Lanthanide Nitrate Research Articles

Two Heterometallic Ionic Compounds with Isolated [3d] and [4f] Complex Units: Field‐Induced Single‐Ion Magnet (SIM) Behavior Observed from a Mononuclear Dysprosium(III) Complex

AbstractTwo new complexes, [Fe3(μ3‐O)(inicH)6(H2O)3][Gd(NO3)6]·(NO3)4·nH2O (1) and [Fe3(μ3‐O)(inicH)6(H2O)3][Dy(NO3)5 (H2O)]·(NO3)5·n(H2O) (2) with two isolated complex moieties, were generated when isonicotinic acid was treated with iron(III) nitrate and the corresponding lanthanide(III) nitrate in water. The structures were determined by single‐crystal X‐ray diffraction studies. In these compounds, the anionic lanthanide complexes are encapsulated by trinuclear [Fe3(μ3‐O)(inicH)6(H2O)3]7+ cationic cluster units, which is facilitated by hydrogen‐bonding interactions. Investigation of the magnetic properties reveals that 2 shows slow relaxation of magnetization at low magnetic field (Hdc = 1.0 kOe), with an energy barrier of 23 K originating from a single [Dy(NO3)5(H2O)]2– anion.

Fundamental Study on Magnetic Separator Using Oxygen Dissolved Perfluorocarbon

In this study, we have designed a magnetic separator for medical valuable substance. The substance shows diamagnetism and the density is slightly higher than water. A magneto Archimedes separation is effective in those substances. The separation is a technique to utilize the difference of the levitation place decided by the magnetic susceptibility and the density of substances under the magnetic field. However, the medium used for separation is a paramagnetic liquid in which the manganese chloride and the rare earth nitrate were dissolved, and there are such problems as the metal salt adhesion to the substance and the equipment. When food and a medicine are treated as a separation substance, the security is important in practical use. The oxygen dissolved perfluorocarbon under the pressure was used as the medium. Under atmospheric pressure, a metallic compound doesn't remain on the surface of the separation substance and equipment. Dissolved oxygen concentration rises by pressurization according to Henry's law. By controlling of the pressure and the external magnetic field, the separation of a plastic and KCl used as imitation sample succeeded. The magnetic force and the pressure needed for the separation were estimated from calculations and the separation experiments. We report these results.

Synthesis and lanthanide coordination chemistry of phosphine oxide decorated dibenzothiophene and dibenzothiophene sulfone platforms.

Syntheses for new ligands based upon dibenzothiophene and dibenzothiophene sulfone platforms, decorated with phosphine oxide and methylphosphine oxide donor groups, are described. Coordination chemistry of 4,6-bis(diphenylphosphinoylmethyl)dibenzothiophene (8), 4,6-bis(diphenylphosphinoylmethyl)dibenzothiophene-5,5-dioxide (9) and 4,6-bis(diphenylphosphinoyl)dibenzothiophene-5,5-dioxide (10) with lanthanide nitrates, Ln(NO3)3·(H2O)n is outlined, and crystal structure determinations reveal a range of chelation interactions on Ln(III) ions. The nitric acid dependence of the solvent extraction performance of 9 and 10 in 1,2-dichloroethane for Eu(III) and Am(III) is described and compared against the extraction behavior of related dibenzofuran ligands (2, 3; R = Ph) and n-octyl(phenyl)-N,N-diisobutylcarbamoylmethyl phosphine oxide (4) measured under identical conditions.

Ln(IO3)3 (Ln = Ce, Nd, Eu, Gd, Er, Yb) polycrystals as novel photocatalysts for efficient decontamination under ultraviolet light irradiation.

Ln(IO3)3 (Ln = Ce, Nd, Eu, Gd, Er, Yb) polycrystals were hydrothermally synthesized using lanthanide nitrate or lanthanide oxide and iodic acid as precursors. X-ray diffraction was used to characterize the crystal structures of the Ln(IO3)3 products. Scanning electron microscopy was carried out to observe the microscopic morphologies. The lattice spacings were studied by high-resolution transmission electron microscopy and selected area electron diffraction. We evaluated the photocatalytic efficiency by decomposing methyl orange dye under ultraviolet light irradiation, and the Ln(IO3)3 products show excellent photocatalytic properties. To rule out the effect of photosensitization, 2,4-dichlorophenol was also photodegraded. As one of the key factors of photocatalysis, ultraviolet-visible diffuse reflectance spectra of the Ln(IO3)3 samples were also studied, and all products have strong absorption in the ultraviolet region.

A novel lanthanide-organic wave-like network with 1H-Imidazole-4,5-Dicarboxylate and oxalate: Structure, photoluminescence, and magnetic properties

The solvothermal reaction of lanthanide nitrate and H4Diida ligand (H4Diida = 2-(4,5-dicarboxy-1H-imidazol-2-yl)-1H-imidazole-4,5-dicarboxylic acid) in the presence of ammonium oxalate results in a new three-dimensional (3D) lanthanide-organic framework, namely, {[Pr(Ida)(μ2-C2O4)0.5(H2O)2] · H2O}n (H2Ida = 1H-imidazole-4,5-dicarboxylic acid). H4Diida ligand can be in situ into Ida2− ions under the conditions, as unequivocally proved by these similar situations occurred in other systems. Single crystal X-ray diffraction analysis reveals the formation of a novel wave-like structure. It crystallizes in the monoclinic system, space group of P21/c. The polymer is built from two kinds of parallel alternately 1D infinite chain through the carboxylate double-linking adjacent Pr3+ cations, forming an extended 2D bilayer-like structure along the yz plane. Moreover, the polymer further stacks via weak interactions to generate a 3D supramolecular framework. The photoluminescence and magnetic properties for the polymer were also investigated and discussed.

ChemInform Abstract: Effect of the pH on the Formation of NaYF4:Yb:Er Nanopowders by Co‐Crystallization in Presence of Polyethyleneimine.

AbstractCubic single‐phase samples of the title nanopowders are obtained by addition of rare earth nitrate solutions to aqueous NaF/polyethyleneimine mixtures at pH 10, whereas single‐phase hexagonal precipitates are prepared by addition of aqueous NaF solutions to aqueous rare earth nitrate/polyethyleneimine mixtures at pH 12.

Co-Precipitation Synthesis and Photoluminescence Properties of Ce<sup>3+</sup> Activated Terbium Aluminum Garnet (Tb<sub>1<i>-x</i></sub>Ce<sub><i>x</i></sub>)<sub>3</sub>Al<sub>5</sub>O<sub>12</sub> (0≤<i>x≤</i>0.05) Yellow Phosphors

Ce3+activated terbium aluminum garnet ((Tb1-xCex)3Al5O12, 0≤x≤0.05) phosphors have been converted from their precursors synthesized via co-precipitation from mixed solutions of aluminum and rare earth nitrates with ammonium hydrogen carbonate (AHC) as the precipitant. Detailed characterizations of the precursors and the phosphor oxides were performed by the combined techniques of X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetry/thermogravimetry (DSC/TG), and photoluminescence spectroscopy. The co-precipitated precursors possess a general composition of (NH4)x(Tb,Ce)3Al5(CO3)y(OH)z·nH2O, and the particles, having diameters of about 50nm, are well dispersed. Calcining the precursors at 1000°C for 4 h in the air and then reducing in a hydrogen atmosphere at 1000°C for 2 h yielded a phase pure garnet solid-solution of (Tb1-xCex)3Al5O12. The cubic lattice of garnet allows the Ce3+activators to reside at the dodecahedral interstitial sites. The resultant garnet phosphors with various Ce3+contents exhibit nearly identical positions of the PLE/PE bands, but significantly different intensities. Upon blue-light excitation at 470nm, the garnet phosphors exhibit broad band emissions peaking at 560nm. The garnet phosphors show a luminescence quenching concentration of 1.5at% for Ce3+.

A series of 3D isomorphous lanthanide coordination polymers based on flexible dicarboxylate ligand: Synthesis, structure, characterization, and properties

Seven lanthanide coordination polymers, namely, {[Ln(BDOA)1.5(H2O)]·H2O}n (Ln = Ce(I), Pr(II), Nd(III), Sm(IV), Eu(V), Gd(VI), and Tb(VII), H2BDOA = benzene-1,4-dioxydiacetic acid), have been synthesized through hydrothermal reactions of lanthanide nitrate with H2BDOA ligands and characterized by elemental analysis, infrared spectroscopy and single crystal X-ray diffraction. Findings indicate that I–VI are isomorphous and isostructural, containing the subunit of cavate 10-membered cages (Ln2O2(OCO)2), while VII possesses the subunit of cavate 14-membered cages (Tb2(OCO)4), based on which to assemble into three-dimensional porous architectures via BDOA2− ligands, hydrogen bonds and C–H⋯π interactions. I and III present antiferromagnetic behaviors and lanthanide contraction effect exists in I–VI. Luminescent studies suggest the typical intense emissions of Ln(III) ions occur in the visible region and therefore the coordination polymers display good selectivity towards some certain metal ions such as Ca2+ and Cd2+, showing promising potential as selective luminescent probes of these metal ions.

Two Series of Lanthanide Metal‐Organic Frameworks Constructed from Crown‐Ether‐Like Secondary Building Units

AbstractTwo series of lanthanide metal‐organic frameworks, [KLn3(FDCA)5(H2O)5]·solvent (1Ln) (Ln = La 1, Ce 2, Pr 3), [K4Ln8(FDCA)14(H2O)30]·2(H2FDCA)·DMAC·10(H2O) (2Ln) (Ln = Eu 4, Gd 5, Tb 6, Dy 7, Er 8, DMAC = N,N‐dimethylacetamide), have been prepared by solvothermal reactions of 2,5‐furandicarboxylic acid (H2FDCA) and KNO3 with the corresponding lanthanide nitrate. X‐ray crystal structure analyses show that 1Ln possesses a 3D network based on the “16‐crown‐6‐like” secondary building unit (SBU), whereas 2Ln exhibits a 1D framework with a “23‐crown‐9‐like” SBU. The structural investigation unambiguously demonstrated that the lanthanide contraction affects the formation of 1Ln and 2Ln. Meanwhile, the solid‐state photoluminescent properties of 4 and 6 were also investigated at room temperature and the luminescence intensity of 4 is sensitive to small molecules.

Structures, luminescent and magnetic properties of a series of (3,6)-connected lanthanide–organic frameworks

Through hydrothermal reactions with corresponding lanthanide nitrates and 4-(4-carboxyphenylsulfonyloxy)-3-metnoxybenzoic acid (H2vspc), seven novel three-dimensional (3D) lanthanide-organic frameworks ([Ln(vspc)(Hvspc)(H2O)]n [Ln = Pr (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6) and Er (7)]) have been synthesized and structurally characterized. All of them are isostructural and crystallize in the monoclinic crystal system, P21/c space group. Their structures feature a (3,6)-connected topological network, in which Ln(3+) were connected by carboxylate groups to give a 1D lanthanide chain, and the adjacent chains are further spanned by vspc(2-) and Hvspc(-) anions to form a 3D framework. The luminescent properties and lifetimes of 2 (Eu(III)), 4 (Tb(III)), and 5 (Dy(III)) have been studied, and the corresponding luminescent lifetimes are 0.53, 0.99 and 0.014 ms, respectively. The magnetic investigations reveal that compound displays weak antiferromagnet interaction, 4 and 5 exhibit ferromagnetic coupling, and compound 5 exhibits slow magnetic relaxation behavior.

Hydrazinium lanthanide oxalates: synthesis, structure and thermal reactivity of N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce, Nd

New hydrazinium lanthanide oxalates N2H5[Ln2(C2O4)4(N2H5)]·4H2O, Ln = Ce (Ce-HyOx) and Nd (Nd-HyOx), were synthesized by hydrothermal reaction at 150 °C between lanthanide nitrate, oxalic acid and hydrazine solutions. The structure of the Nd compound was determined from single-crystal X-ray diffraction data, space group P2₁/c with a = 16.315(4), b = 12.127(3), c = 11.430(2) Å, β = 116.638(4)°, V = 2021.4(7) Å(3), Z = 4, and R1 = 0.0313 for 4231 independent reflections. Two distinct neodymium polyhedra are formed, NdO9 and NdO8N, an oxygen of one monodentate oxalate in the former being replaced by a nitrogen atom of a coordinated hydrazinium ion in the latter. The infrared absorption band at 1005 cm(-1) confirms the coordination of N2H5(+) to the metal. These polyhedra are connected through μ2 and μ3 oxalate ions to form an anionic three-dimensional neodymium-oxalate arrangement. A non-coordinated charge-compensating hydrazinium ion occupies, with water molecules, the resulting tunnels. The N-N stretching frequencies of the infrared spectra demonstrate the existence of the two types of hydrazine ions. Thermal reactivity of these hydrazinium oxalates and of the mixed isotypic Ce/Nd (CeNd-HyOx) oxalate were studied by using thermogravimetric and differential thermal analyses coupled with gas analyzers, and high temperature X-ray diffraction. Under air, fine particles of CeO2 and Ce(0.5)Nd(0.5)O(1.75) are formed at low temperature from Ce-HyOx and CeNd-HyOx, respectively, thanks to a decomposition/oxidation process. Under argon flow, dioxymonocyanamides Ln2O2CN2 are formed.

Unusual complexation of nitrate with lanthanides in a wet ionic liquid: a new approach for aqueous separation of trivalent f-elements using an ionic liquid as solvent

The energetics of lanthanide nitrate complexation in a wet ionic liquid (IL; saturated with water as seen in the aqueous separation process) differs entirely from that in dry IL.

Rare Earth Metal Complexes of a Mesogenic Schiff-Base, N,N′-di-(4-decyloxysalicylidene)-1′, 4′-diaminobutane: Synthesis and Characterization

A mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-1′,4′-diaminobutane, (H2L) that exhibits smectic-B and nematic mesophases, was synthesized and its structure studied by elemental analysis, mass spectrometry, NMR & IR techniques. H2L, upon condensation with hydrated lanthanide(III) nitrates yields LnIII complexes of the composition [Ln2(LH2)3(NO3)4](NO3)2, where LnIII = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho. The PrIII complex shows smectic-A and nematic phases. The IR and NMR spectral data imply a bidentate bonding of H2L in zwitterionic form (as LH2) to the LnIII ions through two phenolate oxygen atoms, rendering the overall geometry of the complexes possibly to distorted mono-capped octahedra.

Microstructure and thermal properties of inflight rare-earth doped thermal barriers prepared by suspension plasma spray

Rare-earth doped yttria-stabilized zirconia (YSZ) coatings with lower thermal conductivity have been fabricated via suspension plasma spray by dissolving rare-earth nitrates into YSZ powder-ethanol suspensions prior to plasma spraying. The effect of dopant concentration and dopant type on properties of the coatings was determined by comparing two coatings containing different concentrations of the same dopant pair (Nd 2 O 3 /Yb 2 O 3 ), and three coatings having similar concentrations of different dopant pairs (Nd 2 O 3 /Yb 2 O 3 , Nd 2 O 3 /Gd 2 O 3 , and Gd 2 O 3 /Yb 2 O 3 ). The porosity content of the coating was found to increase with increased total rare-earth dopant concentration but did not significantly change with dopant pairs. The cross-sectional morphology of every coating displayed a cauliflower-like structure. However, the most heavily doped coating exhibited a larger surface roughness and feathery features in the columnar structures. The thermal conductivity measurement showed that the thermal conductivity decreased with increased Nd 2 O 3 /Yb 2 O 3 concentration. Among coatings containing different dopant pairs, the Gd 2 O 3 /Yb 2 O 3 doped coating exhibited lowest conductivity.

Linear, Edge‐Sharing Heterometallic Trinuclear [CoII–LnIII–CoII] (LnIII = GdIII, DyIII, TbIII, and HoIII) Complexes: Slow Relaxation of Magnetization in the DyIII Derivative

AbstractThe sequential reaction of a multisite coordination ligand (LH4) with lanthanide (III) nitrates followed by the addition of Co(NO3)2·6H2O in a 4:1:2 ratio in the presence of triethylamine afforded a series of heterometallic, linear trinuclear complexes [Co2Ln(LH3)4]·3NO3 [Ln = DyIII (1), GdIII (2), TbIII (3), and HoIII (4)]. These tricationic complexes contain nitrate counteranions. The cationic portion of these complexes consists of three metal ions that are arranged in a linear fashion; a central LnIII is present between the two terminal CoII ions and is attached to the latter through two phenoxide bridging groups. This arrangement generates two contiguous four‐membered CoLnO2 rings. The CoII ions are six‐coordinate (2N, 4O) in a distorted octahedral geometry, whereas the central lanthanide ion is eight‐coordinate (8O) in a distorted square‐antiprismatic geometry. Magnetic studies of these complexes have been performed and indicate a slow relaxation of the magnetization for the DyIII derivative 1.

Effect of the pH on the formation of NaYF4:Yb:Er nanopowders by co-crystallization in presence of polyethyleneimine

Study of nanopowder precipitation from aqueous sodium fluoride and yttrium and/or other rare earth nitrate solutions in the presence of polyethyleneimine (PEI) has revealed the strong dependence of the solid phase composition upon the solutions’ pH values and the order of reagent addition. The conditions for single phase formation have been determined for both cubic and hexagonal NaYF4-type phases. Cubic single-phase samples were obtained by adding rare earth element nitrate solutions to aqueous NaF–PEI mixtures at pH=10; while hexagonal single-phase precipitates were synthesized by the addition of aqueous NaF to aqueous rare earth element nitrate solutions+PEI mixtures at pH=12.

Solution–combustion synthesis and photoluminescence properties of YBO3:Tb3+ phosphor powders

YBO3:Tb3+ nanocrystalline phosphors were successfully deposited by a solution–combustion method, using rare-earth nitrates, urea and boric acid as starting materials. The crystal structure, morphology, chemical composition and photoluminescence properties of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). The results of SEM and XRD revealed that the powders were composed of spherical YBO3:Tb3+ nanocrystals with average grain size of between 50 and 100nm. The electron diffraction spectroscopy (EDS) confirmed the presence of the Y, B, O, and C. The XRD measurements revealed YBO3:Tb3+ (JCPDS:83-1205) structure when annealed at 1000°C for 2h. The YBO3:Tb3+ powders exhibited emissions at 490, 545 and 585nm, which were assigned to the 5D4–7F6, 5D4–7F5 and 5D4–7F4 transitions of Tb3+, respectively. Among them, the green emission at 545nm (5D4–7F5) was dominant.

Complexes of lanthanide nitrates with tri-isopropylphosphine oxide

The complexes formed on reaction of tri-isopropylphosphine oxide ((C3H7)3PO=iPr3PO = L) and lanthanide nitrates have been studied. The new compounds have been characterised by elemental analysis, infrared and 31P NMR spectroscopy in CD2Cl2 solution. On reaction of lanthanide nitrates and L in 1:3 ratios, well defined Ln(NO3)3L3 are obtained for Ln=La–Eu with complexes for the heavier lanthanides forming mixtures of Ln(NO3)3L3 and Ln(NO3)3L2. Analytically pure complexes Ln(NO3)3L2 can be isolated for Yb and Lu. Single crystal X-ray structures for Ln(NO3)3L3, Ln=La (1), Ce (2), Pr (3), the ionic complex [Er(NO3)2L3(H2O)][NO3] (4) and Ln(NO3)3L2, Ln=Yb (5), Lu (6) are reported. The 31P solution NMR spectra of Ln(NO3)3L3 show that the complexes are fluxional at ambient temperature with spectra consistent with static structures observed at lower temperatures for some complexes. The structures and solution properties are discussed in terms of the steric and electronic properties of the ligand.

Phosphatization Coating-Forming Mechanism Based on Green Phosphating Accelerator Rare Earth Nitrate

Experimental results show that the samples gained in bath added Rare earth nitrate (REN), relative to the sample got in bath without REN, improve the anti-corrosion power of the coating because of increasing of covering rate of formless crystal Zn2Fe(PO4)2·4H2O (marked P) crystals and the ratio of P/(P+H) (H is the mark of Zn3(PO4)2 crystal) in the coating, combination of which with components parsing by EDS indicates that the sequence of contribution elements P and Zn to erosion resistance of coatings is P>Zn. And the correlative mechanism was discussed, which has it clear that RE is materially a catalyst holding excellent ability of carrying oxygen and cathode depolarization, its concentration gets so constant in certain range that it is much steadier and more efficient than the usual consumptive oxidants like nitrates. In a word, REN plays the role of surface regulator, accelerant and densification agent, which speeds up the phosphating, and bids it effective to enhance the anti-corrosion power of the coating. The addition of REN, not only promote the phosphating film formation and substantial reduction or exemption of nitrite. So, REN is green phosphating accelerator of live up to one's name.

Advance Effect of Rare Earth Nitrates on Green Process of Phosphating

It had validated by experiments why appending rare earth nitrate (REN) into the bath affects notably on development of coating-forming, corrosion resistance as well as on urgency varieties of appearance and component of the coating. The causation rests with the fact that REN not only makes metal surface depolarized and cathodic reactions accelerated, but also acts as crystal nucleus with gel forms on the metal surface to speed up the coating-forming and develop the anti-corrosion capacity of the coating. The optimal level of addition of REN is 30-55 mg·L-1.