Structure and mesomorphism of neodymium(III) alkanoates

The structural and thermal behavior of all members of the homologous series of neodymium(III) alkanoates, ranging from neodymium(III) butyrate to neodymium(III) eicosanoate are described. Neodymium(III) butyrate monohydrate, Nd(C3H7COO)3.H2O crystallizes in space group P1 (No. 2), Z = 2. The lattice parameters are a = 9.824(2) A, b = 11.974(2) A, c = 14.633(2) A, alpha = 86.21(2) degrees, beta = 75.92(2) degrees, gamma = 77.97(2) degrees. The crystal structure consists of ionic layers of neodymium ions, separated by bilayers of butyrate anions. In the ionic layers, the neodymium ions are connected by bridging tridentate carboxylate groups to zigzag chains, whereas the chains are connected among themselves by bridging bidentate carboxylate groups. The two crystallographically different neodymium ions are both having coordination number 9, with a geometry close to a monocapped square antiprism. The structure of the higher homologues can be derived from the structure of neodymium butyrate by extending the alkyl chains. These compounds have a lamellar bilayer structure with planes of neodymium(III) ions coordinated to the carboxylate groups and with the alkyl chains in an all-trans conformation. All homologous compounds from neodymium(III) pentanoate to neodymium(III) pentadecanoate display a thermotropic mesophase, which was identified by high-temperature X-ray diffraction as a smectic A phase. For the series from neodymium(III) pentanoate to neodymium(III) undecanoate an additional high viscosity mesophase is present between the crystalline state and the smectic A mesophase.     

A novel process for preparation of hybrid nanosized neodymium oxybromide and neodymium oxide

Russian Journal of General Chemistry - A novel process to prepare hybrid nanosized neodymium oxybromide and neodymium oxide from neodymium(III) nitrate hexahydrate has been developed. The...     

Luminescence of neodymium(III) carboxylate complexes with different ligands

The spectral and luminescent characteristics of neodymium(III) carboxylate complexes with different nitrogen- and phosphorus-containing neutral ligands were studied and the relationship between the intensity of luminescence and the composition of the coordination sphere was established. The most intensive luminescence of neodymium(III) compounds in the IR region was observed from the complexes with toluic and cinnamic acids.     

Sorption of neodymium(III) ions by natural mordenite-containing tuff

Equilibrium in the system constituted by a mordenite-containing tuff and neodymium(III) was studied in a wide range of concentrations (10^?5–10^?2 M) in sorption from neodymium sulfate solutions. Isotherms of absorption of neodymium ions were constructed and kinetic parameters of the sorption process were determined.     

Neodimium(III) luminescence in the mixed ligand compounds with β-diketones

The luminescent spectral characteristics of neodymium(III) tris- and tetrakis-β-diketonates and β-diketonate acido complexes were investigated. The dependence between the intensity of the luminescence and the composition of the coordination sphere of the complexes was revealed. The most intense luminescence in the IR region possess the neodymium(III) compounds which are the mixed ligand complexes with β-diketones and phosphorus-containing neutral ligands.     

Study of the Possibility of Using Salt Metathesis Reactions for the Synthesis of the Neodymium and Samarium β-Diketiminate Chalcogenide Complexes. Unexpected Reduction of Sm(III) to Sm(II)

Russian Journal of Coordination Chemistry - The possibilities of the ion exchange reactions between the neodymium(III) and samarium(III) diiodo-β-diketiminate complexes...     

BODIPY chromophores as efficient green light sensitizers for lanthanide-induced near-infrared emission

A new boron dipyrromethene (BODIPY) modified 8-hydroxylquinoline ligand (8-HOQ-BODIPY) is synthesized for the sensitization of near-infrared emission of lanthanide(III) ions. The BODIPY unit, as revealed by single-crystal X-ray diffraction analysis, aligns almost perpendicularly to the 8-HOQ unit. The ligand exhibits strong absorption at ~506 nm and fluorescence at 510 nm in organic solvents with quantum yields ranging from ~0.45 in dichloromethane to 0.015 in ethanol. It forms stable ytterbium(III), erbium(III) and neodymium(III) complexes with 3:1 ligand-to-metal molar ratios. Upon excitation (~522 nm), the neodymium(III) and erbium(III) complexes emit weakly at 1060 and 1382 nm, respectively, whereas the ytterbium(III) complex exhibits strong emission at 976 and 1003 nm. The results demonstrate the potential of BODIPY dyes as efficient and robust visible light sensitizers for lanthanide-based NIR emitters in medical diagnosis.     

Complexation and Electronic Spectra of Neodymium(III)–Amino Acid–1,10-Phenanthroline Systems in Aqueous Solution

Complexation of neodymium(III)-glutamate(glu)-phenanthroline(phen), neodymium(III)-aspartate(asp)-phenanthroline(phen) ternary systems and the corresponding binary systems in aqueous solution are discussed at various values of pH. Based on change regularity of hypersensitive transition intensities, the neodymium(III)-aspartate-phenanthroline ternary complex has a general formula of Nd(asp)₃phen, but the composition of the complex of Nd(III) with glutamate and phenanthroline is complicated and has not been determined. The electronic spectra of these complexes were studied, Slater-Condon parametersF _k ^s and the Lande parameter ξ_4f were obtained. The rms deviation between calculated and observed energy levels is less than 43 cm⁻¹. Bonding in these complexes are also investigated and bonding parameters calculated. The results show that Nd(III) and amino acids form complexes by ionic linkage with carboxylic oxygens, but with some weak covalency. Besides, the degrees of covalency in ternary complexes are larger than those in binary complexes.     

IR luminescence of neodymium(III) and ytterbium(III) complexes with acylpyrazolones in solutions

Acylpyrazolones (L1–L5) have been synthesized and the conditions of their complexation with neodymium(III) and ytterbium(III) ions in aqueous solutions have been elucidated. The component ratio in the synthesized complexes is Nd(Yb): L = 1: 1. The conditions of excitation and luminescence of the ligands and complexes have been studied. The formation of mixed-ligand complexes upon the introduction of trioctyl- or triphenylphosphine oxide leads to a considerable rise of neodymium and ytterbium. In the presence of 1,10-phenanthroline and bathophenanthroline, competing complexation leads to a 20–70% decrease in luminescence intensity. The introduction of water-miscible organic solvents (30 vol %) decreases the Nd(III) and Yb(III) luminescence intensity by a factor of 9–20.     

Neodymium ethylenediaminedisuccinates

Conclusions Using high-resolution spectrography the authors have shown that in the system ethylenediaminedisuccinate-neodymium (III) chloride there are formed two forms of unprotonized monocomplexonates of the same composition but differing in the number of donor atoms of the ligand cordinated with the central neodymium ion. One of the forms of neodymium monoethylenediaminedisuccinate contains free donor groups and can therefore form polynuclear complexes with the aquo ions of neodymium introduced into the solution.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1431–1435, July, 1979.     

Gelation in Extraction Systems with Basic Copper(II) and Neodymium(III) Alkyl Phosphates

Gelation in extraction systems containing purified or commercial di(2-ethylhexyl) hydrogen phosphate (HDEHP), copper(II) or neodymium(III) hydroxides, hydrocarbon solvent, and water was studied at different ratios of the metal and extractant. The region was determined in which gelation caused by formation of basic neodymium(III) di(2-ethylhexyl) phosphates occurs in decane. Some characteristics of organogels in the HDEHP (commercial)-Cu(OH)₂-organic diluent (decane, hexane or toluene)-H₂O extraction systems were studied.     

Supramolecular assembly of p-sulfonatecalix[4]arene through aquated neodymium (III) ions

A novel mononuclear complex of p-sulfonatecalix[4]arene and neodymium (III) ions in the presence of pyridine N-oxide has been investigated by X-ray diffraction study, which reveal that the bi-layer sheet structure is formed in the solid state. An aquated neodymium ion connects the adjacent calixarene-pyridine N-oxide complex units through multiple hydrogen bonds to stabilize the bi-layer structure.     

Electrode process of Nd-Fe alloy formed on iron electrode in molten chlorides

The cyclic voltammetry, convolution voltammetry and chronopotentiometry were used to study the electrode process of Nd (III) reduced on iron electrode in molten NaCl-KCl-NdCl₃ from 700 to 850°C. The electrodeposited products were analysed by X-ray diffraction. The results indicate that the intermetallic compound Fe₂Nd forms first, and then the metallic neodymium deposits when Nd (III) is reduced on iron electrode. The Nd-Fe alloys rich in neodymium can be obtained by electrolysis with iron cathode in molten chlorides. The Nd-Fe alloys are composed of Fe₂Nd and Nd.     

Synthesis,characterization and cytotoxicity evaluation of new cerium(III), lanthanum(III) and neodymium(III) complexes

Complexes of cerium(III), lanthanum(III) and neodymium(III) with coumarin‐3‐carboxylic acid (HCCA) were synthesized by mixing of equimolar amounts of the respective metal nitrates and coumarin‐3‐carboxylic acid in ethanol. The complexes were characterized and identified by elemental analysis, IR and Raman spectroscopy. DTA and TGA were applied to study the compositions of the compounds. The vibrational study showed bidentate coordination of CCA^? to Ln(III) ions through the carbonyl oxygen and the carboxylic oxygen atoms. The newly synthesized compounds were assayed for cytotoxicity against SKW‐3, HL‐60 and Reh cells. The complexes of cerium(III) and lanthanum(III) showed marginal cytotoxic activity against SKW‐3 and Reh cells as compared with the inorganic salts at concentration 200 µM . The complex of neodymium(III) induced approximately 50% reduction of the survival HL‐60 and SKW‐3 cells at concentration 200 µM . Copyright © 2007 John Wiley & Sons, Ltd.     

Standard Enthalpies of Formation of Neodymium(III) and Erbium(III) Succinates and Malates

The enthalpies of solution of neodymium(III) and erbium(III) succinates and malates in the system HCl ? 100H₂O were determined and used to calculate the standard enthalpies of formation of these salts.     

Complex formation between neodymium(III) and 2,2′-dipyridyl in solvents of various polarities

The interaction of neodymium(III) with 2,2′-dipyridyl (2,2′-Dipy) in solvents with permittivities of from 5 to 78 units was studied spectrophotometrically. The Nd(III): 2,2′-Dipy ratios and complex stability constants were determined. Suggestions concerning the influence of solvents on complex formation in the systems were advanced.     

Polarography of metal-gallic complexes

The polarographic behavior of metal ions in perchlorate media containing gallic acid is described. Tungsten(VI) forms a complex with gallic acid which yields a single wave in these media, useful in the polarographic determination of tungsten. Evidence for complexation of chromium(III), copper(II), iron(III), molybdenum(VI), uranium(VI), vanadium(V), tungsten(VI), praseodymium(III), samarium(III), neodymium(III) and gadolinium(III) is obtained and the behavior of these metal ions is summarized.     

Thermogravimetric investigation of scandium,yttrium and the rare earth metal diliturates

Thermolysis curves for scandium, yttrium, lanthanum, cerium(III), neodymium, samarium, gadolinium, dysprosium and erbium diliturates are described, Scandium diliturate forms a 15-hydrate which dehydrates in 3 steps. The other diliturates all form 12-hydrates which dehydrate smoothly. All of the anhydrous diliturates are thermally stable to about 240°.Solubilities in water for scandium, yttrium, lanthanum, cerium(lll), neodymium, samarium. gadolinium, dysprosium and erbium diliturates are given. Scandium diliturate is the most soluble and neodymium diliturate the least soluble. Solubilities of rare earth diliturates not investigated can be predicted approximately.Methods for thermogravimetric determination of yttrium, lanthanum, neodymium, samarium, gadolinium, dyprosium, and erbium as the diliturates have been developed. The precipitates are quite dense, easily handled and filterable. Weighing as the diliturate salts gives these determinations a very favorable gravimetric factor.     

Some Properties of Petroleum Sulfoxides Suitable for Extraction in Hydrometallurgy

Several fractions of diesel fuel recovered from Arlan crude oil were treated with hydrogen peroxide, and the sulfoxides formed by oxidation of petroleum sulfides were isolated with aqueous sulfuric acid. The water solubility of these sulfoxides and their limiting extraction capacity with respect to neodymium nitrate were determined. Correlations between several characteristics of the petroleum sulfoxides [water solubility, limiting extraction capacity with respect to neodymium(III) nitrate, phase separation time under standard conditions, and viscosity] and the boiling range of corresponding petroleum fractions were analyzed.     

Membrane transport of metal ions with lipophilic aminomethylphosphine oxides

The processes of membrane transport of ions of scandium(III), samarium(III), gadolinium(III), neodymium(III), aluminum(III), and a number of alkali and alkaline earth metals through liquid membrane impregnated with aminophosphoryl carriers of different structures were studied. Selectivity of bis (dialkylphosphinyl)amines towards scandium was found to be significantly higher than the selectivity of diphosphinylpiperazine and monophosphinylamine in particular. The dependence of transfer efficiency on the concentration of substrates and carriers was revealed. Optimal conditions for transporting rare and trace metal ions through the membrane were found, and the mechanism of transmembrane transport was discussed.