SmCl3 Research Articles

Samarium and europium beta”-alumina derivatives characterized by XPS

Characterization of samarium, and europium beta”-alumina derivatives has been carried out using x-ray photoelectron spectroscopy(XPS). Beta”-alumina has been widely studied as a material capable of incorporating many different cations into its lattice structure, such as sodium and many of the lanthanide elements. This unique behavior has been recently explored at Oak Ridge National Laboratory for separating samarium and europium from each other. The XPS of samarium and europium in the beta”-alumina structure are reported here. Additionally, the XPS spectra of the europium and samarium trichloride starting materials are presented in the database.

Efficient method for the cycloaminomethylation of glycoluril

The efficient method for the cycloaminomethylation of glycoluril to yield 2,6-ditert-butylhexahydro-1H,5H-2,3a,4a,6,7a,8a-hexaazacyclopenta[def]fluorene-4,8-dione is described. The material is synthesized employing water as the solvent, and is isolated by filtration. This is an improvement over the previous reported synthetic method, which relied on the use of samarium trichloride catalysis, as well as silica gel column chromatographic purification to obtain the target product.

Reaction-Mediator-Based Chlorination for the Recycling of Titanium Metal Scrap Utilizing Chloride Waste

In this study, a novel chlorination technique for metallic titanium (Ti) was devised in order to establish a recycling process that uses both Ti metal scrap and iron chloride (FeClx) waste, and its feasibility was demonstrated. Direct reaction between Ti and FeClx has drawbacks such as slow kinetics of Ti chlorination and high volatilization of FeClx. To overcome these, the authors proposed a chlorination technique utilizing a reaction mediator in molten salt. Based on thermodynamic analyses of lanthanoid chlorides, some fundamental experiments were carried out with samarium trichloride (SmCl3) as a reaction mediator. It was experimentally demonstrated that SmCl3 in molten magnesium chloride (MgCl2) can smoothly chlorinate Ti metal into gaseous titanium tetrachloride (TiCl4), and the by-product SmCl2 in the molten salt can be regenerated into SmCl3 by FeCl2. Thus, SmCl3 in a molten salt works efficiently as a reaction mediator, and the newly proposed chlorination technique has the potential to make the Ti recycling process more efficient and environmentally friendly. [doi:10.2320/matertrans.M-M2014838]

Concentration dependence of the structure of aqueous solutions of samarium trichloride according to X-ray diffraction

Aqueous solutions of samarium chloride in a wide range of concentration under ambient conditions are studied by X-ray diffraction analysis. The small-angle peaks in experimental scattering intensity curves are interpreted. It is shown that highly concentrated solutions are characterized by a unique structure that differs heavily from the structure of dilute systems. It is found that small-angle peaks also appear in the intensity curves of dilute solutions, indicating that the so-called long-range order is preserved in these solutions. It is revealed that the contributions to the total scattering pattern that govern the appearance of prepeaks are interionic interactions of different types (e.g., cation-cation, anion-cation, and anion-anion interactions) in concentrated systems and the distances between the cations in dilute solutions.

Ultraviolet–Visible Diffuse Reflection Investigation of the Thermal Decomposition of Samarium Trichloride Hexahydrate

The thermal decomposition of the hexahydrate of samarium trichloride under an air atmosphere and under low pressure has been monitored through the use of ultraviolet–visible (UV-vis) diffuse reflection spectroscopy. The unique ability of lanthanide spectroscopy to investigate the near environment surrounding the samarium ion allowed for the identification of the hexa-, penta-, tetra-, tri-, di-, and monohydrates in both cases, as well as the formation of samarium oxychloride formed as the final decomposition product. The decomposition temperatures and the products observed in this report are compared to those obtained by other thermal and iso-thermal analyses of this compound, as well as the analogous decomposition of europium trichloride hexahydrate. Structural and environmental variations associated with the compounds, as indicated by the reflectance spectra, are discussed.

Lanthanide(III) complexes of N4O4 Schiff base macrocycle: Luminescence and formation of heterodinuclear d–f complexes

The new macrocyclic Schiff base lanthanide(III) complexes of the formula [Ln(H4L)Cl3]·nH2O (Ln=Pr(III), Nd(III), Sm(III), Gd(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III) and Lu(III)) have been synthesized in the template condensation of 1,3-diamino-2-hydroxypropane and 2,6-diformyl-4-methylphenol in the presence of the appropriate Ln(III) chlorides. The obtained compounds have been characterized in solution by NMR spectroscopy, and the 1H and 13C NMR spectra of [Pr(H4L)Cl3]·H2O, [Nd(H4L)Cl3]·H2O, [Sm(H4L)Cl3]·H2O and [Yb(H4L)Cl3]·4H2O complexes have been assigned on the basis of COSY, NOESY and HMQC techniques. The analysis of isotropic shifts of the paramagnetic Ln(III) derivatives indicate the unsymmetrical coordination of the lanthanide(III) ions within the macrocyclic ligand H4L. 1H NMR spectroscopy has also been used to follow transformation of the [Ln(H4L)]3+ complexes into heterodinuclear derivatives, [LnCo(H2L)]3+ and [LnCo(HL)]2+. Emission and excitation spectra as well as luminescence decay time measurements (at 293 and 77K) were used to characterize the photophysical properties of the mononuclear Eu(III), Gd(III) and Yb(III) [Ln(H4L)Cl3]·nH2O complexes in solid-state. Energy transfer from the ligand to the Yb(III) ions has been proved at both room temperature and 77K. The f–f luminescence of Nd(III) and Er(III) was not observed neither by the excitation through the ligand (1π–1π∗) nor the lanthanide ion absorption transitions both at 293 and 77K. In the case of Eu(III) complex the energy transfer only occurs at 77K, while at room temperature a thermally activated back energy transfer process from 5D0 Eu(III) excited state to the ligand triplet states has been proposed. The 4f–4f emission spectrum of Eu(III) in a low site symmetry with the dominating 5D0→7F4 transition has been demonstrated for the first time.

N,N′-Bis(2,6-diisopropylphenyl)methanimidamidato][η8-1,4-bis(trimethylsilyl)cyclooctatetraenyl](tetrahydrofuran)samarium(III) toluene monosolvate

The title compound, [Sm(C25H35N2)(C14H24Si2)(C4H8O)]·C7H8, was prepared by treatment of anhydrous samarium trichloride with a 1:1 mixture of in situ-prepared Li(DippForm) [DippFormH = N,N′-bis­(2,6-diisopropyl­phen­yl)methanimidamide] and Li2(COT′′) [COT′′ = 1,4-bis­(trimethyl­sil­yl)cyclo­octa­tetra­enyl] in tetra­hydro­furan (THF). Despite the presence of two very bulky ligands (COT′′ and DippForm), the mol­ecule still contains one coordinated THF ligand. The overall coordination geometry around the SmIII atom resembles a three-legged piano-stool with the COT′′ ligand being η8-coordinated and the DippForm− anion acting as an N,N′-chelating ligand [Sm—N = 2.5555 (15) and 2.4699 (15) Å]. The asymmetric unit also contains a disordered mol­ecule of toluene, the refined ratio of the two components being 0.80 (4):0.20 (4).

Hydrophilic polymer supported nanoparticles prepared from samarium trichloride and lanthanum trichloride in liquid-phase

Nanoparticles were obtained by the reaction of SmCl3·6H2O with sodium borohydride (NaBH4) in the presence of sodium polyacrylate (PAA) with average molecular weight of 5,100 as a capping polymer. The resulting colloidal solution was placed on a Cu grid and characterized by transmission electron microscope (TEM) measurement, which clearly indicated the generation of nanoparticles. The reaction of LaCl3 with NaBH4 in the presence of PAA led to preparation of lanthanum nanoparticles, similarly as samarium nanoparticles.

Synthesis and Solid-State Structures of Pyrazolylmethane Complexes of the Rare Earths

In this paper, we report the first examples of trispyrazolylmethane complexes of rare earths. Reaction of LnCl3 with Tpm* (tris(3,5-dimethylpyrazolyl)methane) in THF or acetonitrile gives good yields of the [Ln(Tpm*)Cl3] (Ln = Y, Ce, Nd, Sm, Gd, Yb). Tpm* adducts of the lanthanide triflates [Ln(Tpm*)(OTf)3(THF)] (Ln = Y, Ho, Dy) may also be prepared. The X-ray crystal structures of [Y(Tpm*)Cl3], [Sm(Tpm*)Cl3(THF)], and [Ln(Tpm*)(OTf)3(THF)] (Ln = Y, Ho) are reported. The halide/triflate complexes may be used to prepare the aryloxide complexes [Ln(Tpm*)(OArMe2)3] (Ln = Y, Nd, Sm, Yb; ArMe2 = C6H3-2,6-(CH3)2), which are fluxional in solution as a result of interactions between the Tpm* and the aryloxide groups. The structures of the Nd and Sm complexes have been determined. Finally, the reaction of [Nd(BH4)3(THF)3] with Tpm* in THF results in the displacement of two THF molecules to give [Nd(Tpm*)(BH4)3(THF)]. Infrared spectra are consistent with tridentate borohydride coordination. The X-ray structures of these compounds indicate that the Tpm* ligand is less strongly bound than its anionic trispyrazolylborate analogues.

Potentiometric study of Sm–O compounds formation in the molten LiCl–KCl eutectic at 450°C. Determination of a E-pO2− stability diagram

Reactions between samarium trichloride and oxide ions were studied in the fused LiCl–KCl eutectic by potentiometric titration, using an yttria-stabilized zirconia electrode. In the experimental conditions used in this work, the titration curves indicate the formation of insoluble samarium oxychloride. Based on these curves, the calculated solubility product is found to be 10−7.54±0.17, in molal scale. Characterization of the precipitated compound by X-ray diffraction analysis corroborated the oxychloride formation. The combination of the solubility product, the previously determined electrochemical properties and, in the cases that experimental data are not available, the thermochemical data, allowed to set up the potential-pO2− stability diagram. This diagram summarises the properties of samarium species in LiCl–KCl at a given temperature and concentration.

Ein ungewöhnliches biphenylsubstituiertes Lithiumchlorotriarylsamarat

AbstractAn Unusual Biphenylsubstituted LithiumchlorotriarylsamarateThe reaction of the lithium biphenyl LiPmph (Pmph = 2′,3′,4′,5′,6′‐pentamethylbiphenyl) with samarium trichloride in a molar ratio of 3 to 1 affords under elimination of only 2 equivalents lithium chloride the lithium samarate [(thf)3Li][ClSm(Pmph)3(thf)] in a yield of 45°. In the obtained contact ion pair the samarium atom shows an only slightly distorted trigonal bipyramid coordination. Equatorial and axial positions are occupied by three propeller like arranged biphenyl substituents, the Cl{···Li(thf)3} ligand, and a THF molecule, respectively. A rather unusual folding of the aryl ligands leads to comparably short distances of the Sm atom to the ortho‐C–H‐bonds and therefore to the formation of strong agostic interactions.

Synthesis and Characterization of Homoleptic Lanthanide Guanidinate Complexes and Their Catalytic Activity for the Ring‐Opening Polymerization of Trimethylene Carbonate

AbstractTwo methods to synthesize homoleptic guanidinate lanthanide complex are described. The samarium guanidinate complex [Sm{Ph2NC(NCy)2}3]·2C7H8 (1) can be synthesized by the metathesis reaction of lithium guanidinate with anhydrous samarium trichloride in a 3:1 molar ratio. The analogous complexes [Ln{Ph2NC(NCy)2}3]·2C7H8 [Ln = Yb (2), Nd (3)] can also be synthesized by the insertion reaction of N,N′‐dicyclohexylcarbodiimide into the Ln−N bond of [(THF)4Li][Ln(NPh2)4] in a 3:1 molar ratio in good yield. Complexes 1−3 were characterized by elemental analysis, IR and 1H NMR spectroscopy. The molecular structures of complexes 1 and 3 were further determined by X‐ray diffraction techniques. These complexes showed high activity for the ring‐opening polymerization of trimethylene carbonate (TMC), giving polymers with Mw/Mn ranging from 1.41−1.73. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Determination of a stability potential-pO2- diagram of samarium in the eutectic LiCl-KCl

Abstract:Reaction between samarium trichloride and oxide ions was studied in the fused LiCl – KCl eutectic mixture at 723 K, by potentiometry with an yttria-stabilised zirconia membrane electrode. Titration curve demonstrated the existence of a precipitated samarium oxychloride (SmOCl), under this experimental conditions, with a solubility product value of 7.59 ţ 0.3 (molality scale). The combination of this value with the standard potentials allowed setting up the potential–pO2- stability diagram which summarises the properties of Sm species in the eutectic LiCl – KCl melt.

Magnesium and lanthanide ions promoted electrochemical coupling of aliphatic esters and tetrahydrofuran for the synthesis of acetals

Electroreduction of aliphatic esters in THF was found to be promoted by the catalytic amount of porphine–magnesium(II) complexes and afforded 2-alkoxytetrahydrofuran derivatives, the coupling products between alkoxide anions formed by the electroreduction of aliphatic esters and THF cation generated by the anodic oxidation of the solvent (THF). In this reaction, chlorophyll a extracted from Trifolium repens L was remarkably effective. In addition, lanthanide metal(III) ions such as samarium trichloride were also found to be effective for the electroreduction of aliphatic esters.

Mechanochemical synthesis and characterisation of nanoparticulate samarium-doped cerium oxide

The synthesis of 20 mol% samarium-doped cerium oxide nanoparticles was studied from the mechanochemical reaction between samarium trichloride, sodium hydroxide and cerium hydroxide. XRD and high-resolution TEM characterisation showed chemically homogeneous 10–30 nm crystallites having a lattice parameter of 5.435 Å and a surface area of 48.7 m 2/g.

A Regio-and Stereoselective Synthesis of β-Amino Alcohols

The regio-and stereoselective ring opening of epoxide with aromatic amines catalyzed by samarium trichloride and the enantioselective ring opening of cyclohexene oxide with aniline catalyzed by lanthanide complexes were studied.

A Facile Synthesis of 1,3,5-Triaryl Benzenes from Acetophenone Diethyl Ketals in the Presence of Acetyl Chloride and SmCl3

Samarium trichloride, SmCl3, has been found to be an efficient catalyst for the synthesis of 1,3,5-triaryl benzenes from acetophenone diethyl ketals in the presence of acetyl chloride under solvent of pentane and mild conditions.

ChemInform Abstract: A Facile Method for the Cleavage of Acetals by the Combined Use of Samarium Trichloride and Chlorotrimethylsilane.

AbstractAcetals such as (I), (III), (V), and (VI) are cleaved smoothly to form the corresponding carbonyl compounds on treatment with a combined reagent consisting of samarium trichloride and chlorotrimethylsilane.

A Facile Method for the Cleavage of Acetals by the Combined Use of Samarium Trichloride and Chlorotrimethylsilane

Abstract Cleavage of acetals by a stoichiometric or a catalytic amount of samarium trichloride and chlorotrimethylsilane in the absence of a proton source proceeded smoothly giving the corresponding carbonyl compounds in high yields.

SYNTHESIS AND PHYSICO-CHEMICAL STUDIES ON NEODYMIUM(III) AND SAMARIUM(III) COMPLEXES WITH TETRAAZA MACROCYCLIC LIGANDS

Abstract Reactions of nsodymium trichloride and samarium trichloride with 6,7,13,14-R4-3, 10-X2-[14]-5,7,12,14-tetraens-l.5.8.12-N4,-[2.4.9.11-N4] (R = CH3, X = O (L1 (1)): R = C6,H5, X = O (L1 (2)); R = CH3, X = S (L2 (1)) and R = C6H5. X = S (L2 (2)) have been studied in ethanol and complexes of the type [M(L1 (1) or L1(2))]Cl3, and [M (L2 (1) or L2 (2))(H2O)2]Cl3, (M = Nd(III) and Sm(III)) have been isolated. In addition. macrocyclic complexes of Nd(III) and Sm(III) with another series of tetraaza ligands, viz. 5.6.11.12-R4-3.8-X2-[12]-4,6.lO,12-tetraene-1,4,7,10-N4-[2.9-N2] (R = CH3, X = O (L3 (1)); R = C6H5. X = O (L3 (2)): R = CH3. X = S (L4 (1)); R = C6H5, X = S (L4 (2)), formulated as [M(L3 (1), L3 (2), L4 (1) or L4 (2))(H2O)2]Cl3 (M = Nd(III) and Sm(III)) have been prepared by template condensation of Nd(III) and Sm(III) complexes of diacetylbis(semicarbazone/thiosemicarbazone) or benziibis(semicdrbazone/thiosemicarbazone) with diacetyl or benzil. The complexes have been identified by elemental a...