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1.
Sensors (Basel) ; 22(3)2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35161647

RESUMO

A novel bidentate Schiff base (L) is here proposed for the detection of Zn ions in water. The structure of the synthesized Schiff base L was characterized by FT-IR, 1H NMR and 13C NMR. Optical characteristics were addressed by UV-Visible spectroscopy and Photoluminescence (PL) measurements. PL demonstrated that L displays a "turn-off" type fluorescence quenching in the presence of Zn2+ ion in aqueous solution, indicating its ability to preferentially coordinate this ion. Based on these findings, an L-M (where M is a suitable membrane) modified screen-printed carbon electrode (SPCE) was developed to evaluate the electrochemical behavior of the Schiff base (L) with the final objective of undertaking the electroanalytical determination of Zn ions in water. Using various electrochemical techniques, the modified L-M/SPCE sensor demonstrates high sensitivity and selectivity to Zn ions over some common interferents ions, such as Ca2+, Mg2+, K+, Ni++ and Cd++. The potentiometric response of the L-M/SPCE sensor to Zn ions was found to be linear over a relatively wide concentration range from 1 µM to 100 mM.


Assuntos
Carbono , Bases de Schiff , Eletrodos , Íons , Ligantes , Espectroscopia de Infravermelho com Transformada de Fourier , Zinco
2.
Mater Sci Eng C Mater Biol Appl ; 110: 110642, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32204075

RESUMO

In this work, a new tridentate ligand, its some novel zinc halide/pseudohalide complexes and their antimicrobial and cytotoxic effects of them are described. Characterization data of these compounds have been achieved via several physical and micro analytical techniques. As typical one, X-ray crystal structure analysis of zinc azide complex was run showing zinc center is penta-coordinated by three nitrogen atoms from Schiff base ligand and two terminal azide nitrogen atoms as a distorted square pyramidal geometry. Hirshfeld surfaces analysis clears the important role of interactions related to azide groups (NH⋯N and CH⋯N hydrogen bonds) in the stabilization of its supramolecular structure. According to data obtained from thermal analysis (TG/DTG/DTA), all complexes are decomposed at four or more thermal stages below 1000 °C. Moreover antimicrobial activities of the compounds were screened against some gram positive and gram negative bacteria. Furthermore anticancer activities of the complexes were studied against MDA-MB468 and k562 as two cancer cell lines. In final, three zinc complexes were also synthesized in nano scale by sonochemical method and one of them was utilized as the precursor for preparation of nanostructure ZnO confirmed by XRD pattern and SEM image.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Nanoestruturas/química , Temperatura , Zinco/química , Antifúngicos/farmacologia , Bactérias/efeitos dos fármacos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Cristalografia por Raios X , Fragmentação do DNA/efeitos dos fármacos , Fungos/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Ligantes , Testes de Sensibilidade Microbiana , Conformação Molecular , Nanoestruturas/ultraestrutura , Espectroscopia de Prótons por Ressonância Magnética , Bases de Schiff/química , Espectrofotometria Ultravioleta , Vibração , Difração de Raios X
3.
Ultrason Sonochem ; 42: 723-730, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29429723

RESUMO

A new selective and sensitive optical sensor based on the incorporation of new synthesized N'-(2-hydroxy-5-iodobenzylidene) isonicotinohydrazide (HIBIN) as an effective reagent into the nanoporous of a transparent glass like material through the sol-gel process was developed which was suitable for the determination of copper (II) ions in aqueous solutions. The thin film sensors were constructed by spin-coating of prepared sol onto glass plate and their surface morphology were studied by field emission scanning electron microscopy (FE-SEM) and atomic force microscope (AFM) technique. Influence of sonication time on immobilization of HIBIN into silica matrix was investigated through calculation of leaching percentage. The Results shown that sonication time of 35 min is suitable to give more stable thin films without fluctuation in sensitivity and response time of presented sensor for a long period of time. The proposed optical sensor can be used for determination of copper (II) ions in the range of 9.1 × 10-8-1.12 × 10-5 mol L-1with a detection limit of 1.8 × 10-8 mol L-1. It also showed relative standard deviation 3.4 and 0.72% for reproducibility and repeatability respectively, along with a fast response time about of 2 min. The constructed optode is stable in wet conditions and could be stored for at least 6 weeks without observing any change in its sensitivity. The developed sensor was successfully applied to the determination of copper (II) in fruit juice and water samples which results were confirmed by atomic absorption spectrometry method.


Assuntos
Cobre/análise , Sucos de Frutas e Vegetais/análise , Isoniazida/química , Limite de Detecção , Dispositivos Ópticos , Sonicação , Cobre/química , Desenho de Equipamento , Géis , Concentração de Íons de Hidrogênio , Reprodutibilidade dos Testes , Dióxido de Silício/química , Fatores de Tempo , Água/química
4.
Ultrason Sonochem ; 38: 134-144, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28633812

RESUMO

A bidentate Schiff base ligand and its nano-structured cobalt(II) complex were synthesized under ultrasound irradiation and then their structures were identified by physical and spectral techniques SEM and XRD techniques were used to confirm the nanostructure character of the complex. Single crystal X-ray diffraction analysis showed that the complex crystallizes in the triclinic system with space group of P1¯ and two crystallographically independent molecules participate in its asymmetric unit. In the structure of complex, cobalt center is four-coordinated by two iminic nitrogens of bidentate Schiff base ligand and two bromide anions in a distorted tetrahedral geometry. Crystal packing analysis well indicates that C-H⋯Br, C-H⋯π and π⋯π are the most intermolecular interactions. Moreover Hirshfeld surface analysis and 2D Fingerprint plots were applied for more investigation of intermolecular interactions. In addition, sonochemically prepared cobalt(II) bromide complex was subjected to calcination process under air atmosphere for preparation of cobalt oxide nanoparticles. The XRD pattern confirmed the simultaneous formation of CoO and Co3O4 nanoparticles.

5.
J Colloid Interface Sci ; 500: 241-252, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28411431

RESUMO

Ultrasound irradiation, cloud point and adsorption methods were coupled to develop a new technique for the simultaneous removal of Cd(II), Ni(II), Pb(II) and Cu(II) ions after their complexation with (E)-4-((2-hydroxybenzylidene) amino) naphthalene-1-sulfonic acid (HBANSA). In order to reduce cost and improve practicability of process, chitosan gel (CSG) composited with bismuth(III) phosphate/iron(III) phosphate nanoparticles (CSG-BiPO4/FePO4) were hydrothermally synthesized followed by their characterization using FE-SEM, EDS and XRD analysis. The operational parameters such as metal ions concentration, CSG-BiPO4/FePO4 mass, sonication time and temperature were investigated and optimized using central composite design (CCD). In addition, the possible significant correlation between these variables and removal efficiency was studied from which the maximum efficiencies were obtained at 5.57mg/L, 51.49°C, 0.018g and 10.73min corresponding to metal ions concentration, temperature, CSG-BiPO4/FePO4 and sonication time, respectively. Moreover, at these conditions, the removal percentages of the Cd(II), Ni(II), Pb(II) and Cu(II) ions were found to be 96.24, 93.73, 95.55 and 97.47, respectively. After applying various isotherms, the Langmuir isotherm model was found to be most appropriate model for describing and fitting the experimental equilibrium data and thus maximum mono-layer adsorption capacities of 8.61, 8.54, 8.65 and 8.62mgg-1 were obtained for Cd(II), Pb(II), Cu(II) and Ni(II) ions, respectively. The study of kinetics showed well applicability of pseudo second order kinetic model with maximum mass transfer rate in adsorption process.

6.
Acta Crystallogr C Struct Chem ; 72(Pt 3): 239-42, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26942435

RESUMO

Transition metal complexes of Schiff base ligands have been shown to have particular application in catalysis and magnetism. The chemistry of copper complexes is of interest owing to their importance in biological and industrial processes. The reaction of copper(I) chloride with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, systematic name: (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]} in a 1:1 molar ratio in dichloromethane without exclusion of air or moisture resulted in the formation of the title complex µ-chlorido-µ-hydroxido-bis(chlorido{(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}copper(II)) dichloromethane sesquisolvate, [Cu2Cl3(OH)(C20H18N4O4)2]·1.5CH2Cl2. The dinuclear complex has a folded four-membered ring in an unsymmetrical Cu2OCl3 core in which the approximate trigonal bipyramidal coordination displays different angular distortions in the equatorial planes of the two Cu(II) atoms; the chloride bridge is asymmetric, but the hydroxide bridge is symmetric. The chelate rings of the two Nca2en ligands have different conformations, leading to a more marked bowing of one of the ligands compared with the other. This is the first reported dinuclear complex, and the first five-coordinate complex, of the Nca2en Schiff base ligand. Molecules of the dimer are associated in pairs by ring-stacking interactions supported by C-H...Cl interactions with solvent molecules; a further ring-stacking interaction exists between the two Schiff base ligands of each molecule.


Assuntos
Complexos de Coordenação/química , Cobre/química , Bases de Schiff/química , Cristalografia por Raios X , Ligação de Hidrogênio , Ligantes , Estrutura Molecular
7.
Acta Crystallogr C Struct Chem ; 71(Pt 7): 578-83, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26146396

RESUMO

Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}(thiocyanato-κN)(triphenylphosphane-κP)copper(I)], [Cu(NCS)(C20H18N4O4)(C18H15P)] or [Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and (1)H NMR spectroscopy, and X-ray crystallography [from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with a trans conformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinating via the imine N atoms to the Cu(I) atom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattened gauche conformation, resulting in a rather bowed shape overall for the ligand. The NCS(-) ligand is coordinated through its N atom. The geometry around the Cu(I) atom is distorted tetrahedral, with a small N-Cu-N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN-Cu-P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 129: 382-91, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-24747864

RESUMO

Some novel nano-sized structure zinc complexes of a new Schiff base ligand entitled as (3-nitro-benzylidene)-{2-[2-(3-nitro-phenyl)-imidazolidine-1-yl]-ethyl}-amine(L) with general formula of ZnLX2 wherein X=Cl(-), Br(-), I(-), SCN(-) and N3(-) have been synthesized under ultrasonic conditions. The ligand and its complexes have been characterized by elemental analysis, molar conductance measurements, FT-IR, (1)H and (13)C NMR and UV-Visible spectroscopy. The resulting data from spectral investigation especially (1)H and (13)C NMR well confirmed formation of an imidazolidine ring in the ligand structure. Transmission electron microscopy (TEM) showed nano-size structures with average particle sizes of 21.80-78.10nm for the zinc(II) Schiff base complexes. The free Schiff base and its Zn(II) complexes have been screened in vitro both for antibacterial activity against some gram-positive and gram-negative bacteria and also for antifungal activity. The metal complexes were found to be more active than the free Schiff base ligand. The results showed that ZnL(N3)2 is the most effective inhibitor against Escherichia coli, Pseudomonas aereuguinosa, Staphylococcus aureus and Candida albicans while ZnLBr2 was found to be more effective against Bacillus subtillis than other compounds. Moreover, DNA cleavage potential of all compounds with plasmid DNA was investigated. The results showed that the ligand and ZnLCl2 complex cleave DNA more efficiently than others. In final, thermal analysis of ligand and its complexes revealed that they are decomposed via 2-3 thermal steps in the range of room temperature to 1000°C. Furthermore some activation kinetic parameters such as A, E(*), ΔH(*), ΔS(*) and ΔG(*) were calculated based on TG/DTA plots by use of coats - Redfern relation. Positive values of activation energy evaluated for the compounds confirmed the thermal stability of them. In addition to, the positive ΔH(*), and ΔG(*) values suggested endothermic character for the thermal decomposition steps.


Assuntos
Anti-Infecciosos/química , Complexos de Coordenação/química , Clivagem do DNA/efeitos dos fármacos , Imidazolidinas/química , Nanoestruturas/química , Bases de Schiff/química , Zinco/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Complexos de Coordenação/farmacologia , DNA/química , Humanos , Imidazolidinas/farmacologia , Nanoestruturas/ultraestrutura , Bases de Schiff/farmacologia , Análise Espectral , Termogravimetria , Temperatura de Transição , Zinco/farmacologia
9.
Mater Sci Eng C Mater Biol Appl ; 35: 195-204, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24411369

RESUMO

In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV-visible, (1)H and (13)C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX2 (X=Cl(-), Br(-), I(-), SCN(-) and N3(-)) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3-4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E*), enthalpy (∆H*), entropy (∆S*) and Gibbs free energy change (∆G*) of the thermal decomposition steps were performed based on the Coats-Redfern relation.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Fungos/fisiologia , Bases de Schiff/química , Zinco/química , Zinco/farmacologia , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antifúngicos/síntese química , Antifúngicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Fungos/efeitos dos fármacos , Teste de Materiais , Condutividade Térmica
10.
Artigo em Inglês | MEDLINE | ID: mdl-22658997

RESUMO

Synthesis, spectroscopic, electrochemical behavior and theoretical investigation of some zinc complexes of a new Schiff base ligand of bis((E) 3-(2-nitrophenyl)-2-propenal)propane-1,2-diimine (L) with a general formula of ZnLX(2)(X=Cl(-), Br(-), I(-), SCN(-) and N(3)(-)) are described. The ligand and its complexes were identified by elemental analysis, molar conductivity, UV-Visible spectra, FT-IR spectra, (1)H NMR and (13)C NMR spectra. The complexes were found to be molecular and non-electrolyte based on conductivity measurement. The spectral data confirm coordination of ligand and anions(X(-)) to zinc ion center. Electrochemical behavior of ligand and complexes were investigated by cyclic voltammetry technique exhibiting different redox behavior of complexes with respect to free ligand so that the ligand and complexes showed quasi-reversible and irreversible electron transfer processes respectively. Molecular structures of the ligand and complexes have been optimized at the UB3LYP/LANL2MB(*) level of theory. Accordingly some theoretical thermodynamical and/or structural parameters such as HF-energy, Gibbs free energy, enthalpy, selected bond distances, bond angles and torsion angles of optimized structures are presented.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Técnicas Eletroquímicas/métodos , Iminas/química , Iminas/síntese química , Zinco/química , Elétrons , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Bases de Schiff/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Torção Mecânica , Vibração
11.
Mater Sci Eng C Mater Biol Appl ; 32(7): 1888-1892, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062671

RESUMO

A new optical uranyl (IV) selective sensor by incorporation of 1,1'-2,2'-(1,2-phenylene)bis(ethene-2,1-diyl)dinaphthalen-2-ol (PBED), dibutyl phthalate (DBP) and sodium tetraphenylborate (Na-TPB) in the plasticized poly vinyl chloride membrane matrices has been constructed. In the proposed optode, PBED functions as both ionophore and chromoionophore while DBP has synergistic effect on the complexation of uranyl ion (UO22+) by PBED. Following the optimization of influences of variables, the proposed sensor due to its high stability, reproducibility and relatively long lifetime has good selectivity and sensitivity for uranyl ion over a large number of alkali, alkaline earth, transition, and heavy metal ions. The response of the proposed optode is linear over the concentration range of 3.99×10-6 up to 8.06×10-5molL-1 of UO22+ within a detection limit of 9.99×10-7molL-1 and response time less than 10min. The proposed optical sensor was applied successfully for the determination and evaluation of UO22+ ion content in water samples.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 81(1): 122-7, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21733744

RESUMO

Synthesis, spectroscopic and thermal studies of some complexes of a new N(2)-Schiff base ligand of N(1),N(2)-bis((E)-2-methyl-3-phenylallylidene)ethane-1,2-diamine (L) with a general formula of MLX(2) (M = Zn(II), Cd(II) and Hg(II); X = Cl(-), Br(-), I(-), SCN(-) and N(3)(-)) are described. The ligand and its complexes were characterized by elemental analysis, molar conductance, UV-vis spectra, FT-IR spectra, MS, (1)H NMR and (13)C NMR spectra. The conductivity measurement as well as spectral data indicated that the complexes are non-electrolyte. (1)H and (13)C NMR spectra have been studied in DMSO-d(6) and/or CDCl(3). The thermal behavior of the complexes shows weight loss by decomposition of the anions and ligand segments in the subsequent steps. Activation thermodynamic parameters of decomposition such as E*, ΔH*, ΔS* and ΔG* were calculated from TG curves.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Bases de Schiff/química , Bases de Schiff/síntese química , Elementos de Transição/química , Físico-Química , Análise Diferencial Térmica , Microanálise por Sonda Eletrônica , Ligantes , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Modelos Biológicos , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral , Termodinâmica
13.
J AOAC Int ; 92(4): 1208-18, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19714992

RESUMO

New iodide ion-selective electrodes based on bis(2-methyl-3-phenyl-propenylidene)1,2-propanediamine)mercury(II) bromide [Hg(BMPPMB)Br2], bis (5-bromo salicylaldehyde) ethylenediimine vanadyl(IV) [VO(5-Br Salen)], and bis(5-bromo salicylaldehyde) ethylenediimine uranyl(VI) [UO2(5-Br Salen)] carriers are described. The electrodes exhibited Nernstian slopes of -58.3 +/- 1.0, -58.5 +/- 1.4, and -59.0 +/- 1.2 mV/decade for Hg(BMPPMB)Br2, VO(5-Br Salen), and UO2(5-Br Salen) iodide ion concentration in the range of 1.0 x 10(-6)-0.1 M, with detection limits of about 0.6, 0.5, and 0.3 microM, respectively. The potentiometric responses of the electrodes were independent of pH over the range 1.7-10.6, 2.2-11.3, and 2.1-11.1, with satisfactory reproducibility. The electrodes had response times of < or =5 s and could be used for at least 84, 80, and 100 days for Hg(BMPPMB)Br2, VO(5-Br Salen), and UO2(5-Br Salen), respectively, without any considerable divergence in their potential responses.


Assuntos
Iodetos/análise , Ionóforos/análise , Eletrodos , Grafite , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Membranas Artificiais , Preparações Farmacêuticas/análise , Cloreto de Polivinila , Potenciometria , Espectrofotometria Ultravioleta
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 73(2): 231-7, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19303352

RESUMO

Synthesis and spectroscopic studies on four-coordinate complexes of cadmium(II) and mercury(II) halides with a new asymmetrical bidentate Schiff base ligand of N,N'-bis[alpha-methylcinamaldehydene]propane-1,2-diamine(L) are described. The ligand and its complexes were characterized by elemental analysis, molar conductance, UV-visible spectra, FT-IR spectra, MS, (1)H NMR and (13)C NMR spectra. The complexes are non-electrolytes in DMF. The electronic spectra of the complexes were recorded in DMF solution. (1)H and (13) C NMR spectra been studied in CDCl(3). The molar conductance as well as spectral properties indicated the complexes do not dissociate in DMF and retain their coordination. FT-IR and NMR spectra of the complexes exhibit downfield as well as upfield shifts of the free ligand resonances that show change in geometry during the coordination. The suggested structure of the complexes is pseudo-tetrahedral. Molecular structures of the complexes have been optimized by MM+ calculations that supported pseudo-tetrahedral geometry around the metal (II) ions.


Assuntos
Cádmio/química , Mercúrio/química , Bases de Schiff/química , Análise Espectral/métodos , Estrutura Molecular
15.
Chemosphere ; 74(4): 583-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19027140

RESUMO

A simple and relatively fast approach for developing a solid phase extraction has been described and used for determination of trace quantities of some heavy and transition metal ions with sodium dodecyl sulfate (SDS)-coated poly vinyl chloride (PVC) modified with bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) ligand. The adsorbed ions were stripped from the solid phase by 10 mL of 3M nitric acid as eluent. The eluting solution was analyzed for metals content (cadmium, chromium, cobalt, copper, lead and zinc) by flame atomic absorption spectrometry (FAAS). The main factors such as pH, amount of ligand and PVC, amount and type of surfactant, and condition of eluting solutions on the sorption recovery of metal ions have been investigated in detail. The relative standard deviation was found in the range of 1.0-3.2% for 0.2 microg mL(-1)of metals ions. After optimization of the extraction condition and the instrumental parameters, a detection limit was found to be in the range of 1.2-3.1 microg L(-1), with enrichment factor of 50 was achieved. The method was successfully applied for the determination of these metals contents in real samples with satisfactory results.


Assuntos
Metais Pesados/isolamento & purificação , Cloreto de Polivinila/química , Dodecilsulfato de Sódio/química , Adsorção , Concentração de Íons de Hidrogênio , Metais Pesados/análise , Metais Pesados/química , Reprodutibilidade dos Testes , Extração em Fase Sólida , Espectrofotometria Atômica , Elementos de Transição/análise , Elementos de Transição/química , Elementos de Transição/isolamento & purificação
16.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 8): m1004-5, 2009 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-21583304

RESUMO

In the title complex, [Mn(2)(C(19)H(20)N(2)O(4))(2)(C(19)H(22)N(2)O(4))(2)](PF(6))(2), the Mn(III) ion is coordinated by two O [Mn-O = 1.855 (2) and 1.887 (2) Å] and two N [Mn-N = 1.982 (3) and 1.977 (3) Å] atoms from the tetra-dentate Schiff base ligand and a coordinated axial ligand [Mn-O = 2.129 (2) Å]. The centrosymmetric dimer contains two Jahn-Teller-distorted Mn(III) ions, each in a nearly octa-hedral geometry, connected through two phenolate bridges from two ligands. There are two stereogenic centers. The methyl group and the H atom attached to the middle propane C atom are disordered over two positions with occupancy factors in the ratio 0.58:0.42. The crystal is therefore a mixture of two diasteroisomers, viz. RS/SR and RR/SS. In the axial ligand, the two benzene rings form a dihedral angle of 56.97 (5)° and the dihedral angle between the two MnNC(3)O chelate rings is 2.98 (12)°

17.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 7): m703, 2009 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-21582649

RESUMO

In the title complex, [Ni(C(21)H(24)N(2)O(4))], the Ni(II) ion has a slightly distorted square-planar geometry, coordinated by the two N and two O atoms of a new tetra-dentate Schiff base ligand. The dihedral angle between the planes of the two NiNC(3)O chelate rings is 14.37 (12)°.

18.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 7): o1662-3, 2009 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-21582924

RESUMO

The title Schiff base, C(21)H(26)N(2)O(2), contains two intra-molecular O-H⋯N hydrogen bonds between the hydroxyl groups and the nearest imine N atoms, each leading to a six-membered ring. Weak C-H⋯O hydrogen bonds result in a ladder network running along the a axis. In addition, inter-molecular C-H⋯π inter-actions serve to stabilize the extended structure.

19.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 6): m617, 2009 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-21582987

RESUMO

The Co(II) atom in the title monomeric Schiff base complex, [CoCl(2)(C(21)H(22)N(2))], is bonded to two Cl atoms and to two N atoms of the Schiff base ligand N,N'-bis-[(E)-3-phenyl-prop-2-en-1-yl-idene]propane-1,3-diamine in a distorted tetra-hedral geometry. The mol-ecule has an idealised mirror symmetry, but is not located on a crystallographic mirror plane.

20.
Ann Chim ; 97(10): 1015-26, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18153996

RESUMO

Photocatalytic degradation of benzylamine and aniline on TiO2, Pt-modified TiO2, ZnO and ZnS in aqueous solution has been investigated. The degradation of the compounds follows a pseudo-first-order kinetics according to Langmuir-Hinshelwood model. The degradation process of benzylamine and aniline was evaluated by ninhydrin spectrophotometric method using UV-visible spectrophotometer in lambda(max) = 538 and 525 nm, respectively. The results showed the order of Pt/TiO2 > TiO2 > ZnO > ZnS for photocatalytic activity. In addition increasing of the Pt-loading was found to enhance the degradation rate of the compounds up to the optimal amount of 5 wt. % onto the surface of TiO2 so that the rates of degradation were increased about two times. Rate constants for photodegradation of benzylamine and aniline were found to be 1.4 x 10(-3) min(-1) and 0.7 x 10(-3) min(-1) for TiO2 as photocatalyst, while 2.7 x 10(-3) min(-1) and 1.7 x 10(-3) min(-1) for (5 wt.%) Pt/TiO2 as photocatalyst. Running the reactions in various pH (5-11), indicated that the pH = 8 and 10 or Higher are the optimum pH for photocatalytic degradation of benzylamine and aniline respectively. The effects of some other parameters such as amount of photocatalyst, flux of oxygen and irradiation time were evaluated. Furthermore, the Langmuir-Hinshelwood rate constant k(r) and adsorption constant K(A) for the titled compounds are reported.


Assuntos
Compostos de Anilina/efeitos da radiação , Benzilaminas/efeitos da radiação , Platina , Titânio , Catálise , Cinética , Luz , Fotólise , Compostos de Platina , Água
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