Magnetic,Spectral, Thermal,and Electrical Properties of Coordination Polymers Derived from Terpolymers

Coordination polymers of Cu(II), Ni(II), Co(II), zinc(II), chromium(IU), iron(IU), oxovanadium(N), and dioxouranium-(VI) with p-hydroxybenzoic acid (PHB)-thiourea (T)-trioxane (T) (PHBTT) polymer were prepared. The analytical data agree with 1:1 metal-ligand stoichiometry. Magnetic susceptibility, visible and IR spectra, and thermal and electrical conductivities of the chelates have been studied and probable structures assigned to the chelates.     

Thermal analysis of some metal benzohydroxamates

The preparation and thermal analysis of metal chelates of benzohydroxarnic acid (BHA) with Al(III), Cd(II), Co(II), Cu(II) (two compounds), Fe(III), La(III), Pb(II), Mn(II), Ni(II), U(VI) and Zn(II) is discussed. The Al(III), La(III), Pb(II) and Mn(II) chelates are new compounds. DTA and TGA curves of the chelates and of BHA are presented, and the heats of decomposition of the chelates are estimated.     

Reversed-phase ion-pair high performance liquid chromatographic determination of Co(III)-, Ni(II)-, V(V)- and Fe(III)-2-(2-benzothiazolylazo)-5-(3-sulforpropyl)aminophenol chelates

The separation and determination of Co(III), Ni(II), V(V) and Fe(III) chelates with 2-(2-benzothiazolylazo)-5-(3-sulfopropyl)aminophenol (BTASPAP) by reversed-phase ion-pair HPLC was investigated. In the presence of the oxidant potassium iodate, BTASPAP reacts with Co(III), Ni(II), V(V) and Fe(III) to form stable, negatively charged, water-soluble chelates. The chelates were separated on a C(18) siloxane bonded phase and eluted within 7 min with acetonitrile-acetate-water (36:1:63 v/v) containing 0.2 mol 1(-1) acetic acid-sodium acetate buffer (pH 3.0) and 1.0 mmol 1(-1) tetrabutylammonium bromide. The detection limits of Co(III), Ni(II), V(V) and Fe(III) at 565 nm are 0.3, 0.8, 0.3 and 1.0 ng (signal-to-noise ratio = 2), respectively. The method was applied to the determination of Co, Ni, V and Fe in four samples of standard alloys.     

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

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. Alpha-methyldopa (alpha-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), alpha-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.     

Fractional sublimation of some metal chelates of thenoyltrifluoroacetone

Studies on the fractional sublimation of various metal β-diketone chelates have been extended to include the chelates of thenoyltrifluoroacetone (TTA). Many of the common metal chelates were found to be stable, to sublime readily, and to form well-defined zones in the vacuum fractional sublimator. Of the 17 chelates reported only those of manganese (II) and iron(II) were not volatile. The chelates of UO₂(II), Zr(IV), Pb(II), and Cr(III) partially decomposed during sublimation and their recovery was incomplete. The recovery of the sublimed chelates of Ni(II), Mg(II), Al(III), Pd(II), Co(II), Cu(II). Fe(III), Tl(III), Zn(II) and Be(II) ranged from 87 to 100%, with most recoveries being quantitative. The sublimation recrystallization zone temperatures of the various chelates are compared to those of the metal acetylacetonates and the benzoyltrifluoroacetonates; in general, the metal chelates of TTA sublime more readily than those of benzoyltrifluoroacetone but are potentially less useful for fractional sublimation separations than the corresponding metal acetylacetonates. Even so, a quantitative separation of iron(III) from Ni(II), Al(III), Mn(II), and Fe(II) is proposed that depends upon the fractional sublimation of the TTA chelates.     

Structure investigation, spectral, thermal, X-ray and mass characterization of piroxicam and its metal complexes

[M(H2L)2](A)2.yH2O (where H2L: neutral piroxicam (Pir), A: Cl- in case of Ni(II) or acetate anion in case of Cu(II) and Zn(II) ions and y=0-2.5) and [M(H2L)3](A)z.yH2O (A: SO4(2-) in case of Fe(II) ion (z=1) or Cl(-) in case of Fe(III) (z=3) and Co(II) ions (z=2) and y=1-4) chelates are prepared and characterized using elemental analyses, IR, magnetic and electronic reflectance measurements, mass spectra and thermal analyses. IR spectra reveal that Pir behaves a neutral bidentate ligand coordinated to the metal ions through the pyridyl-N and carbonyl-O of the amide moiety. The reflectance and magnetic moment measurements reveal that these chelates have tetrahedral, square planar and octahedral geometrical structures. Mass spectra and thermal analyses are also used to confirm the proposed formulae and the possible fragments resulted from fragmentation of Pir and its chelates. The thermal behaviour of the chelates (TGA and DTA) are discussed in detail and the thermal stability of the anhydrous chelates follow the order Ni(II) congruent with Cu(II) Fe(II)相似文献   

Pre-column chelation liquid chromatographic separation and determination of trace V,Cu, Co,Pd, Fe and Ni

Conditions for the separation by reversed-phase liquid chromatography (LC) of V(V), Cu(II), Co(III), Pd(II), Fe(III) and Ni(II) chelates with 2-(5-bromopyridylazo)-5-diethylaminophenol (5-Br-PADAP) were studied. Six species of metal chelates were separated successfully with methanol-acetonitrile-water (72:12:16, v/v/v) containing 0.13 M NaCl and 0.29 mM cetyltrimethylammonium bromide (pH 5.0) as the mobile phase on a Nucleosil C₁₈ (5 μm) column (250 × 4 mm i.d.).The conditions of the determination of these metal chelates are discussed. A simple and rapid method for the determination of trace amounts of V(V), Cu(II), Co(III), Pd(II) and Ni(II) simultaneously by reversed-phase LC has been developed. The detection limits are 5 × 10^?12, 1 × 10^?10, 3 × 10^?11, 5.3 × 10^?9 and 2 × 10^?10 g, respectively. The method is applied to the determination of these metals in natural waters and mineral samples.     

Chelate von β-dicarbonylverbindungen und ihren derivaten: Teil XLVII. Dünnschichtchromatographisches verhalten von metallchelaten mit thiodibenzoylmethan und acetylthioacetaniliden

The thin-layer chromatographic behaviour of thiodibenzoylmethane chelates with cobalt(III), zinc(II), mercury(II), palladium(II), platinum(II) and rhodium(III), and also of acetylthioacetanilide chelates with cobalt(III), nickel(II), zinc(II) and cadmium(II) on alumina is described. Different binary mixtures of eluents are used. The influence of solvent parameters and of the layer material, possible separations and the influence of substituents in the acetylthioacetanilides are discussed.     

Thermal analysis of some metal n-benzoyl-n-phenylhydroxylamine chelates

The preparation and thermal analysis of the metal chelates of N-benzoyl-N-phenylhydroxylamine (BPHA) with Al(III), Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II) and Zn(II) is discussed. The differential thermal analysis apparatus is described in detail. DTA and TGA curves of BPHA arid the chelates from 25 to 700° in oxygen and in nitrogen are presented.     

Spectrophotometric studies on ion-pair extraction equilibria of the iron(ii) and iron(III) complexes with 4-(2-pyridylazo)resorcinol

The ion-pair extraction equilibria of the iron(II) and iron(III) chelates of 4-(2-pyridylazo)resorcinol (PAR, H(2)L) are described. The anionic chelates were extracted into chloroform with benzyldimethyltetradecylammonium chloride (QC1) as counter-ion. The extraction constants were estimated to be K(ex1)(Fe(II)) = [Q{Fe(II)(HL)L}](0)/[Q(+)][{Fe(II)(HL)L}(-)] = 10(8.59 +/- 0.11), K(ex2)(Fe(II)) = [Q(2){Fe(II)L(2)}](o)/ [Q(+)](2)[{Fe(II)L(2)}(2-)] = 10(12.17 +/- 0.10) and K(ex1)(Fe(III)) = [Q{Fe((III))L(2)}](o)/(Q(+)][{Fe(III)L(2)}(-)] = 10(6.78 +/- 0.15) at I = 0.10 and 20 degrees , where [ ](o) is concentration in the chloroform phase. Aggregation of Q{Fe(III)L(2)} in chloroform was observed and the dimerization constant (K(d) = [Q(2){Fe(III)L(2)}(2)](o)/[Q{Fe(III)L(2)}](o)(2)) was evaluated as log K(d) = 4.3 +/- 0.3 at 20 degrees . The neutral chelates of {Fe(II)(HL)(2)} and {Fe(III)(HL)L}, and the ion-pair of the cationic chelate, {Fe(III)(HL)(2)}ClO(4), were also extracted into chloroform or nitrobenzene. The relationship between the forms and extraction properties of the iron(II) and iron(III) PAR chelates are discussed in connection with those of the nickel(II) and cobalt(III) complexes. Correlation between the extraction equilibrium data and the elution behaviour of some PAR chelates in ion-pair reversed-phase partition chromatography is also discussed.     

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.     

Uranyl binary and ternary chelates of tenoxicam Synthesis, spectroscopic and thermal characterization of ternary chelates of tenoxicam and alanine with transition metals

Ternary Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and UO(2)(II) chelates with tenoxicam (Ten) drug (H(2)L(1)) and dl-alanine (Ala) (HL(2)) and also the binary UO(2)(II) chelate with Ten were studied. The structures of the chelates were elucidated using elemental, molar conductance, magnetic moment, IR, diffused reflectance and thermal analyses. UO(2)(II) binary chelate was isolated in 1:2 ratio with the formula [UO(2)(H(2)L)(2)](NO(3))(2). The ternary chelates were isolated in 1:1:1 (M:H(2)L(1):L(2)) ratios and have the general formulae [M(H(2)L(1))(L(2))(Cl)(n)(H(2)O)(m)].yH(2)O (M=Fe(III) (n=2, m=0, y=2), Co(II) (n=1, m=1, y=2) and Ni(II) (n=1, m=1, y=3)); [M(H(2)L(1))(L(2))](X)(z).yH(2)O (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)). IR spectra reveal that Ten 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 confirm that all the chelates have octahedral geometry except Cu(II) and Zn(II) chelates have tetrahedral structures. Thermal decomposition of the chelates was discussed in relation to structure and different thermodynamic parameters of the decomposition stages were evaluated.     

Thin-Layer Chromatography of Metal Ions Complexed with Anils (V). Detection,Separation and Determination

Abstract

p-Diethylaminoanil of phenylglyoxal a bidentate ligand was used for complexation with Hg(II), UO₂(II), Au(III), Pt(IV) Mg(II), Bi(III), Sb(III) and Be(II) ions. The chelates were characterized by their analysis, molar conductance and infrared spectra. T.L.C. detection, separation and determination of these complexes on starch bound silica gel layers was studied Long persisting dark coloure of the complexes rendered the spots self descernible and no locating agent was required. A maximum four complexes could be resolved and identified. Errors in determinations and maximum separation limits were also deduced.     

Structure and behavior of organic analytical reagents : Dimethylglyoxime and its oxygen monomethyl ether

The titration procedure described in previous papers of this series has been applied to a study of some metallic chelates of dimethylglyoxime and of its O-monomethyl ether. Evidence is presented for the existence of dimethylglyoxime chelates with Zn (II), Pb (II), Cd (II), and La (III) in addition to the known Cu (II), Ni (II), and Co (II) complexes. Formation constants are calculated for these complexes, and for those of dimethylglyoxime O-monomethyl ether, on the basis of their most probable structures. The results indicate that the famed specificity of dimethylglyoxime fur nickel does not lie in any special stability of this chclate. but in some other factor, possibly solubility. A comparison of the chelates of dimethylglyoxime with those of its O-ether is discussed in terms of such structural factors as hydrogen bonding and steric hindrance. Heat content and entropy changes have been calculated for the chelation of dimethylglyoxime with Cu (II) and Ni (II) ions.     

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

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 chelates 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.     

Capillary gas chromatographic analysis of pyrrolidinedithiocarbamate metal chelates

Pyrrolidinedithiocarbamate (PDTC) chelates of Zn(II), Cu(II), Ni(II), Co(III), Fe(III), Mn(II), Cr(III), and VO(II) were analysed by capillary GC on a DB-1701 column (30 m x 0.25 mm id) with flame ionisation detection (FID). Linear calibrations were attained within "1-30 microg/mL" for Ni(II), Fe(III), Mn(II), Cr(III), Cu(II), and VO(II), and within "2-50 microg/mL" for Co(III) and Zn(II). The limits of detection were in the "150-500 ng/mL" range, corresponding to 15-50 pg amounts reaching the FID system. The optimised method was applied to the determination of Cu(II) and Ni(II) in coins, and that of Zn(II), Cu(II), Ni(II), Fe(III), Mn(II), Cr(III), and VO(II) in pharmaceutical preparations with relative standard deviations within 1.1-5.2%. The results obtained are in good agreement with sewage water samples and the declared values for the pharmaceutical formulations, or with the results of AAS of metal contents in coins, pharmaceutical preparations, and sewage water samples.     

Reversed-phase HPLC determination of Co(II), Ni(II) and Fe(III) as their 2-(2-thiazolylazo)-5-dimethylaminophenol chelates

The optimum chromatographic separation conditions for Co(II), Ni(II), and Fe(III) chelates with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM) were investigated. The compositions of chelates were also determined by the HPLC method and thus the possible structure of chelates was given. A precolumn derivatization method was used, followed by separation on an octyl-bonded silica stationary phase with a methanol-tetrahydrofuran-water (40:9:51, v/v/v) mobile phase containing pH 5.8 acetate buffer and 1 x 10(-4)M TAM. The detection limits of Co(II), Ni(II), and Fe(III) at 560 nm are 0.03, 0.02 and 0.1 ng (S N = 2 ), respectively. They can be determined by means of the proposed method without interference from other common metal ions and have been determined in five standard alloys with satisfactory results.     

Potentiometric, spectroscopic and thermal studies on the metal chelates of 1-(2-thiazolylazo)-2-naphthalenol

The synthesis and characterization of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Pd(II) and UO2(II) chelates of 1-(2-thiazolylazo)-2-naphthalenol (TAN) were reported. The dissociation constants of the ligand and the stability constants of the metal complexes were calculated pH-metrically at 25 degrees C and 0.1 M ionic strength. The solid complexes were characterized by elemental and thermal analyses, molar conductance, IR, magnetic and diffuse reflectance spectra. The complexes were found to have the formulae [M(L)2] for M = Mn(II), Co(II), Ni(II), Zn(II) and Cd(II); [M(L)X].nH2O for M = Cu(II) (X = AcO, n = 3), Pd(II) (X = Cl, n = 0) and UO2(II) (X = NO3, n = 0), and [Fe(L)Cl2(H2O)].2H2O. The molar conductance data reveal that the chelates are non-electrolytes. IR spectra show that the ligand is coordinated to the metal ions in a terdentate manner with ONN donor sites of the naphthyl OH, azo N and thiazole N. An octahedral structure is proposed for Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II) and UO2(II) complexes and a square planar structure for Cu(II) and Pd(II) complexes. The thermal behaviour of these chelates shows that water molecules (coordinated and hydrated) and anions are removed in two successive steps followed immediately by decomposition of the ligand molecule in the subsequent steps. The relative thermal stability of the chelates is evaluated. The final decomposition products are found to be the corresponding metal oxides. The thermodynamic activation parameters, such as E*, delta H*, delta S* and delta G* are calculated from the TG curves.     

Optimized relaxivity and stability of [Gd(H(2,2)-1,2-HOPO)(H2O)]- for use as an MRI contrast agent

Relaxometry and solution thermodynamic measurements show that Gd(H(2,2)-1,2-HOPO) is a good candidate as a contrast agent for magnetic resonance imaging (MRI-CA). Acidic, octadentate H(2,2)-1,2-HOPO forms a very stable Gd(III) complex [pGd=21.2(2)]. The coordination sphere at the Gd(III) center is completed by one water molecule that is not replaced by common physiological anions. In addition, this ligand is highly selective for Gd(III) binding in the presence of Zn(II) or Ca(II). The symmetric charge distribution of the 1,2-HOPO chelates is associated with favorably long electronic relaxation time T1,2e comparable to those of GdDOTA. This, in addition to the fast water exchange rate typical of HOPO chelates, improves the relaxivity to r1p=8.2 mM-1 s-1 (0.47 T). This remarkably high value is unprecedented for small-molecule, q=1 MRI-CA.     

Potential of ethylenediaminedi(o-hydroxyphenylacetic acid) and N,N'-bis(hydroxybenzyl)ethylenediamine-N,N'-diacetic acid for the determination of metal ions by capillary electrophoresis

Two aromatic polyaminocarboxylate ligands, ethylenediaminedi(o-hydroxyphenylacetic acid) (EDDHA) and N,N′-bis(hydroxybenzyl)ethylenediamine-N,N′-diacetic acid (HBED), were applied for the separation of transition and heavy metal ions by the ion-exchange variant of electrokinetic chromatography. EDDHA structure contains two chiral carbon centers. It makes it impossible to use the commercially available ligand. All the studied metal ions showed two peaks, which correspond to meso and rac forms of the ligand. The separation of metal–HBED chelates was performed using poly(diallyldimethylammonium) polycations in mixed acetate–hydroxide form. Simultaneous separation of nine single- and nine double-charged HBED chelates, including In(III), Ga(III), Co(II)–(III) and Mn(II)–(III) pairs demonstrated the efficiency of 40 000–400 000 theoretical plates. The separation of Co(III), Fe(III) complexes with different arrangements of donor groups and oxidation of Co(II), Mn(II), Fe(II) ions in reaction with HBED have been discussed.