Die Kristallstruktur von Ph3PNBr · Br2

Crystal Structure of Ph₃PNBr · Br₂ Ph₃PNBr · Br₂ ( 1 ) has been prepared besides of other products from the reaction of Ph₃PNH with bromine, forming orange‐yellow single crystals which are characterized by IR‐spectroscopy and by a crystal structure determination. Space group P2₁/n, Z = 4, lattice dimensions at 20 °C: a = 916.76(10), b = 1351.42(8), c = 1494.9(2) pm, β = 96.191(5)°, R₁ = 0.0538. 1 has a molecular structure in which the Br₂ molecule is coordinated at the nitrogen atom of the N‐bromine‐phosphoraneimine Ph₃PNBr in a linear arrangement N–Br–Br with bond lengths N–Br of 224.5(6) pm and Br–Br of 248.4(1) pm. The nitrogen atom of 1 is ψ‐tetrahedrally coordinated in addition by the phosphorus atom with a P–N distance of 165.3(6) pm and by the covalently bonded bromine atom with a bond length of 188.9(6) pm.     

Die Kristallstruktur von (PPh4)2[Mo2(O2C?Ph)4Br2] · 2 CH2Br2

Crystal Structure of (PPh₄)₂[Mo₂(O₂C? Ph)₄Br₂] · 2 CH₂Br₂ The title compound, prepared by the reaction of Mo₂(O₂C? Ph)₄ with PPh₄Br and PPh₄N₃, respectively, under the assistance of CH₂Br₂, was characterized by an X-ray structure determination. Space group P2₁/n, Z = 2, R = 0.074 (5261 independent observed reflexions). The lattice dimensions are at ?70°C: a = 1562.9, b = 1406.2, c = 1662.1 pm, β = 94.11°. the compound consists of PPh₄^⊕ ions, CH₂Br₂ molecules, and centrosymmetric anions [Mo₂(O₂C? Ph)₄Br₂]^2?. The axis Br? Mo?Mo–Br is nearly linear (bond angle 175.6°) with bond lengths MoMo = 212.3 pm and Mo? Br = 303 pm, corresponding with a weak electrostatic Mo? Br bond. In the FIR spectrum the Mobr stretching vibration is found at 85 cm^?1, which corresponds with the low value of the force constant of 0.24 N · cm^?1.     

Bi12,86Ni4Br6 und Bi12,86Ni4I6: Subhalogenide mit intermetallischen und salzartigen Schichtpaketen in alternierender Abfolge

Bi_12.86Ni₄Br₆ and Bi_12.86Ni₄I₆: Subhalides with Alternating Intermetallic and Salt‐like Layers The reaction of bismuth and nickel with bromine or iodine at 730 K yields black, air insensitive, needle shaped crystals of the ternary subhalides Bi_12.86Ni₄X₆ (X = Br, I). The isotypic compounds crystallize in the orthorhombic space groups Immm with a = 405.69(6) pm, b = 874.00(8) pm, c = 3744.7(4) pm for X = Br, and a = 410.05(5) pm, b = 912.84(7) pm, c = 3826.7(3) pm for X = I. The crystal structures contain characteristic fragments of the intermetallic phase Bi₃Ni: chains consisting of face‐sharing mono‐capped trigonal prisms of bismuth atoms with a nickel atom in the center of each prism. The chains form corrugated layers which are separated by halogen atoms and oligomeric [Bi_nX_4n+2] units of varying length. The halogenobismutate(III) units consist of trans‐edge‐sharing [BiX₆] octahedra. They are disordered within the crystal structures. The non‐integer stoichiometric coefficients of Bi_12.86Ni₄X₆ are due to the metric adjustment between the ionic and intermetallic parts of the structure. Extended Hückel calculations indicate, that the partial oxidation of the intermetallic phase causes a strengthening of the chemical bonding within the Bi₃Ni chains. The subiodide Bi_12.86Ni₄I₆ is paramagnetic and shows ferromagnetic ordering below 25 K.     

Die Gadoliniumcarbidhalogenide Gd4C2X3 (X = Cl,Br)

The Gadolinium Carbide Halides, Gd₄C₂X₃ (X = Cl, Br) The compounds Gd₄C₂X₃ (X = Cl, Br) and Tb₄C₂Br₃ have been prepared by reaction of the metals (RE), REX₃, and C in sealed Ta capsules at 1 100° and 1 300°C, respectively. Monophasic samples of Gd₄C₂Br₃ and Tb₄C₂Br₃ were obtained by reacting stoichiometric mixtures of the starting materials for five days. The needle shaped crystals are bronze-coloured and sensitive to air and moisture. Gd₄C₂X₃ crystallizes in the space group Pnma (No. 62) with lattice constants a = 1 059.6(4), b = 368.4(1), c = 1 962.7(8) pm (Gd₄C₂Cl₃), a = 1 084.4(1), b = 373.0(1), c = 2 036.1(1) pm (Gd₄C₂Br₃). According to Guinier photographs, Tb₄C₂Br₃ is isotypic (a = 1 074.3(2), b = 370.6(1), c = 2 019.4(1) pm). In the crystal structure C is octahedrally coordinated by Gd. The Gd₆ octahedra are linked via common edges to form corrugated layers. The X-anions coordinate all free edges and corners of these layers and connect them via Xⁱ? Xⁱ contacts parallel [001]. Gd₄C₂Br₃ shows metallic conductivity. The magnetic susceptibility follows at high temperatures a Curie Weiss law with an effective moment of 7.95 μ_B. At temperatures below 50 K antiferromagnetic order is observed.     

Gd2IFe2 und Y2Br2Fe2+x: Übergänge zwischen Clusterverbindungen und intermetallischen Phasen

Gd₂IFe₂ and Y₂Br₂Fe_2+x: Intermediates between Cluster Compounds and Intermetallic Phases The compounds Gd₂IFe₂ and Y₂Br₂Fe_2+x were prepared for the first time. Single crystal investigations (Gd₂IFe₂: P6₃/mmc, a = 401.43(5), c = 1 718.0(2) pm; Y₂Br₂Fe_2.23: R3 m, a = 390.66(5), c = 3 402.0(7) pm) revealed trigonal prisms of rare-earth metal atoms centered by Fe atoms and condensed into layers. These intermetallic slices are separated by one (Gd₂IFe₂) or two (Y₂Br₂Fe_2+x) layers of halide atoms. The range of homogeneity of Y₂Br₂Fe_2+x (0.16 ≤ x ≤ 0.23) is due to a partial occupation of the octahedral voids between the Br bilayers. Bonding was analysed via Extended-Hückel calculations. Strong metal—metal bonds occur between the interstitial Fe atoms (d_{Fe? Fe} = 232.7 pm (Gd₂IFe₂) and 226.9 pm (Y₂Br₂Fe_2.23)). Both compounds are metallic conductors. Gd₂IFe₂ orders ferrimagnetically at 280 K. In the case of Y₂Br₂Fe_2+x a magnetic phase transition is observed at 117 K.     

TiOBr; Darstellung,Eigenschaften und Struktur*

TiOBr was prepared by reaction of Ti with TiO₂ and Br₂. The compound forms fiat reddish-brown needles and shows a temperature independent weak paramagnetism. It crystallises in the orthorhombic system (Pmmn; a = 3.787, b = 3.487, c = 8.529 Å) with the FeOCl type of structure. The interatomic distances are Ti?O = 1.952; 2.245 Å (2X) and Ti?Br = 2.544 Å (2X).     

Einkristall-Röntgenstrukturanalysen an Verbindungen mit kovalenter Metall–Metall-Bindung. IV. Die Molekül- und KristallStruktur von Mn2(CO)8[μ-Sn(Br)Mn(CO)5]2

Single Crystal X-Ray Analysis of Compounds with Covalent Metal—Metal Bonds. IV. Molecular and Crystal Structure of Mn₂(CO)₈[μ-Sn(Br) Mn(CO)₅]₂ Mn₂(CO)₈[μ-Sn(Br)Mn(CO)₅]₂ crystallizes in the monoclinic crystal system (a = 881.7 pm; b = 1237.6 pm; c = 1551.1 pm und β = 63.54°) in the space group P2₁/n with two formula units in the cell. The structure was solved by means of 2601 symmetrically independent reflections using the heavy atom method. The central molecule fragment of Mn₂(CO)₈ · [μ-Sn(Br)Mn(CO)₅]₂ consists of a planar Mn₂Sn₂ rhombus with a Mn? Mn-bond (Mn? Mn = 308.6(1) pm) across the metal ring. Besides the bonds to both Mn ring atoms each Sn(IV) atom has a terminal bond to a Br and Mn(CO)₅ ligand, building up a distorted tetrahedron around the Sn(IV) atom. The terminal ligands in Mn₂(CO)₈[μ-Sn(Br)Mn(CO)₅]₂ are in transposition with respect to the ring. The mean values for the remaining bond distances are: Sn? Mn = 263.0(1) pm; Sn? Br = 255.4(1) pm; Mn? C = 184.4(6) pm; C? O = 113.3(7) pm. A comparison of the Sn₂Mn₂ ring with similar metal rings has been given.     

Silylierte Phosphanimin-Komplexe von Chrom(II), Palladium(II) und Kupfer(II). Die Kristallstrukturen von [CrCl2(Me3SiNPMe3)2], [PdCl2(Me3SiNPEt3)2] und [CuCl2(Me3SiNPMe3)]2

Silylated Phosphaneimine Complexes of Chromium(II), Palladium(II), and Copper(II). The Crystal Structures of [CrCl₂(Me₃SiNPMe₃)₂], [PdCl₂(Me₃SiNPEt₃)₂], and [CuCl₂(Me₃SiNPMe₃)]₂ The title compounds have been prepared by the reaction of the silylated phosphaneimines Me₃SiNPR₃ (R = CH₃, C₂H₅) with CrCl₂(THF)₂, PdCl₂ and CuCl₂, respectively, in dichloromethane suspensions. All donor-acceptor complexes were characterized by IR spectroscopy and by crystal structure determinations. [ CrCl₂(Me₃SiNPMe₃ )₂]: Space group Pccn, Z = 4, structure determination with 2104 observed unique reflections, R = 0.045. Lattice dimensions at ?70°C: a = 1326.3, b = 1562.5, c = 1171.5 pm. Within the monomeric molecular structure the chromium atom is planarly coordinated within the trans-configuration of the Cl atoms and the N atoms with distances of Cr? Cl = 235.94 pm and Cr? N = 211.7 pm. [ PdCl₂(Me₃SiNPEt₃)₂ ]: Space group P2₁/n, Z = 2, structure determination with 2412 observed unique reflections, R = 0.031. Lattice dimensions at 20°C: a = 917.3, b = 1390.2, c = 1161.7 pm, β = 95.80°. Within the monomeric molecular structure the palladium atom is planarly coordinated within the trans-configuration of the Cl atoms and the N atoms with distances of Pd? Cl = 222.9 pm and Pd? N = 209.5 pm. [ CuCl₂(Me₃SiNPMe₃)₂ ]: Space group Pbca, Z = 4, structure determination with 1861 observed unique reflections, R = 0.067. Lattice dimensions at ?70°C: a = 1440.2, b = 1205.1, c = 1536.5 pm. The compound forms centrosymmetric dimeric molecules, in which the Cu atoms are linked via almost symmetrical chloro-bridges with Cu? Cl distances of 231.4 pm. The distance Cu? N is 196.7 pm.     

CsNb3Br7S: Synthese,Struktur und Bindungsverhältnisse

CsNb₃Br₇S: Synthesis, Structure, and Bonding States The reaction of NbBr₅ with Nb, Cs and S in a sealed Nb container affords CsNb₃Br₇S at 800°C (3 days). Further on isotypic compounds of the general formula ANb₃X₇Ch with A = Rb, Cs; X = Cl, Br and Ch = S, Se are obtained. CsNb₃Br₇S crystallizes monoclinic (space group P2₁/a, Z = 2), with the lattice parameters a = 707.4(2), b = 1 888.4(4), c = 994.1(2) pm and β = 98.59(2)°. The crystal structure contains Nb₃ clusters being linked by two additional Nb? Nb bonds to form infinite chains. Adjacent chains are bridged by Cs atoms in a cubeoctahedral coordination sphere of Br atoms. Similar with Nb₃Br₈ seven electrons occupy metal—metal bonding states.     

Nb2Y2X6, a Novel Type of NbIV Compounds with Cross-linked Nb2 and Y2 Dumbbells (Y = Se,Te; X = Br,I)

The compounds Nb₂Se₂Br₆, Nb₂Te₂Br₆, and Nb₂Te₂I₆ were prepared from the elements in sealed quartz ampoulès at 1073 K. The crystalline solids, exhibiting a metallic lustre, are insensitive against moisture and oxygen. All compounds undergo several reversible thermal transitions with temperature (DTA). Beside binary halides only NbYX₃ is present in the gas phase. The structures consist of one-dimensional infinite chains of halogen bridged Nb₂(Y₂)X₄ units containing single side-on bonded Nb₂ and Y₂ dumbbells forming a quasi tetrahedral Nb₂Y₂ cluster (Nb? Nb ? 283.2; 287.5; 293.2 pm; Se? Se ? 230.5 pm; Te? Te ? 267.0; 268.5 pm). The structural and magnetic properties clearly prove the formal oxidation states Nb⁴⁺ and Y^1?, unexpected from stoichiometry. (Structural data: all P2/a (No. 13); Nb₂Se₂Br₆: a = 1254.0(12); b = 689.7(10); c = 662.4(10) pm; β = 98.9(1)°; Z = 2; 1274 hkl; R = 0.066. Nb₂Te₂Br₆: a = 1259.7(13); b = 713.5(9); c = 667.0(9) pm; β = 97.6(1)°; 1557 hkl; R = 0.043. Nb₂Te₂I₆: a = 1347.3(3); b = 742.9(2); c = 714.1(2) pm; β = 98.52(2)°; 1540 hkl; R = 0.026).     

The mono-, sesqui-, and dibromides of indium: InBr,In2Br3, and InBr2

Of the four reduced indium bromides, InBr, In₂Br₃, InBr₂, and In₄Br₇, synthesis, crystal growth and structure determination of the first three is reported. InBr (orthorhombic), Cmcm, Z = 4, a = 446.6(1), b = 1236.8(2), c = 473.9(1) pm, V_m = 39.42(1) cm³ mol^?1) crystallizes with the TlI-type structure. In₂Br₃ (orthorhombic, Pnma, Z = 16, a = 1300.6(5), b = 1649.8(5), c = 1289.7(9) pm, V_m = 104.16(9) cm³ mol ^?1), isotypic with Ga₂Br₃, is according to In₂[In₂Br₆] a mixed-valence In^I–In^II-bromid with eclipsed [In₂Br₆]^2? groups with d(In–In) = 268.8 and 271.6 pm, respectively. InBr₂(?In[InBr₄]) is a mixed-valence In^I? In^III bromide with the GaCl₂-type structure (orthorhombic, Pnna, Z = 8, a = 798.6(2), b = 1038.5(2), c = 1042.5(5) pm, V_m = 65.09(4) cm³ mol^?1).     

Crystal Structures of MBi2Br7 (M = Rb,Cs) – Filled Variants of AX7 Sphere Packing

The reinvestigation of the pseudo‐binary systems MBr–BiBr₃ (M = Rb, Cs) revealed two new phases with composition MBi₂Br₇. Both compounds are hygroscopic and show brilliant yellow color. The crystal structures were solved from X‐ray single crystal diffraction data. The isostructural compounds adopt a new structure type in the triclinic space group P$\bar{1}$ . The lattice parameters are a = 755.68(3) pm, b = 952.56(3) pm, c = 1044.00(4) pm, α = 76.400(2)°, β = 84.590(2)°, γ = 76.652(2)° for RbBi₂Br₇ and a = 758.71(5) pm, b = 958.23(7) pm, c = 1060.24(7) pm, α = 76.194(3)°, β = 83.844(4)°, γ = 76.338(3)° for CsBi₂Br₇. The crystal structures consist of M⁺ cations in anticuboctahedral coordination by bromide ions and bromidobismuthate(III) layers ²_∞[Bi₂Br₇]^–. The 2D layers comprise pairs of BiBr₆ octahedra sharing a common edge. The Bi₂Br₁₀ double octahedra are further connected by common vertices. The bismuth(III) atoms increase their mutual distance in the double octahedra by off‐centering so that the BiBr₆ octahedra are distorted. The CsBi₂Br₇ type can be interpreted as a common hexagonal close sphere packing of M and Br atoms, in which 1/4 of the octahedral voids are filled by Bi atoms. The structure type was systematically analyzed and compared with alternative types of common packings. The existence of a compound with the suggested composition CsBiBr₄ could not be verified experimentally.     

Darstellung von Nonahalogenodiplatinaten(IV), [Pt2X9]−, X  Cl,Br Spektroskopische Charakterisierung,Normalkoordinatenanalyse und Kristallstruktur von (PPN)[Pt2Br9]

Preparation of the Nonahalogenodiplatinates(IV), [Pt₂X₉]^?, X ? Cl, Br Spectroscopic Characterization, Normal Coordinate Analysis, and Crystal Structure of (PPN)[Pt₂Br₉] On heating the tetrabutylammonium salts (TBA)₂[PtX₆], with trifluoroacetic acid the nonahalogenodiplatinates(IV) (TBA)[Pt₂X₉], with X ? Cl, Br are formed. The X-ray structure determination on (PPN)[Pt₂Br₉] (orthorhombic, space group Pca2, Z = 4) shows for the anions pairs of face-sharing octahedra with nearly D_3h symmetry. The mean terminal and bridging Pt? Br bond lengths are determined to be 2.42 and 2.52 Å, respectively. The electrostatic interaction of the Pt atoms results in the Pt? Pt distance of 3.23 Å and an elongation as it has been forecasted by the MO scheme for d⁶ systems. Using the structural data a normal coordinate analysis based on a general valence force field for [Pt₂Br₉]^? has been performed, revealing a good agreement of the calculated frequencies with the bands observed in the IR and Raman spectra. The stronger bonding of the terminal as compared to the bridging ligands is shown by the valence force constants, f_a(Br₁) = 1,55 > f_d(Br_b) = 0,93 mdyn/ Å.     

3s-Gd2C2Br2: Eine neue Stapelvariante

3s-Gd₂C₂Br₂: An Isomorph with a New Stacking Sequence Gd₂C₂Br₂ has been described in [1]. Here we describe the new stacking variant 3s-Gd₂C₂Br₂ prepared by reaction of stoichiometric amounts of GdBr₃, Gd, and C at 1 320 K. 3s-Gd₂C₂Br₂ with a stacking sequence different to that described in [1] crystallizes in space group C2/m with lattice constants a = 706.6(2) pm, b = 382.7(1) pm, c = 996.7(4) pm and β = 99.95(3)°. In the structure C₂ units are octahedrally surrounded by Gd atoms. Such Gd₆(C₂) octahedra are condensed via edges to form sheets, which are separated by two layers of Br-ions. In contrast to the modification described previously three slabs BrGd(C₂)GdBr are stacked in [103] direction until identity is reached. The isotypic 3s-Tb₂C₂Br₂ has also been prepared at 1 370 K. It is characterized by the lattice constants a = 701.5(3) pm, b = 380.1(1) pm, c = 994.8(3) pm and β = 100.05°.     

Thiokomplexe des Molybdäns Kristallstruktur eines Mischkristalls (PPh3Me)2[Mo2Br6(NO)4]/(PPh3Me)2[Mo2Br6S2(NO)2]

Thiocomplexes of Molybdenum. Crystal Structure of a Mixed Single Crystal (PPh₃Me)₂[Mo₂Br₆(NO)₄]/(PPh₃Me)₂[Mo₂Br₆S₂(NO)₂] The reactions of (PPh₄)₂MoS₄ with MoBr₄ and MoBr₂(NO)₂ resp. lead to the binuclear complexes (PPh₄)₂[S₂MoS₂MoBr₃(SMe₂)] and (PPh₄)[S₂MoS₂MoBr₂(NO)₂], in which the molybdenum atoms are linked by sulfido bridges. The preparation of (PPh₃Me)₂S₆ and (AsPh₄)₂S₇ from Na₂S₄ and PPh₃MeBr, and AsPh₄Cl, respectively, in ethanol solution is described. Disulfido briges are a feature of (AsPh₄)₂[Mo₂Br₆(S₂)₂(SMe₂)₂], which is obtained from MoBr₄(SMe₂)₂ and (AsPh₄)₂S₇. Mixed single crystals containing 2/3 (PPh₃Me)₂[Mo₂Br₆(NO)₄] and 1/3 (PPh₃Me)₂[Mo₂Br₆S₂(NO)₂] are formed in the reaction of MoBr₂(NO)₂ with (PPh₃Me)₂S₆, as shown by X-ray single crystal structure determination. The compound crystallizes monoclinic in the space group C2/c (Internat. Tab. Nr. 15) with four formula units per unit cell (2351 independent observed reflexions, R_w = 0.037). The cell parameters are a = 1603 pm, b = 1549 pm, c = 1863 pm; β = 92.2°. The complexes consist of PPh₃Me^⊕ cations and the dimeric anions [Mo₂Br₆(NO)₄]^2? and [Mo₂Br₆S₂(NO)₂]^2? which occur in the ratio 2:1. In these the molybdenum atoms are connected via MoBr₂Mo bridges of slightly different lengths (Mo? Br 265 pm and 267 pm) forming a controsymmetric double octahedron. All molybdenum atoms have two terminal bromo ligands with Mo? Br bond lengths of 258 pm and 260 pm; in the [Mo₂Br₆(NO)₄]^2? ion each molybdenum has two covalently bonded nitrosyl groups on cis-position with Mo? N bond lengths of 183 pm. In the [Mo₂Br₆S₂(NO)₂]^2? ion one of the two nitrosyl groups at each metal atom is substituted by a terminal sulfido ligand with a Mo? S bond length of 240 pm. The i.r. spectra are reported.     

Ag3Bi14Br21: ein Subbromid mit Bi24+‐Hanteln und Bi95+‐Polyedern – Synthese,Kristallstruktur und Chemische Bindung

Ag₃Bi₁₄Br₂₁: a Subbromide with Bi₂⁴⁺ Dumbbells and Bi₉⁵⁺ Polyhedra – Synthesis, Crystal Structure and Chemical Bonding Black crystals of Ag₃Bi₁₄Br₂₁ = (Bi₉⁵⁺)[Ag₃Bi₃Br₁₅^3?](Bi₂Br₆^2?), the first argentiferous bismuth subhalide, were obtained from a stoichiometric melt of Ag, Bi, and BiBr₃. The compound crystallizes in the monoclinic space group P2₁/m with lattice parameters a = 1277.78(5) pm, b = 1466.87(6) pm, c = 1342.62(5) pm, and β = 108.47(1)° at 110(5) K. In contrast to all other bismuth subhalides that contain an electron‐rich transition metal, the silver atoms are not bonded to bismuth atoms. Instead they are integrated into the anionic bromometallate network, which consists of [MBr₆]‐octahedra (M = Ag, Bi) that share edges and vertices. These corrugated sheets alternate with tessellated layers formed by Bi₉⁵⁺ polycations and hitherto unknown (Bi^II₂Br₆)^2? groups. The latter anions contain Bi₂⁴⁺ dumbbells (299 pm) and can be represented by the structured formula [Br₂Bi^II(μ–Br)₂Bi^IIBr₂]^2?. The multi‐center bonding within the Bi₉⁵⁺ cluster and the bent single‐bond in the Bi₂ dumbbell can be visualized using the electron localization indicator (ELI‐D).     

Bi34Ir3Br37: Ein pseudosymmetrisches Subbromid aus Bi5+- und Bi62+-Polykationen sowie [IrBi6Br12]–- und [IrBi6Br13]2–-Clusteranionen

Bi₃₄Ir₃Br₃₇: A Pseudo-Symmetric Subbromide with Bi₅⁺ and Bi₆²⁺ Polycations, and [IrBi₆Br₁₂]^– and [IrBi₆Br₁₃]^2– Cluster Anions The melting reaction of Ir with Bi and BiBr₃ yields black, lustrous, air insensitive crystals of the subbromide Bi₃₄Ir₃Br₃₇. The triclinic crystal structure (space group P 1, a = b = 1303.4(2) pm, c = 1647.4(4) pm, α = β 90°, γ = 120°, V = 2423.7 × 10⁶ pm³) deceives pseudo symmetry with respect to the rhombohedral space group R 3, which results in multiply twinned crystals. The structure can formally be subdivided in four new types of ionic groups: (a) cuboctahedral [IrBi₆Br₁₂]^– clusters, (b) [IrBi₆Br₁₃]^2– clusters with an additional Br atom, (c) Bi₅⁺ square pyramids, and (d) distorted Bi₆²⁺ octahedra. The compound shows a range of homogeneity due to variable contributions of the different clusters.     

Modified Tellurium Subhalides in the New Structure Type [Te15X4]n[MOX4]2n (M = Mo,W; X = Cl,Br)

The reactions of Te₂Br with MoOBr₃, TeCl₄ with MoNCl₂/MoOCl₃, and Te with WBr₅/WOBr₃ yield black, needle-like crystals of [Te₁₅X₄][MOX₄]₂ (M = Mo, W; X = Cl, Br). The crystal structure determinations [Te₁₅Br₄][MoOBr₄]₂: monoclinic, Z = 1, C2/m, a = 1595.9(4) pm, b = 403.6(1) pm, c = 1600.4(4) pm, β = 112.02(2)°; [Te₁₅Cl₄][MoOCl₄]₂: C2/m, a = 1535.3(5) pm, b = 402.8(2) pm, c = 1569.6(5) pm, β = 112.02(2)°; [Te₁₅Br₄][WOBr₄]₂: C2, a = 1592.4(4) pm, b = 397.5(1) pm, c = 1593.4(5) pm, β = 111.76(2)° show that all three compounds are isotypic and consist of one-dimensional ([Te₁₅X₄]²⁺)_n and ([MOX₄]^?)_n strands. The structures of the cationic strands are closely related to the tellurium subhalides Te₂X (X = Br, I). One of the two rows of halogen atoms that bridges the band of condensed Te₆ rings is stripped off, and additionally one Te position has only 75% occupancy which leads to the formula ([Te₁₅X₄]²⁺)_n (X = Cl, Br) for the cation. The anionic substructures consist of tetrahalogenooxometalate ions [MOX₄]^? that are linked by linear oxygen bridges to polymeric strands. The compounds are paramagnetic with one unpaired electron per metal atom indicating oxidation state M^v, and are weak semiconductors.     

Zur Polymorphie von In5Br7

On the Polymorphism of In₅Br₇ The existence of two polymorphs of In₅Br₇ has been proved by single crystal structure determinations. In₅Br₇ (tP192) crystallizes with the tetragonal space group P4₁2₁2 and lattice parameters a_t = 1318.9(5) pm and c_t = 3723.8(9) pm (293 K). Concerning monoclinic In₅Br₇ (mC192), the centrosymmetric space group C2/c with lattice parameters a_m = 1867.3(4) pm, b_m=1867.0(5) pm, c_m = 1918.0(7) pm, and β_m = 103.96(2)° (293 K) has been confirmed. Both modifications of In₅Br₇ are built up from layers of the same type. These layers with a thickness of about 930 pm consist of structure fragments [InBr₂]⁴⁺ and [InBr₁₂]^4–. The anion is composed of two ethan‐like [InBr₆]^2– units, which contain In–In bonds. The stacking sequence of the layers with symmetry C 1 2 (1) differs for the two modifications of In₅Br₇. The tetragonal form is generated by applying a 4₁ screw axis; the monoclinic polymorph is formed by introducing inversion centers between the layers. The adequate name of In₅Br₇ = In[InBr₆]Br is triindium(I)‐hexabromodiindate(II)(In–In)‐bromide.     

Über Münzmetall‐Quecksilber‐Chalkogenidhalogenide. II Hydrothermalsynthese,Kristallstruktur und Phasenumwandlung von CuHgSCl und CuHgSBr

On Coinage Metal Mercury Chalcogenide Halides II: Hydrothermal Synthesis, Crystal Structure, and Solid State Phase Transition of CuHgSCl and CuHgSBr The hydrothermal reaction of CuCl and CuBr with HgS in concentrated aqueous HX (X = Cl, Br) as solvent at 670 K in sealed glass ampoules yields yellow‐orange crystals of CuHgSCl and CuHgSBr. Both compounds crystallize isotypically (orthorhombic, Pbam, a = 984.01(8), b = 1775.1(2), c = 409.59(3) pm for CuHgSCl and a = 1003.7(4), b = 1833.6(5), c = 412.4(2) pm for CuHgSBr, Z = 8). The structures consist of plane folded HgS chains connected by pairs of distorted CuS₂X₂ tetrahedra sharing the X—X‐edge (X = Cl, Br) in which the copper atoms occupy off‐centered positions. The large displacement factors of the Cu atoms represent thermal vibrations as shown by additional X‐ray investigations at different temperatures. The single‐crystal structure determination shows that the earlier structure model, based on powder diffraction data, is incorrect. The structure type of CuHgSCl und CuHgSBr shows distinct similarities to the structure type of the already known compounds CuHgSeBr, AgHgSBr and AgHgSI (MHgYX). At 323 K CuHgSBr undergoes a second order phase transition into a higher symmetric structure of the MHgYX type (orthorhombic, Pmam, a = 1009.2(3), b = 918.40(4), c = 413.81(2) pm) with halved b‐axis.