New chromogens of the ferroin type-X synthesis and chelation properties of some 2-thiazolyl- and 2-pyrimidinylhydrazones

Preparation of some new hydrazones which possess the ferroin chromophoric group is described, together with results of spectrophotometric studies of their chelation reactions with iron(II), copper(I), cobalt(II) and nickel(II). Several of the new compounds show promise as highly sensitive chromogenic reagents for simultaneous determinations of these metals.     

Synthetic and Thermal Studies of Polymeric Chelates of Some Bis-Biurets with First Transition Series Metals

Some new coordination polymers have been synthesized by combining adipyl bis-biuret and azelyl bis-biuret with metals of first transition series viz Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). They were characterized by elemental analysis, infrared and reflectance spectral and magnetic studies. A detailed thermal study was carried out and thermal stability compared. The results obtained have been discussed.This revised version was published online in November 2005 with corrections to the Cover Date.     

Synthesis and characterization of 4-(alkylaminoisonitrosoacetyl)biphenyls and their complexes

Three new substituted 4-(alkylaminoisonitrosoacetyl)biphenyls (ligands) derived from 4-biphenylhydroxymoyl chloride and corresponding amines were synthesized. The following aromatic and aliphatic amines were used for ligands: ethanolamine, 2-amino-4-methylphenol, and 2-(aminomethyl)pyridine. Mononuclear or binuclear cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), and lead(II) complexes with these ligands were synthesized. These compounds were characterized by elemental analyses, AAS, infrared spectra, and magnetic susceptibility measurements. The ligands were additionally characterized by ¹H NMR. The results suggest that the ligands act as tridentate ligands. The text was submitted by the authors in English.     

New chromogens of the ferroin type-VII Some 3-substituted-1,2,4-triazines, 3,5-disubstituted-1,2,4-triazolines and triazoles, and 2,4- and 2,6-bis triazinyl and triazolinyl substituted pyridines

Chelation and chromogenic properties of 39 new ferroin compounds in reactions with iron(II), copper(I), and cobalt(II) have been investigated spectrophotometrically. The results demonstrate that the chromogenic properties of triazole and triazoline heterocycles are inferior to triazine and pyridine when incorporated into the ferroin chromophore grouping. The triazole and triazoline compounds also undergo hydrolytic decomposition, strongly catalysed by iron(II), making them unsuitable as colorimetric reagents. An outstanding chromogen was found from among the triazine derivatives which is superior in sensitivity to all ferroin-type chromogens previously studied.     

Chemically modified multiwalled carbon nanotubes as efficient and selective sorbent for separation and preconcentration of trace amount of Co(II), Cd(II), Pb(II), and Pd(II)

Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized by glutaric dihydrazide (GDH) and characterized with FT-IR technique. This new sorbent was used for enrichment and preconcentration of Co(II), Cd(II), Pb(II), and Pd(II) ions. The adsorption was achieved quantitatively on MWCNTs at pH 4.0, and then the retained metal ions on the adsorbent were eluted with 1.5 mol L^?1 HNO₃. The effects of analytical parameters including pH of the solution, eluent type, sample volume, and matrix ions were investigated for optimization of the presented procedure. The adsorption capacity of the adsorbent at optimum conditions was found to be 33.6, 29.2, 22.1, and 36.0 mg g^?1 for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The LOD values of the method were 0.16, 0.19, 0.17, and 0.12 ng mL^?1 (3Sb, n = 10) for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The RSDs values of the method were 0.75, 0.85, 1.16, and 1.30 ng mL^?1 for Co(II), Cd(II), Pb(II), and Pd(II), respectively. The method was applied for the determination of analytes in soil, well water, and wastewater samples with satisfactory results.     

Synthesis, characterization and thermal behavior of 4-chloromethyl-2-(2-hydroxybenzilidenehydrazino) thiazole and its complexes with Cr(III), Co(II), Ni(II) and Cu(II)

A new ligand, 4-chloromethyl-2-(2-hydroxybenzilidenehydrazino) thiazole, has been synthesized from dicholoroacetone and 2-hydroxybenzylidenethiosemicarbazon. Metal complexes of the ligand were prepared from acetate salts of Co(II), Cu(II), Ni(II) and chloride of Cr(III) in dry acetone. Characterization of the ligand and its complexes was made by microanalyses, FT-IR, 13C, 1H NMR and UV-vis spectroscopy, magnetic susceptibility and thermogravimetric analysis. In the light of these results, it was suggested that two ligands coordinate to each metal atom by hydroxyl oxygen, imino nitrogen and thiazole ring nitrogen to form high spin octahedral complexes with Cr(III), Co(II), Ni(II) and Cu(II).     

Synthesis, characterization, and fluorescence behavior of four novel macrocyclic emissive ligands containing a flexible 8-hydroxyquinoline unit

Four emissive macrocyclic ligands mono-substituted with an 8-hydroxyquinoline pendant arm are presented. The new compounds have been used for metal-ion detection, which results from the competition between PET (photo-induced electron transfer) and PPT (photo-induced proton transfer) mechanisms. Solid metal complexes with divalent Cu(II), Zn(II), and Cd(II), and trivalent metal ions Al(III) and Cr(III) have been also synthesized and characterized. The compounds have been isolated as mononuclear or dinuclear (Cu(II)) complexes, confirming the stoichiometry observed in solution.     

New chromogens of the ferroin type-VIII Some di- and trisubstituted 1,2,4-triazines, 3-substituted-9H-indeno[1,2-e]-1,2,4-triazin-9-ones, and di- and trisubstituted 1,2,4-triazolines

Thirty-six new ferroin compounds have been investigated as possible chelation regents for the calorimetric detection and determination of trace amounts of iron(II), copper(I), and cobalt(II). Spectral data, solution conditions favourable for chelate formation, and other data are reported. The results reveal that incorporation of triazoline heterocycles in ferroin chromophore groupings generally leads to poor chromogenic properties, except with respect to cobalt. Triazine groups, however, can give rise to superior properties. The most sensitive iron(II) chromogen of the ferroin type found to date and a promising new cobalt chromogen are described.     

Synthesis and characterization of new ketooximes and their complexes

The starting point of the research was the reaction of chloroacetyl chloride with biphenyl in the presence of aluminum chloride. 4-Biphenylhydroximoyl chloride (HL) was obtained by reacting synthesized 4-(chloroacetyl)biphenyl with alkyl nitride. Four new substituted 4-(alkylaminoisonitrosoacetyl)biphenyles (ketooximes) were prepared by reacting 4-biphenylhydroximoyl chloride with corresponding amines in EtOH. The following amines were used for ligands: p-toluidine, p-chloroaniline, pyrrolidine, and 4-aminoacetophenone. Mononuclear complexes with a metal-ligand ratio of 1: 2 were prepared using cadmium(II), cobalt(II), copper(II), nickel(II), lead(II), and zinc(II) salts. These compounds have been characterized by elemental analyses, AAS, infrared spectra and magnetic susceptibility measurements. The ligands have been further characterized by ¹H NMR. The results suggest that the ketooximes act as bidentate ligands which bond metal ions through the oxime and carbonyl oxygen. The text was submitted by the authors in English.     

Preparation of sinapinaldehyde modified mesoporous silica materials and their application in selective extraction of trace Pb(II)

A new solid phase extractant, sinapinaldehyde (SA) modified SBA-15 mesoporous silica, was developed for selective extraction and preconcentration of trace Pb(II) from aqueous solutions. The successful immobilization of SA on SBA-15 and the strong interaction between SA-SBA-15 and Pb(II) were characterized and confirmed by FTIR spectroscopy and scanning electron microscopy. Parameters such as solution pH, shaking time, eluent condition and sample volume were optimized so that the maximum removal of Pb(II) from solution could be achieved. At pH 4.0, the maximum adsorption capacity of the sorbent for Pb(II) was found to be 33.6?mg?g^?1 and the adsorbed Pb(II) could be completely eluted using a mixed solution of 2?M HCl and 5% CS(NH₂)₂. Some common metal ions such as K(I), Na(I), Mg(II), Ca(II), Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) did not interfere with the adsorption of trace Pb(II). The detection limit of the present method was found to be 1.3?ng?mL^?1 and the relative standard deviation was less than 2.0% (n?=?8). These results suggested that this new sorbent is very efficient and selective for the removal of trace Pb(II) in water samples.     

New chromogens of the ferroin-type-I. Substituted triazines related to 6-cyano-2,2'-bipyridine

A spectrophotometric study has been made of the iron(II), cobalt(II), nickel(II) and copper(I) chelates of seven new compounds that contain the ferroin functional grouping. None of the new compounds proved to be superior to chromogenic reagents currently in use, but the results are of interest in designing new chromogens.     

Synthesis,characterization, and biological activity of metal complexes of azohydrazone ligand

A new azohydrazone, 2-hydroxy-N′-2-hydroxy-5-(phenyldiazenyl)benzohydrazide (H₃L) and its copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), cadmium(II), mercury(II), vanadyl(II), uranyl(II), iron(III), and ruthenium(III) complexes have been prepared and characterized by elemental and thermal analyses as well as spectroscopic techniques (¹H-NMR, IR, UV-Vis, ESR), magnetic, and conductivity measurements. Spectral data showed a neutral bidentate, monobasic bidentate, monobasic tridentate, and dibasic tridentate bonding to metal ions via the carbonyl oxygen in ketonic or enolic form, azomethine nitrogen, and/or deprotonated phenolic hydroxyl oxygen. ESR spectra of solid vanadyl(II) complex (2), copper(II) complexes (3–5), and (7) and manganese(II) complex (10) at room temperature show isotropic spectra, while copper(II) complex (6) shows axial symmetry with covalent character. Biological results show that the ligand is biologically inactive but the complexes exhibit mild effect on Gram positive bacteria (Bacillus subtilis), some octahedral complexes exhibit moderate effect on Gram negative bacteria (Escherichia coli), and VO(II), Cd(II), UO(II), and Hg(II) complexes show higher effect on Fungus (Aspergillus niger). When compared to previous results, metal complexes of this hydrazone have a mild effect on microorganisms due to the presence of the azo group.     

Synthesis of certain pyridinyl and diazinyl hydrazones containing one or more ferroin groups, and their chromogenic reactions with iron, copper, cobalt and nickel

Fifteen new hydrazones with one or more ferroin groups were prepared, and their chelation and chromogenic properties with iron(II), copper(I), cobalt(II) and nickel(II) were investigated. Improved sensitivity in the spectrophotometric determination of cobalt, copper, and nickel is provided by several of the new compounds. Several others are capable of forming unusually stable and interesting binuclear iron(II) complexes.     

微晶酚酞富集-分光光度法测定痕量Zn(II)

建立了一种利用修饰有结晶紫(CV^＋)的微晶酚酞作为固态吸附剂分离富集溶液中痕量Zn(II)的新方法, 富集后的Zn(II)含量可直接用光度法测定. 控制一定条件, Zn(II)能与常见阳离子Ni(II), Cd(II), Al(III), Ca(II), Mg(II), Co(II), Mn(II), Cu(II), Pb(II), Fe(III)等完全分离, 且富集时基本不受, , Br^－, Cl^－, I^－,等阴离子影响. 微晶酚酞对Zn(II)的吸附容量为25.8 mg/g; 富集因数可达200倍, 回收率在97.7%～102%之间, RSD小于2.7%. 该方法已成功应用于实际水样中Zn(II)的富集测定, 结果令人满意.     

Chemically-modified activated carbon with ethylenediamine for selective solid-phase extraction and preconcentration of metal ions

A new method that utilizes ethylenediamine-modified activated carbon (AC-EDA) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) prior to the measurement by inductively coupled plasma optical emission spectrometry (ICP-OES). The new sorbent was prepared by oxidative surface modification. Experimental conditions for effective adsorption of trace levels of Cr(III), Fe(III), Hg(II) and Pb(II) were optimized with respect to different experimental parameters using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.0. Complete elution of absorbed metal ions from the sorbent surface was carried out using 3.0 mL of 2% (%w/w) thiourea and 0.5 mol L⁻¹ HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.4, 28.9, 60.5 and 49.9 mg g⁻¹ for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The time for 94% adsorption of target metal ions was less than 2 min. The detection limits of the method was found to be 0.28, 0.22, 0.09 and 0.17 ng mL⁻¹ for Cr(III), Fe(III), Hg(II) and Pb(II), respectively. The precision (R.S.D.) of the method was lower 4.0% (n = 8). The prepared sorbent as solid-phase extractant was successfully applied for the preconcentration of trace Cr(III), Fe(III), Hg(II) and Pb(II) in natural and certified samples with satisfactory results.     

Synthesis,Structural, and Physico-Chemical Study of Transition Metal Complexes with Schiff Base: A Product of Condensation of 2- N -Tosylaminobenzaldehyde and Tryptamine

A new Schiff base, the product of 2-N-tosylaminobenzaldehyde and tryptamine condensation, was synthesized and investigated. A physicochemical study and quantum chemical simulation of the azomethinee tautomerism were performed. Its complexes with Zn(II), Cu(II), Ni(II), Co(II), and Fe(III) were synthesized and studied.     

钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)、锌(Ⅱ)的双-N(2-羟基乙基)水杨醛亚胺螯合物的合成及其抗癌活性的初步试验

合成了-N(2-羟基乙基)水杨醛亚胺合钴(Ⅱ)、镍(Ⅱ)、铜(Ⅱ)和锌(Ⅱ)并为元素分析和红外光谱数据所表征。其中三种螯合物为新的席地夫碱金属配合物。用体外美兰法对Co(Ⅱ)、Ni(Ⅱ)和Cu(Ⅱ)配合物进行了抗癌活性试验。结果表明,这些螯合物对六种人体肿瘤具有抑瘤活性。     

New chromogens of the ferroin type-IX 2-pyridyl and pyrazinylhydrazones of some pyridyl, pyrazinyl and pyridazinyl ketones and of isatin and phenylglyoxal

Chromogenic properties of 22 new hydrazones, all ferroin-type compounds, have been evaluated with respect to iron(II), copper(I), cobalt(II) and nickel(II). Some show promise as sensitive reagents for the determination of trace amounts of these metal ions. Stoichiometric ratios were determined for the iron(II) chelates and interpreted to distinguish between syn- and anti-isomers.     

Study of the concentration and separation of cadmium with microcrystalline phenolphthalein modified by crystal violet

A new method for cadmium separation and concentration with microcrystalline phenolphthalein modified by crystal violet (CV) was developed in the paper. In the presence of potassium iodide (KI) and CV, cadmium are quantitatively absorbed on microcrystalline phenolphthalein in the pH range 1.0-6.0 as the forms of water-insoluble ion-associated complexes (CdI₃⁻)·(CV⁺) and (CdI₄²⁻)·(CV⁺)₂. Effect of different parameters such as phenolphthalein amount, stirring time, the concentration of CV and KI, various salts and metal ions was studied in detail. During the present study, a significant enhancement of the extraction of cadmium was observed. Cd(II) can be completely separated from Zn(II), Fe(II), Co(II), Ni(II), Mn(II), Cr(III) and Al(III) in this microcrystalline system and well concentrated without the interference of these metal ions at high level. The possible reactive mechanism of cadmium concentration has been discussed. Analytical results obtained by this new method were very gratifying.     

Potentiometric and Thermodynamic Studies of Some Metal–Cysteine Complexes

A new and simple potentiometric method is developed to determine the stability constants of cysteine complexes with Mn(II), Cu(II), Zn(II), Cd(II), and Ce(III) metal ions using a modified Bjerrum method. Potentiometric titrations were performed in water and water/dioxane mixtures at five different temperatures. The least and highest stable complexes were those of Cu(II) and Zn(II), respectively. Furthermore, by conducting the experiments at temperatures of 15, 20, 25, 35, and 45 °C, the thermodynamic parameters ΔH°, ΔS°, and ΔG° for the pertinent complexes were calculated. The results show that the ΔH° values of the complexes are positive except for Zn(II). Negative values of ΔG° are evidence for the spontaneity of the reactions.