Samarium Cation Research Articles

Heterovalent Samarium Cation‐Doped SnO2 Electron Transport Layer for High‐Efficiency Planar Perovskite Solar Cells

Tin oxide (SnO2) has demonstrated significant potential as an electron transport layer (ETL) owing to its low‐temperature processing in perovskite solar cells (PSCs). However, the poor energy‐level alignment and the presence of interface defects between the SnO2 and perovskite layer aggravate the power conversion efficiency (PCE) of the PSCs. Herein, heterovalent samarium cation (Sm3+) is deliberately doped into SnO2, optimizing the energy‐level alignment between SnO2 and the perovskite layer, and effectively passivating the oxygen vacancy defects on the surface of SnO2. Experimental and theoretical conclusions reveal that Sm‐doping successfully passivates the defects in the ETL and improves the perovskite crystal quality, thereby reducing interface charge recombination, and enhancing electron extraction from perovskite to the SnO2 layer. Consequently, the optimized Sm‐doped SnO2‐based PSCs achieve a PCE of 24.10% with a VOC of 1.174 V, negligible hysteresis, and improved durability under ambient conditions.

Lanthanide (Sm, Dy) Complexes with the 9,10-Phenanthrenediimine Redox-Active Ligand: Synthesis and Structures

The complex formation of the redox-active ligand bis(N, N’-2,6-diisopropylphenyl)-9,10-phenanthrenediimine (DippPDI) with alkaline metal (Li, K) and lanthanide (Sm, Dy) cations is studied. The reduction of DippPDI with an alkaline metal excess affords the dianionic form of the ligand (DippPDA2–), which crystallizes with the potassium cation as the coordination polymer [K2(DippPDA)(Thf)3] (Thf is tetrahydrofuran, THF). The reaction of equimolar amounts of the lithium salt with the dianionic form of the ligand and neutral diimine affords the lithium complex with the radical-anion form (DippPSI•–) crystallized as [Li(DippPSI)(Thf)2]. The samarium(III) complex [SmCp*(DippPDA)(Тhf)] (I) is formed by the reduction ofDippPDI with samarocene [Sm (Thf)2] (Cp* is pentamethylcyclopentadienide): both the samarium(II) cation and Cp*– anion are oxidized in the reaction.DippPDI does not react with similar ytterbocene. The dysprosium(III) complexes are synthesized by the ion exchange reactions between DyI3(Thf)3.5 and potassium or lithium salt with theDippPDA2-dianion. Similar complexes [Dy(DippPDA)I(Thf)2] (IIThf) and [Dy(DippPDA)I(Thf)(Et2O)] () are formed in the reactions with the potassium salt depending on the solvent used: a THF-hexane or a diethyl ether-n-hexane mixture, respectively. The coordination of the dysprosium cation by the π system of the conjugated fragment of the NCCN ligand is observed in IIThf, whereas in this coordination is absent. The reaction with Li2(DippPDA) affords the binary complex salt [Li(Тhf)3(Et2O)][DyI2(DippPDA)(Тhf)] (III, crystallization from a THF-Et2O mixture). The crystallization from THF gives the [Li(Тhf)4][DyI2(DippPDA)(Thf)] salt (III') containing the same anion as III. The structures of all new complexes are studied by X-ray diffraction (XRD, CIF files CCDC nos. 2260307–2260313).

Synthesis, Crystal Structures, and Optical and Magnetic Properties of Samarium, Terbium, and Erbium Coordination Entities Containing Mono-Substituted Imine Silsesquioxane Ligands.

Mono-substituted cage-like silsesquioxanes of the T8-type can play the role of potential ligands in the coordination chemistry. In this paper, we report on imine derivatives as ligands for samarium, terbium, and erbium cations and discuss their efficient synthesis, crystal structures, and magnetic and optical properties. X-ray analysis of the lanthanide coordination entities [MCl3(POSS)3]·2THF [M = Er3+ (3), Tb3+ (4), Sm3+ (5)] showed that all three compounds crystallize in the same space group with similar lattice parameters. All compounds contain an octahedrally coordinated metal atom, and additionally, 3 and 5 structures are strictly isomorphous. However, surprisingly, there are two different molecules in the crystal structure of the terbium coordination entity 4, monomer (sof 65%) and dimer (sof 35%), with one and two metal centers. Absorption measurements of the investigated materials recorded at 300 K showed that regardless of the lanthanide involved, their energy band gap equals 2.7 eV. Moreover, the analogues containing Tb3+ and Sm3+ exhibit luminescence typical of these rare earth ions in the visible and infrared spectral range, while the compound with Er3+ does not generate any emission. Direct current variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3-5 were performed between 1.8 and 300 K. The magnetic properties of 3 and 4 are dominated by the crystal field effect on the Er3+ and Tb3+ ions, respectively, hiding the magnetic influence between the magnetic cations of adjacent molecules. Complex 5 exhibits a nature typical for the paramagnetism of the samarium(III) cation.

The thermal decomposition of Samarium-Thiocyanate-Based ionic liquids

New lanthanide containing ionic liquids (ILs) based on thiocyanate complexes of the type [BMIM]x-3[Ln(NCS)x(H2O)y] (BMIM = 1-Butyl-3-Methylimidazolium; x = 6,7,8; y = 0–2, x + y < 10; Ln = Y, La-Yb) have been reported in recent studies. These complexes are highly efficient in dissolving lanthanide complexes within ILs.The present work includes a thermal decomposition study of the anhydrous ionic liquids of this type with Samarium cation as the lanthanide. The thermal decomposition of [BMIM][NCS], [BMIM]3[Sm(NCS)6], [BMIM]4[Sm(NCS)7] and [BMIM]5[Sm(NCS)8] was investigated by employing a combination of thermo-gravimetric analysis (TGA), and temperature programmed desorption (TPD) coupled with mass spectrometry.The decomposition temperature of the samarium-containing ILs were found to be higher than that measured for [BMIM][NCS], suggesting stabilization of the ILs by complexation to the samarium cation. Thermal gravimetric analysis of [BMIM]x-3[Sm(NCS)x] confirms that the thermal decomposition occurs in a stepwise fashion to give Sm(NCS)3 via a [BMIM]3[Sm(NCS)6] intermediate, whereby [BMIM][NCS] units are decomposed to give gaseous products. Additional experimental evidence obtained with TPD-MS supporting this decomposition route and reveal that each [BMIM][NCS] unit decomposes by the rapid nucleophilic attack of the thiocyanate anion at the C-N bond of the methyl- and butyl- imidazole groups, and their proposed reaction mechanism are introduced here.

Contrasting Effect of Additives on Photoinduced Reactions of SmI2.

The work described herein compares the effect of additives (HMPA, methanol, ethylene glycol, pinacol, N-methylethanolamine) on thermal and photochemical reactions of samarium diiodide (SmI2 ). In thermal reactions, additives that coordinate to SmI2 induce a significant increase in reaction rate. In photochemical reactions, the presence of an electronegative atom with a highly localized negative charge on the substrate leads to a rate deceleration. In order to benefit from the columbic interaction with the positively charged samarium cation, these substrates react preferentially by an inner sphere reduction mechanism. The addition of ligands prevents this close interaction causing rate retardation. Furthermore, studies demonstrate that excited state quenching of SmII by ethylene glycol and other additives indicate that it is unlikely to be the major cause for the observed rate retardation. This effect provides a simple diagnostic tool to distinguish between an inner and an outer sphere reduction mechanism.

Samarium cation (Sm+) reactions with H2, D2, and HD: SmH+ bond energy and mechanistic insights from guided ion beam and theoretical studies.

Guided ion beam tandem mass spectrometry is used to study the reaction of the lanthanide samarium cation (Sm+) with H2 and its isotopologues (HD and D2) as a function of collision energy. Modeling the resulting energy dependent product ion cross sections from these endothermic reactions yields 2.03 ± 0.06 eV (two standard deviations) for the 0 K bond dissociation energy of SmH+. Quantum chemical calculations are performed to determine stabilities of the ground and low-energy states of SmH+ for comparison with the experimentally measured thermochemistry. The calculations generally overestimate the SmH+ bond energy, but a better agreement between experiment and theory is achieved after correcting for spin-orbit energy contributions, with coupled-cluster with single, double and perturbative triple excitations/complete basis set [CCSD(T)/CBS] results reproducing the experiment well. In the HD reaction, the SmH+ product is observed to be favored over the SmD+ by about a factor of three, indicating that the reaction proceeds via a direct mechanism with short-lived intermediates. This is consistent with quantum chemical calculations of relaxed potential energy surface scans of SmH2 +, which show that there is no strongly bound dihydride intermediate. The reactivity and hydride bond energy of Sm+, which has a valence electron configuration typical of most lanthanides, are compared with previous results for the lanthanide cations La+, Gd+, and Lu+, which exhibit configurations more closely related to the group 3 metal cations, Sc+ and Y+. Periodic trends across the lanthanide series and insights into the role of the electronic configurations on hydride bond strength and reactivity with H2 are discussed.

Electrochemical Formation of Divalent Samarium Cation and Its Characteristics in LiCl-KCl Melt.

The electrochemical reduction of trivalent samarium in a LiCl-KCl eutectic melt produced highly stable divalent samarium, whose electrochemical properties and electronic structure in the molten salt were investigated using cyclic voltammetry, UV-vis absorption spectroscopy, laser-induced emission spectroscopy, and density functional theory (DFT) calculations. Diffusion coefficients of Sm2+ and Sm3+ were electrochemically measured to be 0.92 × 10-5 and 1.10 × 10-5 cm2/s, respectively, and the standard apparent potential of the Sm2+/3+ couple was estimated to be -0.82 V vs Ag|Ag+ at 450 °C. The spectroelectrochemical study demonstrated that the redox behavior of the samarium cations obeys the Nernst equation ( E°' = -0.83 V, n = 1) and the trivalent samarium cation was successfully converted to the divalent cation having characteristic absorption bands at 380 and 530 nm with molar absorptivity values of 1470 and 810 M-1 cm-1, respectively. Density function theory calculations for the divalent samarium complex revealed that the absorption signals originated from the 4f6 to 4f55d1 transitions. Additionally, laser-induced emission measurements for the Sm cations in the LiCl-KCl matrix showed that the Sm3+ ion in the LiCl-KCl melt at 450 °C emitted an orange color of fluorescence, whereas a red colored emission was observed from the Sm2+ ion in the solidified LCl-KCl salt at room temperature.

NMR study of 1,7-diamino-4-oxyheptane-1,1,7,7-tetraphosphonic acid interaction with samarium(III) cation

1,7-Diamino-4-oxypentane-1,1,7,7-tetraphosphonic acid has been synthesized while searching for potential components for 153Sm radiopharmaceuticals. Its interaction with samarium(III) cation has been studied by 13C and 31P NMR spectroscopy in comparison with 1,5-diamino-3-oxypentane-N,N'-tetra-(methylenephosphonic acid) which is the ligand component of the osteotropic drug Samarium 153Sm oxabifore. NMR spectroscopy provides a simple, convenient, and informative method for studying interactions between the ligand and prospective radionuclide cation.

Recovery of samarium from cobalt–samarium solution using phosphoric acid

Cobalt–samarium alloys are generally used for producing magnets. Samarium falls under the class of rare earth elements, which are precious and expensive, because of which they are often recovered by recycling processes to save cost. There are a few reported processes for the recycling of rare earth elements; however, these processes have disadvantages, including the requirement for high temperatures and use of harmful gases. In this paper, a novel technique to recover samarium without encountering the difficulties reported in previous methods is presented. Because rare earth phosphates are the main components of rare earth ore, a novel phosphate process is suggested in this work. The cobalt–samarium solution was mixed with phosphoric acid solution and then adjusted to several pH with sodium hydroxide solution and nitric acid. The precipitates were filtered and dried. The ratio of samarium and cobalt in the precipitates and filtered solutions was estimated by the ICP (inductively coupled plasma) method. As an ideal phenomenon, samarium phosphate was filtered off, so that the filtrate contained the cationic cobalt species. The Sm/Co and P/(Co+Sm) ratios; concentrations of samarium, cobalt, and phosphoric acid; and pH were varied to study the precipitation of samarium compounds. In this work, over 99% of samarium cation was recovered from the cobalt–samarium solution using phosphoric acid. This novel process was observed to be useful for the recovery of samarium, and it may find applications in the recycling and recovery of other rare earth elements of interest.

Reversed Electron Apportionment in Mesolytic Cleavage: The Reduction of Benzyl Halides by SmI2.

The paradigm that the cleavage of the radical anion of benzyl halides occurs in such a way that the negative charge ends up on the departing halide leaving behind a benzyl radical is well rooted in chemistry. By studying the kinetics of the reaction of substituted benzylbromides and chlorides with SmI2 in THF it was found that substrates para-substituted with electron-withdrawing groups (CN and CO2 Me), which are capable of forming hydrogen bonds with a proton donor and coordinating to samarium cation, react in a reversed electron apportionment mode. Namely, the halide departs as a radical. This conclusion is based on the found convex Hammett plots, element effects, proton donor effects, and the effect of tosylate (OTs) as a leaving group. The latter does not tend to tolerate radical character on the oxygen atom. In the presence of a proton donor, the tolyl derivatives were the sole product, whereas in its absence, the coupling dimer was obtained by a SN 2 reaction of the benzyl anion on the neutral substrate. The data also suggest that for the para-CN and CO2 Me derivatives in the presence of a proton donor, the first electron transfer is coupled with the proton transfer.

Synthesis and Crystal Structure of the New Samarium Oxyhydroxide, SmO(OH)

A single crystal of SmO(OH) was grown out of a high temperature lithium hydroxide melt and characterized by single crystal X-ray diffraction. SmO(OH) crystallizes in the monoclinic space group P21/m with a = 4.3605(3) A, b = 3.7725(3) A, c = 6.1490(4) A, and β = 108.4500(10)°. The material exhibits a three-dimensional crystal structure consisting of corner- and edge-shared SmO7 polyhedra. The samarium cation is observed in a distorted monocapped trigonal prismatic coordination environment. Two kinds of oxygen atoms are found, and these represent oxide (O2−) and hydroxide (OH−) ligands, respectively. The synthesis and crystal structure of a new samarium oxyhydroxide, SmO(OH) is reported.

Novel Supramolecular Assemblies Based on Coordination of Samarium Cation to Cucurbit[5]uril

In the present study, we introduce the coordination of samarium-Q[5] systems in the absence and presence of the third species, and the corresponding supramolecular assemblies are dependent upon the addition of the third species. In the absence of the third species, a samarium cation (nitrate salt) coordinates to a Q[5] molecule and forms a molecular bowl; in the presence of an organic molecule (hydroquinone), a one-dimensional polymer of ···Sm-Q[5]-Sm-Q[5]-Sm··· is formed through direct coordination of Sm cation to the portal carbonyl oxygens. In the presence of nickel cations (chloride salt), an infinite 1D supramolecular chain is constructed of samarium/cucurbit[5]uril molecular bowl through ion-dipole interaction and hydrogen binding; in addition, the stacking of the supramolecular chains forms a novel hexagonal open framework. Remarkably, in the presence of copper cations (chloride salt), Q[5]-based hexagonal netting sheets are constructed of 6-Q[5]-ring structures.

Flexible Coordination Mode of a Donor-Functionalized Terphenyl Ligand in Monomeric Cp-Based Lanthanocenes

The synthesis and structural characterization of monomeric Cp-based metallocene compounds of the rare-earth elements samarium, yttrium, and ytterbium of general composition Cp2LnDanip (Danip = 2,6-di-o-anisylphenyl) is reported, featuring a donor-functionalized terphenyl moiety as a coligand. Depending on the size of the rare-earth element employed, different coordination modes of the terphenyl moiety are observed. In the case of the relatively large samarium cation both methoxy groups from the terphenyl ligand symmetrically coordinate to the metal cation. However, when smaller cations (yttrium and ytterbium) are employed, a flexible, asymmetric coordination mode of the terphenyl ligand is found.

Poly[tetraaqua-μ4-squarato-di-μ3-squarato-disamarium(III)

The structure of the title compound, [Sm2(C4O4)3(H2O)4]n, consists of infinite-chain structural units, built from edge-sharing samarium SmO7(H2O)2 polyhedra and linked via bis-monodendate squarate (sq1) groups. The chains extend along [100] in a zigzag mode and are interconnected by bis-chelating squarate (sq2) ligands into layers parallel to (101). Inter­layer hydrogen bonds strengthen the cohesion of the three-dimensional network. The samarium cation is coordinated by four O atoms from sq1 units and three O atoms from sq2 units, in addition to two water O atoms. The best representation of the samarium SmO7(H2O)2 polyhedron is distorted tricapped trigonal-prismatic. The sq1 ligand has one metal-free O atom and relates three Sm atoms in a bis-monodentate and chelation fashion, the second squarate, sq2, is strictly centrosymmetric and acts as a bis-chelating ligand.

Isolation and Structural Characterization of New Samarium(III) Bromide–HMPA Complexes

Abstract The crystal structures of new samarium(III) bromide–HMPA complexes were accurately determined by single crystal X-ray analysis. The Lewis acidity of samarium(III) cation is discussed based on the crystal structures of several samarium(III)–HMPA complexes.

Capillary Electrophoresis as an Efficient Tool in the Determination of Low Association Constants between Polyhydroxy Compound and Samarium Cation

Journal of High Resolution ChromatographyVolume 22, Issue 11 p. 595-598 Research Article Capillary Electrophoresis as an Efficient Tool in the Determination of Low Association Constants between Polyhydroxy Compound and Samarium Cation Benoît Henry, Corresponding Author Benoît Henry Commissariat à l'Energie Atomique de Saclay, DSM/DRECAM/SCM, 91191 Gif-Sur-Yvette Cedex, FranceCommissariat à l'Energie Atomique de Saclay, DSM/DRECAM/SCM, 91191 Gif-Sur-Yvette Cedex, FranceSearch for more papers by this author Benoît Henry, Corresponding Author Benoît Henry Commissariat à l'Energie Atomique de Saclay, DSM/DRECAM/SCM, 91191 Gif-Sur-Yvette Cedex, FranceCommissariat à l'Energie Atomique de Saclay, DSM/DRECAM/SCM, 91191 Gif-Sur-Yvette Cedex, FranceSearch for more papers by this author First published: 09 December 1999 https://doi.org/10.1002/(SICI)1521-4168(19991101)22:11<595::AID-JHRC595>3.0.CO;2-PCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume22, Issue111 November 1999Pages 595-598 RelatedInformation

Synthesis and X-ray Crystal Structure Determination of the First Homoleptic Four-Coordinate Phosphido Complex of Samarium: Sm[(&mgr;-P(t)Bu(2))(2)Li(thf)](2).

The reaction of Sm(OSO2CF3)3 with 5 equiv of LiPtBu2 in tetrahydrofuran is reported. The molecular structure of the title complex features the four-coordinate samarium(II) cation in a distorted tetrahedral environment. This complex is the first representative of divalent samarium surrounded by four only-phosphorus-containing substituents.

Thermodynamics of the weak interaction between samarium cation and xylitol in water: A chemical model

The thermodynamic characterization of the weakly complexed model system Sm3+-xylitol has been carried out. The standard Gibbs energy enthalpy, entropy, volume and heat capacity of complexation of Sm3+ by xylitol have been determined in water at 25°. The stability constant and the enthalpy change have been simultaneously determined by using a calorimetric method. The thermodynamic properties characterizing solely the specific interaction between the cation and the complexing sequence of hydroxyl groups of the ligand have been isolated. The stability constant and the volume of complexation have also been estimated from a similar treatment of the apparent molar volumes. It was found that the reaction between Sm3+ and the complexing site of xylitol in water is characterized by: K = 8.1, ΔrGo = −5.2 kJ-mol−1, ΔrHo = −13.7 kJ-mol−1, TΔrSo = −8.5 kJ-mol−1, ΔrVo = 8.8 cm3-mol−1 and ΔrC p o = 51 J-K−1-mol−1.

Stereoselective Formation oftrans-Decalin andcis-Decalin Skeletons via Hydroxy Group Directed Cyclization Induced by Samarium(II) Iodide

By treating the anti-hydroxyketones (1 and 2) and the syn-hydroxyketones (4 and 5) with samarium(II) iodide, the ketone-olefin coupling cyclizations took place in a stereocontrolled manner to give the trans-decalin diol (3) and the epimeric mixtures of the cis-decalin diols (6 and 7) respectively. The observed stereochemistries on the reductive coupling products are established by chelation of the samarium(III) cation generated in the process, with the hydroxyl groups incorporated in the starting materials.

Samarium complex is uniquely reactive

Chemists at the University of California, Irvine, have discovered a way to insert two carbon monoxide molecules into a carbon-carbon double bond by the use of an organosamarium complex. The net reaction converts an alkene to a bis-enolate. William J. Evans, a chemistry professor at Irvine, and Donald K. Drummond, a graduate student, worked with the divalent organosamarium complex bis(pentamethylcyclopentadienyl) samarium(II) bis(tetrahydrofuranate) or [C 5 (CH 3 ) 5 ] 2 -Sm(THF) 2 [ J. Am. Chem. Soc. , 110 , 2772 (1988)]. The structure of this complex is somewhat analogous to that of ferrocene—in which two parallel cyclopentadienyl groups sandwich an iron cation—in that the aromatic pentamethylcyclopentadienyl groups sandwich the samarium cation. In the samarium complex, however, the pentamethylcyclopentadienyl groups are not parallel to each other. Rather, they are tilted, allowing the samarium to bind to the oxygen atoms on two tetrahydrofuran groups. Evans and coworkers have shown that this samarium co...