The Zintl Phase Eu2Si

The Zintl phase Eu₂Si was synthesized from elemental europium and silicon in a sealed tantalum tube in a high‐frequency furnace at 1270 K and subsequent annealing at 970 K. Investigation of the sample by X‐ray powder and single crystal techniques revealed: Co₂Si (anti‐PbCl₂) type, space group Pnma, a = 783.0(1), b = 504.71(9), c = 937.8(1) pm, wR2 = 0.1193, 459 F² values and 20 variables. The structure contains two europium and one silicon site. ¹⁵¹Eu Mössbauer spectroscopic data show a single signal at an isomer shift of −9.63(3) mm/s, compatible with divalent europium. Within the Zintl concept electron counting can be written as (2Eu²⁺)⁴⁺Si⁴⁻, in agreement with the absence of Si‐Si bonding. Each silicon atom has nine europium neighbors in the form of a tri‐capped trigonal prism. The silicon coordinations of the Zintl phases Eu₂Si, Eu₅Si₃, EuSi, and EuSi₂ are compared.     

Synthesis and Crystal Structure of Europium(II) Tartrate Tetrahydrate, [Eu(C4H4O6)(H2O)2](H2O)2

Single crystals of [Eu(C₄H₄O₆)(H₂O)₂](H₂O)₂ were obtained from the combination of solutions of EuCl₂, previously obtained by electrolysis of an aqueous solution of EuCl₃, and tartraric acid, neutralized by LiOH. The crystal structure (orthorhombic, P2₁2₁2₁, Z = 4, a = 948.9(1), b = 954.6(1), c = 1098.4(1) pm; R(F) = 0.0242 and R_w(F²) = 0.0585 for I > 2σ(I); R(F) = 0.0256 and R_w(F²) = 0.0592 for all data) is isotypic with [Ca(C₄H₄O₆)(H₂O)₂](H₂O)₂ and [Sr(C₄H₄O₆)(H₂O)₂](H₂O)₂ exhibiting a three‐dimensional structure. The divalent cations (Eu²⁺, Ca²⁺, Sr²⁺) are eight‐coordinate by oxygen atoms that originate from carboxylate and hydroxyl groups of the tartraric dianion and two of the four water molecules.     

Abstandsvergleich M–H/M–D aus Röntgen‐ und Neutronenbeugungsdaten am Beispiel von Na3Rh(H/D)6

Comparison of the Distances M–H/M–D from X‐Ray and Powder Neutron Scattering Data on the Example of Na₃Rh(H/D)₆ Mixtures of NaNH₂, NaN₃ and Rh heated to 600 °C in autoclaves for salt melts show no indication of formation of ternary nitrides, but unexpectedly single crystals of a ternary hydride, Na₃RhH₆, were obtained. These crystals were isolated by washing the reaction product with liquid ammonia at room temperature. During this procedure metallic sodium – formed by decomposition of both the amide and the azide at elevated temperatures – is removed. X‐ray diffraction measurements on single crystals of Na₃RhH₆ allowed to even refine the displacement parameters of the hydrogen atoms and to compare the obtained results with data from powder neutron scattering of Na₃RhD₆ published by Bronger, Gehlen and Auffermann [1]. Only little differences are found between the lattice parameters, atomic positions and, noteworthy, the resulting distances Rh–H and Rh–D, respectively.     

Preparation,Structure, and Optical Properties of the 1D Chain Red Luminescent Europium Coordination Polymer: {[Eu2L6(DMF)­(H2O)]·2DMF·H2O}n (L = C9H6ClO2–)

The 1D chain red luminescent europium coordination polymer: {[Eu₂L₆(DMF)(H₂O)] · 2DMF · H₂O}_n ( I ) (L = 4‐chloro‐cinnamic acid anion, C₉H₆ClO₂^–, DMF = N, N‐dimethylformamide) was synthesized by the reaction of Eu(OH)₃ and 4‐chloro‐cinnamic acid ligand. The structure of the coordination polymer was determined by single‐crystal X‐ray diffraction analysis. It reveals that there exists two crystallographically nonequivalent europium atoms in each unit of this coordination polymer and Eu³⁺ ions are connected by two alternating bridging modes to form an endless polymer structure. The luminescent properties and energy transfer process in the complex are investigated at room temperature.     

Europium substitution into intermetallic phases grown in Ca/Zn flux

Replacement of calcium with europium in the phases Ca₂₁Ni₂Zn₃₆ and CaNi₂Zn₃ was attempted to explore the possibility of substitution in metal flux reactions and potential magnetic interactions between closely spaced Eu²⁺ ions. Limited substitution occurs when Eu is added to the reaction of nickel in a Ca/Zn flux mixture, up to stoichiometries of Eu_5.8(3)Ca_15.2(3)Ni₂Zn₃₆ and Eu_0.42(8)Ca_0.58(8)Ni₂Zn₃. Structural characterization and magnetic susceptibility studies on Eu_xCa_21−xNi₂Zn₃₆ phases indicate that the Eu and Ca ions do not form an even solid solution on their sites, but instead segregate in separate regions of the crystals. The europium-rich regions of the samples order ferromagnetically, with T_C dependent on the size of the clusters. If the concentration of Eu in the flux is raised above 20 mol%, a new compound Eu_1.63(1)Ca_1.37(1)Ni₂Zn₃ (Cmcm, a=4.1150(5) Å, b=16.948(2) Å, c=10.302(1) Å, Z=4, R₁=0.0396) is produced.     

The Crystal Structure of Binuclear Metal Complexes of 7-Azaindole: Cu2 (CH3CO2)2 (C7H5N2)2(C7H6N2)2 AND Ni2(C7H5N2)4.2DMF

The crystal and molecular structures have been determined by single-crystal X-ray methods for the binuclear metal ions (II) complexes of 7-azaindole (1H-pyrrolo [2,3-b] pyridine, C₇H₆N₂ denoted by HL), Cu₂(CH₃CO₂)₂.·L₂(HL)₂ and Ni₂L₄.2DMF. The dark green crystal of Cu₂(CH₃CO₂)₂L₂(HL)₂ was found to crystallize in the monoclinic space group P 2₁/n with a = 9.566(2), b = 12.752(2), c = 12.852(4) Å, β = 99.23(3)⁰, V = 1547 Å, Z = 2, the final R = 0.062 and Rw = 0.053 for 1488 observations from 2722 unique reflections. The Cu-Cu distance is 2.747(2), Cu-N (L^?, bridge) is 1.966(7), Cu-N (HL, axial) is 2.229(8), and Cu-O is 2.031(6)Å. The red crystal of Ni₂L₄.2DMF was was found to crystallize in the triclinic space group \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm P \bar 1} $$\end{document} with a = 8.907(5), b = 9.462(2), c = 10.217(2) Å, α = 90.48(2), β = 91.09(3), γ = 110.69(3)⁰, V =805 ų, Z = 1, the final R = 0.063 and Rw = 0.069 for 1489 observations from 2834 unique reflections. The Ni-Ni distance is 2.594(2), Ni-N is 1.905(7) Å. These two molecules lie on crystllographic inversion centers and exhibit ligand disorder.     

Synthesis, Crystal Structure and Band Structure of EuMg6Sn3.67

EuMg6Sn3.67 has been synthesized by reacting the mixture of the corresponding pure elements at high temperature, and structurally characterized by single-crystal X-ray diffraction study. EuMg6Sn3.67 crystallizes in hexagonal space group P63/m (No. 176) with a = 11.7259(4), c = 4.5507(2), V = 541.88(4)3 , Z = 2, Mr = 734.60, Dc = 4.502 g/cm3 , μ = 14.348 mm-1 , F(000) = 638, the final R = 0.0128 and wR = 0.0378 for 464 observed reflections with Ⅰ > 2σ(Ⅰ). EuMg6Sn3.67 is closely related to the Ba2Mg12Ge7.33 structure type and features a three-dimensional Mg6Sn3.67 framework with one-dimensional hexagonal tunnels along the c-axis occupied by the Eu atoms. Electronic structure calculation indicates that the title compound is metallic.     

Fluoridhaltige Gäste in Alumosilicaten: Tetrafluoroborate in dem Sodalithen Na8Al6Si6O24(BF4)2

In the course of investigations on optical properties resulting from the interaction of fluorides with alumosilicate host materials and rare earth guests, a well defined BF₄^– ion wasfound to be incorporated within the sodalite of composition Na₈Al₆Si₆O₂₄(BF₄)₂. The resulting cubic molecular structure, which was determined by Rietveld methods (space group P4 n, a = 906.91 pm, wRp = 0.045, Rp = 0.027), contains one anion in each sodalite cage and is, contrarily to expectations, thermally stable. NMR spectroscopic investigations indicated a fast rotatory motion of the BF₄^– tetrahedra at room temperature and agreed with the tetrahedral BF₄^– ions found in IR and Raman spectra. Preliminary attempts to obtain a luminescent material by incorporation of Eu³⁺ through aqueous ion exchange only yielded low rare earth concentrations, giving rise to characteristic red emission lines at 581 nm (⁵D₀ → ⁷F₁) and 615 nm (⁵D₀ → ⁷F₂) in a 1:2 intensity ratio. The material unexpectedly exhibited a strong broad band emission at 520 nm after calcination under Ar, which is attributed to the formation of an Eu²⁺ species. Further calcination under air partially reestablished the Eu³⁺ emission.     

KEu2Cl6 und K1, 6Eu1, 4Cl5: Zwei neue gemischtvalente Europiumchloride

KEu₂Cl₆ and K_1.6Eu_1.4Cl₅: Two New Mixed‐Valent Europium Chlorides The reaction of the binary chlorides EuCl₃, EuCl₂ and KCl yields the mixed‐valent compounds KEu₂Cl₆ and K_1.6Eu_1.4Cl₅. KEu₂Cl₆ (hexagonal, P6₃/m, Z = 1, a = 788.87(13), c = 411.41(6) pm, R₁ = 5.40 %) crystallizes with an addition‐variant of the UCl₃‐type of structure with tricapped trigonal prismatic coordination for the europium cations. The K⁺ ions reside in channels along [001] and exhibit extremely large displacement parameters U₃₃. The crystal structure of K_1.6Eu_1.4Cl₅ (orthorhombic, Pnma, Z = 4, a = 1260.49(12), b = 871.05(9), c = 787.18(10) pm, R₁ = 4.77 %) is closely related to that one of K₂EuCl₅ if the K⁺ and the Eu³⁺ ions are partly substituted for Eu²⁺. Absorption spectra show transitions, which can be assigned to Eu²⁺ and Eu³⁺ ions, and additional transitions due to interaction of both cations occupying common positions.     

Reaction of a ruthenium B-carboranyl hydride complex and BH3(SMe2): Selective formation of a pincer-supported metallaborane LRu(B3H8)

Reaction of a boryl hydride pincer complex (POBOP)Ru(H)(PPh₃) (POBOP?=?1,7-OP(i-Pr)₂-m-2-carboranyl) and BH₃(SMe₂) at 70?°C led to the selective formation of a pincer-supported metallaborane (POBOP)Ru(B₃H₈). Single crystal structure of (POBOP)Ru(B₃H₈) was determined. This complex features coordination of the carborane cluster through adjacent boryl and borane groups that impose significantly different trans-influence on the coordinated B₃H₈ fragment.     

A Microporous Metal-Organic Framework with Unique Aromatic Pore Surfaces for High Performance C2H6/C2H4 Separation

Developing adsorptive separation processes based on C₂H₆-selective sorbents to replace energy-intensive cryogenic distillation is a promising alternative for C₂H₄ purification from C₂H₄/C₂H₆ mixtures, which however remains challenging. During our studies on two isostructural metal–organic frameworks ( Ni-MOF 1 and Ni-MOF 2 ), we found that Ni-MOF 2 exhibited significantly higher performance for C₂H₆/C₂H₄ separation than Ni-MOF-1 , as clearly established by gas sorption isotherms and breakthrough experiments. Density-Functional Theory (DFT) studies showed that the unblocked unique aromatic pore surfaces within Ni-MOF 2 induce more and stronger C−H⋅⋅⋅π with C₂H₆ over C₂H₄ while the suitable pore spaces enforce its high C₂H₆ uptake capacity, featuring Ni-MOF 2 as one of the best porous materials for this very important gas separation. It generates 12 L kg⁻¹ of polymer-grade C₂H₄ product from equimolar C₂H₆/C₂H₄ mixtures at ambient conditions.     

Synthesis and Characterization of Three Zinc Phosphonates Based on 5‐Phosphonoisophthalic Acid, (HO2C)2C6H3PO3H2

Three new Zn‐phosphonates based on 5‐phosphonoisophthalic acid, (HO₂C)₂C₆H₃PO₃H₂ (H₄L), [Zn₂(H₂O)(O₂C)₂C₆H₃PO₃] · H₂O ( 1 ), Zn₂(H₂O)₂(O₂C)₂C₆H₃PO₃ ( 2 ), and KZn[H(O₂C)₂C₆H₃PO₃] ( 3 ) have been hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction ( 1 : triclinic, , a = 742.49(3) pm, b = 846.37(4) pm, c = 992.84(4) pm, α = 80.936(2)°, β = 81.574(2)°, γ = 73.139(3)°, V = 586.28(4) · 10⁶ pm³, R1 = 0.0583, wR2 = 0.1347 (for I > 2σ(I)); 2 : monoclinic, P2₁/m, a = 464.78(9) pm, b = 1329.2(3) pm, c = 974.5(3) pm, β = 95.80(3)°, V = 599.0(2) · 10⁶ pm³, R1 = 0.0395, wR2 = 0.1086 (for I > 2σ(I)); 3 : monoclinic, P2₁/c, a = 501.9(1) pm, b = 2489.9(5) pm, c = 946.2(5) pm, β = 105.38(3)°, V = 1140.0(7) · 10⁶ pm³, R1 = 0.0365, wR2 = 0.0848 (for I > 2σ(I))). The title compounds 1 and 2 have the same chemical composition but exhibit different structures and are therefore polymorphs. Thus, in compound 1 , isolated ZnO₄‐tetrahedra, and in 2 , infinite double‐chains of corner‐sharing ZnO₆ polyhedra are observed. In, KZn[H(O₂C)₂C₆H₃PO₃] ( 3 ) K⁺‐ions have been incorporated into the structure leading to the formation of a bimetallic inorganic‐organic hybrid compound.     

Synthesis and Crystal Structure of an Oligomeric Lithium Bis(amido)hydridooxidoaluminate Cluster, [{Li(C14H30N2)AlHO1/2}4]

The lithium bis(amido)hydridooxidoaluminate cluster [{Li(C₁₄H₃₀N₂)AlHO_1/2}₄] has been synthesized during systematic metallation/hydrometallation studies of a series of 1,4‐diazabut‐1‐enes with lithium aluminiumhydride. Formation of the complex is presumably derived from partial hydrolysis of the related lithium bis(amido)dihydridoaluminate and has been characterized using single crystal X‐ray diffraction. The complex crystallizes in the monoclinic space group C2/c (No. 15) with a = 25.012(2) Å, b = 10.673(2) Å, c = 28.673(3) Å, β = 115.855(7)°, V = 6887(1) ų, Z = 4. The complex exhibits an oligomeric structure of crystallographic C₂ symmetry, comprised of complex multicyclic units arising from extensive metal, hydride, oxide and ligand bridging interactions. These associations give rise to edge‐fused, non‐planar NAlOLi four‐membered rings tightly binding two of the diamido‐chelated aluminate units, with these in turn aggregating further via two of the μ²‐hydrides involving lithium atoms.     

Eu2(3,4-DMBA)6(PHEN)2的晶体结构及HRS研究

合成了铕（Ⅲ）与３,４－二甲基苯甲酸（３,４－ＨＤＭＢＡ）、邻菲咯啉（ＰＨＥＮ）形成的晶体配合物Ｅｕ２（３,４－ＤＭＢＡ）６（ＰＨＥＮ）２．测定其分子量Ｍ＝１５５９．３５,晶体属三斜晶系,Ｐ１空间群,ａ＝１．２６６５（４）ｎｍ,ｂ＝１．３５６７（４）ｎｍ,ｃ＝１．０７５５（４）ｎｍ,α＝９８．８７（３）°,β＝１０８．２５（３）°,γ＝８７．９８（２）°,Ｚ＝１,最终的偏离因子Ｒ＝０．０３１．以Ｅｕ（Ⅲ）离子为荧光探针,在７７Ｋ下测定了配合物的高分辨光谱（ＨＲＳ）．铕配合物的激发光谱、发光光谱、时间分辨光谱和发光寿命测定结果表明,该配合物中存在两种化学环境不同的Ｅｕ（Ⅲ）离子格位     

Active Sites Decorated Nonpolar Pore-Based MOF for One-step Acquisition of C2H4 and Recovery of C3H6

Herein, a 2-fold interpenetrated metal-organic framework (MOF) Zn-BPZ-TATB with accessible N/O active sites in nonpolar pore surfaces was reported for one-step C₂H₄ purification from C₂H₆ or C₃H₆ mixtures as well as recovery of C₃H₆ from C₂H₆/C₃H₆/C₂H₄ mixtures. The MOF exhibits the favorable C₂H₆ and C₃H₆ uptakes (>100 cm³ g⁻¹ at 298 K under 100 kPa) as well as selective adsorption of C₂H₆ and C₃H₆ over C₂H₄. The C₃H₆- and C₂H₆-selective feature were investigated detailedly by experimental tests as well as sorption kinetic studyies. Molecular modelling revealed the multiple interactions between C₃H₆ or C₂H₆ molecules and methyl groups as well as triazine rings in pores. Zn-BPZ-TATB not only can directly generate 323.4 L kg⁻¹ and 15.4 L kg⁻¹ of high-purity (≥99.9 %) C₂H₄ from C₃H₆/C₂H₄ and C₂H₆/C₂H₄ mixtures, but also provide a large high-purity (≥99.5 %) C₃H₆ recovery capacity of 60.1 L kg⁻¹ from C₃H₆/C₂H₄ mixtures. More importantly, the high-purity C₃H₆ (≥99.5 %) and C₂H₄ (≥99.9 %) with the productivities of 38.2 and 12.7 L kg⁻¹ can be simultaneously obtained from C₂H₆/C₃H₆/C₂H₄ mixtures through a single adsorption/desorption cycle.     

X-Ray Structural Analysis of a Novel Lithium Hydride/Lithium tert-Butoxide Superaggregate: Li33H17(OtBu)16

Extraordinary solubility in hydrocarbons is exhibited by the novel superaggregate Li₃₃H₁₇(OtBu)₁₆, which crystallizes from photolyzed solutions of lithium tert-butoxide and tert-butyllithium (ROLi:RLi≥7:3). The structure of the compound (the framework of Li, H, and O atoms without tBu groups is shown on the right) resembles a disrupted lithium hydride lattice with an inner hydride-rich core and an outer shell of lipophilic tert-butoxide groups.     

In-situ formation of 2H phase MoS2/cerium-zirconium oxide nanohybrid for potential electrochemical detection of an anticancer drug flutamide

The developing field of sensors is highly motivated and attracted by two-dimensional transition metal dichalcogenides (TMDs) with transition metal oxide integration. Initially, molybdenum disulfide (MoS₂), one among the TMDs with cerium-zirconium oxide (CZO), was one-pot synthesized via hydrothermal method for sensing flutamide (FLD). The as-synthesized hybrid nanocomposite was characterized to understand their physical and chemical presence. MoS₂-CZO was well assigned with crystalline nature observed from X-ray powder diffraction and X-ray photoelectron spectroscopy. High-resolution transmission electron microscopy confirms the irregularly arranged nanoparticles wrapped with MoS₂ sheets. The wide surface area with more electroactive sites has provided higher conductance of the MoS₂-CZO/glassy carbon electrode. The limit of detection was 0.005 μM with a linear range of 0.019 μM to 668.5 μM, sensitivity 0.353 μA μM?1 cm^?2. The practical feasibility was analyzed with human urine and river water samples, whereas the obtained results showed excellent FLD detection. The fabricated MoS₂-CZO with all these distinguished analyses will be an outbreak in the field of electrochemical sensors.     

邻甲基苯甲酸铕与邻啡咯啉络合物的热分解动力学及寿命

采用TG DTG技术研究了Eu2 (o MBA) 6 (PHEN) 2 (o MBA :邻甲基苯甲酸根离子 ;PHEN :1 ,1 0 邻啡咯啉 )在静态空气中的非等温热分解机理及动力学。根据TG曲线确定了热分解过程中的中间产物及最终产物。运用Acher法、Madhusudanan Krishnan Ninan (MKN)法和Ozawa法对非等温动力学数据进行分析 ,得到第一步热分解反应的机理函数和动力学参数 ,同时用等温TG法得到失重 1 0 %为寿终指标的寿命方程 :lnτ=-2 4 3 690 +1 .5 2 84× 1 0 4 T。     

Synthesis,crystal structure,and luminescence of a quaternary binuclear europium complex [Eu2(phth)2(Hphth)2(phen)2(H2O)4]

A quaternary binuclear europium complex [Eu₂(phth)₂(Hphth)₂(phen)₂(H₂O)₄] (H₂phth?=?phthalic acid, phen?=?1,10-phenanthroline) has been synthesized. The structure was determined by X-ray crystallography which reveals that it is binuclear with each europium nine-coordinate. Intermolecular hydrogen bonds link the complex units to form a 3D supermolecular network. Its properties have been studied by means of luminescence spectrum and thermal analysis. Fluorescence spectra show that the complex exhibits strong red emission.