LiLa2F3(SO4)2 und LiEr2F3(SO4)2: Fluoridsulfate der Selten‐Erd‐Elemente mit Lithium

LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂: Fluoride‐Sulfates of the Rare‐Earth Elements with Lithium The reaction of LiF with the anhydrous sulfates M₂(SO₄)₃ (M = La, Er) in sealed gold ampoules yields single crystals of the pseudo quaternary compounds LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂. According to X‐ray single crystal investigations, LiLa₂F₃(SO₄)₂ crystallizes with the monoclinic (I2/a, Z = 4, a = 828.3(2), b = 694.7(1), c = 1420.9(3) pm, β = 95.30(2)°, R_all = 0.0214) and LiEr₂F₃(SO₄)₂ with the orthorhombic crystal system (Pbcn, a = 1479.1(2), b = 633.6(1), c = 813.7(1) pm, R_all = 0.0229). A common feature of both structures is a dimeric unit of metal atoms connected via three fluoride ions. This leads to relatively short metal‐metal distances (La³⁺–La³⁺: 389 pm, Er³⁺–Er³⁺: 355 pm). In LiLa₂F₃(SO₄)₂, Li⁺ is surrounded by four oxygen atoms of four sulfate groups and one fluoride ion in form of a trigonal bipyramid, in LiEr₂F₃(SO₄)₂ two further fluoride ligands are attached.     

Tieftemperatur‐Oxidation in flüssigem Ammoniak: [Eu2(Ind)4(NH3)6], das erste Indolat eines Selten‐Erd‐Elementes

Low‐Temperature Oxidation in Liquid Ammonia: [Eu₂(Ind)₄(NH₃)₆], the First Indolate of a Rare Earth Element Intensively yellow to orange coloured, transparent crystals of [Eu₂(Ind)₄(NH₃)₆] were obtained by low‐temperature oxidation of europium metal with indole (C₈H₆NH) in liquid ammonia at —50 °C and subsequent melting of the reaction mixture in excess indole at 120 °C. [Eu₂(Ind)₄(NH₃)₆] has a dimeric structure and contains divalent Eu. The coordination sphere around the europium atoms consists of five N atoms of two cisoid indolate anions and three NH₃ molecules as well as an η⁵‐coordinating π‐system of another indolate ligand, bridging to the next Eu atom with an sp²‐orbital.     

Synthese und Kristallstruktur von NaPr2F3(SO4)2

Synthesis and Crystal Strucure of NaPr₂F₃(SO₄)₂ Light green single crystals of NaPr₂F₃(SO₄)₂ have been obtained by the reaction of Pr₂(SO₄)₃ and NaF in sealed gold ampoules at 1050 °C. In the crystal structure (monoclinic, I2/a, Z = 4, a = 822.3(1), b = 692.12(7), c = 1419.9(2) pm, β = 95.88(2)°) Pr³⁺ is coordinated by four F^– ions and six oxygen atoms which belong to five SO₄^– ions. Thus, one of the latter acts as a bidentate ligand. The [PrO₆F₄] units are connected via three common fluoride ions to pairs with a Pr–Pr distance of 386 pm. Na⁺ is sevenfold coordinated by three fluorine and four oxygen atoms.     

Synthese von Y2O2(CN2) und Leuchtstoffeigenschaften von Y2O2(CN2):Eu

Synthesis of Y₂O₂(CN₂) and Luminescence Properties of Y₂O₂(CN₂):Eu Crystalline powders of the new compound Y₂O₂(CN₂) were prepared by solid state reactions from different mixtures of YCl₃/YOCl/Y₂O₃ and Li₂(CN₂) at temperatures between 620 °C and 650 °C. Structure refinements based on X‐ray powder diffraction revealed that trigonal Y₂O₂(CN₂) crystallizes with a structure that is closely related to that of Y₂O₂S, whereas linear N‐C‐N units replace sulphur atoms in Y₂O₂S. In addition, a hexagonal polytype of Y₂O₂(CN₂) was obtained in which a different stacking sequence of yttrium atoms creates a doubling of the c‐axis. Europium‐doped samples of Y₂O₂(CN₂) were prepared and the luminescence properties of Y₂O₂(CN₂):Eu are presented.     

Pr30Ti24I8O25Se58: Eine hochsymmetrische Struktur mit isolierten [Ti6(O)Se8]‐Clustereinheiten

Pr₃₀Ti₂₄I₈O₂₅Se₅₈: A Highly Symmetric Structure with Isolated [Ti₆(O)Se₈]‐Cluster Units Black crystals of Pr₃₀Ti₂₄I₈O₂₅Se₅₈ have been prepared by the reaction of Pr₂Se₃, Pr₂O₂Se, TiSe_2–x, and I₂ at 900 °C. Its crystal structure can be described as a variation of the NaCl structure type (space group Fm 3 m, a = 2319.91(15) pm, Z = 4). The compound contains the first example of a [Ti₆(O)Se₈] cluster. These clusters form a cubic close packing, where the octahedral and tetrahedral holes are occupied by “superoctahedral” and “supertetrahedral” building units, respectively.     

Cluster self-organization of germanate systems: Suprapolyhedral precursor nanoclusters and self-assembly of CAN-Na8(Al6Ge6O24)Ge(OH)6(H2O)2 and CAN-Cs2Na6(Al6Ge6O24)Ge(OH)6) zeolite crystal structures re]20100419

Geometrical and topological analysis of zeolite crystal structures having a tetrahedral framework of the cancrinite (CAN) type, namely, (CAN) Na₈(Al₆Ge₆O₂₄)Ge(OH)₆(H₂O)₂ (acentric space group P6₃, hP64, Na-CAN) and Cs₂Na₆(Al₆Ge₆O₂₄)Ge(OH)₆ (P6₃, hP52, CsNa-CAN), is carried out with the use of computer techniques (the TOPOS 4.0 program package). An AT ₆ hexapolyhedral precursor nanocluster centered with a template cation A (Na, Cs) is identified. The topological type of a two-dimensional (2D) crystalforming T-net 4.6.12, which corresponds to a uninodal semiregular Shubnikov net, is recognized. The full 3D reconstruction of crystal structure self-assembly is performed as follows: precursor nanocluster → primary chain → microlayer → microframework → … framework. The symmetry of an AT6 precursor nanocluster is described by point group 3; the symmetry axis passes through the center of the nanocluster and cation A. The coordination number (CN) of a precursor nanocluster, which characterizes the nanocluster stacking in the macrostructure, is six. In both structures, six Na atoms and a Ge(OH)₆ polyhedral species are spacers filling the voids between AT ₆ precursor nanoclusters. The Ge(OH)₆ polyhedral species is characterized by four and two orientationally allowed positions in Na-CAN and CsNa-CAN, respectively. The minimal number of suprapolyhedral AT ₆ precursor nanoclusters required for the 3D microframework to form is 16; that is, 96 tetrahedra are involved in microframework self-assembly.     

Li2EuSiO4, ein Europium(II)-dilithosilicat: Eu[(Li2Si)O4]

Li₂EuSiO₄, an Europium(II) Litho-Silicate: Eu[(Li₂Si)O₄] Single crystals of Li₂EuSiO₄ were first obtained by reaction of Eu₂SiO₄ with a melt of LiCl at 800 °C in a sealed tantalum tube. It crystallizes with the trigonal space group P3₁21, Z = 3, with a = 502.70(5), c = 1247.0(2) pm. The tetrahedra [LiO₄] and [SiO₄] are connected via common corners and thereby build up a three-dimensional network that leaves space for Eu²⁺ which is in an eightfold coordination. Li₂SrSiO₄ is isotypic with a = 502.59(4) and c = 1247.1(1) pm.     

Das Chloridnitrat PrCl2(NO3) · 5 H2O mit kationischen und anionischen Komplexen gemäß [PrCl2(H2O)6][PrCl2(NO3)2(H2O)4]

The Chloride Nitrate PrCl₂(NO₃) · 5 H₂O with Cationic and Anionic Complexes according to [PrCl₂(H₂O)₆][PrCl₂(NO₃)₂(H₂O)₄] Green single crystals of PrCl₂(NO₃) · 5 H₂O have been obtained from an aqueous solution of PrCl₃ and Pr(NO₃)₃. The crystal structure [monoclinic, P2/c, Z = 4, a = 1228.8(3), b = 648.4(1), c = 1266.0(4) pm, β = 91.91(3)°] contains cationic and anionic Pr³⁺ complexes according to [PrCl₂(H₂O)₆][PrCl₂(NO₃)₂(H₂O)₄]. Both nitrate groups of the anionic complex act as bidentate chelating ligands. Hydrogen bonds are observed with water molecules as donors and chlorine as well as oxygen atoms as acceptors.     

Eu(ClO4)3: First Single Crystals of an Anhydrous Rare‐Earth Perchlorate

Single crystals of Eu(ClO₄)₃ have been obtained by slow dehydration of a hydrous product prepared by the reaction of Eu₂O₃ with HClO₄. The crystal structure (hexagonal, P6₃/m, Z = 2, a = 924.96(9), c = 574.86(8) pm) consists of tricapped trigonal [EuO₉] prisms and [ClO₄] tetrahedra. One of the oxygen atoms in the ClO₄ group does not coordinate to Eu³⁺ and points towards the empty channel which runs in the direction [001].     

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.     

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.     

Two New Benzoate‐di(methylcyclopentadienyl)ytterbium(III) Complexes: [Yb(MeCp)2(O2CC6F5)]2 and [Yb(MeCp)2(O2C‐o‐HC6F4)]2

Transparent orange crystals of [Yb(MeCp)₂(O₂CC₆F₅)]₂ and [Yb(MeCp)₂(O₂C‐o‐HC₆F₄)]₂ were obtained by oxidation of Yb(MeCp)₂ with M(O₂CR) (M = ¹/₂ Hg, Tl; R = C₆F₅, o‐HC₆F₄) in tetrahydrofuran. They have a dimeric structure with bridging bidentate (O, O')‐benzoate groups and eight coordinated ytterbium. Both crystallise isotypic in the orthorhombic space group Pbca. Room temperature as well as low temperature single crystal X‐ray investigations show the o‐H/F positions in [Yb(MeCp)₂(O₂C‐o‐HC₆F₄)]₂ not to be ordered.     

On the proton-acceptor properties of [TeMo6O24]6− in Na4(NH4)2[TeMo6O24] · 16H2O

Colourless triclinic single crystals of Na₄(NH₄)₂[TeMo₆O₂₄] · 16H₂O were grown in aqueous solution (space group P1 , a = 1 075.3(1), b = 1 074.2(1), c = 1 089.8(1) pm, = 96.259(9), β = 118.556(7), γ = 113.355(8)°, Z = 1, 295 K, 311 parameters, 3 689 reflections, R_g = 0.0197). There are two crystallographically independent Na⁺ cations. Na(1) is coordinated octahedrally by four water molecules and two oxygen atoms of the centrosymmetric [TeMo₆O₂₄]^6? anion. Na(2) is bound to five water molecules in a considerably distorted trigonally bipyramidal fashion. These bipyramids are linked with NH₄⁺ by hydrogen bonds to yield centrosymmetric cluster cations consisting of two NH₄⁺ and two Na(H₂O)₅⁺ each. Hydrogen bonds envolving all except one (O(10)) of the oxygen atoms of the [TeMo₆O₂₄]^6? anion as almost equivalent proton acceptors regardless of their bonding mode to Te and Mo, respectively, establish further connections to NH₄⁺ and the water of crystallization.     

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.