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.     

Synthesis of narrowly size-distributed metal salt/poly(HEMA) hybrid particles in inverse miniemulsion: versatility and mechanism

Hybrid particles containing different hydrophilic metal salts such as tetrafluoroborates of iron(II), cobalt(II), nickel(II), copper(II), and zinc(II), and nitrates of cobalt(II), nickel(II), copper(II), zinc(II), and iron(III), and cobalt(II) chloride were synthesized via inverse miniemulsion polymerization of 2-hydroxyethyl methacrylate (HEMA). All salts delivered narrowly size-distributed hybrid particles with the exception of iron(III), where only the nitrate salt could be successfully employed. The size and size distribution of the hybrid particles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The particle morphology and the distribution of salt in the dried particles were observed by TEM. The influences of the type of metal salts and salt content on the particle size distribution were extensively investigated.     

Liquid chromatographic determination of chelates of cobalt (II), copper (II) and iron (II) with 2-thiophonaldehyde-4-phenyl-3-thiosemicarbazone

Summary A new chelating reagent 2-thiophenaldehyde-4-phenyl-3-thiosemicarbazone (TAPT) has been examined for high performance liquid chromatographic (HPLC) separations of cobalt (II), copper(II) and iron (II) or cobalt (II), nickel (II), iron (II), copper (II) and mercury (II) as metal chelates on a C₁₈, 5μm column (250×4 mm i.d.) The chelates were eluted isocratically with methanol: acetonitrile: water containing sodium acetate and tetrabutylammonium bromide (TBA), and detected at 254 nm. A solvent extraction procedure was developed for simultaneous determination of the metals with detection limits within 0.02–2.5 μ g.mL⁻¹. The method was applied to the determination of copper, cobalt and iron in natural waters.     

Microdetermination of Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Hg, Pb, Bi and U in inorganic and organometallic compounds with morpholinium morpholine-N-dithiocarboxylate

The chelates of morpholinium morpholine-N-dithiocarboxylate with manganese(II), iron(II), iron(III), cobalt(II), nickel, copper(II), zinc, silver, cadmium, mercury(II), lead, bismuth and uranium(VI) have been prepared and their compositions elucidated. Simple, accurate and relatively rapid procedures for the gravimetric and titrimetric microdetermination of these metals in inorganic and organometallic compounds are presented.     

Coprecipitation with yttrium phosphate as a separation technique for iron(III), lead, and bismuth from cobalt, nickel, and copper matrices

The coprecipitation behavior of 44 elements (47 ions because of chromium(III,VI), arsenic(III,V), and antimony(III,V)) with yttrium phosphate was investigated at various pHs. Yttrium phosphate could quantitatively coprecipitate iron(III), lead, bismuth, and indium over a wide pH range; however, 18 ions, including alkali metals and oxo anions, such as vanadium(V), chromium(VI), molybdenum(VI), tungsten(VI), germanium(IV), arsenic(III,V), selenium(IV), and tellurium(VI), were scarcely collected. In addition, 19 ions, including cobalt, nickel, and copper(II), were hardly coprecipitated at pHs below about 3. Based on these results, the separation of iron(III), lead, and bismuth from cobalt, nickel, and copper(II) matrices was investigated. Iron(III), lead, and bismuth ranging from 0.5 to 25 μg could be separated effectively from a solution containing 0.5 g of cobalt, nickel, or copper at pH 3.0. The separated iron(III), lead, and bismuth could be determined by inductively coupled plasma atomic emission spectrometry using internal standardization. The detection limits (3σ, n = 7) of iron(III), lead, and bismuth were 0.008, 0.137, and 0.073 μg, respectively. The proposed method was applied to the analyses of metals and chlorides of cobalt, nickel, and copper.     

Iron(II), cobalt(III), nickel(II) and copper(II) chelates of furan and thiophene azo-oximes

Summary Complexes of furan and thiophene azo-oximes with iron(II), cobalt(III), nickel(II) and copper(II) have been prepared and characterised. Iron(II), cobalt(III) and copper(II) complexes are diamagnetic in the solid state. The diamagnetism of the copper(II) chelates is suggestive of antiferromagnetic interaction between two copper centres.¹H n.m.r. spectral data suggest atrans-octahedral geometry for the tris-chelates of cobalt(III). Nickel(II) complexes are paramagnetic, in contrast to the diamagnetism of the analogous complexes of arylazooximes. The electronic spectra are suggestive of octahedral geometry for the iron(II), cobalt(III) and nickel(II) complexes, andD _4h -symmetry for copper(II). Infrared data indicate N-bonding of the oximino-group to the metal ions.     

Chelating ion-exchangers containing n-substituted hydroxylamine functional groups: Part V. Iron,copper, and uranium separations on Duolite CS-346 resin

The separation of iron(III), copper(II) and uranyl(II) ions from a series of salt solutions by chelating ion exchange on Duolite CS-346 resin by pH control is described. Recoveries of these ions from cobalt and nickel salt solutions were quantitative. Iron may also be separated from copper by selective sorption with pH control, and uranium from iron and copper by selective desorption with sodium carbonate solution as eluent.     

Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2)

Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency.     

Synthesis, characterization and antimicrobial activity of 3d transition metal complexes of a biambidentate ligand containing quinoxaline moiety

A new series of oxovanadium(IV), chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), and copper(II) complexes of the 3-hydrazino quinoxaline-2-one (HQO) were prepared and characterized. The ligand exhibits biambidenticity. It behaves as a bidentate ON donor in oxovanadium(IV), iron(III) and copper(II) complexes and as a bis bidentate ONNN donor in chromium(III), manganese(II), cobalt(II) and nickel(II) complexes. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, thermal, infrared, ¹H NMR, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry was suggested for all the complexes. All the complexes show subnormal magnetic moments. The ligand, HQO, and its complexes were tested against one strain Gram +ve bacteria (Staphylococcus aureus), Gram −ve bacteria (Escherichia coli). The prepared metal complexes exhibited higher antimicrobial activities than the parent ligand.     

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.     

Determination of uranium, iron, copper, and nickel from ore samples by MEKC using N,N'-ethylene bis(salicylaldimine) as complexing reagent

An analytical procedure has been developed for the separation of dioxouranium(VI), iron(III), copper(II), nickel(II), cobalt(II), cobalt(III), palladium(II), and thorium(IV) by MEKC using N,N'-ethylene bis(salicylaldimine) (H(2)SA(2)en) as a complexing reagent with total runtime <4.5 min. SDS was used as micellar medium at pH 8 with sodium tetraborate buffer (0.1 M). An uncoated fused-silica capillary with an effective length of 50 cm x 75 microm id was used with an applied voltage of 30 kV with photodiode array detection at 231 nm. Linear calibrations were obtained within 0.111-1000 microg/mL of each element with LODs within 37-325 ng/mL. The developed method was tested for analysis of uranium ore samples indicating its presence within 103-1789 microg/g with RSD within 0.79-1.87%. Likewise copper, nickel, and iron in their combined matrix were also simultaneously determined with RSD 0.4-1.6% (n = 6).     

Liquid chromatographic determination of cobalt(II), copper(II) and iron(II) using 2-thiophenaldehyde-4-phenyl-3-thiosemicarbazone as derivatizing reagent

The complexing reagent 2-thiophenaldehyde-4-phenyl-3-thiosemicarbazone (TAPT) was examined for high performance liquid chromatographic (HPLC) separations of cobalt(II), copper(II) and iron(II) or cobalt(II), nickel(II), iron(II), copper(II) and mercury(II) as metal chelates on a Microsorb C-18, 5-mum column (150x4.6 mm i.d.) (Rainin Instruments Woburn, MA, USA). The complexes were eluted isocratically with methanol:acetonitrile:water containing sodium acetate and tetrabutyl ammonium bromide (TBA). UV detection was at 254 nm. The solvent extraction procedure was developed for simultaneous determination of the metals, with detection limits within 0.5-2.5 mug ml(-1) in the final solution. The method was applied for the determination of copper, cobalt and iron in pharmaceutical preparation.     

Synthesis and metallochromic properties of some new mono- and bishydrazones of benzil and 2,2'-pyridil

Preparation of some new mono- and bishydrazones 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), nickel(II) and zinc(II). Several of the new compounds show promise as chromogenic reagents for these metals. The results are also of interest with regard to structure-reaction relationships.     

Reaction of 3d-transition metal nicotinates and isonicotinates with thiosemicarbazide

Reaction of iron(II), cobalt(II), nickel(II), and copper(II) nicotinates and isonicotinates with thiosemicarbazide were studied, and the resulting coordination compounds were characterized by elemental analyses, IR spectra, diffuse reflectance spectra, and thermogravimetric data.     

A new selective and high affinity polymeric complexing agent for transition metal ions

Summary The synthesis and characteristics of a new chelating glycinohydroxamate-containing polymer resin is described. The functionality of the polymer is 1.76 mmolg^–1. The hydrogen capacity, water regain and adsorption capacities for iron(III), cadmium(II), cobalt(II), copper(II), nickel(II) and zinc(II) were measured at various pH values; uptake of the metal ions increased with pH and was quantitative above pH 3 for most of the metal ions. All cations studied showed high exchange rates towards the resin. The half saturation times for iron(III), cadmium(II), copper(II) and zinc(II) were all less than 1 min. The coordination behaviour of the resin was studied with the help of e.p.r., i.r., u.v. and potentiometry. The pK _a of the resin is 10.70 and the log value of the stability constants for iron(III), copper(II), lead(II), zinc(II), cobalt(II), manganese(II), cadmium(II) and nickel(II) were measured as 21.81, 19.50, 19.20, 18.59, 18.51, 18.46, 18.37 and 18.36, respectively, at 25 ° C and I = 0.2M KCl.     

Spectrophotometric estimation of cobalt(II) with nitrilotriacetic acid

A convenient and efficient method for the estimation of cobalt(II) ions in the presence of other metal ions is described. Interference of metal ions such as iron(II), iron(III), nickel(II), manganese(II), and copper(II) have been investigated. Only iron(III) ions seriously affect this determination. Copper(II) and nickel(II) ions do not interfere if present in a molar-ratio less than 1:2 in the cobalt(II) ion solution. Cobalt(II)-nickel(II) and cobalt(II)-copper(II) binary mixtures can be efficiently analyzed at selective wavelengths.     

Metal complexes of anti-inflammatory drugs—I. Complexes of iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) with 4-hydroxy-3-(5-methyl-3-is

The preparation, spectroscopic and magnetic properties are reported for complexes of iron(III), cobalt(II), nickel(II), copper(II) and zinc(II) with th     

The application of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane to the extraction of metal ions

The use of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (Tet) in chloroform solutions provides quantitative extraction of lead(II), cadmium(II), copper(II) and zinc(II) at different pH values from solutions containing perchlorate and cyclohexanecarboxylic acid. Nickel(II) and cobalt(II) ions are not extracted quantitatively. Single extractions of mixtures of copper with transition metals gave the best separations for the copper/nickel system. Separations of copper from cobalt, lead, manganese and iron were less satisfactory.     

Picolinaldehyde 4-phenyl-3-thiosemicarbazone as a spectrophotometric reagent for the selective determination of small amounts of cobalt in the presence of iron

The characteristics and analytical applications of picolinaldehyde 4-phenyl-3-thiosemicarbazone are described. This compound gives coloured reactions with cobalt(II), iron(II) and (III), nickel(II), copper(II), palladium(II) and other ions, that are much more sensitive than those with picolinaldehyde thiosemicarbazone. The 1:2 yellow cobalt(II) complex has been used for the spectrophotometric determination of cobalt in the presence of iron, and applied to steel analysis.     

Syntheses,Spectral, Thermal and Electrochemical Studies of 3-Carboxylacetonehydroxamic Acid and its Iron(Ii), Cobalt(Ii), Nickel(Ii), Copper(Ii) and Zinc(Ii) Complexes

3-Carboxylacetonehydroxamic acid (CAHA) and its iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes were synthesized and characterized by elemental analysis, UV-Vis and IR spectra and magnetic susceptibility. The pK _a1 and pK _a2 values of the ligand in aqueous solution were found to be 6.5 ± 0.1 and 8.6 ± 0.1, which correspond to dissociation of carboxyl and hydroxamic protons, respectively. The dianion CAH acts as a tetradentate ligand through the hydroxamate and carboxylate groups and coordinates to the divalent metal ions, forming coordination polymers with a metal-to-ligand ratio of 1 : 1 in the solid state. FTIR spectra and thermal decomposition of the ligand and its metal complexes were recorded and briefly discussed. The electrochemical behavior of the complexes was investigated by square wave voltammetry and cyclic voltammetry at neutral pH. In contrast to the solid state, the iron(II) and copper(II) cations form stable complex species with a metal-to-ligand ratio of 1 : 2 in solution. The iron(II), cobalt(II) and nickel(II) complexes show two-electron irreversible reduction behavior, while the copper(II) and zinc(II) complexes undergo quasi-reversible and reversible electrode reactions, respectively. The stability constants of the complexes were determined by square wave voltammetry.