Non-transition Metal Ions Research Articles

Synthesis, spectroscopic characterization and magnetic properties of homo- and heterodinuclear complexes of transition and non-transition metal ions with a new Schiff base ligand

Four homodinuclear complexes of Ni(II)–Ni(II), Cu(II)–Cu(II), Co(II)–Co(II) and Co(III)–Co(II) and five heterodinuclear complexes of Co(III)–Zn(II), Co(III)–Cu(II), Co(III)–Ni(II), Cu(II)–Zn(II) and Zn(II)–Cu(II) with the octadentate Schiff base compartmental ligand 1,8- N-bis(3-carboxy)disalicylidene-3,6-diazaoctane-1,8-diamine (H 4fsatrien) have been synthesized. The complexes have been characterized with the help of elemental analyses, molecular weights, molar conductances, magnetic susceptibilities and spectroscopic (UV–vis, IR, ESR) data. Cryomagnetic data also helped to elucidate the structural features of the Cu(II) complexes.

New functional materials AC3B4O12 (Review)

The physical properties of perovskites of the type AC3B4O12, whose structure derives from simple perovskites ABO3, are reviewed. The A position is subject to strong structural distortions and splits into two new positions A and C. In the structure of AC3B4O12 vacancies and any cations with a large radius, irrespective of their charge state, can be present in the icosahedral environment of A: Na+, Cd2+, Ca2+, Sr2+, Y3+, Ln3+, and Nd4+. The C position in the square environment of oxygen can be occupied only by the Jahn–Teller cations Cu2+ and Mn3+. Transition and nontransition metal ions—Mn3+, Fe3+, Al3+, Cr3+, Ti4+, Mn4+, Ge4+, Ru4+, Ir4+, Ta5+, Nb5+, Ta5+, Sb5+—can occupy the B position in an octahedral environment. Some members of the family of complex perovskites possess properties which are characteristic for systems with heavy fermions; collinear and noncollinear magnetic structures with high ordering temperatures occur in these materials; tunneling magnetoresistance and high permittivity are observed. The diversity and unique properties make these materials attractive for practical applications.

Factors that affect Li mobility in layered lithium transition metal oxides

The diffusion constant of Li in electrode materials is a key aspect of the rate capability of rechargeable Li batteries. The factors that affect Li mobility in layered lithium transition metal oxides are systematically studied in this paper by means of first-principles calculations. In close packed oxides octahedral ions diffuse by migrating through intermediate tetrahedral sites. Our results indicate that the activation barrier for Li hopping is strongly affected by the size of the tetrahedral site and the electrostatic interaction between ${\mathrm{Li}}^{+}$ in that site and the cation in the octahedron that shares a face with it. The size of the tetrahedral site is determined by the $c$-lattice parameter which has a remarkably strong effect on the activation barrier for Li migration. The effect of other factors such as cation mixing and doping with nontransition metal ions can be interpreted quantitatively in terms of the size and electrostatic effect. A general strategy to design high rate electrode materials is discussed.

Heavy metal precipitation by polycation–polyanion complex of PEI and its phosphonomethylated derivative

The removal of various heavy metal ions such as Cu 2+, Co 2+, Zn 2+, Ni 2+ and Pb 2+ from aqueous solutions by precipitation with polyelectrolyte complex of PPEI and PEI was conducted. Heavy metal binding with PPEI was initially allowed to occur and then upon equilibration, PEI was added to initiate precipitation of the polyelectrolyte complex together with the heavy metal ion. The PPEI–PEI system was found effective for heavy metal scavenging purposes even in the presence of high concentrations of non-transition metal ions like Na +. Heavy metal concentration may be reduced beyond emission standards for industrial wastewaters. The PPEI–PEI polyelectrolyte complex was found to be more effective than traditional precipitation methods for the treatment of a representative electroless Ni plating waste solution.

Effect of co-existing biologically relevant molecules and ions on DNA photocleavage caused by pyrene and its derivatives.

Inorganic ions, coenzymes, amino acids, and saccharides could co-exist with toxic environmental chemicals, such as polycyclic aromatic hydrocarbons (PAHs), in the cell. The presence of these co-existing chemicals can modulate the toxicity of the PAHs. One of the genotoxic effects by PAHs is light-induced cleavage, or photocleavage, of DNA. The effect of inorganic ions I-, Na+, Ca2+, Mg2+, Fe3+, Mn2+, Cu2+, and Zn2+ and biological molecules riboflavin, histidine, mannitol, nicotinamide adenine dinucleotide (NAD), glutathione, and glutamic acid on the DNA photocleavage by pyrene, 1-hydroxypyrene (1-HP), and 1-aminopyrene (1-AP), is studied. The non-transition metal ions Na+, Ca2+, and Mg2+, usually have very little inhibitory effects, while the transition metal ions Fe3+, Cu2+, and Zn2+ enhance, Mn2+ inhibits the DNA photocleavage. The effect by biological molecules is complex, depending on the photochemical reaction mechanisms of the compounds tested (1-AP, 1-HP and pyrene) and on the chemical nature of the added biological molecules. Riboflavin, histidine, and mannitol enhance DNA photocleavage by all three compounds, except that mannitol has no effect on the photocleavage of DNA by pyrene. Glutathione inhibits the DNA photocleavage by 1-AP and 1-HP, but has no effect on that by pyrene. NAD enhances the DNA photocleavage by 1-AP, but has no effect on that by 1-HP and pyrene. Glutamic acid enhances the DNA photocleavage by 1-AP and pyrene, but inhibits that by 1-HP. These results show that the co-existing chemicals may have a profound effect on the toxicity of PAHs, or possibly on the toxicity of many other chemicals. Therefore, if one studies the toxic effects of PAHs or other toxic chemicals, the effect of the co-existing chemicals or ions needs to be considered.

Adsorption behaviour of non-transition metal ions on a synthetic chelating resin bearing iminoacetate functions

Glycidyl methacrylate–divinylbenzene (GMA/DVB) resin bearing iminoacetate function was prepared through subsequent treatment of (GMA/DVB) resin by ethylenediamine and potassium chloroacetate, respectively. The chelating resin obtained showed a powerful adsorption character towards non-transition metal ions (Zn 2+, Cd 2+ and Pb 2+) as well as alkaline earth metal ions (Ca 2+ and Mg 2+). The sodium form of the resin gave a slightly higher uptake capacity towards metal ions compared to the hydrogen form. The resin sample loaded with metal ions was regenerated using HCl (0.5–2.0 M) without activity loss.

Preparation and characterization of LiNi 0.7Co 0.2Ti 0.05M 0.05O 2 (M=Mg, Al and Zn) systems as cathode materials for lithium batteries

The effects of doping with Ti and non-transition metal ions Mg/Al/Zn in LiNi 0.8Co 0.2O 2 on the structural and electrochemical properties were studied. Structural analysis by X-ray diffraction (XRD) revealed that except for the Mg-doped system, there was a high degree of cation mixing, which led to decreases in capacity. However, the systems showed cycling stability. The Mg-doped system had a good capacity of 150 mAh/g over 30 cycles.

Differences between Mg2+ and Transition Metal Ions in the Activation of Calcineurin

Exogenous metal ion activation of calcineurin catalyzed hydrolysis of para-nitrophenyl phosphate was kinetically characterized at 20, 25, 30, and 37°C. Analysis yielded estimates for thermodynamic parameters for the activation of calcineurin by each of the metal ions. Values for ΔGMe° were varied with the best activators resulting in more stable enzyme–metal ion complexes and with ΔGMe° dominated by the entropic component. Mg2+ was the only nontransition metal ion which supported significant activity and showed some distinct characteristics including a negative ΔSMe°, suggesting that activation by Mg2+ may have resulted in a unique enzyme–metal ion form. Circular dichroism showed that metal ions increased the α-helical content of calcineurin, but little significant differences in the spectra were identified between using activating and nonactivating metal ions. Activating Mg2+, but not nonactivating Ca2+, did cause changes in the Fourier transform infrared photoacoustic spectrum of calcineurin compared to the spectrum of calcineurin with Mn2+. Other metal ions, Co2+ and Ni2+, also caused no changes in the infrared spectrum. Possible explanations for these differences between Mg2+ and transition metal ions in the activation of calcineurin are discussed.

Sensing of transition metals through fluorescence quenching or enhancement. A review

A series of fluorescent sensors for transition metal ions were synthesized by linking a light-emitting subunit, anthracene, to a polyaza chelating subunit, either a dioxotetraamine or a tetraamine. Sensing of the divalent cations CuII, NiII and ZnII was investigated through spectrofluorimetric titrations in acetonitrile–N water (4:1) solutions. The selective recognition of CuII and NiII among other transition and non-transition metal ions is signalled through full quenching of fluorescence; discrimination between the two ions can be achieved by performing titrations at controlled pH. The system containing the tetraamine fragment, whose interaction with CuII and NiII induces fluorescence quenching, is also sensitive to ZnII, but in this case the recognition is signalled through a fluorescence enhancement.

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

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 witho-phenylenediamine have been synthesized and characterized on the basis of elemental analyses, electronic, IR and1H 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.

Chelate Compounds of a Selected Non-Transition and Transition Metal Ions with Some Salicylic Acid Derivatives

A series of binary complexes of Zn(II), Hg(II), Pb(II), La(III), Ce(III), Th(IV) and UO2(II) with 3,5-dinitrosalicylic acid and 5-sulphosalicylic acid have been isolated and characterized. The solution equilibria of these complexes have been studied pH-metrically. The formation constants (log K) at 25±1°C and ionic strength of 0.2M NaClC4 have been calculated. Stability of the complexes formed in relation to ligand molecular structure and nature of the metal ion has been examined and discussed.

A thermometric titration study of the interaction of Al3+, Co2+, Ni2+ and Zr4+ with xylenol orange

A thermometric titrimetry study of the interaction in aqueous solution of A13+, Co2+, Ni2+ and Zr4+ with xylenol orange has revealed in each case a linear reaction heat/[Mn+] relationship at a specified pH, thereby suggesting the potential of metallochromic indicators for the analytical determination of these metals in water. The effect of pH on the reaction heat is investigated and is interpreted in terms of the ability of these metal cations to complex with the known xylenol orange species existing at the various pH studied. An interference study, involving transition and non-transition metal ions, is also reported and the interference effect, as measured by the deviation ofQ′/Q from unity (Q′ andQ are the relevant reaction heats in the presence and absence of interfering ion), is partially explained in terms of the coordination numbers, relative sizes and crystal field stabilization energies of the cations studied and the known behaviour of xylenol orange in aqueous solution.

A XANES investigation of the bonding of divalent lead in solids

XANES (X-ray absorption near-edge structure) spectra of divalent lead compounds have been studied at both the Pb LIII and LI edges using synchrotron x rays from CHESS (Cornell High Energy Synchrotron Source). The combined LIII and LI near-edge spectral features strongly support a sp3d2 hybridization scheme in covalently bonded yellow PbO. The absorption features associated with the spectra of ionic halides (PbF2, PbCl2, and PbI2) and the oxysalts [Pb(NO3)2, PbSO4, and PbCrO4] have been shown to be consistent with crystal field splittings of the final states using group theoretical arguments. The XANES spectra of a series of PbO–PbCl2 glasses have also been studied to elucidate the nature of bonding and confirm the local structure derived from x-ray diffraction experiments. Shape resonance features associated with LIII and LI edge XANES have also been discussed. This investigation illustrates the novel use of XANES spectroscopy in studying the bonding of nontransition metal ions.

Organic-Inorganic Molecular Composites as Possible Low-Dimensional Conductors: Photo-Polymerization of Organic Moieties Intercalated in Inorganic Layer Compounds

Abstract We wish to draw attention to the potential for unusual electronic behaviour in composites formed on a molecular scale between organic and inorganic layer materials. Intercalation of organic molecules in inorganic layer compounds by Van der Waals or donor-acceptor interaction is common but defined stoichiometry and orientation of the organic molecules may be obtained by making salts in which organic cations are bound electrostatically to infinite inorganic anions. Many transition and non-transition metal ions M form halide (X) salts (RNH3)2MX4 where R is a long thin organic moiety, most simply alkyl, and the MX4 form infinite layers like a single layer of the cubic perovskite structure. A brief overview of the structures is given but we concentrate on efforts to extend the series to organic cations containing functional groups. Simplest among these are isolated double and triple bonds, e.g. CH2=CHCH2NH+ 3 and CH≡CCH2NH+ 3 but diacetylenic cations have also been employed to give such salts as (CICH...

Metal chelates of phosphonate-containing ligands—IV (Stability of some 1,6-hexamethylenediamine- N, N, N′, N′-tetra(methylenephosphonic) acid metal chelates)

The stability constants of the complexes formed between the anion of 1,6-hexamethylenediamine- N, N, N′, N′-tetra(methylenephosphonic) acid and some transition and non-transition metal ions have been measured potentiometrically at a temperature of 25° and an ionic strength of 0.1 M (KNO 3). The acid dissociation constants of the ligand and stability constants of the protonated complexes are also reported. Comparisons are made with the acid dissociation constants of the analogous compounds EDTA, ENTMP and HDTA, and possible structural formulae are given.

Metal chelates of phosphonate-containing ligands—V Stability of some 1-hydroxyethane-1,1-diphosphonic acid metal chelates

A detailed study of the complexes formed between 1-hydroxyethane-1,1-diphosphonic acid and twelve metal ions, including the alkaline earth and transition non-transition metal ions, is reported. The formation constants of the protonated and unprotonated complexes are measured from potentiometric data and possible structural formulae are given. The results reveal that only mononuclear (1:1) di-, mono- and unprotonated metal chelates are formed and that the general order of stability for the unprotonated complexes is Zn > Mn > Ca > Cu > Cd > Pd > Ni > Co ⋍ Sr > Mg > Ag > Ba.

Matching between Lewis acids and Lewis bases on the basis of quantitative softness values and their relation with the stability of the complexes—I

The quantitative values of softness of Lewis bases, E m ‡ , and of Lewis acids, E n ‡ , have been calculated. The difference in the values of E n ‡ and E m ‡ , derived for a complex formed between a Lewis acid and base has been designated by ΔE nm ‡ . The stability of the complexes in terms of ΔE nm ‡ values has been expressed by “Matching Constant” which is represented by the following relations for different type of metal ions: |E n ‡E m ‡| fo non-transition metal ions, |E n ‡E m ‡| + CFSE for transition metal ions, |E n ‡E m ‡| + βY for metal ions having predominant covalent preference, and |E n ‡E m ‡|+( 1 10 )· CFSE for lanthanides. The matching con values have been found to be directly related to the thermodynamic stability (log k) of metal complexes.

Diffuse Reflectance Spectra of Rare Earth Benzoylacetonates in Ultraviolet region

Abstract Rare earth β-diketonates are promising laser materials. Their solid state spectra is expected to give their spectral characteristics. The diffuse reflectance spectra of some rare earth β-diketonates and esters in ultraviolet region have been reported recently by the authors1. The ultraviolet absorption spectra of transition metal chelates have also been reported2,3 recently. The spectra of the non-transition metal ion chelates usually consist4 only of the metal charge transfer and ligand intramolecular transitions. The ligand transitions in all the cases are characteristic of the coordinated ligand. The spectrum of the ligand, however, helps in assigning the transitions of the co-ordinated ligand. A comparison of the spectrum of ligands and their rare earth complexes1,5,6 shows that on complexation no new bands appear in ultraviolet suggesting that unlike transition metal β-diketonates2,3, charge transfer bands do not appear in the present case. The ligand intramolecular transitions are expected ...