Darstellung und Kristallstruktur von Ca5Hg3 und Sr5Cd3

Preparation and Crystal Structure of Ca₅Hg₃ and Sr₅Cd₃ Both the incongruently melting compounds, Ca₅Hg₃ and Sr₅Cd₃, have been synthesized from stoichiometric amounts of the pure elements. They crystallize with the Cr₅B₃ type of structure: space group I4/mcm, Z = 4; Ca₅Hg₃ (Sr₅Cd₃): a = 818.9(1) (871.7(1)) pm, c = 1 470.1(3) (1 660.1(3)) pm, c/a = 1.80 (1.90), R = 2.33% (2.97%). The most remarkable fragments are dumbbells X₂, which have interatomic distances only slightly longer than the sum of Pauling's covalent radii: Hg? Hg (Cd? Cd) = 306 (298) pm. The structure can be constructed by rhombic dodecahedra as the only constituent moieties. These rhombic dodecahedra are built up by eight Ca (Sr) atoms and six Hg (Cd) atoms and are furthermore centered by an additional Ca (Sr) atom. Along [001] the rhombic dodecahedra share common vertices, but along [110] they are interconnected via common triangular faces. This kind of face sharing is responsible for the short distances obtained between the polyhedra, which leads to the occurrence of the dumbbells mentioned above.     

Hydrothermal Synthesis and Crystal Structure of AgVMO5 (M = Se,Te)

Single crystals of AgVSeO₅ and AgVTeO₅ were obtained under hydrothermal conditions at 190 °C by reacting stoichiometric amounts of AgNO₃, NaVO₃, TeO₂ and SeO₂, respectively. AgVSeO₅ crystallizes in Pbcm with a = 418.14(3) pm, b = 2007.70(6) pm, c = 521.17(2) pm, V = 437.52(2) × 10⁶ pm³ and Z = 4, as red needles. The structure consists of VO₅ square pyramids, trigonal SeO₃ pyramids and AgO₈ polyhedra, as primary building units. The VO₅ square pyramids are linked to chains running along the c‐axis, by sharing oxygen atoms in the basal plane in cis‐position. The remaining basal O atoms of the VO₅ moieties are shared with two oxygen atoms of the SeO₃ units. The resulting polyanionic strands of composition [VSeO₅]^? are interconnected by silver atoms to form a three dimensional network. AgVTeO₅ crystallizes as yellow needles in P2₁/c with a = 586.59(1) pm, b = 1137.98(2) pm, c = 680.78(1) pm, β = 102.733(1)°, V = 443.26(1) × 10⁶ pm³ and Z = 4. The structure consists of VO₄ tetrahedra, Ψ‐trigonal‐bipyramidal TeO₄ units and AgO₈ polyhedra as primary building units. The TeO₄ groups form dimers by edge sharing, which are linked through vertices to the VO₄ tetrahedra. The resulting one dimensional polyanion is extending along [101]. The structural motifs and charge distribution according to Se⁴⁺/V⁵⁺, and Te⁴⁺/V⁵⁺ respectively, seem to allow for a reshuffling of the charge distribution, thus inducing interesting physical phenomena, at elevated temperatures or pressures.     

Zur Struktur der basischen Diquecksilber(I)-nitrate. II. Kristallstruktur des Hg10(OH)4(NO3)6

Crystal Structure of the Basic Dimercury(I) Nitrates. II. Crystal Structure of Hg₁₀(OH)₄(NO₃)₆ . The crystal structure of Hg₁₀(OH)₄(NO₃)₆ has been determined from single crystal x-ray diffraction data. The unit cell is triclinic, space group P1 , a = 999.4(5), b = 909.9(5), c = 765.9(2) pm, α = 85.98(4), β = 78.70(3), γ = 109.83(5)°; Z = 1, R = 6.2%, R_w = 8.2%. Finite cationic chains [(Hg₂)₅(OH)₄(NO₃)₂]⁴⁺ are joined together by weak van der Waals-type interactions between neighbouring Hg and O atoms, thus forming ribbons running along [100]. The coordination sphere of the Hg atoms is completed by further nitrate ions, which lead to the formation of a loose framework. Thereby the metal atoms are not surrounded by simple coordination polyhedra.     

Synthesis and Crystal Structure of Rubidium Lanthanum Tetraacetate,RbLa(CH3COO)4

The anhydrous rubidium tetraacetato lanthanate, RbLa(CH₃COO)₄, is obtained together with Rb₂La(CH₃COO)₅(H₂O) as colourless single crystals from a 1 : 2 mixture of Rb₂CO₃ and La(CH₃COO) · 1.5 H₂O in acetic acid by slow evaporation. The crystal structure [orthorhombic, Pnnm, Z = 2, a = 1242.0(3), b = 1650.1(4), c = 698.0(4) pm, R = 0.028, R_w = 0.071] contains La³⁺ nine coordinate by oxygen atoms of six acetate ligands. The polyhedra are connected to dimers and further to double chains running parallel to [001]. These [La(CH₃COO)₄]^– double chains are surrounded by four like double chains and connected by Rb⁺ ions that are seven coordinate by oxygen atoms.     

Über Komplexe Fluoride des zweiwertigen Palladiums

On Complex Fluorides of Divalent Palladium For the first time single crystals of the new compounds RbPdPdF₅, KPdPdF₅, and K₂CsPdF₅ have been obtained. Orange brown RbPdPdF₅ crystallizes orthorhombic, space group Imma–D_2h²⁸ (No. 74) with a = 633.6(1) pm, b = 765.5.(1) pm, c = 1067.5(1) pm and Z = 4 and is isotypic with CsPdPdF₅ [1]. Structure related KPdPdF₅ (also orange brown) crystallizes orthorhombic too, but in space group Pnma–D_2h¹⁶ (No. 62) with a 614.12(9) pm, b = 748.7(1) pm, c = 1065.0(2) pm and Z = 4. K₂CsPdF₅, light yellow, crystallizes tetragonal with a = 736.3(1) pm, c = 628.0(1) pm, Z = 2, and is isotypic with Rb₂CsPdF₅ (space group P4/mbm? D_4h⁵ Nr. 127), an ordered structure variant of the Rb₃PdF₅-Type [1].     

Polykationische Hg‐Pnictid‐Gerüste mit einer neuen Füllungsvariante in den Strukturen von Hg3As2TlCl3 und Hg3Sb2TlBr3

Polycationic Hg‐Pnictide Frameworks with a Novel Kind of Filling in the Structures of Hg₃As₂TlCl₃ and Hg₃Sb₂TlBr₃ Hg₃As₂TlCl₃ and Hg₃Sb₂TlBr₃ were prepared from mixtures of Hg₂X₂, HgX₂ (X = Cl, Br), As or Sb and Tl in sealed evacuated glass ampoules in temperature gradients 330 °C → 290 °C for Hg₃As₂TlCl₃ (red, transparent crystals) and 290 °C → 260 °C for Hg₃Sb₂TlBr₃ (black crystals). The structures of the diamagnetic compounds were determined based on single crystal X‐ray diffraction data. Both compounds crystallize isotypically in the orthorhombic space group Pbcm with Z = 4 and the lattice constants a = 629.2(5) pm, b = 1234.1(7) pm and c = 1224.8(9) pm for Hg₃As₂TlCl₃ and a = 661.0(4) pm, b = 1311.2(9) pm and c = 1307.1(2) pm for Hg₃Sb₂TlBr₃. The structures can be described either as a cubic closest packing of As₂/Sb₂ dumb‐bells and halide anions with all octahedral interstices filled with Hg²⁺ and Tl⁺, or as a polycationic framework (Hg₃Y₂)²⁺ (Y = As, Sb) consisting of pnictide‐pnictide dumbbells each connected by six Hg atoms to a three dimensional porous arrangement. The centers of the cavities are occupied by Tl⁺ ions which are coordinated by six halide ions in distorted octahedral form. These TlX₆ octahedra share corners in all directions in the motive of the ReO₃ structure type. This new structure type shows a close relationship to the cubic family of compounds of the general formula (Hg₆Y₄)[MX₆]X (Y = As, Sb; M = Mo, Ti, Bi, Sb; X = Cl, Br). The halide ions are connected to the Hg atoms of the polycationic network and to the Tl⁺ ions. Extended Hueckel calculations were used to explain the bonding character of the thallium–halide and mercury–halide bonds.     

Synthese,Kristallstrukturen und Magnetismus von (Hg6As4)[MoCl6]Cl, (Hg6As4)[TiCl6]Cl und (Hg6As4)[TiBr6]Br

Polycationic Hg–As Frameworks with Trapped Anions. II Synthesis, Crystal Structure, and Magnetism of (Hg₆As₄)[MoCl₆]Cl, (Hg₆As₄)[TiCl₆]Cl, and (Hg₆As₄)[TiBr₆]Br (Hg₆As₄)[MoCl₆]Cl is obtained by reaction of Hg₂Cl₂, Hg, As, and MoCl₄ in closed, evacuated glass ampoules in a temperature gradient 450 → 400 °C in form of dark red cubelike crystals. (Hg₆As₄)[TiCl₆]Cl and (Hg₆As₄)[TiBr₆]Br are also formed in closed, evacuated ampoules from Hg₂X₂ (X = Cl, Br), Hg, As, and Ti metal at 275 °C and 245 °C in form of dark green and black crystals, respectively. All three compounds are air and light sensitive. They crystallize isotypically (cubic, Pa 3, a = 1207.8(4) pm for (Hg₆As₄)[MoCl₆]Cl, a = 1209.4(3) pm for (Hg₆As₄)[TiCl₆]Cl, a = 1230.9(3) pm for (Hg₆As₄)[TiBr₆]Br, Z = 4). The structures consist of a three‐dimensionally connected Hg–As framework which is made up of As₂ groups (As–As distance averaged 242 pm) each connected via six Hg atoms to six neighbouring As₂ groups. There are two cavities of different size in the polycationic framework. The bigger cavity is filled with [MoCl₆]^3–, [TiCl₆]^3–, and [TiBr₆]^3– ions of nearly ideal octahedral shape, the smaller cavity with discrete halide ions. The magnetic properties of the two Ti containing compounds are in accordance with a d¹ paramagnetism. The temperature dependence and the magnitude of the magnetic moment can be interpreted with consideration of the spin‐orbit coupling. The so far known representatives of this structure type can be characterised by the ionic formula (Hg₆Y₄)⁴⁺[MX₆]^3–X^– (Y = As, Sb; M = Sb³⁺, Bi³⁺, Mo³⁺, Ti³⁺; X = Cl, Br).     

Ein neuer Zugang zu Alkalivanadaten(IV,V) Die Kristallstruktur von Rb2V3O8

A New Access to Alkali Vanadates(IV,V) Crystal Structure of Rb₂V₃O₈ By heating vanadium(V) oxide with rubidium iodide to 500°C, the vanadium experiences partial reduction and Rb₂V₃O₈ is obtained. It has the fresnoite structure. Crystal data: a = 892.29(7), c = 554.49(9) pm at 20°C, tetragonal, space group P4bm, Z = 2. X-ray crystal structure determination with 620 observed reflexions, R = 0.027. V₂O₇ units share vertices with VO₅ square pyramids, forming layers; a layer can be regarded as association product of VO²⁺ and V₂O₇^4? ions. The Rb⁺ ions between the layers have pentagonal-antiprismatic coordination.     

Darstellung von Organylquecksilber(II)‐di(methansulfonyl)amiden und Kristallstruktur von Ph–Hg–N(SO2Me)2

Polysulfonylamines. CXXIV. Preparation of Organylmercury(II) Di(methanesulfonyl)amides and Crystal Structure of Ph–Hg–N(SO₂Me)₂ Four N,N‐disulfonylated organylmercury(II) amides R–Hg–N(SO₂Me)₂, where R is Me, ⁱPr, Me₃SiCH₂ or Ph, were obtained on treating the appropriate chlorides RHgCl with AgN(SO₂Me)₂, and characterized by ¹H and ¹³C NMR spectra. In the crystal structure of the phenyl compound (orthorhombic, space group Pbca, Z = 8, X‐ray diffraction at –95 °C), the molecule exhibits a covalent and significantly bent C–Hg–N grouping [bond angle 172.7(3)°; Hg–C 204.0(8), Hg–N 209.1(7) pm]. One sulfonyl oxygen atom forms a short intramolecular Hg…O contact [296.1(5) pm] and simultaneously catenates glide‐plane related molecules via a second Hg…O interaction 297.6(5) pm], thus conferring upon Hg^II the effective coordination number 4 and a geometrically irregular coordination polyhedron (bond angles from 173 to 54°).     

The crystal structures of two Mercury Perrhenates

The mercury perrhenates with the empirical formulas HgReO₄ and Hg₂ReO₅ were prepared by annealing powdered mixtures of mercury(II)oxide and mercury(II)metaperrhenate Hg(ReO₄)₂ in sealed silica tubes. Their crystal structures were determined from single-crystal X-ray data. HgReO₄ crystallizes dimeric with nearly linear O₃Re? O? Hg? Hg? O? ReO₃ molecular units and Hg₂ReO₅ has a solid state structure, where Hg(I) and Hg(II) together with oxygen atoms form 14-membered rings, which are condensed to two-dimensionally infinite polycationic nets of composition (Hg₂²⁺ · 2 HgO)_n. These nets are separated from each other by tetrahedral ReO₄^? anions.     

Zur Struktur der basischen Diquecksilber(I)-nitrate. I kristallstruktur des Hg2OH(NO3) · Hg2(NO3)2

The Crystal Structure of the Basic Dimercury (I) Nitrates. I. The Crystal Structure of Hg₂OH(NO₃) · Hg₂(NO₃)₂ The unit cell of Hg₂OH(NO₃) · Hg₂(NO₃)₂ is orthorhombic, space group Cc2a - standard setting Aba2 (C) — with a = 2017.1(5) pm, b = 935.8(3) pm, c = 1121.7(3) pm and contains 8 formula units. Characteristic are chains [Hg₂OH(Hg₂)_2/2]³⁺ parallel [001]. These are interconnected to a three-dimensional network by nitrate ions coordinated to mercury. The structure achieves additional stabilization through weak hydrogen bonds between oxygen atoms of the hydroxy groups and neighbouring nitrate ions. The bonding relationship of one hydrogen atom to four tetrahedrally correlated oxygen atoms is discussed.     

The Monohydrate of Basic Mercuric Nitrate, [Hg(OH)](NO3)(H2O)

Colourless single crystals of [Hg(OH)](NO₃)(H₂O) were obtained by slow evaporation of an aqueous solution of Hg(NO₃)₂ and Bi(NO₃)₃. The crystal structure (orthorhombic, Pbca, Z = 8, a = 943.2(2), b = 697.6(1), c = 1349.0(2) pm, R₁(all) = 0.0780) contains [Hg(OH)] = …OH–Hg–OH–Hg… zig zag chains (O–Hg–O angle: 168°, Hg–O–Hg angle: 112°, Hg–OH distance: 212 pm) to which one water molecule is attached loosely. The [Hg(OH)](H₂O) chains are connected via bis‐monodentate‐bridging nitrate ions to corrugated layers that are stacked in the [001] direction. Hg²⁺ has an effective 2+2+2(+1) coordination.     

Polysulfonylamine. XXXVII. Darstellung von Quecksilberdimesylamiden. Kristall- und Molekülstrukturen von Hg[N(SO2CH3)2]2, Hg[{N(SO2CH3)2}2(DMSO)2] und Hg[{N(SO2CH3)2}2(HMPA)]

Polysulfonyl Amines. XXXVII. Preparation of Mercury Dimesylamides. Crystal and Molecular Structures of Hg[N(SO₂CH₃)₂]₂, Hg[{N(SO₂CH₃)₂}₂(DMSO)₂], and Hg[{N(SO₂CH₃)₂}₂(HMPA)] Hg[N(SO₂CH₃)₂]₂ ( 1 ) and Hg₂[N(SO₂CH₃)₂]₂ ( 2 a ) are formed as colourless, sparingly soluble precipitates when solutions of Hg(NO₃)₂ or Hg₂(NO₃)₂ in dilute nitric acid are added to an aqueous HN(SO₂CH₃)₂ solution. By a similar reaction, Hg₂[N(SO₂C₆H₄ ? Cl? 4)₂]₂ is obtained. 1 forms isolable complexes of composition Hg[N(SO₂CH₃)₂]₂ · 2 L with L = dimethyl sulfoxide (complex 3 a ), acetonitrile, dimethyl formamide, pyridine or 1,10-phenanthroline and a (1/1) complex Hg[N(SO₂CH₃)₂]₂ · HMPA ( 4 ) with hexamethyl phosphoramide. Attempted complexation of 2 a with some of these ligands induced formation of Hg⁰ and the corresponding Hg^II complexes. Crystallographic data (at -95°C) are for 1: space group 14₁/a, a = 990.7(2), c = 2897.7(8) pm, V = 2.844 nm³, Z = 8, D_x = 2.545Mgm^?3; for 4a: space group P1 , a = 767.8(2), b = 859.2(2), c = 925.2(2)pm α = 68.44(2), β = 86.68(2), γ = 76.24(2)°, V = 0.551nm³, Z = 1, D_x = 2.113 Mgm^?3; for 4: space group P2₁/c, a = 1041.3(3), b = 1545.4(3), c = 1542.5(3) pm, β = 100.30(2)°, V = 2.474nm³, Z = 4, D_x = 1.944Mgm³. The three compounds form molecular crystals. The molecular structures contain a linear or approximately linear, covalent NHgN moiety; the Hg? N distances and N? Hg? N angles are 206.7(4) pm and 176.3(2)° for 1, 207.2(2) pm and 180.0° for 3a, 205.7(4)/206.7(4) pm and 170.5(1)° for 4. In the complexes 3a and 4, the 0-ligands are bonded to the Hg atoms perpendicularly to the N? Hg? N axes, leading in 3a to a square-planar trans-(N₂O₂) coordination with Hg? 0 261.2(2) pm and N? Hg? O 92.3(1)/87.7(1)°, in 4 to a slightly distorted T-shaped (N₂O) geometry with Hg? 0 246.2(4)pm and N? Hg? 0 96.7(1)/92.0(1)°. In all three structures, the primary coordination is extended to a severely distorted (N₂O₄) hexacoordination by the appropriate number of secondary, inter- and/or intramolecular Hg…?0 inter-actions (0 atoms from sulfonyl groups, Hg…?O distances in the range 280—300pm). The intramolecular Hg…?O interactions give rise to nearly planar four-membered [HgNSO] rings. The molecule of 1 has a two-fold axis through the bisector of the N? Hg? N angle, the molecule of 3a an inversion center at the Hg atom. The molecule of 4 has no symmetry.     

Präparation,Kristallstruktur und thermisches Verhalten der Quecksilber(I)phosphate α-(Hg2)3(PO4)2, β-(Hg2)3(PO4)2 und (Hg2)2P2O7

Contributions on Crystal Structures and Thermal Behaviour of Anhydrous Phosphates. XXIII. Preparation, Crystal Structure, and Thermal Behaviour of the Mercury(I) Phosphates α-(Hg₂)₃(PO₄)₂, β-(Hg₂)₃(PO₄)₂, and (Hg₂)₂P₂O₇ Light-yellow single crystals of (Hg₂)₂P₂O₇ have been obtained via chemical vapour transport in a temperature gradient (500 °C → 450 °C, 23 d) using Hg₂Cl₂ as transport agent. Characteristic feature of the crystal structure (P2/n, Z = 2, a = 9,186(1), b = 4,902(1), c = 9,484(1) Å, β = 98,82(2)°, 1228 independent of 5004 reflections, R(F) = 0,066 for 61 variables, 7 atoms in the asymmetric unit) are Hg₂²⁺-units with d(Hg1–Hg1) = 2,508 Å and d(Hg2–Hg2) = 2,519 Å. The dumbbells Hg₂²⁺ are coordinated by oxygen, thus forming polyhedra [(Hg1₂)O₄] and [(Hg2₂)O₆]. These polyhedra share some oxygen atoms. In addition they are linked by the diphosphate anion P₂O₇^4– (ecliptic conformation; ∠(P,O,P) = 129°) to built up the 3-dimensional structure. Under hydrothermal conditions (T = 400 °C) orange single crystals of the mercury(I) orthophosphates α-(Hg₂)₃(PO₄)₂ and β-(Hg₂)₃(PO₄)₂ have been obtained from (Hg₂)₂P₂O₇ and H₃PO₄ (c = 1%). The crystal structures of both modifications have been refined from X-ray single crystal data [α-form (β-form): P2₁/c (P2₁/n), Z = 2 (2), a = 8,576(3) (7,869(3)), b = 4,956(1) (8,059(3)), c = 15,436(3) (9,217(4)) Å, β = 128,16(3) (108,76(4))°, 1218 (1602) independent reflections of 4339 (6358) reflections, R(F) = 0,039 (0,048) for 74 (74) variables, 8 (8) atoms in the asymmetric unit]. In the structure of α-(Hg₂)₃(PO₄)₂ three crystallographically independent mercury atoms, located in two independent dumbbells, are coordinated by three oxygen atoms each. Thus, [(Hg₂)O₆] dimers with a strongly distorted tetrahedral coordination of all mercury atoms are formed. Such dimers are present besides [(Hg₂)O₅]-polyhedra in the less dense crystal structure of β-(Hg₂)₃(PO₄)₂ (d(Hg–Hg) = 2,518 Å). The mercury(I) phosphates are thermally labile and disproportionate between 200 °C (β-(Hg₂)₃(PO₄)₂) and 480 °C (α-(Hg₂)₃(PO₄)₂) to elemental mercury and the corresponding mercury(II) phosphate.     

Über Fluoride des einwertigen und des zweiwertigen Quecksilbers

On Fluorides of Univalent and Divalent Mercury For the first time Rb₂HgF₄ and Cs₂HgF₄, both colourless, have been obtained. From single crystal investigations they crystallize tetragonal in the K₂NiF₄-type of structure, space group I4/mrnm-D_4h¹⁷ (No. 139) with a = 455.6 pm, c = 1375.7 pm, Z = 2 for Rb₂HgF₄ and a = 462.5 pm, c = 1451.8 pm, Z = 2 for Cs₂HgF₄. The determination of the crystal structure of Hg₂F₂ confirmed the unit cell [1] with a = 367.00(4) pm, c = 1090.1(2) pm, Z = 2 space group I4/mrnm-D_4h¹⁷ (No. 139).     

Preparation,Single Crystal Structure Analysis,and Thermal Behaviour of the Acidic Mercury(I) Phosphate (Hg2)2(H2PO4)(PO4)

Yellowish single crystals of acidic mercury(I) phosphate (Hg₂)₂(H₂PO₄)(PO₄) were obtained at 200 °C under hydrothermal conditions in 32% HF from a starting complex of microcrystalline (Hg₂)₂P₂O₇. Refinement of single crystal data converged at a conventional residual R[F² > 2σ(F²)] = 3.8% (C2/c, Z = 8, a = 9.597(2) Å, b = 12.673(2) Å, c = 7.976(1) Å, β = 110.91(1)°, V = 906.2(2) ų, 1426 independent reflections > 2σ out of 4147 reflections, 66 variables). The crystal structure consists of Hg₂²⁺‐dumbbells and discrete phosphate groups H₂PO₄^– and PO₄^3–. The Hg₂²⁺ pairs are built of two crystallographically independent Hg atoms with a distance d(Hg1–Hg2) = 2.5240(6) Å. The oxygen coordination sphere around the mercury atoms is asymmetric with three O atoms for Hg1 and four O atoms for Hg2. The oxygen atoms belong to the different PO₄ tetrahedra, which in case of H₂PO₄‐groups are connected by hydrogen bonding. Upon heating over 230 °C, (Hg₂)₂(H₂PO₄)(PO₄) condenses to (Hg₂)₂P₂O₇, which in turn disproportionates at higher temperatures into Hg₂P₂O₇ and elemental mercury.     

PrSeTe2, ein geordnetes ternäres Polychalkogenid mit NdTe3‐Struktur

PrSeTe₂, an Ordered Ternary Polychalcogenid with NdTe₃ Structure Single crystals of PrSeTe₂ have been obtained by reaction of the elements in a LiCl/RbCl flux at 970 K during 7 days. PrSeTe₂ crystallizes in space group Cmcm (No. 63), with four formula units per unit cell. The lattice constants are a = 426.1(1) pm, b = 2506.0(5) pm, and c = 426.0(1) pm. The crystal structure is an ordered ternary variant of the NdTe₃ type. It consists of a puckered double layer of praseodymium and selenium atoms [PrSe] sand wiched by two square planar layers of tellurium atoms [Te] yielding a stacking —[Te]—[Te]—[PrSe]— along [010]. The Te atoms build regular 4⁴ nets with Te—Te distances of 301, 3(1) pm. DFT calculations propose that this compounds should be metallic mainly due to contributions of the Pr f‐electrons. The band structure shows no significance for a distortion in the [Te]—nets.     

Rb6LiPr11Cl16[SeO3]12: Ein chloridisch derivatisiertes Rubidium‐Lithium‐Praseodym(III)‐Oxoselenat(IV)

Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂: A Chloride‐Derivatized Rubidium Lithium Praseodymium(III) Oxoselenate(IV) Transparent green square platelets with often truncated edges and corners of Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂ were obtained by the reaction of elemental praseodymium, praseodymium(III,IV) oxide and selenium dioxide with an eutectic LiCl–RbCl flux at 500 °C in evacuated silica ampoules. A single crystal of the moisture and air insensitive compound was characterized by X‐ray diffraction single‐crystal structure analysis. Rb₆LiPr₁₁Cl₁₆[SeO₃]₁₂ crystallizes tetragonally in the space group I4/mcm (no. 140; a = 1590.58(6) pm, c = 2478.97(9) pm, c/a = 1.559; Z = 4). The crystal structure is characterized by two types of layers parallel to the (001) plane following the sequence 121′2′1. Cl^? anions form cubes around the Rb⁺ cations (Rb1 and Rb2; CN = 8; d(Rb⁺?Cl^?) = 331 – 366 pm) within the first layer. One quarter of the possible places for Rb⁺ cations within this CsCl‐type kind of arrangement is not occupied, however the Cl^? anions of these vacancies are connected to Pr³⁺ cations (Pr4) above and below instead, forming square antiprisms of [(Pr4)O₄Cl₄]^9? units (d(Pr4?O) = 247–249 pm; d(Pr4?Cl) = 284–297 pm) that work as links between layer 1 and 2. Central cations of the second layer consist of Li⁺ and Pr³⁺. While the Li⁺ cations are surrounded by eight O^2? anions (d(Li?O5) = 251 pm) in the shape of cubes again, the Pr³⁺ cations are likewisely coordinated by eight O^2? anions as square antiprisms (for Pr1, d(Pr1?O2) = 242 pm) and by ten O^2? anions (for Pr2 and Pr3), respectively. The latter form tetracapped trigonal antiprisms (Pr2, d(Pr2?O) = 251–253 pm and 4 × 262 pm) or bicapped distorted cubes (Pr3, d(Pr3?O) = 245–259 pm and 2 × 279 pm). The non‐binding electron pairs (“lone pairs”) at the two crystallographically different Ψ¹‐tetrahedral [SeO₃]^2? anions (d(Se⁴⁺?O^2?) = 169–173 pm) are directing towards the empty cavities between the layer‐connecting [(Pr4)O₄Cl₄]^9? units.     

Darstellung,spektroskopische Charakterisierung und Kristallstrukturen von Quecksilber(II)‐bis(tetracyanoborat) Hg[B(CN)4]2 und Diquecksilber(I)‐bis(tetracyanoborat) Hg2[B(CN)4]2

Preparation, Spectroscopic Characterization and Crystal Structures of Mercury(II)‐bis(tetracyanoborate) Hg[B(CN)₄]₂ and Dimercury(I)‐bis(tetracyanoborate) Hg₂[B(CN)₄]₂ Hg[B(CN)₄]₂ ( 1 ) is synthesised by the reaction between Hg(NO₃)₂ and K[B(CN)₄]₂. In a comproportionation reaction of 1 with elemental mercury the corresponding mercury(I) salt Hg₂[B(CN)₄]₂ ( 2 ) is obtained. The compounds were characterised by vibrational‐ and NMR‐spectroscopy, and their crystal structures were determined. Hg[B(CN)₄]₂ crystallizes in the trigonal system in the space group P3¯m1 with a = 781.75(3) pm, c = 601.68(2) pm, V = 318.44(2)ų, and one formula unit per unit cell. For Hg₂[B(CN)₄]₂ an orthorhombic unit cell with a = 568.9(1) pm, b = 3280.9(7) pm, c = 601.68(2) pm, V = 1389.6(5)Å, and Z = 4 is observed.