylate complexes, where salicylate was derived from different ionic liquids, indicated that there was no significant influence of the cation of the ionic liquid on the stability of the complexes. The ABS based on 1-butyl-3-methylimidazolium salicylate has been applied as the sample preparation step prior to voltammetric determination of Cu(II). The effect of volume of aqueous sample and IL and extraction time were investigated and optimum extraction conditions were determined. The obtained detection limits were 8 ng dm -3 . The optimized method was applied for the determination of Cu(II) in tap water, wastewater, and urine. The study indicated that application of the ABS based on 1-butyl-3-methylimidazolium salicylate ionic liquid could be successfully applied as the sample preparation method for the determination of Cu(II) from various environmental samples. Graphical abstract Aqueous biphasic system based on task-specific ionic liquid as a sample pretreatment for selective determination of Cu(II) in biological and

Theoretical study of the magnetic behavior of hexanuclear Cu(II) and Ni(II) polysiloxanolato complexes.

Science.gov (United States)

Ruiz, Eliseo; Cano, Joan; Alvarez, Santiago; Caneschi, Andrea; Gatteschi, Dante

2003-06-04

A theoretical density functional study of the exchange coupling in hexanuclear polysiloxanolato-bridged complexes of Cu(II) and Ni(II) is presented. By calculating the energies of three different spin configurations, we can obtain estimates of the first-, second-, and third-neighbor exchange coupling constants. The study has been carried out for the complete structures of the Cu pristine cluster and of the chloroenclathrated Ni complex as well as for the hypotethical pristine Ni compound and for magnetically dinuclear analogues M(2)Zn(4) (M = Cu, Ni).

Insolubilization of Chestnut Shell Pigment for Cu(II Adsorption from Water

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Zeng-Yu Yao

2016-03-01

Full Text Available Chestnut shell pigment (CSP is melanin from an agricultural waste. It has potential as an adsorbent for wastewater treatment but cannot be used in its original state because of its solubility in water. We developed a new method to convert CSP to insolubilized chestnut shell pigment (ICSP by heating, and the Cu(II adsorption performance of ICSP was evaluated. The conversion was characterized, and the thermal treatment caused dehydration and loss of carboxyl groups and aliphatic structures in CSP. The kinetic adsorption behavior obeyed the pseudo-second-order rate law, and the equilibrium adsorption data were well described with both the Langmuir and the Freundlich isotherms. ICSP can be used as a renewable, readily-available, easily-producible, environmentally-friendly, inexpensive and effective adsorbent to remove heavy-metal from aquatic environments.

Effect of the competition of Cu(II) and Ni(II) on the kinetic and thermodynamic stabilities of Cr(III)-organic ligand complexes using competitive ligand exchange (EDTA).

Science.gov (United States)

Cunha, Graziele da Costa; Goveia, Danielle; Romão, Luciane Pimenta Cruz; de Oliveira, Luciana Camargo

2015-05-01

The effect of competition of Cu(II) and Ni(II) on the kinetic stability of Cr(III) complexed with natural organic matter (NOM) was characterized using EDTA exchange with single-stage tangential-flow ultrafiltration. For a water sample from Serra de Itabaiana, 3% of spiked Cr(III) was exchanged, while for a sample from the Itapanhaú River, 7, 10, 10, and 21% was exchanged in experiments using Cr(III) alone and in combination with Cu(II), Ni(II), or Cu(II) + Ni(II), respectively. Times required to reach exchange equilibrium with EDTA were less than 360 min. The influence of competition from Ni(II) and Cu(II) on the availability of complexed Cr(III) was low, demonstrating preference of the ligand sites for Cr(III). This was correlated with sample humification, as confirmed by EPR and (13)C NMR analyses. Exchange efficiency was in the order Cu > Ni > Cr, and the process could be readily described by first order kinetics, with average rate constants of 0.35-0.37 h(-1). Copyright © 2015 Elsevier Ltd. All rights reserved.

Base Catalytic Approach: A Promising Technique for the Activation of Biochar for Equilibrium Sorption Studies of Copper, Cu(II Ions in Single Solute System

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Sharifah Bee Abdul Hamid

2014-04-01

Full Text Available This study examines the feasibility of catalytically pretreated biochar derived from the dried exocarp or fruit peel of mangostene with Group I alkali metal hydroxide (KOH. The pretreated char was activated in the presence of carbon dioxide gas flow at high temperature to upgrade its physiochemical properties for the removal of copper, Cu(II cations in single solute system. The effect of three independent variables, including temperature, agitation time and concentration, on sorption performance were carried out. Reaction kinetics parameters were determined by using linear regression analysis of the pseudo first, pseudo second, Elovich and intra-particle diffusion models. The regression co-efficient, R2 values were best for the pseudo second order kinetic model for all the concentration ranges under investigation. This implied that Cu(II cations were adsorbed mainly by chemical interactions with the surface active sites of the activated biochar. Langmuir, Freundlich and Temkin isotherm models were used to interpret the equilibrium data at different temperature. Thermodynamic studies revealed that the sorption process was spontaneous and endothermic. The surface area of the activated sample was 367.10 m2/g, whereas before base activation, it was only 1.22 m2/g. The results elucidated that the base pretreatment was efficient enough to yield porous carbon with an enlarged surface area, which can successfully eliminate Cu(II cations from waste water.

SPE coupled to AAS trace determination of Cd(II) and Zn(II) in food samples using amine functionalized GMA-MMA-EGDMA terpolymer: Isotherm and kinetic studies.

Science.gov (United States)

Islam, Aminul; Kumar, Suneel; Zaidi, Noushi; Ahmad, Hilal

2016-12-15

An ethylenediamine functionalized glycidyl methacrylate (GMA) based terpolymeric chelating resin was synthesized for the separation and preconcentration of Cd(II) and Zn(II) by SPE from bread, rice and fruit juice prior to FAAS determination. The resin was characterized by FT-IR, TGA/DTA, SEM, BET analysis and EDS. Synthesized resin shows a good capacity of 53.96mgg(-1) for Cd(II) and 24.19mgg(-1) for Zn(II) at pH 8.0. Five isotherm equilibrium models were studied to explain the sorption phenomenon out of which Langmuir, Dubinin-Radushkevich, Scatchard and Temkin models were found to be the best fitted. The limit of detection (LOD) and limit of quantification (LOQ) were observed to be 1.5 and 5.1μgL(-1) for Cd and 1.2 and 4.1μgL(-1) for Zn. The reliability of the method was investigated by the analysis of SRM and the recovery of analytes from various spiked food samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Influence of Pyrolytic Temperature on Sorption Ability of Carbon Xerogel Based on 3-Aminophenol-formaldehyde Polymer for Cu(II) Ions and Phenol.

Czech Academy of Sciences Publication Activity Database

Veselá, P.; Slovák, V.; Zelenka, T.; Koštejn, Martin; Mucha, M.

2016-01-01

Roč. 121, SEP (2016), s. 29-40 ISSN 0165-2370 Institutional support: RVO:67985858 Keywords : temperature of pyrolysis * sorption mechanism * Cu(II) ions Subject RIV: CI - Industrial Chemistry , Chemical Engineering Impact factor: 3.471, year: 2016

SEPARATION OF Fe (III, Cr(III, Cu(II, Ni(II, Co(II, AND Pb(II METAL IONS USING POLY(EUGENYL OXYACETIC ACID AS AN ION CARRIER BY A LIQUID MEMBRANE TRANSPORT METHOD

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La Harimu

2010-06-01

Full Text Available Fe (III, Cr(III, Cu(II, Ni(II, Co(II, and Pb(II  metal ions had been separated using poly(eugenyl oxyacetic acid as an ion carrier by bulk liquid membrane transport method. The effect of pH, polyeugenyl oxyacetic acid ion carrier concentration, nitric acid concentration in the stripping solution, transport time, and metal concentration were optimized. The result showed that the optimum condition for transport of metal ions was at pH 4 for ion Fe(III and at pH 5 for Cr(III, Cu(II, Ni(II, Co(II, and Pb(II ions. The carrier volumes were optimum with concentration of 1 x 10-3 M at 7.5 mL for Cr(III, Cu (II,  Ni(II, Co(II ions and at 8.5 mL for Fe(III and Pb(II ions. The concentration of HNO3 in stripping phase was optimum at 2 M for Fe(III and Cu(II ions, 1 M for Cr(III, Ni(II and Co(II ions, and 0.5 M for Pb(II ion. The optimum transport times were 36 h for Fe(III and Co(II ions, and 48 h for Cr(III, Cu (II, Ni(II, and Pb(II ions. The concentration of metal ions accurately transported were 2.5 x 10-4 M for Fe(III and Cr(III ions, and 1 M for Cu (II, Ni(II, Co(II, and Pb(II ions. Compared to other metal ions the transport of Fe(III was the highest with selectivity order of Fe(III > Cr(III > Pb(II > Cu(II > Ni(II > Co(II. At optimum condition, Fe(III ion was transported through the membrane at 46.46%.   Keywords: poly(eugenyl oxyacetic acid, transport, liquid membrane, Fe (III, Cr(III, Cu(II, Ni(II, Co(II, and Pb(II ions

CFA-13 - a bifunctional perfluorinated metal-organic framework featuring active Cu(i) and Cu(ii) sites.

Science.gov (United States)

Fritzsche, J; Denysenko, D; Grzywa, M; Volkmer, D

2017-11-07

The synthesis and crystal structure of the mixed-valent perfluorinated metal-organic framework (Me 2 NH 2 )[CFA-13] (Coordination Framework Augsburg University-13), (Me 2 NH 2 )[CuCu(tfpc) 4 ] (H 2 -tfpc = 3,5-bis(trifluoromethyl)-1H-pyrazole-4-carboxylic acid) is described. The copper-containing MOF crystallizes in the monoclinic crystal system within the space group P2 1 /n (no. 14) and the unit cell parameters are as follows: a = 22.3887(19), b = 13.6888(8), c = 21.1804(13) Å, β = 90.495(3)°, V = 6491.0(8) Å 3 . (Me 2 NH 2 )[CFA-13] features a porous 3-D structure constructed from two types of secondary building units (SBUs). Besides novel trinuclear [Cu(pz) 4 ] - coordination units, the network also exhibits Cu(ii) paddle-wheel SBUs. (Me 2 NH 2 )[CFA-13] is fully characterized by single crystal X-ray diffraction, thermogravimetric analysis, variable temperature powder X-ray diffraction, IR spectroscopy, photoluminescence, gas sorption measurements and pulse chemisorption experiments. M[CFA-13] (M = K + , Cs + ) frameworks were prepared by postsynthetic exchange of interchannel dimethylammonium cations. Moreover, it was shown that CO molecules can be selectively bound at Cu(i) sites of [Cu(pz) 4 ] - units, whereas Cu(ii) paddle-wheel units bind selectively NH 3 molecules.

Modeling of solvent extraction equilibrium of Cu(II from sulphuric Acid solution with MOC-55TD

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Alguacil, F. J.

1999-06-01

Full Text Available The extraction of Cu(II from acidic sulphate aqueous solutions using the commercial MOC-55TD extractant is studied. A predictive model, which consists in a set of non-linear mass action and mass balance equations is proposed. The model was solved using a tailor-made equation-solving program. The extraction of copper can be described by the formation of CuR₂ species (log K_ext= 0.717 ± 0.03 in the organic phase. The copper equilibrium isotherm was also obtained at 20°C.

Se estudia la extracción de Cu(II de disoluciones acuosas acidas, en medio sulfato, mediante la oxima comercial MOC-55TD. Se propone un modelo para predecir la extracción del metal; este modelo consiste en una serie de ecuaciones no lineales de acción de masas y balance de masas. El modelo se resolvió empleando un programa de ordenador específicamente definido para este tipo de equilibrios. La extracción de cobre se describe por la formación de la especie CuR₂ (log K_ext= 0,717 ± 0,03 en la fase orgánica. Se ha obtenido la isoterma de extracción de cobre a 20 °C.

Kinetic studies of the impact of thiocyanate moiety on the catalytic properties of Cu(II) and Fe(III) complexes of a new Mannich base

Science.gov (United States)

Ayeni, Ayowole O.; Watkins, Gareth M.

2018-04-01

Four new metal complexes of a novel Mannich base 5-methyl-2-((4-(pyridin-2-yl)piperazin-1-yl)methyl)phenol (HL) have been prepared. The compounds were characterized by an array of analytical and spectroscopic methods including Nuclear Magnetic Resonance, Infra-red and UV-Visible spectroscopy. Compounds 1-4 behaved as effective catalysts towards the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to its corresponding quinone in the presence of molecular oxygen in DMF solution while compound 4 proved to be the best catalyst with a turnover rate of 17.93 ± 1.10 h-1 as other complexes showed lower rates of oxidation. Also with the exception of dinuclear iron complex (4); thiocyanate containing Cu(II) complex exhibited lower catecholase activity compared to the Cu(II) complex without it.

A new photoactive Ru(II)tris(2,2'-bipyridine) templated Zn(II) benzene-1,4-dicarboxylate metal organic framework: structure and photophysical properties.

Science.gov (United States)

Whittington, Christi L; Wojtas, Lukasz; Gao, Wen-Yang; Ma, Shengqian; Larsen, Randy W

2015-03-28

It has now been demonstrated that Ru(ii)tris(2,2'-bipyridine) (RuBpy) can be utilized to template the formation of new metal organic framework (MOF) materials containing crystallographically resolved RuBpy clusters with unique photophysical properties. Two such materials, RWLC-1 and RWLC-2, have now been reported from our laboratory and are composed of RuBpy encapsulated in MOFs composed of Zn(ii) ions and 1,3,5-tris(4-carboxyphenyl)benzene ligands (C. L. Whittington, L. Wojtas and R. W. Larsen, Inorg. Chem., 2014, 53, 160-166). Here, a third RuBpy templated photoactive MOF is described (RWLC-3) that is derived from the reaction between Zn(ii) ions and 1,4-dicarboxybenzene in the presence of RuBpy. Single Crystal X-ray diffraction studies determined the position of RuBpy cations within the crystal lattice. The RWLC-3 structure is described as a 2-fold interpenetrated pillared honeycomb network (bnb) containing crystallographically resolved RuBpy clusters. The two bnb networks are weakly interconnected. The encapsulated RuBpy exhibits two emission decay lifetimes (τ-fast = 120 ns, τ-slow = 453 ns) and a bathochromic shift in the steady state emission spectrum relative to RuBpy in ethanol.

Synthesis, characterization, density functional study and antimicrobial evaluation of a series of bischelated complexes with a dithiocarbazate Schiff base ligand

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E. Zangrando

2017-02-01

Full Text Available A nitrogen-sulfur Schiff base HL (1 derived from S-hexyldithiocarbazate and 4-methylbenzaldehyde has been reacted with different divalent metal ions in 2:1 molar ratio, producing neutral complexes (2–7 of general formula MIIL2 (where M = Ni, Cu, Zn, Cd, Pd and Pb. All compounds were characterized using established physico-chemical and spectroscopic methods. The single crystal structures of CuII and ZnII complexes are compared and discussed with those of NiII and PdII already reported by us, underlining the geometrical variations occurring in the HL ligand upon coordination. The metal complexes, as revealed by the X-ray diffraction analyses, show a square planar or tetrahedral coordination geometry, and in the former case either a cisoid or transoid configuration of chelating ligands. Density functional theory (DFT and time-dependent density functional theory (TD-DFT calculations have been performed on the isolated cis/trans complexes of Ni and Pd complexes in order to evaluate the stability of the isomer isolated in solid state. The thermodynamic parameters for trans to cis isomerization of NiL2 complex [ΔH = −29.12 kJ/mol and ΔG = −43.97 kJ/mol] indicated that the trans isomer (observed in solid state is more stable than the cis one. On the other hand, relative enthalpy [ΔH = −4.37 kJ/mol] and Gibbs free energy [ΔG = −5.50 kJ/mol] of PdL2 complex disclosed a small difference between the energies of the two isomers. Experimental UV–vis and TD-DFT calculation confirmed that these complexes have distinctive LMCT bands with a broad shoulder at 400–550 nm. With the purpose of providing insight into the properties and behavior of the complexes in solution, photoluminescence and electrochemical experiments have been also performed. Finally, the anti-bacterial activity of these compounds was evaluated against three pathogenic Gram-negative organisms such as Escherichia coli, Salmonella typhi and Shigella flexneri, but

Evaluating Design Parameters for Breakthrough Curve Analysis and Kinetics of Fixed Bed Columns for Cu(II Cations Using Lignocellulosic Wastes

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Zaira Zaman Chowdhury

2014-12-01

Full Text Available A continuous adsorption study for removal of Cu(II cations from wastewater using a fixed-bed column was conducted. A granular carbonaceous activated adsorbent produced by carbonization of the outer rind, or exocarp, of mangostene fruit shell was used for column packing. The effects of feed flow rate, influent cation concentration, and bed depth on the breakthrough curve were investigated at pH 5.5. Experimental analysis confirmed that the breakthrough curves were dependent on flow rate, initial concentration of Cu(II cations, and bed height related to the amount of activated carbon used for column packing. Thomas, Yoon–Nelson, and Adams–Bohart models were applied to analyze the breakthrough curves at different conditions. Linear regression analysis of experimental data demonstrated that Thomas and Yoon–Nelson models were appropriate to explain the breakthrough curve, while the Adams–Bohart model was only applicable to predict the initial part of the dynamic process. It was concluded that the column packed with fruit rind based activated carbon can be used to treat Cu(II-enriched wastewater.

Estudio de los mecanismos de activación de la esfalerita con Cu(II y Pb(II

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Dávila Pulido, G. I.

2011-08-01

Full Text Available This article presents results of an experimental study on the sphalerite activation with Cu(II and Pb(II, whose main objective was to investigate the activation mechanisms and to evaluate the magnitude of the hydrophobization achieved with both chemical species. The hydrophobicity acquired by the mineral due to the interaction with the activator and collector (sodium isopropyl xanthate is characterized making use of the contact angle technique. The results show that Cu(II replaces the Zn of the external layers of the mineral, promoting the sulfide (S^2– oxidation to produce a mixture of CuS, Cu₂S and S°, of hydrophobic nature. The subsequent interaction with xanthate increases the hydrophobicity of the mineral surface. In turn, Pb(II activation of sphalerite is due to the formation of a PbS layer that reacts with xanthate to produce hydrophobic species (e.g., PbX₂. It is also observed that the hydrophobicity of sphalerite activated with Pb(II is favored under air atmospheres, as compared to that obtained under nitrogen atmospheres. It is concluded that the hydrophobicity achieved by lead activation may be of the same order of magnitude to that deliverately induced by copper activation.

Este artículo presenta los resultados de un estudio experimental sobre la activación de esfalerita (ZnS con Cu(II y Pb(II, cuyo objetivo principal consistió en investigar los mecanismos de activación y en evaluar la magnitud relativa de la hidrofobización alcanzada con ambas especies químicas. La hidrofobicidad que la superficie mineral adquiere como resultado de la interacción con los activadores y colectores tipo xantato (ditiocarbonatos alquílicos, R-O-CS₂ –, se caracteriza mediante la técnica del ángulo de contacto. Los resultados muestran que el Cu(II es intercambiado por el Zn de las capas exteriores del cristal, promoviendo la oxidación de sulfuro (S^2– para producir una mezcla de

Anti-inflammatory drugs interacting with Zn(II), Cd(II) and Pt(II) metal ions.

Science.gov (United States)

Dendrinou-Samara, C; Tsotsou, G; Ekateriniadou, L V; Kortsaris, A H; Raptopoulou, C P; Terzis, A; Kyriakidis, D A; Kessissoglou, D P

1998-09-01

Complexes of Zn(II), Cd(II) and Pt(II) metal ions with the anti-inflammatory drugs, 1-methyl-5-(p-toluoyl)-1H-pyrrole-2-acetic acid (Tolmetin), alpha-methyl-4-(2-methylpropyl)benzeneacetic acid (Ibuprofen), 6-methoxy-alpha-methylnaphthalene-2-acetic acid (Naproxen) and 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid (indomethacin) have been synthesized and characterized. In the structurally characterized Cd(naproxen)2 complex the anti-inflammatory drugs acts as bidentate chelate ligand coordinatively bound to metal ions through the deprotonated carboxylate group. Crystal data for 1: [C32H26O8Cd], orthorhombic, space group P22(1)2(1), a = 5.693(2) (A), b = 8.760(3) (A), c = 30.74(1) (A), V = 1533(1) A3, Z = 2. Antibacterial and growth inhibitory activity is higher than that of the parent ligands or the platinum(II) diamine compounds.

Using chiral ionic liquid additives to enhance asymmetric induction in a Diels-Alder reaction.

Science.gov (United States)

Goodrich, P; Nimal Gunaratne, H Q; Hall, L; Wang, Y; Jin, L; Muldoon, M J; Ribeiro, A P C; Pombeiro, A J L; Pârvulescu, V I; Davey, P; Hardacre, C

2017-01-31

A bis-oxazoline ligand has been complexed using Cu(ii) and Zn(ii) trifluoromethanesulfonate and a range of chiral ionic liquid (CIL) additives based on natural products were used as a co-catalyst for a Diels-Alder reaction. The catalytic performance of these systems was compared for the asymmetric Diels-Alder reaction between N-acryloyloxazolidinone and cyclopentadiene with and without the presence of a CIL additive. In the absence of the CIL, both catalysts resulted in low enantioselectivities in conventional solvents and ionic liquids. However, whilst only a minor effect of the CIL was observed for the Cu based catalyst, in the case of the Zn based catalyst, significant enhancements in endo enantioselectivity of up to 50% were found on the addition of a CIL.

Purification of Industrial Phosphoric Acid using Silica Produced from Rice Husk (Part 1)

International Nuclear Information System (INIS)

Gad, H.M.H.; Awwad, N.S.; El-Khalafawy, A.; Daifullah, A.A.M.; El-Reefy, S.A.; Aly, H.F.

2008-01-01

In this work, silica was extracted from rice husk (RH) by different techniques and used for removal of some heavy metals from industrial phosphoric acid. The data obtained, showed that removal of Cu(II), Cd(II) and Pb(II) is efficient when the silica used is obtained by acidic treatment, while the removal of Fe(III) and Zn(II) is efficient when the silica used was obtained by alkaline treatment of RH. On the other hand, if silica used is obtained from rice husk ash (RHA) it was found more efficient for the removal of Mn. In all cases, the concentration of silica has been characterized by UV-Spectrophotometry. FTIR, SEM and EDX were used for predication of sorption mechanism

Structurally flexible and solution stable [Ln₄TM₈(OH)₈(L)₈(O₂CR)₈(MeOH)_y](ClO₄)₄

DEFF Research Database (Denmark)

Hooper, Thomas N.; Inglis, Ross; Lorusso, Giulia

2016-01-01

the predominant antiferromagnetic interactions in 2a yield an inverse magnetocaloric effect; that is, the temperature increases on lowering the applied field, under the proper experimental conditions. In spite of increasing the magnetic density by adding ions that bring in antiferromagnetic interactions (2a...... effect evolves by introducing either antiferromagnetic or ferromagnetic interactions, or magnetic anisotropy, by substituting the nonmagnetic ZnII (1a) with CuII (2a), NiII (6a) or CoII (7a), respectively. The largest magnetocaloric effect is found for the ferromagnetically coupled complex 6a, while......) or magnetic anisotropy (7a), the magnetocaloric effect is overall smaller in 2a and 7a than in 1a, where only four GdIII spins per molecule contribute to the magnetocaloric properties....

Synthesis, spectroscopic, biological activity and thermal characterization of ceftazidime with transition metals

Science.gov (United States)

Masoud, Mamdouh S.; Ali, Alaa E.; Elasala, Gehan S.; Kolkaila, Sherif A.

2018-03-01

Synthesis, physicochemical characterization and thermal analysis of ceftazidime complexes with transition metals (Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)) were discussed. It's obtained that ceftazidime act as bidentate ligand. From magnetic measurement and spectral data, octahedral structures were proposed for all complexes except for cobalt, nickel and mercury had tetrahedral structural. Hyper chemistry program confirmed binding sites of ceftazidime. Ceftazidime complexes show higher activity than ceftazidime for some strains. From TG and DTA curves the thermal decomposition mechanisms of ceftazidime and their metal complexes were suggested. The thermal decomposition of the complexes ended with the formation of metal oxides as a final product except in case of Hg complex.

Synthesis, characterization and anti-fungal evaluation of Ni(II and Cu(II complexes with a derivative of 4-aminoantipyrine

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Monika Tyagi

2017-01-01

Full Text Available Transition metal complexes of Ni(II and Cu(II metal ions with the general stoichiometry [M(LX]X and [M(LSO4], where M = Ni(II and Cu(II, L = (1E-N-((5-((E-(2,3-dimethyl-1-phenyl-4-pyrazolineiminomethylthiophen-2-ylmethylene-2,3-dimethyl-1-phenyl-4-pyrazolineamine and X = Cl−, NO3− and SO42−, have been synthesized and characterized. The synthesized ligand and metal complexes were characterized by 1H NMR, IR, mass spectrometry, UV–Vis spectra and EPR. In molecular modelling, the geometries of the Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p basis set. The nickel(II complexes were found to have octahedral geometry, whereas the copper(II complexes were of tetragonal geometry. The covalency factor (β and orbital reduction factor (k suggest the covalent nature of the complexes. To develop broad spectrum new molecules against seed-borne fungi, the minimum inhibitory concentration (MIC of the ligand and its metal complexes was evaluated by the serial dilution method.

Pt(II) and Pd(II) complexes with ibuprofen hydrazide: Characterization, theoretical calculations, antibacterial and antitumor assays and studies of interaction with CT-DNA

Science.gov (United States)

Manzano, Carlos M.; Bergamini, Fernando R. G.; Lustri, Wilton R.; Ruiz, Ana Lúcia T. G.; de Oliveira, Ellen C. S.; Ribeiro, Marcos A.; Formiga, André L. B.; Corbi, Pedro P.

2018-02-01

Palladium(II) and platinum(II) complexes with a hydrazide derivative of ibuprofen (named HIB) were synthesized and characterized by chemical and spectroscopic methods. Elemental and thermogravimetric analyses, as well as ESI-QTOF-MS studies for both complexes, confirmed a 1:2:2 metal/HIB/Cl- molar ratio. The crystal structure of the palladium(II) complex was solved by single crystal X-ray diffractometric analysis, which permitted identifying the coordination formula [PdCl2(HIB)2]. Crystallographic studies also indicate coordination of HIB to the metal by the NH2 group. Nuclear magnetic resonance and infrared spectroscopies reinforced the coordination observed in the crystal structure and suggested that the platinum(II) complex presents similar coordination modes and structure when compared with the Pd(II) complex. The complexes had their structures optimized with the aid of DFT methods. In vitro antiproliferative assays showed that the [PdCl2(HIB)2] complex is active over ovarian cancer cell line OVCAR-03, while biophysical studies indicated its capacity to interact with CT-DNA. The complexes were inactive over Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa bacterial strains.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

International Nuclear Information System (INIS)

Monier, M.; Ayad, D.M.; Sarhan, A.A.

2010-01-01

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

Antioxidant, electrochemical, thermal, antimicrobial and alkane oxidation properties of tridentate Schiff base ligands and their metal complexes

Science.gov (United States)

Ceyhan, Gökhan; Çelik, Cumali; Uruş, Serhan; Demirtaş, İbrahim; Elmastaş, Mahfuz; Tümer, Mehmet

2011-10-01

In this study, two Schiff base ligands (HL 1 and HL 2) and their Cu(II), Co(II), Ni(II), Pd(II) and Ru(III) metal complexes were synthesized and characterized by the analytical and spectroscopic methods. Alkane oxidation activities of the metal complexes were studied on cyclohexane as substrate. The ligands and their metal complexes were evaluated for their antimicrobial activity against Corynebacterium xerosis, Bacillus brevis, Bacillus megaterium, Bacillus cereus, Mycobacterium smegmatis, Staphylococcus aureus, Micrococcus luteus and Enterococcus faecalis (as Gram-positive bacteria) and Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Yersinia enterocolitica, Klebsiella fragilis, Saccharomyces cerevisiae, and Candida albicans (as Gram-negative bacteria). The antioxidant properties of the Schiff base ligands were evaluated in a series of in vitro tests: 1,1-diphenyl-2-picrylhydrazyl (DPPH rad ) free radical scavenging and reducing power activity of superoxide anion radical generated non-enzymatic systems. Electrochemical and thermal properties of the compounds were investigated.

Synthesis, Spectral Analysis and Preliminary in Vitro Evaluation of Some Tetrapyrrolic Complexes with 3d Metal Ions

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Radu Socoteanu

2015-08-01

Full Text Available In this paper, two tetrapyrrolic complexes, Zn(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin and Cu(II-5-(3-hydroxyphenyl-10,15,20-tris-(4-acetoxy-3-methoxyphenylporphyrin were synthesized, and characterized from a spectral and biological point of view. The study provided data concerning the behavior of identical external substituents vs. two different core insertions. Some of the properties of the proposed tetrapyrrolic structures were highlighted, having photodynamic therapy of cancer as a targeted biomedical application. Elemental analysis, NMR, FTIR and UV-Vis data in various solvents were provided. A preliminary in vitro study on normal and cancer cultured cells was carried out for biocompatibility assessment in dark conditions. The preliminary in vitro study performed on human peripheral mononuclear cells exposed to tetrapyrrolic compounds (2 µM showed that the proposed compounds had a convenient cytotoxic profile on human normal peripheral blood mononuclear cells under dark conditions. Meanwhile, the investigated compounds reduced the number of metabolically active breast tumor MCF-7 cells, with the exception of Zn(II complex-containing a symmetrical ligand. Accordingly, preliminary in vitro data suggest that the proposed tetrapyrrolic compounds are good candidates for PDT, as they limit tumor expansion even under dark conditions, whilst sparing normal cells.

Zone-refining of beryllium(II) acetylacetonate

International Nuclear Information System (INIS)

Yoshida, Isao; Kobayashi, Hiroshi; Ueno, Keihei

1975-01-01

Zone melting was applied to bis (acetylacetonato) beryllium(II), Be(AA) 2 , to remove trace metal constiutents. The effective distribution coefficient, k, of a minor component measured in a binary mixture with the majority of Be(AA) 2 , fell in the range of 0.4 to 0.8, while the value obtained in a multiple component mixture fell in the range of 0.8 to 0.9 except Zn(II)- and Ni(II) chelates. Cr(AA) 3 was concentrated upward in the direction of the zone travelling, and similar results were obtained with Cu(II)-, Co(III)- Fe(III)- and Al(III) acetylacetonates, while Zn(II)-, Ni(II)- and Mn(III) chelates were fractionated in the both ends of the column. On the other hand, when the zone was moved downward, the minor components were concentrated in the lower end of a column. Efficiency in zone refining was compared to each other between the upward- and downward zone travelling modes on the crude beryllium acetylacetonates obtained from a commercial reagent of beryllium nitrate, and the latter mode was found more effective in the concentration of trace components. Discussion was given on possible mechanisms resulting in the difference in the refining efficiency. (author)

A colorimetric and luminescent dual-modal assay for Cu(II ion detection using an iridium(III complex.

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Dik-Lung Ma

Full Text Available A novel iridium(III complex-based chemosensor bearing the 5,6-bis(salicylideneimino-1,10-phenanthroline ligand receptor was developed, which exhibited a highly sensitive and selective color change from colorless to yellow and a visible turn-off luminescence response upon the addition of Cu(II ions. The interactions of this iridium(III complex with Cu2+ ions and thirteen other cations have been investigated by UV-Vis absorption titration, emission titration, and 1H NMR titration.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers

Energy Technology Data Exchange (ETDEWEB)

Monier, M., E-mail: monierchem@yahoo.com [Chemistry Department, Drexel University, Philadelphia, PA (United States); Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt); Ayad, D.M.; Sarhan, A.A. [Chemistry Department, Faculty of Science, Mansoura University, Mansoura (Egypt)

2010-04-15

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction.

Adsorption of Cu(II), Hg(II), and Ni(II) ions by modified natural wool chelating fibers.

Science.gov (United States)

Monier, M; Ayad, D M; Sarhan, A A

2010-04-15

The graft copolymerization of ethyl acrylate (EA) onto natural wool fibers initiated by potassium persulphate and Mohr's salt redox initiator system in limited aqueous medium was carried out in heterogeneous media. Ester groups of the grafted copolymers were partially converted into hydrazide function groups followed by hydrazone formation through reaction with isatin. Also the application of the modified fibers for metal ion uptake was studied using Cu(II), Hg(II) and Ni(II). The modified chelating fibers were characterized using FTIR spectroscopy, SEM and X-ray diffraction. 2009 Elsevier B.V. All rights reserved.

One Dimensional Coordination Polymer of Zn(II) for Developing Multifunctional Nanoparticles.

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Agarwal, Rashmi A

2017-10-16

A variety of nanoparticles (NPs) including Ag, Au, Pd, Cr and mixed Cu/Fe have been synthesized in a non-activated (without solvent removal) one dimensional coordination polymer (CP) of Zn(II) via two different mechanisms, acid formation and redox activity of the framework. Main driving force to grow these NPs within the cavities of CP is the presence of free oxygens of one of the monodentate carboxylate groups of BDC ligand. These free oxygens act as anchoring sites for the metal ions of the metal precursors. Chemical and physical characteristics of the NPs within the framework have been evaluated by the high resolution transmission electron microscopic (HRTEM) images. Excluding Ag(0) and Pd(0) other NPs are present as combinations of their elemental as well as oxide forms (Au/Au 2 O 3 , Cr/Cr 2 O 3 /CrO 2 and Cu/Cu 2 O, Fe/FeO). Synthesized Ag NPs within the framework show remarkable antibacterial efficacy at extremely low concentrations. Ag, Au and Cu/Fe NPs show ferromagnetic properties within the framework at room temperature. This polymer has potential to sequester highly toxic Cr(VI) to non toxic Cr(0), Cr(III) and Cr(IV) species.

Synthesis, characterization, and application of novel Zn(II)-ionic imprinted polymer for preconcentration of Zn(II) ions from aqueous solution

Science.gov (United States)

Wirawan, T.; Supriyanto, G.; Soegianto, A.

2018-04-01

Preparation of a new Zn2+ ion-imprinted polymer (Zn-IIP) is presented in this report. The Zn-IIP are prepared by precipitation polymerization using 8-hydroxyquinoline (8HQ) as a ligand, methacrylic acid (MAA) as functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker has been prepared. The benzoyl peroxide and ethanol/acetonitrile (2:1) mixture were used as initiator and porogen, respectively. Precipitation polymerization was carried out by heating in a water bath at 60°C for 8 hours. After polymerization, cavities in the polymer particles corresponding to the Zn2+ ions were created by leaching the polymer with 2 mol L-1 HNO3. The polymer was washed with aquabidest and dried in an oven at the temperature of 60°C for 24 hours. The Zn-IIP was characterized by Fourier Transform Infrared Spectrophotometry (FT-IR) and Scanning Electron Microscopy (SEM). The synthesized Zn-IIP was used as a new adsorbent for solid phase extraction (SPE) of Zn(II) prior to Flame Atomic Absorption Spectrometry (FAAS) determination. The experimental parameters for SPE, such as pH of the sample, loading rate, and elution volume, have been optimized. The effect of pH of the sample on the extraction of analyte was studied in batch mode. The effects of loading rate and elution volume on the extraction of analyte were studied in dynamic mode by loading of the sample through IIP-SPE cartridge containing 100 mg of the synthesized Zn-IIP. The imprinted polymer (Zn-IIP) have bands at 3433.06 cm-1 (O-H), 1508.23 cm-1 (C=N aromatics), 1284.5 cm-1 (C-N aromatics), 1056.9 cm-1 (C-O phenol), 1724.24 cm-1 (C=O), and 1639.38 cm-1 (conjugated C=O with C=C). The Scanning Electron Microscopy (SEM) images of IIP and IIP show that the IIP is seen to have more cavities than NIP. The optimum pH for quantitative Zn(II) retention was 5.5, and the elution was completed with 2 mL of 1.0 mol L-1 nitric acid. The optimum loading rate was 0.5 mL min-1. The recovery of Zn(II) from solution

Synthesis, spectral, antitumor, antioxidant and antimicrobial studies on Cu(II), Ni(II) and Co(II) complexes of 4-[(1H-Benzoimidazol-2-ylimino)-methyl]-benzene-1,3-diol.

Science.gov (United States)

El-wakiel, Nadia; El-keiy, Mai; Gaber, Mohamed

2015-08-05

A new Schiff base of 2-aminobenzimidazole with 2,4-dihydroybezaldehyde (H₃L), and its Cu(II), Ni(II) and Co(II) complexes have been synthesized and characterized by elemental analyses, molar conductance, thermal analysis (TGA), inductive coupled plasma (ICP), magnetic moment measurements, IR, EI-mass, UV-Vis. and ESR spectral studies. On the basis of spectral studies and analytical data, it is evident that the Schiff base acts as dibasic tridentate ligand coordinating via deprotonated OH, NH and azomethine nitrogen atom. The results showed that Co(II) and Ni(II) complexes have tetrahedral structure while Cu(II) complexes has octahedral geometry. The kinetic and thermodynamic parameters of the thermal decomposition stages have been evaluated. The studied complexes were tested for their in vitro antimicrobial activities against some bacterial strains. The anticancer activity of the ligand and its metal complexes is evaluated against human liver Carcinoma (HEPG2) cell. These compounds exhibited a moderate and weak activity against the tested HEPG2 cell lines with IC₅₀ of 9.08, 18.2 and 19.7 μg/ml for ligand, Cu(II) and Ni(II) complexes, respectively. In vitro antioxidant activity of the newly synthesized compounds has also been evaluated. Copyright © 2015 Elsevier B.V. All rights reserved.

Zn(II) coordination polymers with flexible V-shaped dicarboxylate ligand: Syntheses, helical structures and properties

Energy Technology Data Exchange (ETDEWEB)

Li, Lin [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Chong-Bo, E-mail: cbliu@nchu.edu.cn [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Yang, Gao-Shan [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Xiong, Zhi-Qiang [Center for Analysis and Testing, Nanchang Hangkong University, Nanchang 330063 (China); Liu, Hong [School of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063 (China); Wen, Hui-Liang [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China)

2015-11-15

Hydrothermal reactions of 2,2′-[hexafluoroisopropylidenebis(p-phenyleneoxy)]diacetic acid (H{sub 2}L) and zinc ions in the presence of N-donor ancillary ligands afford four novel coordination polymers, namely, [Zn{sub 2}(μ{sub 2}-OH)(μ{sub 4}-O){sub 0.5}(L)]·0.5H{sub 2}O (1), [Zn(L)(2,2′-bipy)(H{sub 2}O)] (2), [Zn{sub 3}(L){sub 3}(phen){sub 2}]·H{sub 2}O (3) and [Zn{sub 2}(L){sub 2}(4,4′-bipy)] (4) (2,2′-bipy=2,2′-bipyridine; 4,4′-bipy=4,4′-bipyridine; phen=1,10-phenanthroline). Their structures have been determined by single-crystal X-ray diffraction analyses, elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complex 1 shows a 3-D clover framework consisting of [Zn{sub 4}(µ{sub 4}-O)(µ{sub 2}-OH){sub 2}]{sup 4+} clusters, and exhibits a novel (3,8)-connected topological net with the Schläfli symbol of {3·4·5}{sub 2}{3"4·4"4·5"2·6"6·7"1"0·8"2}, and contains double-stranded and two kinds of meso-helices. 2 displays a helical chain structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with meso-helix chains. 3 displays a 2-D {4"4·6"2} parallelogram structure, which is further extended via hydrogen bonds into a 3-D supramolecular structure with single-stranded helical chains. 4 shows a 2-D {4"4·6"2} square structure with left- and right-handed helical chains. Moreover, the luminescent properties of 1–4 have been investigated. - Graphical abstract: Four new Zn(II) coordination polymers with helical structures based on flexible V-shaped dicarboxylate ligand have been synthesized and structurally characterized. Photoluminescent properties have been investigated. - Highlights: • Four novel Zn(II) coordination polymers with V-shaped ligand were characterized. • Complexes 1–4 show diverse intriguing helical characters. • Fluorescence properties of complexes 1–4 were investigated.

Sorption Behavior of Cu(II From Acidic SolutionUsing Weathered Basalt Andesite Products

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Rajesh Singh

2007-01-01

Full Text Available Wastewater discharged from electroplating industry pose a serioushazard due to their heavy metal load. The objective of this work is to evaluatethe removal of Cu(II from acidic solution by sorption onto Weathered BasaltAndesite Products (WBAP. WBAP has been characterized and utilized forremoval of copper from aqueous solution over wide range of initial metal ionconcentration (25 mg/L to 500 mg/L, contact duration (0-8 h, sorbent dose(5-35 g/L, pH (1.0 to 6.0, and temperature (276 K to 333 K. The sorptionpattern of Cu ions onto WBAP followed Langmuir, Freundlich, and Dubinin-Kaganer-Radushkevich isotherms. The thermodynamic parameters (∆H0, ∆S0,and ∆G0 for Cu sorption onto WBAP were also determined.

Effect of pre-pyrolysis mode on simultaneous introduction of nitrogen/oxygen-containing functional groups into the structure of bagasse-based mesoporous carbon and its influence on Cu(II) adsorption.

Science.gov (United States)

Wan, Zeqing; Li, Kunquan

2018-03-01

A convenient effective microwave pre-pyrolysis treatment to synthesize biomass-based mesoporous carbon with higher nitrogen/oxygen-chelating adsorption for Cu(II) is reported here, in which phosphoric acid impregnated bagasse was used as a microwave absorber and porogen. For comparison, conventional electric-heating pyrolyzed carbon was prepared and doped with nitrogen/oxygen groups. Nitrogen adsorption, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS) and batch adsorption were employed to investigate the effects of the two pre-pyrolysis modes on the sample physicochemical and Cu(II) adsorptive properties. The 22-min-microwave-pyrolyzed bagasse mesoporous activated carbon (MBAC, 85.32% mesoporosity) contained 10.52% O, which is 3.94% more than electric-heating pyrolyzed mesoporous activated carbon (89.52% mesoporosity). After electrophilic aromatic substitutions of N/O doping, the former possessed more N (5.83%) and more O (21.40%), confirming that time-saving energy-efficient microwave pyrolysis favors the formation of defective C/O atoms in or at the edges of the graphite layer of MBAC, which are highly active and tend to act as preferred reactive positions for the doping of N/O-containing groups simultaneously compared with conventional electric-heating pyrolysis. These N and O species existed mainly as COOH, OH, NH and NH 2 functional groups, and were confirmed by XPS to be active sites for metal binding via electrostatic attraction, hydrogen bonding, a chelate effect and complexation, resulting in the great enhancement of Cu(II) adsorption. Langmuir isotherm and pseudo-second-order kinetic fitting further proved that Cu(II) adsorption by N/O-doped MBAC is ascribed mainly to chemisorption. Therefore, rapid microwave pre-pyrolysis provides a promising route to prepare excellent-performance N/O-doped carbon adsorbents. Copyright © 2017 Elsevier Ltd. All rights reserved.

A series of coordination polymers constructed from R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands: Syntheses, structures and fluorescence properties

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Zhou, Yong-Hong; Zhou, Xu-Wan; Zhou, Su-Rong; Tian, Yu-Peng; Wu, Jie-Ying

2017-01-01

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn2Na(sip)2(bpp)3(Hbpp)(H2O)2]·8H2O (1), [Cd3(sip)2(nbi)6(H2O)2]·7H2O (2), [Zn(sip)(nbi)2(H2O)]·Hnbi·3H2O (3), [Cd(hip)(nbi)2(H2O)]·nbi·5H2O (4), [Cd2(nip)2(nbi)2(H2O)2]·DMF (5), and [Cu(nip)(nbi)(H2O)2]·H2O (6) (H3sip=5-sulfoisophthalic acid, H2hip=5-hydroxylisophthalic acid, H2nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=-SO3H, -NO2, and -OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip3- anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3-5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip2- ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied.

Silica gel modified with N-(3-propyl)-O-phenylenediamine: functionalization, metal sorption equilibrium studies and application to metal enrichment prior to determination by flame atomic absorption spectrometry.

Science.gov (United States)

Akl, Magda Ali Abd-elAziz; Kenawy, Ibraheim Mohamed; Lasheen, Rabab Ramadan

2005-08-01

The use of the chemically modified silica gel N-(3-propyl)-O-phenylenediamine (SiG-NPPDA) adsorbent, for the preconcentration and separation of trace heavy metals, was described. SiG-NPPDA sorbs quantitatively (90-100% recovery) trace amounts of nine heavy metals, viz., Cd(II), Zn(II), Fe(III), Cu(II), Pb(II), Mn(II), Cr(III), Co(II) and Ni(II) at pH 7-8. The sorption capacity varies from 350 to 450 micromol g(-1). Desorption was found to be quantitative with 1-2 M HNO3 or 0.05 M Na2EDTA. The distribution coefficient, Kd and the percentage concentration of the investigated metal ions on the adsorbent at equilibrium, C(M,eqm)% (Recovery, R%), were studied as a function of experimental parameters. The logarithmic values of the distribution coefficient, log Kd, ranges between 4.0 and 6.4. Some foreign ions caused little interference in the preconcentration and determination of the investigated nine metals by flame atomic absorption spectrometry (AAS). The adsorbent and its formed metal chelates were characterized by IR (absorbance and/or reflectance), potentiometric titrations and thermogravimetric analysis (TGA and DTG). The mode of chelation between the SiG-NPPDA adsorbent and the investigated metal ions is proposed to be due to the reaction of the investigated metal ions with the two nitrogen atoms of the SiG-NPPDA adsorbent. The present adsorbent coupled with flame AAS has been used to enrich and determine the nine metal ions in natural aqueous systems and in certified reference materials (RSD < or = 5%). The copper, iron, manganese and zinc present in some pharmaceutical vitamin samples were also preconcentrated on SiG-NPPDA adsorbent and determined by flame AAS (RSD < or = 4.2%). Nanogram concentrations (0.07-0.14 ng ml(-1)) of Cd(II), Zn(II), Fe(III), Pb(II), Cr(III), Mn(II), Cu(II), Co(II) and Ni(II) can be determined reliably with a preconcentration factor of 100.

Microencapsulated Aliivibrio fischeri in Alginate Microspheres for Monitoring Heavy Metal Toxicity in Environmental Waters

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Dedi Futra

2014-12-01

Full Text Available In this article a luminescence fiber optic biosensor for the microdetection of heavy metal toxicity in waters based on the marine bacterium Aliivibrio fischeri (A. fischeri encapsulated in alginate microspheres is described. Cu(II, Cd(II, Pb(II, Zn(II, Cr(VI, Co(II, Ni(II, Ag(I and Fe(II were selected as sample toxic heavy metal ions for evaluation of the performance of this toxicity microbiosensor. The loss of bioluminescence response from immobilized A. fischeri bacterial cells corresponds to changes in the toxicity levels. The inhibition of the luminescent biosensor response collected at excitation and emission wavelengths of 287 ± 2 nm and 487 ± 2 nm, respectively, was found to be reproducible and repeatable within the relative standard deviation (RSD range of 2.4–5.7% (n = 8. The toxicity biosensor based on alginate micropsheres exhibited a lower limit of detection (LOD for Cu(II (6.40 μg/L, Cd(II (1.56 μg/L, Pb(II (47 μg/L, Ag(I (18 μg/L than Zn(II (320 μg/L, Cr(VI (1,000 μg/L, Co(II (1700 μg/L, Ni(II (2800 μg/L, and Fe(III (3100 μg/L. Such LOD values are lower when compared with other previous reported whole cell toxicity biosensors using agar gel, agarose gel and cellulose membrane biomatrices used for the immobilization of bacterial cells. The A. fischeri bacteria microencapsulated in alginate biopolymer could maintain their metabolic activity for a prolonged period of up to six weeks without any noticeable changes in the bioluminescence response. The bioluminescent biosensor could also be used for the determination of antagonistic toxicity levels for toxicant mixtures. A comparison of the results obtained by atomic absorption spectroscopy (AAS and using the proposed luminescent A. fischeri-based biosensor suggests that the optical toxicity biosensor can be used for quantitative microdetermination of heavy metal toxicity in environmental water samples.

Synthesis, characterization and biological activity of some transition metals with Schiff base derived from 2-thiophene carboxaldehyde and aminobenzoic acid

Science.gov (United States)

Mohamed, Gehad G.; Omar, M. M.; Hindy, Ahmed M. M.

2005-12-01

Metal complexes of Schiff base derived from 2-thiophene carboxaldehyde and 2-aminobenzoic acid (HL) are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance and thermal analysis (TGA). The ligand dissociation as well as the metal-ligand stability constants were calculated pH metrically at 25 °C and ionic strength μ = 0.1 (1 M NaCl). The complexes are found to have the formulae [M(HL) 2](X) n· yH 2O (where M = Fe(III) (X = Cl, n = 3, y = 3), Co(II) (X = Cl, n = 2, y = 1.5), Ni(II) (X = Cl, n = 2, y = 1) and UO 2(II) (X = NO 3, n = 2, y = 0)) and [M(L) 2] (where M = Cu(II) (X = Cl) and Zn(II) (X = AcO)). The molar conductance data reveal that Fe(III) and Co(II), Ni(II) and UO 2(II) chelates are ionic in nature and are of the type 3:1 and 2:1 electrolytes, respectively, while Cu(II) and Zn(II) complexes are non-electrolytes. IR spectra show that HL is coordinated to the metal ions in a terdentate manner with ONS donor sites of the carboxylate O, azomethine N and thiophene S. From the magnetic and solid reflectance spectra, it is found that the geometrical structure of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, Δ H*, Δ S* and Δ G* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligands, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus pyogones and Fungi (Candida). The activity data show that the metal complexes to be more potent/antibacterial than the parent Schiff base ligand against one or more bacterial species.

Sorption studies of heavy metal ions by salicylic acid–formaldehyde–catechol terpolymeric resin: Isotherm, kinetic and thermodynamics

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Riddhish R. Bhatt

2015-05-01

Full Text Available Terpolymeric resin has been synthesized by condensing salicylic acid with catechol employing formaldehyde as a cross linking agent at 80 ± 5 °C using DMF as a solvent. The resin was characterized by elemental analysis, FTIR, XRD and thermal analysis (TGA, DTA and DTG. The morphology of the resin was studied by optical photographs and scanning electron micrographs (SEM at different magnifications. The physico-chemical properties have been studied. The uptake behavior of various metal ions viz. Ni(II, Cu(II, Zn(II, Cd(II and Pb(II towards synthesized resin has been studied depending on contact time, pH and temperature. The selectivity order found is: Cu(II > Zn(II > Pb(II > Ni(II > Cd(II. The sorption data obtained at optimized conditions were analyzed by six two parameter isotherm models like Langmuir, Freundlich, Temkin, Dubinin–Radushkevich (D–R, Halsey and Harkins–Jura. The Langmuir, Freundlich and Dubinin–Radushkevich (D–R isotherms were found better to describe the sorption data with high correlation for the adsorption with a low SSE value for all the metals under study. The adsorption capacities of the SFC resin for removal of Ni(II, Cu(II, Zn(II, Cd(II and Pb(II were determined with the Langmuir equation and found to be 0.815, 1.104, 1.215, 0.498, and 0.931 mmol/g respectively. The adsorption process follows first order kinetics and specific rate constant Kr was obtained by the application of Lagergren equation. Thermodynamic parameters viz. ΔGads, ΔSads and ΔHads have also been calculated for the metal-resin systems. The external diffusion rate constant (Ks and intra-particle diffusion rate constant (Kid were calculated by Spahn–Schlunder and Weber–Morris models respectively. Desorption studies were done using various desorbing agents viz. de-ionized water, boiled water, various concentrations of HCl, ammonia, thiourea, citric acid and tartaric acid.

Selective and Efficient Solvent Extraction of Copper(II Ions from Chloride Solutions by Oxime Extractants

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Zahra Kaboli Tanha

2016-06-01

Full Text Available Oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (HL1 and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (HL2 were synthesized and characterized by conventional spectroscopic methods. Suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated metal ions by performing competitive extraction experiments of Cu(II, Co(II, Ni(II, Zn(II, Cd(II and Pb(II ions from chloride solutions. Both ligands transfer selectively the copper ions into dichloromethane by a cation exchange mechanism. Conventional log-log analysis and isotherm curves showed that Cu(II ions are extracted as the complexes with 1:2 metal to ligand ratio by both extractants. Verification of the effect of the organic diluent used in the extraction of copper ions by HL1 and HL2 demonstrated that the extraction efficiency varies as: dichloromethane ~ dichloroethane > toluene > xylene > ethylacetate. Time dependency investigation of the extraction processes revealed that the kinetics of the extraction of copper by HL2 is more rapid than that of HL1. The application of the ligands for extraction-separation of copper ions from leach solutions of cobalt and nickel-cadmium filter-cakes of a zinc production plants was evaluated.

A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane

International Nuclear Information System (INIS)

Obuseng, Veronica; Nareetsile, Florence; Kwaambwa, Habauka M.

2012-01-01

Highlights: ► Materials are effective and selective in simultaneous removal of heavy metal ions. ► Use of composite adsorbent of both materials may result in more effective material. ► Seeds biomass has various functional groups involves in metal removal. ► Attainment of sorption equilibrium is rapid for the seeds biomass. ► Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II) > Cu(II) > Cd(II) > Ni(II) > Mn(II) and Zn(II) > Cu(II) > Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn > Cd > Cu > Ni > Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5–8.

Highly stable acyclic bifunctional chelator for {sup 64}Cu PET imaging

Energy Technology Data Exchange (ETDEWEB)

Abada, S.; Lecointre, A.; Christine, C.; Charbonniere, L. [CNRS/UDS, EPCM, Strasbourg (France). Lab. d' Ingenierie Appliquee a l' Analyse; Dechamps-Olivier, I. [Univ. de Reims Champagne Ardenne, Reims (France). Group Chimie de Coordination; Platas-Iglesias, C. [Univ. da Coruna (Spain). Dept. de Quimica Fundamental; Elhabiri, M. [CNRS/UDS, EPCM, Strasbourg (France). Lab. de Physico-Chimie Bioinorganique

2011-07-01

Ligand L{sup 1}, based on a pyridine scaffold, functionalized by two bis(methane phosphonate)aminomethyl groups, was shown to display a very high affinity towards Cu(II) (log K{sub CuL}=22.7) and selectivity over Ni(II), Co(II), Zn(II) and Ga(III) ({delta} log K{sub ML}>4) as shown by the values of the stability constants obtained from potentiometric measurements. Insights into the coordination mode of the ligand around Cu(II) cation were obtained by UV-Vis absorption and EPR spectroscopies as well as density functional theory (DFT) calculations (B3LYP model) performed in aqueous solution. The results point to a pentacoordination pattern of the metal ion in the fully deprotonated [CuL{sup 1}]{sup 6-} species. Considering the beneficial thermodynamic parameters of this ligand, kinetic experiments were run to follow the formation of the copper(II) complexes, indicating a very rapid formation of the complex, appropriate for {sup 64}Cu complexation. As L{sup 1} represents a particularly interesting target within the frame of {sup 64}Cu PET imaging, a synthetic protocol was developed to introduce a labeling function on the pyridyl moiety of L{sup 1}, thereby affording L{sup 2}, a potential bifunctional chelator (BFC) for PET imaging.

Magnetic exchange couplings from noncollinear perturbation theory: dinuclear CuII complexes.

Science.gov (United States)

Phillips, Jordan J; Peralta, Juan E

2014-08-07

To benchmark the performance of a new method based on noncollinear coupled-perturbed density functional theory [J. Chem. Phys. 138, 174115 (2013)], we calculate the magnetic exchange couplings in a series of triply bridged ferromagnetic dinuclear Cu(II) complexes that have been recently synthesized [Phys. Chem. Chem. Phys. 15, 1966 (2013)]. We find that for any basis-set the couplings from our noncollinear coupled-perturbed methodology are practically identical to those of spin-projected energy-differences when a hybrid density functional approximation is employed. This demonstrates that our methodology properly recovers a Heisenberg description for these systems, and is robust in its predictive power of magnetic couplings. Furthermore, this indicates that the failure of density functional theory to capture the subtle variation of the exchange couplings in these complexes is not simply an artifact of broken-symmetry methods, but rather a fundamental weakness of current approximate density functionals for the description of magnetic couplings.

Enhancement strategies for Cu(II), Cr(III) and Cr(VI) remediation by a variety of seaweed species.

Science.gov (United States)

Murphy, V; Hughes, H; McLoughlin, P

2009-07-15

Various chemical treatments have been applied to six brown, red and green seaweed species with a view to enhancing their metal removal for Cu(II), Cr(III) and Cr(VI). Treatment with acetone resulted in the greatest enhancement for both cationic and anionic species with relatively low mass losses (15-35%), indicating its low risk to biomass operational stability. Cation binding was increased by 69%, while the total Cr removal was augmented by 15%. Cr(VI) binding was shown to be an adsorption-coupled reduction, whereby Cr(VI) was bound to the biomass surface at pH 2 and subsequently reduced to Cr(III). Acetone treatment also resulted in biomasses that were capable of converting up to 83% of Cr(VI) in solution to Cr(III). Blocking of carboxyl and amino functionalities had significant negative effects both on total Cr removal as well as percentage conversion of Cr(VI) to Cr(III). Results therefore indicated the significant role played by these moieties in metal binding to these seaweeds. Potentiometric titrations displayed agreement between the degree of esterification and the decrease in Cu(II) removal for Ulva spp. and Polysiphonia lanosa. FTIR analysis identified changes in biomass functionality and availability after chemical modification, the results of which were in agreement with metal removal studies. In conclusion, these biosorbents represent suitable candidates to replace conventional removal technologies for metal bearing wastewaters, in particular for the detoxification of hazardous Cr(VI) waste streams.

Application of Triton X-100 coated poly vinyl chloride as new solid phase for preconcentration of Fe3+, Cu2+ and Zn2+ ions and their flame atomic absorption spectrometric determinations

Directory of Open Access Journals (Sweden)

Mehrorang Ghaedi

2010-04-01

Full Text Available A selective, sensitive and efficient method for preconcentration of trace amounts of Cu(II, Fe(II and Zn(II ions based on the uptake of their complexes with 3-((indolin-3-yl(phenylmethylindoline (IYPMI loaded on Triton X-100 coated poly vinyl chloride has been reported. The influences of the analytical parameters including pH, ligand amount, surfactant type and concentration, eluting condition and sample volume on metal ions recovery were investigated. The method has been successfully applied for the extraction of these ions content in some real samples of soil and plants. The extraction efficiency was > 97% with low relative standard deviation (RSD < 2.4% and the preconcentration factor of 90 (5 mL elution volume for a 450 mL of sample volume.

Preparation and characterisation of some transition metal complexes of niacinamide (vitamin b3)

International Nuclear Information System (INIS)

Hasan, M.M.; Hossain, M.E.; Halim, M.E.

2015-01-01

Niacinamide forms metal complexes of general formula (M(C/sub 6/H/sub 6/N/sub 2/O)2)Cl/sub 2/; where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) in the aqueous medium. The complexes were formulated by comparing the experimental and calculated data for C, H, N and metal. The prepared complexes were characterized by different physicochemical methods. The UV-vis, FTIR spectral analysis and thermo gravimetric analysis (TGA). TGA of these complexes have been discussed. Magnetic susceptibility values indicate that all complexes except Zn complex are paramagnetic in nature. The redox properties of the metal ions in the Mn, Cu and Zn complexes have been discussed from the cyclic voltammetric studies. In all cases the systems are quasi reversible. (author)

Gamma radiolysis of Cu(II) complex of metronidazole

International Nuclear Information System (INIS)

Mandal, P.C.; Bardhan, D.K.; Bhattacharyya, S.N.

1990-01-01

Aqueous solutions of Cu(II)Metronidazole (Cu(II)M) at neutral pH were irradiated with 60 Co γ-rays under different conditions of radiolysis. The radiolytic formation of HNO 2 and Cu(I) was followed. The radiolytic yields of chromophore loss of Cu(II)M were also determined under different conditions. The OH radicals attack the metal complex to give the OH adducts of the ligand at C 2 , C 4 , and C 5 either directly or through the formation of Cu(III) species. The C 5 -OH adduct, however, undergoes oxidative denitration and as a result the metal complex is decomposed. The OH adducts also undergo electron transfer to Cu(II) ion to give reduced complex. No denitration was observed due to the reaction of e eq - with the metal complex. On the other hand, the nitro group of the ligand in the complex undergoes successive 4-electron reduction to give hydroxylamino derivative. From the competition kinetics using t-butyl alcohol as the scavenger of OH in N 2 O saturated solution of the metal complex, the rate constant for the reaction of OH with complex was evaluated to be ca. 2.1x10 9 dm 3 mol -1 s -1 which is of the same order as that observed in the case of free metronidazole. (author)

Removal of Cu(II) and Pb(II) from Aqueous Solutions Using Nanoporous Materials

Science.gov (United States)

Dutta, Debajani; Roy, Sushanta Kumar; Das, Bodhaditya; Talukdar, Anup K.

2018-05-01

The present work deals with the adsorption of Cu2+ and Pb2+ on zeolites (ZSM-5, mordenite) and mesoporous materials (MCM-48, MCM-41). The characterization of the synthesized samples was performed by means of XRD, SEM, and thermogravimetric analysis. The batch method was employed to study the influence of adsorbent nature, contact time, initial metal ion concentration, and adsorbent load. The adsorption on MCM-48 follows a pseudo-second-order kinetic model. This material was found to be more effective for the removal of lead in a batch process as compared to the other adsorbents and the removal efficiency of the materials for Pb(II) followed the order MCM-48 > mordenite > ZSM-5 > MCM-41 and that for Cu(II) followed the order ZSM-5 > mordenite > MCM-41 > MCM-48.

Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

Energy Technology Data Exchange (ETDEWEB)

Saeednia, S., E-mail: sami_saeednia@yahoo.com [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Iranmanesh, P. [Department of physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Ardakani, M. Hatefi; Mohammadi, M.; Norouzi, Gh. [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of)

2016-06-15

Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.

The hierarchical porous structure bio-char assessments produced by co-pyrolysis of municipal sewage sludge and hazelnut shell and Cu(II) adsorption kinetics.

Science.gov (United States)

Zhao, Bing; Xu, Xinyang; Zeng, Fanqiang; Li, Haibo; Chen, Xi

2018-05-04

The co-pyrolysis technology was applied to municipal sewage sludge (MSS) and hazelnut shell with alkaline activating agent K 2 CO 3 under N 2 atmosphere. The innovative bio-char produced by co-pyrolysis had significant physical and chemical characteristics. The specific surface area reached 1990.23 m 2 /g, and the iodine absorption number was 1068.22 mg/g after co-pyrolysis at 850 °C. Although hazelnut shell was a kind of solid waste, it also had abundant cellulose resource, which could contribute to porous structure of bio-char during co-pyrolysis with MSS and decrease total heavy metals contents of raw material to increase security of bio-chars. Meanwhile, the residual fractions of heavy metals in bio-char were above 92.95% after co-pyrolysis at 900 °C except Cd to prevent heavy metals digestion, and the bio-char presented significant immobilization behavior from co-pyrolysis technology. Moreover, the yield and the iodine absorption number of bio-chars under different process variables were analyzed, and it was confirmed that appropriate process variables could contribute the yield and the iodine absorption number of bio-char and prevent to etch pore structure excessively to collapse. The changes of surface functional groups and crystallographic structure before and after co-pyrolysis were analyzed by FTIR and XRD, respectively. The hierarchical porous structure of bio-char was presented by SEM and N 2 adsorption-desorption isotherm. The Cu(II) adsorption capacity of the bio-char was 42.28 mg/g after 24 h, and surface functional groups acted as active binding sites for Cu(II) adsorption. Langmuir model and pseudo-second-order model can describe process of Cu(II) adsorption well.

Characterization of L-cysteine capped CdTe quantum dots and application to test Cu(II) deficiency in biological samples from critically ill patients

Energy Technology Data Exchange (ETDEWEB)

Sáez, Laura; Molina, Jorge; Florea, Daniela I.; Planells, Elena M. [Institute of Nutrition and Food Technology and Department of Physiology, Faculty of Pharmacy, Campus Cartuja, University of Granada, E-18071 Granada (Spain); Cabeza, M. Carmen [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, E-18071 Granada (Spain); Quintero, Bartolomé, E-mail: bqosso@ugr.es [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, E-18071 Granada (Spain)

2013-06-27

Graphical abstract: -- Highlights: •We examinate stability of L-cysteine capped CdTe QD. •Factors influence QD fluorescence response are controlled. •Application in copper deficiency analysis is made. •We report comparison with other techniques. -- Abstract: The catalytic activity of copper ion gives, from the physiological point of view, a central role in many biological processes. Variations in the composition and location of cellular copper have been addressed given their physiological and pathological consequences. In this paper L-cysteine capped CdTe quantum dots is used for the fluorimetric determination of Cu(II) in biological samples from healthy individuals and patients admitted to the Intensive Care Units (ICU). An acceptable homogeneity in the CdTe QDs size has been obtained with an average value of 3 nm. No significant alterations in the spectral properties were observed for 2 months when stored in vacutainers at 6 °C and a concentration of approximately 2 μM. Data from oxidative stress markers such superoxide dismutase, total antioxidant capacity and DNA damage can be correlated with a Cu(II) deficiency for the ICU patients as measured by flame-atomic absorption spectroscopy (FAAS) and inductively coupled plasma source mass spectrometry (ICP-MS). Aqueous solutions 0.3 μM of L-cysteine capped CdTe QDs in MOPS buffer (6 mM, pH 7.4) used at 21 °C in the range 15–60 min after preparation of the sample for the measurements of fluorescence gives contents in Cu(II) for erythrocytes in good agreement with those obtained in FAAS and ICP-MS but the comparative ease of use makes the fluorimetric technique more suitable than the other two techniques for routine analysis.

Kinetic and isotherm studies of Cu(II) biosorption onto valonia tannin resin

Energy Technology Data Exchange (ETDEWEB)

Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54100 Sakarya (Turkey)], E-mail: asengil@sakarya.edu.tr; Ozacar, Mahmut [Department of Chemistry, Science and Arts Faculty, Sakarya University, 54100 Sakarya (Turkey); Tuerkmenler, Harun [Institute of Sciences and Technology, Sakarya University, 54040 Sakarya (Turkey)

2009-03-15

The biosorption of Cu(II) from aqueous solutions by valonia tannin resin was investigated as a function of particle size, initial pH, contact time and initial metal ion concentration. The aim of this study was to understand the mechanisms that govern copper removal and find a suitable equilibrium isotherm and kinetic model for the copper removal in a batch reactor. The experimental isotherm data were analysed using the Langmuir, Freundlich and Temkin equations. The equilibrium data fit well in the Langmuir isotherm. The experimental data were analysed using four sorption kinetic models - the pseudo-first- and second-order equations, the Elovich and the intraparticle diffusion model equation - to determine the best fit equation for the biosorption of copper ions onto valonia tannin resin. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process, whereas the Elovich equation also fits the experimental data well.

The Formation of Metal (M=Co(II), Ni(II), and Cu(II)) Complexes by Aminosilanes Immobilized within Mesoporous Molecular Sieves

International Nuclear Information System (INIS)

Park, Dong Ho; Park, Sung Soo; Choe, Sang Joon

1999-01-01

The immobilization of APTMS(3-(2-aminoethylamino)propyltrimethoxysilane) and AAPTMS(3-(2-(2-aminoethyl) aminoethylamino)propyltrimethoxysilane) on the surface of high quality mesoporous molecular sieves MCM-41 and MCM-48 have been confirmed by F.T.-IR spectroscopy, Raman spectroscopy, 29 Si solid state NMR, and a surface polarity measurement using Reichardt's dye. The formation of metal (Co(II), Ni(II), and Cu(II)) complexes by immobilized aminosilanes have been investigated by photoacoustic spectroscopy(PAS). The assignment of UV-Vis. PAS bands makes it possible to identify the structure of metal complexes within mesoporous molecular sieves. Co(II) ion may be coordinated mainly in a tetrahedral symmetry by two APTMS onto MCM-41, and in an octahedral one by two AAPTMS. Both Ni(II) and Cu(II) coordinated by aminosilanes within MCM-41 form possibly the octahedral complexes such as [Ni(APTMS) 2 (H 2 O) 2 ] 2+ , [Ni(AAPTMS) 2 ] 2+ , [Cu(APTMS) 2 (H 2 O) 2 ] 2+ , and [Cu(AAPTMS)(H 2 O) 3 ] 2+ , respectively. The PAS band shapes of complexes onto MCM-48 are similar to those of corresponding MCM-41 with the variation of PAS intensity. Most of metal ion(II) within MCM-41 and MCM-48 are coordinated by aminosilanes without the impregnation on the surface

Non-enzymatic palladium recovery on microbial and synthetic surfaces.

Science.gov (United States)

Rotaru, Amelia-Elena; Jiang, Wei; Finster, Kai; Skrydstrup, Troels; Meyer, Rikke Louise

2012-08-01

The use of microorganisms as support for reduction of dissolved Pd(II) to immobilized Pd(0) nanoparticles is an environmentally friendly approach for Pd recovery from waste. To better understand and engineer Pd(0) nanoparticle synthesis, one has to consider the mechanisms by which Pd(II) is reduced on microbial surfaces. Escherichia coli, Shewanella oneidensis, and Pseudomonas putida were used as model organisms in order to elucidate the role of microbial cells in Pd(II) reduction under acidic conditions. Pd(II) was reduced by formate under acidic conditions, and the process occurred substantially faster in the presence of cells as compared to cell-free controls. We found no difference between native (untreated) and autoclaved cells, and could demonstrate that even a non-enzymatic protein (bovine serum albumin) stimulated Pd(II) reduction as efficiently as bacterial cells. Amine groups readily interact with Pd(II), and to specifically test their role in surface-assisted Pd(II) reduction by formate, we replaced bacterial cells with polystyrene microparticles functionalized with amine or carboxyl groups. Amine-functionalized microparticles had the same effect on Pd(II) reduction as bacterial cells, and the effect could be hampered if the amine groups were blocked by acetylation. The interaction with amine groups was confirmed by infrared spectroscopy on whole cells and amine-functionalized microparticles. In conclusion, bio-supported Pd(II) reduction on microbial surfaces is possibly mediated by a non-enzymatic mechanism. We therefore suggest the use of amine-rich biomaterials rather than intact cells for Pd bio-recovery from waste. Copyright © 2012 Wiley Periodicals, Inc.

The characteristics of dissolved organic matter (DOM) in storm sewer sediments and the binding interaction with Cu(II) in four typical regions in Beijing, China.

Science.gov (United States)

Zhang, Ziyang; Li, Kun; Zhang, Xiaoran; Li, Haiyan

2017-07-01

In this work, dissolved organic matter (DOM) was extracted from storm sewer sediments collected in four typical regions (residential, campus, traffic and business regions) in Beijing, China. The basic characteristics of DOM were analyzed by UV-visible spectroscopy (UV-Vis), excitation-emission matrix Fluorescence Spectroscopy and Fourier Transform Infrared Spectroscopy. Furthermore, the complexation between DOM and Cu(II) were investigated. The results showed that there were large amount of aromatic structure in the DOM extracted from storm sewer sediments. The microbial activities had also made a contribution to the DOM in storm sewer sediments. The composition of DOM influenced the complexing capacity of Cu(II) greatly, which may be attributed to the protein-like and humic-like substances in storm sewer sediments. This study demonstrated valuable information on the structure present in the DOM of storm sewer sediments and provided new insight for exploring the relationship between DOM and co-existing heavy metals in storm sewer sediments.

Enhanced selective removal of Cu(II) from aqueous solution by novel polyethylenimine-functionalized ion imprinted hydrogel: Behaviors and mechanisms.

Science.gov (United States)

Wang, Jingjing; Li, Zhengkui

2015-12-30

A novel polyethylenimine-functionalized ion-imprinted hydrogel (Cu(II)-p(PEI/HEA)) was newly synthesized by (60)Co-γ-induced polymerization for the selective removal of Cu(II) from aqueous solution. The adsorption performances including the adsorption capacity and selectivity of the novel hydrogel were much better than those of similar adsorbents reported. The hydrogel was characterized via scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis and X-ray photoelectron spectroscopy to determine the structure and mechanisms. The adsorption process was pH and temperature sensitive, better fitted to pseudo-second-order equation, and was Langmuir monolayer adsorption. The maximum adsorption capacity for Cu(II) was 40.00 mg/g. The selectivity coefficients of ion-imprinted hydrogel for Cu(II)/Pb(II), Cu(II)/Cd(II) and Cu(II)/Ni(II) were 55.09, 107.47 and 63.12, respectively, which were 3.93, 4.25 and 3.53 times greater than those of non-imprinted hydrogel, respectively. Moreover, the adsorption capacity of Cu(II)-p(PEI/HEA) could still keep more than 85% after four adsorption-desorption cycles. Because of such enhanced selective removal performance and excellent regeneration property, Cu(II)-p(PEI/HEA) is a promising adsorbent for the selective removal of copper ions from wastewater. Copyright © 2015 Elsevier B.V. All rights reserved.

Adsorption of Pb(II and Cu(II by Ginkgo-Leaf-Derived Biochar Produced under Various Carbonization Temperatures and Times

Directory of Open Access Journals (Sweden)

Myoung-Eun Lee

2017-12-01

Full Text Available Ginkgo trees are common street trees in Korea, and the large amounts of leaves that fall onto the streets annually need to be cleaned and treated. Therefore, fallen gingko leaves have been used as a raw material to produce biochar for the removal of heavy metals from solutions. Gingko-leaf-derived biochar was produced under various carbonization temperatures and times. This study evaluated the physicochemical properties and adsorption characteristics of gingko-leaf-derived biochar samples produced under different carbonization conditions regarding Pb(II and Cu(II. The biochar samples that were produced at 800 °C for 90 and 120 min contained the highest oxygen- and nitrogen-substituted carbons, which might contribute to a high metal-adsorption rate. The intensity of the phosphate bond was increased with the increasing of the carbonization temperature up to 800 °C and after 90 min of carbonization. The Pb(II and Cu(II adsorption capacities were the highest when the gingko-leaf-derived biochar was produced at 800 °C, and the removal rates were 99.2% and 34.2%, respectively. The highest removal rate was achieved when the intensity of the phosphate functional group in the biochar was the highest. Therefore, the gingko-leaf-derived biochar produced at 800 °C for 90 min can be used as an effective bio-adsorbent in the removal of metals from solutions.

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

Science.gov (United States)

Chandra, Sulekh; Kumar, Anil

2007-12-01

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L 1) and semicarbazone (L 2) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L) 2(SO 4) and Cu(L) 2(SO 4) [where L = L 1 and L 2] which are of five coordinated square pyramidal geometry.

Microwave synthesis, spectral, thermal and antimicrobial studies of some Ni(II) and Cu(II) Schiff base complexes

OpenAIRE

Mishra, A. P.; Sharma, Neha; Jain, Rajendra K.

2012-01-01

Se sintetizaron bases de Schiff bidentadas y tridentadas (NO), (ONO) a través de la reacción de condensación entre la metil-isobutilcetona y el 2-amino-4clorofonol y 2-hidroxiacetofenona con la hidracina del ácido isonicotínico. Los complejos metálicos 1:1 o 1:2 han sido preparados mediante la interacción de estas bases de Schiff y los iones Ni(II) y Cu(II). La síntesis fue realizada empleando el método convencional y el de microondas, y los productos fueron caracterizados por análisis elemen...

Optimization of simultaneous electrochemical determination of Cd(II), Pb(II), Cu(II) and Hg(II) at carbon nanotube-modified graphite electrodes.

Science.gov (United States)

Pikna, L'ubomír; Heželová, Mária; Kováčová, Zuzana

2015-01-01

The health of the environment is worsening every day. Monitoring of potentially toxic elements and remediation of environmental pollution are necessary. Therefore, the research and development of simple, inexpensive, portable and effective sensors is important. Electrochemistry is a useful component of the field of environment monitoring. The present study focuses on evaluating and comparing three types of electrodes (PIGE, PIGE/MWCNT/HNO3 and PIGE/MWCNT/EDTA/HNO3) employed for the simultaneous electrochemical determination of four potentially toxic elements: Cd(II), Pb(II), Cu(II) and Hg(II). Cyclic voltammograms were measured in an acetate buffer. The LOD, LOQ, the standard and relative precisions of the method and a prediction intervals were calculated (according to the technical procedure DIN 32 645) for the three electrodes and for each measured element. The LOD for PIGE/CNT/HNO3 (the electrode with narrowest calculated prediction intervals) was 2.98 × 10(-7) mol L(-1) for Cd(II), 4.83 × 10(-7) mol L(-1) for Pb(II), 3.81 × 10(-7) mol L(-1) for Cu(II), 6.79 × 10(-7) mol L(-1) for Hg(II). One of the benefits of this study was the determination of the amount of Hg(II) in the mixture of other elements.

Effect of process parameters on removal and recovery of Cd(II) and Cu(II) from electroplating wastewater by fixed-bed column of nano-dimensional titanium (IV) oxide agglomerates

CSIR Research Space (South Africa)

Debnath, S

2014-01-01

Full Text Available Removal performances of Cd(II) and Cu(II) from water was investigated using agglomerated nanoparticle of hydrous titanium(IV) oxide (NTO) packed fixed bed. The parameters varied were the bed depth, flow rate and feed solution concentrations...

Synthesis, structure, luminescent, and magnetic properties of carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2] (Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato).

Science.gov (United States)

Ehama, Kiyomi; Ohmichi, Yusuke; Sakamoto, Soichiro; Fujinami, Takeshi; Matsumoto, Naohide; Mochida, Naotaka; Ishida, Takayuki; Sunatsuki, Yukinari; Tsuchimoto, Masanobu; Re, Nazzareno

2013-11-04

Carbonato-bridged Zn(II)2Ln(III)2 complexes [(μ4-CO3)2{Zn(II)L(n)Ln(III)(NO3)}2]·solvent were synthesized through atmospheric CO2 fixation reaction of [Zn(II)L(n)(H2O)2]·xH2O, Ln(III)(NO3)3·6H2O, and triethylamine, where Ln(III) = Gd(III), Tb(III), Dy(III); L(1) = N,N'-bis(3-methoxy-2-oxybenzylidene)-1,3-propanediaminato, L(2) = N,N'-bis(3-ethoxy-2-oxybenzylidene)-1,3-propanediaminato. Each Zn(II)2Ln(III)2 structure possessing an inversion center can be described as two di-μ-phenoxo-bridged {Zn(II)L(n)Ln(III)(NO3)} binuclear units bridged by two carbonato CO3(2-) ions. The Zn(II) ion has square pyramidal coordination geometry with N2O2 donor atoms of L(n) and one oxygen atom of a bridging carbonato ion at the axial site. Ln(III) ion is coordinated by nine oxygen atoms consisting of four from the deprotonated Schiff-base L(n), two from a chelating nitrate, and three from two carbonate groups. The temperature-dependent magnetic susceptibilities in the range 1.9-300 K, field-dependent magnetization from 0 to 5 T at 1.9 K, and alternating current magnetic susceptibilities under the direct current bias fields of 0 and 1000 Oe were measured. The magnetic properties of the Zn(II)2Ln(III)2 complexes are analyzed on the basis of the dicarbonato-bridged binuclear Ln(III)-Ln(III) structure, as the Zn(II) ion with d(10) electronic configuration is diamagnetic. ZnGd1 (L(1)) and ZnGd2 (L(2)) show a ferromagnetic Gd(III)-Gd(III) interaction with J(Gd-Gd) = +0.042 and +0.028 cm(-1), respectively, on the basis of the Hamiltonian H = -2J(Gd-Gd)ŜGd1·ŜGd2. The magnetic data of the Zn(II)2Ln(III)2 complexes (Ln(III) = Tb(III), Dy(III)) were analyzed by a spin Hamiltonian including the crystal field effect on the Ln(III) ions and the Ln(III)-Ln(III) magnetic interaction. The Stark splitting of the ground state was so evaluated, and the energy pattern indicates a strong easy axis (Ising type) anisotropy. Luminescence spectra of Zn(II)2Tb(III)2 complexes were observed, while those

Recovery of Cu(II from diluted aqueous solutions by non-dispersive solvent extraction

Directory of Open Access Journals (Sweden)

Alguacil, E. J.

2002-08-01

Full Text Available The removal of copper from diluted aqueous solutions with ACORGA M5640 extractant using non-dispersive solvent extraction technology was studied. It was possible to remove Cu(II below the international standars from solutions having initially as low concentration as 0,01 g/l under various experimental conditions, i.e aqueous pH 4.0, 10 % v/v ACORGA M5640 in Exxol D100, an organic flow of 100 ml/min, and an aqueous flow 50ml/min. Since the removal occurs by chelating ion exchange between copper from solution and protons from the extractant, the former was stripped by using a 180 g/l sulphuric acid solution which flowed (50 ml/min through the tube side organic was passed (400 ml/min through the shell side of the fibers of the module

Se estudia la eliminación del cobre presente en disoluciones acuosas diluidas empleando el agente de extracción ACORGA M5640 y la tecnología de extracción con disolventes no dispersiva. Bajo las condiciones experimentales estudiadas, pH de la fase acuosa 4,0 ±0,1, 10 % v/v ACORGA M5640 en Exxsol D100, flujo de la fase orgánica 100 ml/min, flujo de la fase acuosa 50 ml/min, es posible eliminar el Cu(II, por debajo de los límites marcados internacionalmente, en disoluciones con un contenido tan bajo como 0,01 g/1 del metal. Debido a que la extracción transcurre mediante un intercambio catiónico (y formación de un compuesto tipo quelato entre el cobre presente en el medio acuoso y los protones del agente de extracción, el metal se puede reextraer mediante la utilización de una disolución de 180 g/1 de ácido sulfúrico que fluye (50 ml/min a través de la parte interior de las fibras del módulo, mientras que la fase orgánica fluye (400 ml/min por la parte exterior de las mismas fibras.

Synthesis, crystal structures, spectral, thermal and antimicrobial properties of new Zn(II) 5-iodo- and 5-bromosalicylates

Science.gov (United States)

Košická, Petra; Győryová, Katarína; Smolko, Lukáš; Gyepes, Róbert; Hudecová, Daniela

2018-03-01

Two new analogous zinc(II) complexes containing 5-iodo- and 5-bromosalicylate ligands, respectively, were prepared in single-crystal form and characterized by IR spectroscopy, thermal analysis and elemental analysis. The solid-state structures of prepared complexes were determined by single crystal X-ray crystallography. Both complexes are isostructural and their crystal structures composed of neutral molecules [Zn(5-Xsal)2(H2O)2] (where X = Br, I, sal = salicylato). Central Zn(II) atom is in both complexes coordinated by six oxygen atoms, four of which are from two chelate bonded 5-halosalicylates and remaining two from coordinated water molecules. The found chelate binding mode is in line with the Δ values calculated from IR spectral data. Antimicrobial activity of prepared complexes was studied against selected bacteria, yeast and filamentous fungi. Obtained results indicate that 5-iodosalicylate complex is more antimicrobially active than its 5-bromo substituted analogue.

Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

Science.gov (United States)

Refat, Moamen S.

2013-03-01

Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

Propyl phthalimide-modified thiacalixphenyl[4]arene as a “turn on” chemosensor for Hg(II) ions

Energy Technology Data Exchange (ETDEWEB)

Modi, Krunal; Panchal, Urvi; Mehta, Viren; Panchal, Manthan; Kongor, Anita; Jain, V.K., E-mail: drvkjain@hotmail.com

2016-11-15

Thiacalixphenyl[4]arene tetra N-(3-propyl) phthalimide (TPTN3PPh), a novel thiacalixarene bearing a N-(3-bromopropyl) phthalimide group, was synthesized and characterized by Electrospray Ionization Mass Spectrometry (ESI-MS) and NMR. The ability of TPTN3PPh to recognize the cations Fe(III), Cu(II), Cd(II), Zn(II), Cr(II), Ca(II), Co(II), Mg(II), Ag(I), Pb(II), Sr(II), Hg (II), Th(II), Ba(II), Bi(II), K(I), and Na(I) was evaluated. Only Hg(II) was selectively and sensitively detected using a spectrofluorimetric method, with a detection limit as low as 3.10×10{sup −9} M. Analysis of the binding behavior of TPTN3PPh with Hg(II) revealed 1:2 complex formation. Real sample analysis detected nano levels of mercury ions in a waste water samples.

Coordination chemistry and bioactivity of Ni2+, Cu2+, and Zn2+ complexes containing a bidentate NS ligand, β-N-phenyldithiocarbazic acid, and the crystal structure of β-hydroxy-β-phenylmethylene α-phenylimine

International Nuclear Information System (INIS)

Tarafder, M.T.H.; Ahmed Faizal Shamsuddin; Grouse, Karen A.; Yamin, B.M.; Ali, A.M.; Fun, H.-K.

2003-07-01

A bidentate ligand (PhDTCH) with NS donor sequence was prepared from the reaction between carbon disulfide and phenylhydrazine in ethanol. Complexes of this ligand with Ni(II), Cu(II) and Zn(II) were synthesized and characterized by elemental analyses, and various physicochemical techniques. The metal complexes were all four coordinated. In an attempt to resolve the crystal structure of PhDTCH, an ethanolic solution, after leaving for a few days gave bright crystals of PhD6, β-hydroxy-β-phenylmethylene α-phenylimine, the crystal structure of which has been resolved. The crystal packing indicated that it is monoclinic with a space group of P21/n. All of the compounds were tested against different bacteria and fungi, and also against leukemic cell lines. All of the compounds showed weak biological properties compared to standard drugs. (author)

Coordination compounds of cobalt(II), nickel(II), copper(II), and zinc(II) with pantothenic acid

Energy Technology Data Exchange (ETDEWEB)

Shabilalov, A.A.; Yunuskhodzhaev, A.N.; Khodzhaev, O.F.; Azizov, M.A.

1986-11-01

The compounds Ni(PANA - H)/sub 2/ x 4H/sub 2/O (PANA stands for pantothenic acid, and - H indicates a deprotonated ligand), Cu(PANA - H)/sub 2/ x 2H/sub 2/O, Zn(PANA - H)/sub 2/ x H/sub 2/O, Co(PANA - H)Cl x H/sub 2/O, and Ni(PANA - H)Cl x 3H/sub 2/O have been synthesized on the basis of pantothenic acid and Co(II), Ni(II), Cu(II), and Zn(II) salts in aqueous media. The compounds have been identified by elemental and x-ray diffraction analysis. Some physicochemical properties (solubility, melting point, molar conductivity) of the compounds obtained have been studied. The structure of the compounds isolated has been established on the basis of an analysis of their IR, ESR, and electronic spectra, as well as derivatograms.

Coordination Polymers of N, Nʼ-di-(8-Hydroxyquinolinolyl- 5-methyl-N, N-diethyl-1,3-propane diamine (QEPD

Directory of Open Access Journals (Sweden)

Asha D. Patel

2010-01-01

Full Text Available Coordination polymers containing a novel bis(oxine bidentate ligand, namely N,Nʼ-di(8-hydroxyquinolinolyl-5-methyl-N,Nʼ-diethyl-1,3-propane diamine (QEPD have been prepared with the metal ions Zn(II, Cu(II, Ni(II, Co(II and Mn(II. The novel bis-(bidentate ligand was synthesized by condensation of 5-chloromethyl-8-hydroxyquinoline hydrochloride with N,Nʼ-diethyl-1,2- propane diamine in the presence of a base catalyses. All of these coordination polymers and the parent ligand were characterized by elemental analyses, IR spectral and diffuse reflectance spectral studies. The thermal stability and number- average molecular weights (Mn¯ of all of the coordination polymers were determined by thermogravimetric analyses and non-aqueous conductometric titrations, respectively. In addition, all of the coordination polymers have been characterized by their magnetic susceptibilities.

Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes

Science.gov (United States)

Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M. Arif

2016-05-01

We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.

Mandelazo I as a reagent for Zr(IV) determination

International Nuclear Information System (INIS)

Rakha, T.H.; Filip, P.; Stefan, N.

1984-01-01

A spectrometric study of the reaction of the Zr(IV) ions with Mandelazo I was carried out. Absorption spectra revealed that the maximum absorption of the zirconium compound appears at a wavelength (316 nm) different from the maxima of the reagent (253 and 390 nm). Beer-Lambert law is followed for zirconium concentrations of the order of 8.8 x 10 -5 M (i.e. 8 μg Zr(IV)/mL). Possible interferences of ions such as Be(II), Cu(II), Zn(II), Al(III), Th(IV), U(VI), Mn(II), Fe(III), Co(II) and Ni(II) were investigated in connection with some masking agents such as SO 4 2- and C 2 O 4 2- . Also, the solid state Zr(IV)- Mandelazo I compound was prepared and characterized by nitrogen and thermogravimetric analyses

Characterization and use of in natura and calcined rice husks for biosorption of heavy metals ions from aqueous effluents

Directory of Open Access Journals (Sweden)

M. G. A. Vieira

2012-09-01

Full Text Available Heavy metal removal by adsorption using rice husks as a bioadsorbent was evaluated as an alternative for wastewater treatment. Batch equilibrium experiments and kinetic sorption studies were performed using monocomponent solutions of Ni(II, Cd(II, Zn(II, Pb(II and Cu(II in surface samples of in natura(RH and calcined rice husks (RHA. RHA showed higher potential for removing lead and copper. Experimental data for adsorption isotherms of lead and copper were adjusted by Langmuir, Freundlich and Dubinin-Radushkevick (D-R models, being better represented by the Langmuir model. The calcination of RH increased its surface area, improving its adsorption properties. From a morphological analysis obtained by SEM and diffraction patterns (XRD, a longitudinal fibrous and amorphous structure was observed for RH. TGA resultsindicated a total mass loss of around 60% for RH and 24.5% for RHA.

New 15-membered tetraaza (N4) macrocyclic ligand and its transition metal complexes: Spectral, magnetic, thermal and anticancer activity

Science.gov (United States)

El-Boraey, Hanaa A.; EL-Gammal, Ohyla A.

2015-03-01

Novel tetraamidemacrocyclic 15-membered ligand [L] i.e. naphthyl-dibenzo[1,5,9,12]tetraazacyclopentadecine-6,10,11,15-tetraoneand its transition metal complexes with Fe(II), Co(II), Ni(II), Cu(II), Ru(III) and Pd(II) have been synthesized and characterized by elemental analysis, spectral, thermal as well as magnetic and molar conductivity measurements. On the basis of analytical, spectral (IR, MS, UV-Vis, 1H NMR and EPR) and thermal studies distorted octahedral or square planar geometry has been proposed for the complexes. The antitumor activity of the synthesized ligand and some complexes against human breast cancer cell lines (MCF-7) and human hepatocarcinoma cell lines (HepG2) has been studied. The complexes (IC50 = 2.27-2.7, 8.33-31.1 μg/mL, respectively) showed potent antitumor activity, towards the former cell lines comparable with their ligand (IC50 = 13, 26 μg/mL, respectively). The results show that the activity of the ligand towards breast cancer cell line becomes more pronounced and significant when coordinated to the metal ion.

Selective enrichment and determination of monoamine neurotransmitters by CU(II) immobilized magnetic solid phase extraction coupled with high-performance liquid chromatography-fluorescence detection.

Science.gov (United States)

He, Maofang; Wang, Chaozhan; Wei, Yinmao

2016-01-15

In this paper, iminodiacetic acid-Cu(II) functionalized Fe3O4@SiO2 magnetic nanoparticles were prepared and used as new adsorbents for magnetic solid phase extraction (MSPE) of six monoamine neurotransmitters (MNTs) from rabbit plasma. The selective enrichment of MNTs at pH 5.0 was motivated by the specific coordination interaction between amino groups of MNTs and the immobilized Cu(II). The employed weak acidic extraction condition avoided the oxidation of MNTs, and thus facilitated operation and ensured higher recoveries. Under optimal conditions, the recoveries of six MNTs from rabbit plasma were in the range of 83.9-109.4%, with RSD of 2.0-10.0%. When coupled the Cu(II) immobilized MSPE with high-performance liquid chromatography-fluorescence detection, the method exhibited relatively lower detection limits than the previously reported methods, and the method was successfully used to determine the endogenous MNTs in rabbit plasma. The proposed method has potential application for the determination of MNTs in biological samples. Also, the utilization of coordination interaction to improve the selectivity might open another way to selectively enrich small alkaloids from complex samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Sulfonated Magnetic Nanocomposite Based on Reactive PGMA-MAn Copolymer@Fe3O4 Nanoparticles: Effective Removal of Cu(II Ions from Aqueous Solutions

Directory of Open Access Journals (Sweden)

Reza Hasanzadeh

2016-01-01

Full Text Available Chelating magnetic nanocomposites have been considered as suitable materials for removal of heavy metal ions for water treatment. In this work poly(glycidyl methacrylate-maleic anhydride copolymer (PGMA-MAn is modified with 4-aminobenzenesulfonic acid (ABSAc and subsequently the product reacted with modified Fe3O4 nanoparticles and 1,2-ethanedithiol (EDT in the presence of ultrasonic irradiation for preparation of tridimensional chelating magnetic nanocomposite. Synthesized magnetic nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, X-ray diffraction analysis (XRD, vibrating sample magnetometer (VSM, energy dispersive X-ray analysis (EDX, elemental mapping analysis (EMA, Brunauer-Emmett-Teller (BET, and thermal gravimetric analysis (TGA. The adsorption behavior of Cu(II ions was investigated by synthesized nanocomposite in various parameters such as pH, contact time, metal ion concentration, and adsorbent dosage. The equilibrium distribution coefficient (kd was determined and the findings prove that the kd value is approximately high in the case of all selected metal ions. The synthesized nanocomposite exhibited good tendency for removing Cu(II ions from aqueous solutions even at an acidic pH.

Synthesis of Zn(II) 5,10,15,20-tetrakis(4'-isopropylphenyl) porphyrin and its use as a thin film sensor

Energy Technology Data Exchange (ETDEWEB)

Sayyad, Muhammad H.; Saleem, Muhammad [GIK Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (FES), Topi, District Swabi, NWFP (Pakistan); Karimov, Khasan S. [GIK Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (FES), Topi, District Swabi, NWFP (Pakistan); Physical Technical Institute of Academy of Sciences, Dushanbe (Tajikistan); Yaseen, Muhammad [University of the Punjab, Institute of Chemistry, Lahore (Pakistan); Ali, Mukhtar [Government College of Science, Lahore (Pakistan); Cheong, Kuan Y.; Mohd Noor, Ahmad F. [Universiti Sains Malaysia, School of Materials and Mineral Resources Engineering, Engineering Campus, Nibong Tebal, Penang (Malaysia)

2010-01-15

In this paper, we have reported the synthesis and use of an organic semiconductor Zn(II) 5,10,15,20-tetrakis(4'-isopropylphenyl) porphyrin (ZnTIPP) as an active material in a surface type sensor. Ag/ZnTIPP/Ag sensor was fabricated by thermal sublimation of ZnTIPP on a glass substrate with preliminary deposited surface type silver electrodes. Semiconducting channel between silver electrodes was 0.04 mm x 15 mm. Changes in electrical measurements of the device were observed with increase of relative humidity, illumination, and temperature. A small degree of hysteresis and acceptable response and recovery times were observed over a wide range of relative humidity. Activation energy of the ZnTIPP was estimated. (orig.)

A study of the removal of heavy metals from aqueous solutions by Moringa oleifera seeds and amine-based ligand 1,4-bis[N,N-bis(2-picoyl)amino]butane

Energy Technology Data Exchange (ETDEWEB)

Obuseng, Veronica; Nareetsile, Florence [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana); Kwaambwa, Habauka M., E-mail: hmkwaambwa@yahoo.com [Department of Chemistry, University of Botswana, Private Bag UB 00704, Gaborone (Botswana)

2012-06-12

Highlights: Black-Right-Pointing-Pointer Materials are effective and selective in simultaneous removal of heavy metal ions. Black-Right-Pointing-Pointer Use of composite adsorbent of both materials may result in more effective material. Black-Right-Pointing-Pointer Seeds biomass has various functional groups involves in metal removal. Black-Right-Pointing-Pointer Attainment of sorption equilibrium is rapid for the seeds biomass. Black-Right-Pointing-Pointer Seeds biomass effectiveness is not affected over wide effective pH range. - Abstract: Uptake for lead, copper, cadmium, nickel and manganese from aqueous solution using the Moringa oleifera seeds biomass (MOSB) and amine-based ligand (ABL) was investigated. Experiments on two synthetic multi-solute systems revealed that MOSB performed well in the biosorption and followed the decreasing orders Pb(II) > Cu(II) > Cd(II) > Ni(II) > Mn(II) and Zn(II) > Cu(II) > Ni(II). The general trend of the heavy metal ions uptake by the amine-based ligand followed decreased in the order Mn > Cd > Cu > Ni > Pb, which is the reverse trend for what was observed for MOSB. Comparing the single- and multi-metal solutions, there was no clear effect in the biosorption capacity of MOSB suggesting the presence of sufficient active binding sites for all metal ions studied. The MOSB performance is also not affected by pH in the range 3.5-8.

Synthesis and characterization of monomeric and polymeric Cu(II) complexes of 3,4-ethylenedioxythiophene-functionalized with cyclam ligand

International Nuclear Information System (INIS)

Velauthamurty, Kuhamoorthy; Higgins, Simon J.; Rajapakse, R.M. Gamini; Bandara, H.M.N.; Shimomura, Masaru

2010-01-01

A functionalized EDOT derivative with 1,4,8,11-tetraazacyclotetradecane (cyclam) ligand pendant to the ethylene bridge (4) and its complexes [M(4)(BF 4 ) 2 ], where M(II) = Cu(II), was prepared and characterized. Their electrochemical copolymerization with EDOT was studied. The electro-co-polymerized films were characterized by electrochemical methods, X-ray photoelectron spectroscopy and by X-ray fluorescence spectroscopy. The co-polymerization method was found to afford a good control of the metal concentration in the polymer matrix and represents a good technique for preparing electronically conductive polymers containing redox-active metal complexes.

EDTA excess Zn(II) back-titration in the presence of 4-(2-pyridylazo)-resorcinol indicator and naphthol green β as inert dye for determining Cr(III) as Cr(III)/EDTA complex: Application of the method to a leather industry wastewater

International Nuclear Information System (INIS)

Venezia, M.; Alonzo, G.; Palmisano, L.

2008-01-01

The colour changes of 4-(2-pyridylazo)-resorcinol and naphthol green β as new screening metallochromic indicator in back-titration of EDTA excess with Zn(II) to determine Cr(III)/EDTA complex was investigated with the help of tristimulus colorimetry. Specific colour discrimination (SCD) and L*, a*, b* 1976 parameters were successfully applied to evaluate the quality of colour transition at the end-point in non-alkaline media and in the presence of Zn(II) and Ca(II) which resulted in non-interfering species at 1 x 10 -3 M and 2 x 10 -3 M, respectively. The above concentrations are comparable with those used for Cr(III). Validation of the fast and accurate reported method was performed by atomic absorption spectroscopy. Moreover, the method was applied for determining Cr as Cr(III) in a wastewater effluent deriving from a leather industry

Non-enzymatic palladium recovery on microbial and synthetic surfaces

DEFF Research Database (Denmark)

Rotaru, Amelia-Elena; Jiang, Wei; Finster, Kai

2012-01-01

in the presence of cells as compared to cell-free controls. We found no difference between native (untreated) and autoclaved cells, and could demonstrate that even a non-enzymatic protein (bovine serum albumin) stimulated Pd(II) reduction as efficiently as bacterial cells. Amine groups readily interact with Pd......(II), and to specifically test their role in surface-assisted Pd(II) reduction by formate, we replaced bacterial cells with polystyrene microparticles functionalized with amine or carboxyl groups. Amine-functionalized microparticles had the same effect on Pd(II) reduction as bacterial cells, and the effect could...... be hampered if the amine groups were blocked by acetylation. The interaction with amine groups was confirmed by infrared spectroscopy on whole cells and amine-functionalized microparticles. In conclusion, bio-supported Pd(II) reduction on microbial surfaces is possibly mediated by a non-enzymatic mechanism...

Column Chromatography Of Co(II), Zn(II) And Eu(III) Using Pistachio Shell And Different Mobile Phases

International Nuclear Information System (INIS)

Abdel-Fattah, A.A.

2009-01-01

Pistachio shell particles (0.5-1 mm) have been applied as the stationary phase for studying the column chromatography of Co(II), Zn(II) and Eu(III) at room temperature; 26 + - 1 oC. This solid sorbent has been characterized by thermogravimetric analysis, infra-red spectroscopy and X-ray diffraction. Its surface area and percent of swelling have been also determined. Different eluting agents have been used for eluting the sorbed elements. The elution curves have been done from which the distribution coefficients (K d ), number of theoretical plates (N) and heights equivalent to theoretical plates (H) have been determined. Column performance studies have been conducted for a representative system under certain experimented conditions and Van Deemter equation has been applied. Thermodynamic studies have been applied and thermodynamic functions ( δG 0 ,δH 0 andδ S 0 ) have been calculated for this representative system by determining K d at three different room temperatures (18, 26 and 37 + - 1o C).

Batch removal and optimization of Cu(II) ions from aqueous solution by biosorption on to native and pretreated mangifera indica seeds

International Nuclear Information System (INIS)

Noreen, A.; Ali, G.; Jabeen, M.

2011-01-01

Biosorption is a process that utilizes biomass to sequester toxic heavy metals and is particularly useful for the removal of contaminants from industrial effluents. Present study involved batch experiments for the sorption of Cu(II) onto Mangifera indica seeds kernel particles in order to optimize the biosorbent dose, agitation rate, pH, contact time and initial metal ion concentration. The effect of citric acid pretreatment was also studied. Maximum uptake was observed at pH 5, biosorbent dose 0.5 g and agitation rate 150 rpm. A direct correlation was found to exist between adsorbed Cu(II) ion concentration and initial metal concentration upto a certain level then it reached a saturation value at about 250 mg/L. Biosorption equilibrium was established by 60 min. The maximum metal uptake capacity was 13.2 mg/g at optimized conditions. The uptake capacity of the biomass was increased by chemical pretreatment with citric acid (15.2 mg/g) when compared with the raw biomass (13.2 mg/g). Equilibrium data was fitted to Freundlich and Langmuir isotherm equations and the data was found to well represented by Langmuir isotherm equation with r/sup 2/ = 0.9981 and q/sub max/ = 17.939 mg/g for raw biomass and with r/sup 2/ = 0.9984 and qmax 18.57 mg/g for modified biomass. (author)

Synthesis of a new ONNO donor tetradentate schiff base ligand and binuclear Cu(II) complex: Quantum chemical, spectroscopic and photoluminescence investigations

International Nuclear Information System (INIS)

Sarıoğlu, Ahmet Oral; Ceylan, Ümit; Yalçın, Şerife Pınar; Sönmez, Mehmet; Ceyhan, Gökhan; Aygün, Muhittin

2016-01-01

The Schiff base compound 3,3′-(1,4-phenylimino)-bis-[1,3-bis-(4-methoxyphenyl) propan-1-one)], formulated as C 40 H 36 N 2 O 6, and its Cu(II) complex were synthesized and characterized by analytical analysis, various spectral techniques such as FT-IR, NMR, UV–vis, magnetic measurements and molar conductivity. Thermo gravimetric analysis (TGA and DTA) carried out to obtain information about its thermal stability. The molecular structure and spectroscopic properties of the ligand were obtained with FT-IR, 1 H and 13 C NMR, UV–vis investigations as experimentally and compared with theoretical results obtained from DFT/B3LYP/6-311++G(d,p) basis set. In addition to molecular calculations of the title compound, molecular electrostatic potential (MEP), dipole moments, atomic charges, HOMO–LUMO, NLO and NBO analysis were computed. The calculated results show that the optimized geometry can well reproduce the crystal structure parameters, and the theoretical vibrational frequencies, 1 H and 13 C NMR chemical shifts show good agreement with experimental values. Photoluminescence properties of the ligand and its Cu(II) complex were examined. - Highlights: • FT-IR and 1 H– 13 C NMR spectra were recorded and compared with the theoretical results. • The photoluminescence properties were studied. • NLO, NBO analysis of the molecule were studied. • HOMO and LUMO energies, MEP distribution of the molecule were calculated.

Biosorption of Cu(II) from aqueous solutions by mimosa tannin gel

Energy Technology Data Exchange (ETDEWEB)

Sengil, I. Ayhan [Department of Environmental Engineering, Engineering Faculty, Sakarya University, 54100 Sakarya (Turkey)], E-mail: asengil@sakarya.edu.tr; Ozacar, Mahmut [Department of Chemistry, Science and Arts Faculty, Sakarya University, 54100 Sakarya (Turkey)

2008-09-15

The biosorption of Cu(II) from aqueous solutions by mimosa tannin resin (MTR) was investigated as a function of particle size, initial pH, contact time and initial metal ion concentration. The aim of this study was to understand the mechanisms that govern copper removal and find a suitable equilibrium isotherm and kinetic model for the copper removal in a batch reactor. The experimental isotherm data were analysed using the Langmuir, Freundlich and Temkin equations. The equilibrium data fit well in the Langmiur isotherm. The experimental data were analysed using four sorption kinetic models - the pseudo-first- and second-order equations, and the Elovich and the intraparticle diffusion equation - to determine the best fit equation for the biosorption of copper ions onto mimosa tannin resin. Results show that the pseudo-second-order equation provides the best correlation for the biosorption process, whereas the Elovich equation also fits the experimental data well. Thermodynamic parameters such as the entropy change, enthalpy change and Gibb's free energy change were found out to be 153.0 J mol{sup -1} K{sup -1}, 42.09 kJ mol{sup -1} and -2.47 kJ mol{sup -1}, respectively.

The adsorption of Tl(I), Au(III), Cu(II) and the separation of 199Tl from alpha bombardment of gold target with PDB-18C6

International Nuclear Information System (INIS)

Zhou Dehai; Zhou Jimeng

1989-01-01

The adsorptive behavior of polymer of methyl aldehyde of dibenzo-18-crown-6 (PDB-18C6) in hydrochloric acid medium is studied and it is shown that the adsorption of T1(I), Au(III), and Cu(II) depends on the particle size of the crown ether resins, hydrochloric acid concentration and amount of the crown ether resins used. The difference in the adsorption behavior of different particle sizes of crown ether resins may be used for separating Tl(I), Au(III), and Cu(II) ions. The best eluant of Tl(I) and Au(III) is 0.4 mol/l perchloric acid and 2-ethoxy-ethanol. The recovery for Tl(I) is 82-98.8%. The gold target is bombarded in a 1.2 m cyclotron with 25-27 MeV α-particle with a cumulative beam intensities of 27μA·h, and 199 Tl is separated from the gold target with PDB-18C6. γ-spectrometry has shown that the Tl obtained is 199 Tl of high purity containing only about 0.50% 200 Tl

Cd(II) and Zn(II) Complexes Containing N,N'-Bidentate N-(Pyridin-2-ylmethylene)cyclopentanamine: Synthesis, Characterisation and Methyl Methacrylate Polymerisation

Energy Technology Data Exchange (ETDEWEB)

Song, Yu Jin; Lee, Ha Jun; Lee, Hyo Sun [Kyungpook National University, Daeju (Korea, Republic of)

2014-09-15

The reaction between [CdBr{sub 2}·4H{sub 2}O] and anhydrous [ZnCl{sub 2}] with N,N'-bidentate N-(pyridin-2-ylmethylene)- cyclopentanamine (impy) in ethanol yields dimeric [(impy)Cd(μ-Br)Br]2 and monomeric [(impy)ZnCl{sub 2}] complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in [(impy)Cd(μ-Br)Br]2 and zinc in [(impy)ZnCl{sub 2}] formed a distorted trigonal–bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

Schiff bases derived from L-Tyrosine L-Tryptophan and their Cu(II) chelates as effective means for preventive-treatment of radiation injuries

International Nuclear Information System (INIS)

Malakyan, M.H.; Bajinyan, S.A.; Matosyan, V.H.; Tonoyan, V.J.; Babayan, K.N.; Boyajyan, A.S.; Yeghiazaryan, D.E.; Vardevanyan, L.A.; Sorenson, J.R.J.

2008-01-01

Full text: Study on essential metallo element chelates as radioprotectors presents a promising direction in a search for and development of novel anti-radiation agents and offers a new approach to overcome the pathological effects of ionizing radiation. The key idea elucidating the radioprotective effects of metallo element-containing chelates of amino acid derivatives is their role in stimulation of de novo synthesis of metallo element-dependent enzymes required for recovery of hemopoietic activity and immuno competency lost as a consequence of radiation damage. Aimed to develop novel anti-radiation remedies of less toxicity and high efficacy, Schiff bases derived from L-Tyrosine and L-Tryptophan and their Cu(II) chelates were synthesized. In experiments in vitro and in vivo biological and pharmacological properties of the mentioned Schiff Bases and their copper complexes are under study. According to the results obtained, L-Tyrosinate and L-Tryptophanate Schiff bases are low toxic compounds with a weak antioxidant activity and exert radioprotective effects in case of animal X-ray irradiation at a dose level equal or less than LD 50/30 . Unlike Schiff Bases, their appropriate Cu(II) chelates possess high anti radical/antioxidant activity and manifest expressed radio-protective action at LD 100/30 dose of ionizing radiation. Anti-radiation effects of amino acid Schiff bases and their metallo chelates are manifested in case of both subcutaneous and oral single administration to the animal organism at 10, 20, or 40 mg/kg 1, 3, 6, or 24 hours prior to radiation exposure. Conclusions are drawn basing on determinations of survival and average life-span indices of irradiated animals, as well as on studies for their hematological, biochemical, immunological, biophysical indices. It is revealed that on the background of preliminary administration of the compounds studied to the animal organism the characteristics of DNA are significantly improved, the immune status

EDTA excess Zn(II) back-titration in the presence of 4-(2-pyridylazo)-resorcinol indicator and naphthol green {beta} as inert dye for determining Cr(III) as Cr(III)/EDTA complex: Application of the method to a leather industry wastewater

Energy Technology Data Exchange (ETDEWEB)

Venezia, M.; Alonzo, G. [Dipartimento di Ingegneria e Tecnologie Agro Forestali, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Palmisano, L. [Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita degli Studi di Palermo, Viale delle Scienze, 90128 Palermo (Italy)], E-mail: palmisano@dicpm.unipa.it

2008-03-01

The colour changes of 4-(2-pyridylazo)-resorcinol and naphthol green {beta} as new screening metallochromic indicator in back-titration of EDTA excess with Zn(II) to determine Cr(III)/EDTA complex was investigated with the help of tristimulus colorimetry. Specific colour discrimination (SCD) and L*, a*, b* 1976 parameters were successfully applied to evaluate the quality of colour transition at the end-point in non-alkaline media and in the presence of Zn(II) and Ca(II) which resulted in non-interfering species at 1 x 10{sup -3} M and 2 x 10{sup -3} M, respectively. The above concentrations are comparable with those used for Cr(III). Validation of the fast and accurate reported method was performed by atomic absorption spectroscopy. Moreover, the method was applied for determining Cr as Cr(III) in a wastewater effluent deriving from a leather industry.

Synthesis, spectral and thermal studies of pyridyl adducts of Zn(II) and Cd(II) dithiocarbamates, and their use as single source precursors for ZnS and CdS nanoparticles

OpenAIRE

Onwudiwe, Damian C.; Strydom, Christien A.; Jordaan, Anine; Oluwafemi, Oluwatobi S.; Hosten, Eric

2014-01-01

The synthesis, spectroscopic characterisation, and thermal studies of pyridyl adducts of Zn(II) and Cd(II) complexes of N-ethyl-N-phenyl dithiocarbamate, represented as [ZnL2py] and [CdL2py2], are reported. Single-crystal X-ray structural analysis of the Zn compound showed that it is five-coordinate with four sulphurs from dithiocarbamate and one nitrogen from pyridine in a distorted square pyramidal geometry. The thermogravimetric studies indicate that the zinc and cadmium compou...

Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes.

Science.gov (United States)

Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M Arif

2016-05-15

We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect on the Inhibitory Activity of Potential Microbes on the Complexation of Methyl Anthranilate Derived Hydrazide with Cu, Ni and Zn (II) Metal Ions

International Nuclear Information System (INIS)

Ikram, M.; Rehman, S.; Khan, K.

2013-01-01

The hydrazide ligand 2-amino-(N-aminobezoyl)benzohydrazide (ABH) have been synthesized and characterized by 1H-NMR, 13C-NMR, ES+-MS, elemental analyses and infrared studies. The ligand was complexed with Ni(II), Cu(II) and Zn(II) metal ions and were characterized by analytical and spectroscopic methods including elemental analyses, ES+-MS, conductance, infrared, UV-Visible and magnetic susceptibilities studies. Infrared spectra show that the ligand form complexes through -NH2 and carbonyl moieties, the elemental studies suggested the M(ABH)X2 composition of the coordination compounds. The synthesized complexes were studied for their biological activities against gram negative bacteria including Escherichia coli, Salmonella typhi, Enterobacter aerogenes, Proteus vulgaris, Pseudomonas aeruginosa, Gram positive bacterial strains like Staphylococcus aureus and fungus like Candida albican. These activities show that the metal complexes are more active to the tested microbes as compared to neat ligand. (author)

Organically Modified Silica with Pyrazole-3-carbaldehyde as a New Sorbent for Solid-Liquid Extraction of Heavy Metals

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Smaail Radi

2013-12-01

Full Text Available A new chelating matrix, SiNP, has been prepared by immobilizing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel modified with 3-aminopropyl-trimethoxysilane. This new chelating material was well characterized by elemental analysis, FT-IR spectroscopy, cross polarization magic angle spinning solid state 13C-NMR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore size, and scanning electron microscopy (SEM. The new product exhibits good chemical and thermal stability as determined by thermogravimetry curves (TGA. The new prepared material was used as an adsorbent for the solid-phase extraction (SPE of Pb(II, Cd(II, Cu(II and Zn(II from aqueous solutions using a batch method, prior to their determination by flame atomic adsorption spectrometry. The adsorption capacity was investigated using kinetics and pH effects. Common coexisting ions did not interfere with separation and determination.

Determination of trace impurities in high-purity iron using salting-out of polyoxyethylene-type surfactants

Energy Technology Data Exchange (ETDEWEB)

Matsumiya, Hiroaki, E-mail: h-matsu@numse.nagoya-u.ac.jp [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Sakane, Yuto; Hiraide, Masataka [Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2009-10-19

To an iron sample solution was added polyoxyethylene-4-isononylphenoxy ether (PONPE, nonionic surfactant, average number of ethylene oxides 7.5) and the surfactant was aggregated by the addition of lithium chloride. The iron(III) matrix was collected into the condensed surfactant phase in >99.9% yields, leaving trace metals [e.g., Ti(IV), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pb(II), and Bi(III)] in the aqueous phase. After removing the surfactant phase by centrifugation, the remaining trace metals were concentrated onto an iminodiacetic acid-type chelating resin. The trace metals were desorbed with dilute nitric acid for the determination by inductively coupled plasma-mass spectrometry or graphite-furnace atomic absorption spectrometry. The proposed separation method allowed the analysis of high-purity iron metals for trace impurities at low {mu}g g{sup -1} to ng g{sup -1} levels.

Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions

International Nuclear Information System (INIS)

Ghandour, M.A.; Azab, H.A.; Hassan, A.; Ali, A.M.

1992-01-01

The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO 2 (II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25±0.1 deg C and μ=0.1 moll -1 (NaNO 3 ). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO 2 (II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors)

Potentiometric studies on the complexes of tetracycline (TC) and oxytetracycline (OTC) with some metal ions. Potentiometrische Untersuchungen der Komplexe von Tetracyclin (TC) und Oxytetracyclin (OTC) mit einigen Metall-Ionen

Energy Technology Data Exchange (ETDEWEB)

Ghandour, M A; Azab, H A; Hassan, A; Ali, A M [Assiut Univ. (Egypt)

1992-01-01

The interaction of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Hg(II), Pb(II), Al(III), and UO[sub 2](II) ions with tetracycline (TC) were studied by potentiometric pH titrations. The formation constants of the different binary complexes formed in such systems have been determined at 25[+-]0.1 deg C and [mu]=0.1 moll[sup -1] (NaNO[sub 3]). Potentiometric pH equilibrium measurements have been made under the same conditions for the interaction of oxytetracycline (OTC) and Cu(II), Cd(II), Pb(II), and UO[sub 2](II). The formation of (1:1) binary complexes are inferred from the potentiometric pH titration curves. The protonation constants of TC and OTC were also determined under the same conditions and refined (ESAB2M computer program). The transition metal stability constants are consistent with the Irving-Williams series. (authors).

Extraction of metal cations by polyterephthalamide microcapsules containing a poly(acrylic acid) gel.

Science.gov (United States)

Laguecir, A; Ernst, B; Frère, Y; Danicher, L; Burgard, M

2002-01-01

Polyterephthalamide microcapsules containing a poly(acrylic acid) gel as a macromolecular ligand (PAA-CAPS) were prepared using an original two step polymerization process in a water-in-oil inverse emulsion system. A polyamide microcapsule containing acrylic acid, initiator and cross-linking agent, is formed by interfacial polycondensation of terephthaloyl dichloride with hexamethylenediamine. In situ radical polymerization of the microcapsule core acrylic acid is initiated to obtain encapsulated poly(acrylic acid) gel. Reference polyamide microcapsules, i.e. without ligand (CAPS), were also synthesized. The mean diameter of synthesized microcapsules was 210 microm, and the microcapsule wall thickness was evaluated by SEM and TEM observations of microcapsule cross-section cuts. The microcapsule water content was determined by thermogravimetric experiments. The extractabilities of Cu(II), Ni(II), Co(II) and Zn(II) into PAA-CAPS were examined. The stripping of the various cations can be promoted in diluted hydrochloric acid solutions.

Spectroscopic Behavior of Some A3B Type Tetrapyrrolic Complexes in Several Organic Solvents and Micellar Media

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Radu Socoteanu

2011-08-01

Full Text Available The paper presents spectral studies of some unsymmetrical A3B tetrapyrrolic, porphyrin-type complexes with Cu(II and Zn(II in different solvents and micellar media aimed at estimating their properties in connection with the living cell. The results indicate that the position of the absorption and emission peaks is mostly influenced by the central metal ion and less by the environmental polarity or the peripheric substituents of the porphyrinic core. The comparison between the overall absorption and emission spectra of the compounds in methanol or cyclohexane vs. direct and reverse Triton X micellar systems, respectively, suggests for all compounds the localization at the interface between the polyethylene oxide chains and the tert-octyl-phenyl etheric residue of the Triton X-100 molecules. These findings could be important when testing the compounds embedded in liposomes or other delivery systems to the targeted cell.

Some transition metal ions complexes of tricine (Tn and amino acids: pH-titration, synthesis and antimicrobial activity

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M.E. Zayed

2014-12-01

Full Text Available Equilibrium studies have been carried out on complex formation of M(II (M = Co(II, Cu(II and Zn(II with tricine (Tn and L = amino acids in aqueous solution, at 25 °C and ionic strength of I = 0.1 M (NaNO3. The ternary complexes of amino acids are formed by simultaneous reactions. The concentration distribution of the complexes is evaluated. The solid complexes of [M(II–Tn–Histidine (Hist] have been synthesized and characterized by elemental analysis, infrared, magnetic and conductance measurements. The synthesized complexes have been screened for their antibacterial activities and the complexes show a significant antibacterial activity against four bacterial species: Staphylococcus aureus (Gram +ve, Streptococcus pyogenesr (Gram +ve, Serratia marcescens (Gram −ve and Escherichia coli (Gram −ve. The activity increases by increasing the concentration of the complexes.

Anchoring plant metallothioneins to the inner face of the plasma membrane of Saccharomyces cerevisiae cells leads to heavy metal accumulation.

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Lavinia Liliana Ruta

Full Text Available In this study we engineered yeast cells armed for heavy metal accumulation by targeting plant metallothioneins to the inner face of the yeast plasma membrane. Metallothioneins (MTs are cysteine-rich proteins involved in the buffering of excess metal ions, especially Cu(I, Zn(II or Cd(II. The cDNAs of seven Arabidopsis thaliana MTs (AtMT1a, AtMT1c, AtMT2a, AtMT2b, AtMT3, AtMT4a and AtMT4b and four Noccaea caerulescens MTs (NcMT1, NcMT2a, NcMT2b and NcMT3 were each translationally fused to the C-terminus of a myristoylation green fluorescent protein variant (myrGFP and expressed in Saccharomyces cerevisiae cells. The myrGFP cassette introduced a yeast myristoylation sequence which allowed directional targeting to the cytosolic face of the plasma membrane along with direct monitoring of the intracellular localization of the recombinant protein by fluorescence microscopy. The yeast strains expressing plant MTs were investigated against an array of heavy metals in order to identify strains which exhibit the (hyperaccumulation phenotype without developing toxicity symptoms. Among the transgenic strains which could accumulate Cu(II, Zn(II or Cd(II, but also non-canonical metal ions, such as Co(II, Mn(II or Ni(II, myrGFP-NcMT3 qualified as the best candidate for bioremediation applications, thanks to the robust growth accompanied by significant accumulative capacity.

Anchoring plant metallothioneins to the inner face of the plasma membrane of Saccharomyces cerevisiae cells leads to heavy metal accumulation.

Science.gov (United States)

Ruta, Lavinia Liliana; Lin, Ya-Fen; Kissen, Ralph; Nicolau, Ioana; Neagoe, Aurora Daniela; Ghenea, Simona; Bones, Atle M; Farcasanu, Ileana Cornelia

2017-01-01

In this study we engineered yeast cells armed for heavy metal accumulation by targeting plant metallothioneins to the inner face of the yeast plasma membrane. Metallothioneins (MTs) are cysteine-rich proteins involved in the buffering of excess metal ions, especially Cu(I), Zn(II) or Cd(II). The cDNAs of seven Arabidopsis thaliana MTs (AtMT1a, AtMT1c, AtMT2a, AtMT2b, AtMT3, AtMT4a and AtMT4b) and four Noccaea caerulescens MTs (NcMT1, NcMT2a, NcMT2b and NcMT3) were each translationally fused to the C-terminus of a myristoylation green fluorescent protein variant (myrGFP) and expressed in Saccharomyces cerevisiae cells. The myrGFP cassette introduced a yeast myristoylation sequence which allowed directional targeting to the cytosolic face of the plasma membrane along with direct monitoring of the intracellular localization of the recombinant protein by fluorescence microscopy. The yeast strains expressing plant MTs were investigated against an array of heavy metals in order to identify strains which exhibit the (hyper)accumulation phenotype without developing toxicity symptoms. Among the transgenic strains which could accumulate Cu(II), Zn(II) or Cd(II), but also non-canonical metal ions, such as Co(II), Mn(II) or Ni(II), myrGFP-NcMT3 qualified as the best candidate for bioremediation applications, thanks to the robust growth accompanied by significant accumulative capacity.

Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II

Directory of Open Access Journals (Sweden)

Mustafa Cesme

2011-06-01

Full Text Available A new, simple, sensitive and accurate spectrophotometric method has been developed for the assay of metoprolol tartrate (MPT, which is based on the complexation of drug with copper(II [Cu(II] at pH 6.0, using Britton-Robinson buffer solution, to produce a blue adduct. The latter has a maximum absorbance at 675 nm and obeys Beer’s law within the concentration range 8.5-70 mg/mL. Regression analysis of the calibration data showed a good correlation coefficient (r = 0.998 with a limit of detection of 5.56 mg/mL. The proposed procedure has been successfully applied to the determination of this drug in its tablets. In addition, the spectral data and stability constant for the binuclear copper(II complex of MPT (Cu2MPT2Cl2 have been reported.

A series of coordination polymers constructed from R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands: Syntheses, structures and fluorescence properties

Energy Technology Data Exchange (ETDEWEB)

Zhou, Yong-Hong, E-mail: zhou21921@sina.com [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Zhou, Xu-Wan; Zhou, Su-Rong [School of Chemistry and Material Science, Huaibei Normal University, Huaibei 235000 (China); Tian, Yu-Peng; Wu, Jie-Ying [Department of Chemistry and Chemical Technology, Anhui University, Hefei 230039 (China)

2017-01-15

Six novel Zn(II), Cd(II), and Cu(II) mixed-ligand coordination complexes, namely, [Zn{sub 2}Na(sip){sub 2}(bpp){sub 3}(Hbpp)(H{sub 2}O){sub 2}]·8H{sub 2}O (1), [Cd{sub 3}(sip){sub 2}(nbi){sub 6}(H{sub 2}O){sub 2}]·7H{sub 2}O (2), [Zn(sip)(nbi){sub 2}(H{sub 2}O)]·Hnbi·3H{sub 2}O (3), [Cd(hip)(nbi){sub 2}(H{sub 2}O)]·nbi·5H{sub 2}O (4), [Cd{sub 2}(nip){sub 2}(nbi){sub 2}(H{sub 2}O){sub 2}]·DMF (5), and [Cu(nip)(nbi)(H{sub 2}O){sub 2}]·H{sub 2}O (6) (H{sub 3}sip=5-sulfoisophthalic acid, H{sub 2}hip=5-hydroxylisophthalic acid, H{sub 2}nip=5-nitroisophthalic acid, bpp=1,3-bis(4-pyridyl)propane, and nbi=6-nitrobenzimidazole) have been synthesized hydrothermally by the self-assembly of R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands. Single crystal X-ray analyses reveal that two Zn(II) ions and one Na(I) ion of complex 1 are linked through O atoms to generate a 1D linear chain. Then the 2D supramolecular architectures are constructed via intermolecular interactions. In complex 2, the Cd1 ions are connected by bridging carboxyl groups from sip{sup 3−} anions to form 1D double chain, which are further connected by Cd2 ions to afford 2D layer structure. The adjacent 2D layers are further linked via hydrogen-bonding interactions to give 3D supramolecular network. Compounds 3–5 show 1D chain structures, which are assembled into 2D or 3D supramolecular frameworks via weak interactions. In compound 6, the Cu(II) ions are bridged by the nip{sup 2−} ligands to form 48-membered ring, which is assembled into 1Dchain via the π-π stacking interaction. In addition, the thermal stabilities and fluorescence properties of these compounds have also been studied. - Graphical abstract: A series of Cd(II)/Zn(II)/ Cu(II) coordination polymers based on R-isophthalic acid (R=–SO{sub 3}H, –NO{sub 2}, and –OH) and N-donor ligands have been synthesized under hydrothermal conditions and structurally characterized. Photoluminescent properties

Column Chromatography Of Co(II), Zn(II) And Eu(III) Using Pistachio Shell And Different Mobile Phases

Energy Technology Data Exchange (ETDEWEB)

Abdel-Fattah, A A [Nuclear Chemistry Department, Radioisotopes Production Division, Hot Laboratories Centre, Atomic Energy Authority, Cairo (Egypt)

2009-07-01

Pistachio shell particles (0.5-1 mm) have been applied as the stationary phase for studying the column chromatography of Co(II), Zn(II) and Eu(III) at room temperature; 26{sup +}-{sup 1}oC. This solid sorbent has been characterized by thermogravimetric analysis, infra-red spectroscopy and X-ray diffraction. Its surface area and percent of swelling have been also determined. Different eluting agents have been used for eluting the sorbed elements. The elution curves have been done from which the distribution coefficients (K{sub d}), number of theoretical plates (N) and heights equivalent to theoretical plates (H) have been determined. Column performance studies have been conducted for a representative system under certain experimented conditions and Van Deemter equation has been applied. Thermodynamic studies have been applied and thermodynamic functions ( {delta}G{sup 0} ,{delta}H{sup 0} and{delta} S{sup 0}) have been calculated for this representative system by determining K{sub d} at three different room temperatures (18, 26 and 37{sup +}-{sup 1o}C)

Adsorption of precious metals in water by dendrimer modified magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Yen, Chia-Hsin [Institute of Environmental Engineering, National Chiao Tung University, 300 Hsinchu, Taiwan (China); Lien, Hsing-Lung, E-mail: lien.sam@nuk.edu.tw [Department of Civil and Environmental Engineering, National University of Kaohsiung, 811 Kaohsiung, Taiwan (China); Chung, Jung-Shing [Department of Civil and Environmental Engineering, National University of Kaohsiung, 811 Kaohsiung, Taiwan (China); Yeh, Hund-Der [Institute of Environmental Engineering, National Chiao Tung University, 300 Hsinchu, Taiwan (China)

2017-01-15

Highlights: • A reusable magnetic nano-adsorbent is prepared for precious metal adsorption. • The nano-adsorbent (MNP-G3) is synthesized by magnetic nanoparticles and dendrimer. • Higher valent ions show higher adsorption capacity by MNP-G3 suggesting complexation involved. • The pseudo second-order model best describe the adsorption kinetics. • MNP-G3 modified by EDTA significantly improve its adsorption ability for Ag(I). - Abstract: Magnetic nanoparticles modified by third-generation dendrimers (MNP-G3) and MNP-G3 further modified by ethylenediaminetetraacetic acid (EDTA) (MNP-G3-EDTA) were conducted to investigate their ability for recovery of precious metals (Pd(IV), Au(III), Pd(II) and Ag(I)) in water. Experiments were carried out using batch reactors for the studies of adsorption kinetics, adsorption isotherms, competitive adsorption and regeneration. The pseudo second-order model is the best-fit model among others suggesting that the adsorption of precious metals by MNP-G3 in water is a chemisorption process. Three adsorption isotherms namely Langmuir, Freundlich and Dubinin-Radushkevich isotherm were examined and the results showed the similarities and consistency of both linear and nonlinear analyses. Pd(IV) and Au(III) with higher valence exhibited relatively better adsorption efficiency than Pd(II) and Ag(I) with lower valence suggesting that the adsorption of precious metals by MNP-G3 is a function of valence. In the presence of the competing ion Zn(II), the adsorption efficiency of MNP-G3 for all four precious metals was declined significantly. The use of MNP-G3-EDTA revealed an increase in the adsorption efficiency for all four precious metals. However, the low selectivity of MNP-G3 towards precious metals was not enhanced by the modification of EDTA onto the MNP-G3. The regeneration of metal-laden MNP-G3 can be readily performed by using 1.0% HCl solution as a desorbent solution.

Synthesis and thermal characterization of new ternary chelates of piroxicam and tenoxicam with glycine and DL-phenylalanine and some transition metals

Science.gov (United States)

Zayed, M. A.; El-Dien, F. A. Nour; Mohamed, Gehad G.; El-Gamel, Nadia E. A.

2006-05-01

The ternary chelates of piroxicam (Pir) and tenoxicam (Ten) with Fe(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) in the presence of various amino acids such as glycine (Gly) or DL-phenylalanine (PhA) were prepared and characterized with different physicochemical methods. IR spectra confirm that Pir and Ten behave as a neutral bidentate ligand coordinated to the metal ions via the pyridine- N and carbonyl group of the amide moiety. Gly molecule acted as a uninegatively monodentate ligand and coordinate to the metal ions through its deprotonated carboxylic group. In addition, PhA acted as a uninegatively bidentate ligand and coordinate to the metal ions through its deprotonated carboxylic and amino groups. The solid reflectance spectra and magnetic moment measurements confirm that all the chelates have octahedral geometrical structures while Cu(II)- and Zn(II)-ternary chelates with PhA have square planar geometrical structures. Thermal behaviour of the complexes is extensively studied using TG and DTA techniques. TG results show that water molecules (hydrated and coordinated) and anions are removed in the first and second steps while Gly, PhA, Pir and Ten are decomposed in the next and subsequent steps. The pyrolyses of the chelates into different gases are observed in the DTA curves as exo- or endothermic peaks. Also, phase transition states are observed in some chelates. Different thermodynamic parameters are calculated using Coats-Redfern method and the results are interpreted.

Exploring electronic and steric effects on the insertion and polymerization reactivity of phosphinesulfonato pdii catalysts

KAUST Repository

Neuwald, Boris

2013-11-21

Thirteen different symmetric and asymmetric phosphinesulfonato palladium complexes ([{(X1-Cl)-μ-M}n], M=Na, Li, 1= X(P^O)PdMe) were prepared (see Figure 1). The solid-state structures of the corresponding pyridine or lutidine complexes were determined for (MeO)21-py, (iPrO)21-lut, (MeO,Me2)1-lut, (MeO)31-lut, CF31-lut, and Ph1-lut. The reactivities of the catalysts X1, obtained after chloride abstraction with AgBF4, toward methyl acrylate (MA) were quantified through determination of the rate constants for the first and the consecutive MA insertion and the analysis of β-H and other decomposition products through NMR spectroscopy. Differences in the homo- and copolymerization of ethylene and MA regarding catalyst activity and stability over time, polymer molecular weight, and polar co-monomer incorporation were investigated. DFT calculations were performed on the main insertion steps for both monomers to rationalize the effect of the ligand substitution patterns on the polymerization behaviors of the complexes. Full analysis of the data revealed that: 1) electron-deficient catalysts polymerize with higher activity, but fast deactivation is also observed; 2) the double ortho-substituted catalysts (MeO)21 and (MeO)31 allow very high degrees of MA incorporation at low MA concentrations in the copolymerization; and 3) steric shielding leads to a pronounced increase in polymer molecular weight in the copolymerization. The catalyst properties induced by a given P-aryl (alkyl) moiety were combined effectively in catalysts with two different non-chelating aryl moieties, such as cHexO/(MeO)21, which led to copolymers with significantly increased molecular weights compared to the prototypical MeO1. Catalyst control: The influence of steric and electronic effects on the reactivity of phosphinesulfonato PdII catalysts in polymerization and copolymerization is explored through experimental and DFT methods. A comparison of thirteen different X(P O)PdMe catalysts ((P O)= κ2-P

Dynamics of ligand exchange mechanism at Cu(II) in water: an ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region.

Science.gov (United States)

Moin, Syed Tarique; Hofer, Thomas S; Weiss, Alexander K H; Rode, Bernd M

2013-07-07

Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment.

Dynamics of ligand exchange mechanism at Cu(II) in water: An ab initio quantum mechanical charge field molecular dynamics study with extended quantum mechanical region

International Nuclear Information System (INIS)

Moin, Syed Tarique; Hofer, Thomas S.; Weiss, Alexander K. H.; Rode, Bernd M.

2013-01-01

Ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) were successfully applied to Cu(II) embedded in water to elucidate structure and to understand dynamics of ligand exchange mechanism. From the simulation studies, it was found that using an extended large quantum mechanical region including two shells of hydration is required for a better description of the dynamics of exchanging water molecules. The structural features characterized by radial distribution function, angular distribution function and other analytical parameters were consistent with experimental data. The major outcome of this study was the dynamics of exchange mechanism and reactions in the first hydration shell that could not be studied so far. The dynamical data such as mean residence time of the first shell water molecules and other relevant data from the simulations are close to the results determined experimentally. Another major characteristic of hydrated Cu(II) is the Jahn-Teller distortion which was also successfully reproduced, leading to the final conclusion that the dominating aqua complex is a 6-coordinated species. The ab initio QMCF-MD formalism proved again its capabilities of unraveling even ambiguous properties of hydrated species that are far difficult to explore by any conventional quantum mechanics/molecular mechanics (QM/MM) approach or experiment

The preparation and characterization of Cu(II complexes with N,N’,N”,N’”-tetrakis(2-pyridylmethyl-1,4,8,11-tetraazacyclotetradecane and 2,6-diacetylpyridine bis(semi/thiosemicarbazones

Directory of Open Access Journals (Sweden)

GORDANA VUCKOVIC

2004-03-01

Full Text Available Two new Cu(II mixed-ligand complexes with octadentate N,N’,N”,N’”-tetrakis(2-pyridylmethyl-1,4,8,11-tetraazacyclotetradecane (tpmc and potentially pentadentate ligands 2,6-diacetylpyridine bis(semicarbazone (DAPsc2 or 2,6-diacetylpyridine bis(thiosemicarbazone (DAPtsc2 were prepared. The general formulas: [Cu4 DAPsc2(tpmc2]ClO48·5CH3COCH3·H2O and [Cu2 DAPtsc2(tpmc](ClO44·7C2H5OH were proposed on the basis of elemental analyses and conductometric measurements. The complexes were characterized by magnetic measurement, electronic absorption and IR spectroscopy. For the dinuclear complex, an exo coordination of Cu(II with four nitrogens from tpmc and m-bonded DAPtsc2 through sulfurs and possibly terminal hydrazinic (azomethine nitrogens is assumed. For the tetranuclear complex, it is supposed that one DAPsc2 bridges two [Cu2 tpmc]4+ units using oxygens and terminal hydrazinic nitrogens as ligators. Finally, some antibacterial activity of the complexes was found.

Removal of nickel(II and palladium(II from surface waters

Directory of Open Access Journals (Sweden)

V. Sharifzade

2013-04-01

Full Text Available A new sorbent was prepared using alumina and 5-Br-PADAP, and its adsorption ability for the removal of Ni(II and Pd(II from different waters was investigated. The procedure is based on retention of the analytes on the alumina load with 5-Br-PADAP at pH ~ 6. The separation/preconcentration conditions for the quantitative recoveries were investigated. The limit of detections (LOD based on three times the standard deviations of the blank, were 0.187 and 0.253 ng mL-1 for Ni(II and Pd(II, respectively. Obtained sorption capacities for 1 g sorbent were 6.0 mg Ni(II and 11.0 mg Pd(II. The linearity was maintained in the concentration range of 0.625 to 6.0 ng mL-1 for Ni(II and 0.416 to 7.0 ng mL-1 for Pd(II in the original solution. Eight replicate determinations of a mixture containing 2.0 µg mL-1 each of the elements in the final solution gave relative standard deviation of ±0.82 and ±1.12% for Ni(II and Pd(II, respectively. The proposed method was successfully applied to the determination trace amounts of Ni(II and Pd(II in the surface water samples.DOI: http://dx.doi.org/10.4314/bcse.v27i1.2

Synthesis, spectral and third-order nonlinear optical properties of terpyridine Zn(II) complexes based on carbazole derivative with polyether group

Science.gov (United States)

Kong, Ming; Liu, Yanqiu; Wang, Hui; Luo, Junshan; Li, Dandan; Zhang, Shengyi; Li, Shengli; Wu, Jieying; Tian, Yupeng

2015-01-01

Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on carbazole derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.

Effective and Selective Recovery of Precious Metals by Thiourea Modified Magnetic Nanoparticles

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Hsing-Lung Lien

2013-05-01

Full Text Available Adsorption of precious metals in acidic aqueous solutions using thiourea modified magnetic magnetite nanoparticle (MNP-Tu was examined. The MNP-Tu was synthesized, characterized and examined as a reusable adsorbent for the recovery of precious metals. The adsorption kinetics were well fitted with pseudo second-order equation while the adsorption isotherms were fitted with both Langmuir and Freundlich equations. The maximum adsorption capacity of precious metals for MNP-Tu determined by Langmuir model was 43.34, 118.46 and 111.58 mg/g for Pt(IV, Au(III and Pd(II, respectively at pH 2 and 25 °C. MNP-Tu has high adsorption selectivity towards precious metals even in the presence of competing ions (Cu(II at high concentrations. In addition, the MNP-Tu can be regenerated using an aqueous solution containing 0.7 M thiourea and 2% HCl where precious metals can be recovered in a concentrated form. It was found that the MNP-Tu undergoing seven consecutive adsorption-desorption cycles still retained the original adsorption capacity of precious metals. A reductive adsorption resulting in the formation of elemental gold and palladium at the surface of MNP-Tu was observed.