Darstellung und Strukturen von (Et4N)2[Re(CO)3(NCS)3] und (Et4N)[Re(CO)2Br4]

Syntheses and Structures of (Et₄N)₂[Re(CO)₃(NCS)₃] and (Et₄N)[Re(CO)₂Br₄] Rhenium(I) and rhenium(III) carbonyl complexes can easily be prepared by ligand exchange reactions starting from (Et₄N)₂[Re(CO)₃Br₃]. Using nonoxidizing reagents the facial Re^I(CO)₃ unit remains and only the bromo ligands are exchanged. Following this procedure, (Et₄N)₂[Re(CO)₃(NCS)₃] can be obtained in high yield and purity using trimethylsilylisothiocyanate. The compound crystallizes in the monoclinic space group P2₁/n, a = 18.442(5), b = 17.724(3), c = 18.668(5) Å, β = 92.54(1)°, Z = 8. The NCS^? ligands are coordinated via nitrogen. The reaction of [Re(CO)₃Br₃]^2? with Br₂ yields the rhenium(III) anion [Re(CO)₂Br₄]^?. The tetraethylammonium salt of this complex crystallizes in the noncentrosymmetric, orthorhombic space group Cmc2₁, a = 8.311(1), b = 25.480(6), c = 8.624(1) Å, Z = 4. The carbonyl ligands are positioned in a cis arrangement. Their strong trans influence causes a lengthening of the Re? Br bond distances by at least 0.05 Å.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalysen der Chloro-Iodo-Rhenate(IV) (CH2Py2)[ReCl5I], cis-(CH2Py2)[ReCl4I2] · 2 DMSO,trans-(CH2Py2)[ReCl4I2] · 2 DMSO und fac-(EtPh3P)2[ReCl3I3]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the Chloro-Iodo-Rhenates(IV) (CH₂Py₂)[ReCl₅I], cis -(CH₂Py₂)[ReCl₄I₂] · 2 DMSO, trans -(CH₂Py₂)[ReCl₄I₂] · 2 DMSO, and fac -(EtPh₃P)₂[ReCl₃I₃] [ReCl₅I]^2–, cis-[ReCl₄I₂]^2–, trans-[ReCl₄I₂]^2–, and fac-[ReCl₃I₃]^2– have been synthesized by ligand exchange reactions of [ReI₆]^2– with HCl and are separated by ion exchange chromatography on diethylaminoethyl cellulose. X-ray structure determinations have been performed on single crystals of (CH₂Py₂)[ReCl₅I] ( 1 ) (triclinic, space group P1 with a = 7.685(2), b = 9.253(2), c = 12.090(4) Å, α = 90.06(2), β = 101.11(2), γ = 95.07(2)°, Z = 2), cis-(CH₂Py₂)[ReCl₄I₂] · 2 DMSO ( 2 ) (triclinic, space group P1 with a = 8.662(2), b = 12.109(2), c = 12.9510(12) Å, a = 97.533(11), β = 96.82(2), γ = 89.90(2)°, Z = 2) , trans-(CH₂Py₂)[ReCl₄I₂] · 2 DMSO ( 3 ) (triclinic, space group P1 with a = 9.315(7), b = 9.663(3), c = 15.232(3) Å, α = 80.09(2), β = 81.79(4), γ = 83.99(5)°, Z = 2) and fac-(EtPh₃P)₂[ReCl₃I₃] ( 4 ) (monoclinic, space group P2₁/a with a = 17.453(2), b = 13.366(1), c = 19.420(1) Å, β = 112.132(8)°, Z = 4). The crystal structure of ( 1 ) reveals a positional disorder of the anion sublattice along the asymmetric axis. Due to the stronger trans influence of I compared with Cl on asymmetric axes Cl˙–Re–I′ is caused a mean lenghthening of the Re–Cl˙ distances of 0.020 Å (0.8%) and a shortening of the Re–I′ distances of 0.035 Å (1.3%) with regard to symmetrically coordinated axes Cl–Re–Cl and I–Re–I, respectively. Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salts of all four chloro-iodo-rhenates(IV) are assigned by normal coordinate analyses. The weakening of the Re–Cl˙ bonds and the strengthening of the Re–I′ bonds is indicated by a decrease or increase of the valence force constants each by 9%.     

Neue Halogenochalkogen(IV)‐Säuren: [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10]

Novel Halogenochalcogeno(IV) Acids: [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] Systematic studies on halogenochalcogeno(IV) acids containing tellurium and bromine led to the new crystalline phases [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] ( 1 ) and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] ( 2 ). The [Te₂Br₁₀]^2‐ anions consists of two edge‐sharing distorted TeBr₆ octahedra, the oxonium cations are stabilized by crownether. ( 1 ) crystallizes in the monoclinic space group P2₁/n with a = 14.520(5) Å, b = 22.259(6) Å, c = 16.053(5) Å, β = 97.76(3)° and Z = 4, whereas ( 2 ) crystallizes in the triclinic space group with a = 11.005(4) Å, b = 12.103(5) Å, c = 14.951(6) Å, α = 71.61(3)°, β = 69.17(3)°, γ = 68.40(3)° and Z = 1.     

The Phase Diagram of the System [Ph4P]Br/BiBr3. Synthesis,Crystal Structure,Thermal Behaviour,and Vibrational Spectra of [Ph4P]3[Bi2Br9] · CH3COCH3 and two Modifications of [Ph4P]4[Bi6Br22]

The phase diagram of the system [Ph₄P]Br/BiBr₃ was investigated with the aid of DSC, TG and temperature dependent X‐ray powder diffraction measurements. By varying the reaction conditions, stoichiometry and crystallisation conditions of the reaction between BiBr₃ and [Ph₄P]Br four polynuclear bromobismuthates are formed. We report here the crystal structure of the solvation product [Ph₄P]₃[Bi₂Br₉] · CH₃COCH₃, which crystallises with monoclinic symmetry in the S. G. P2₁/n No. 14, a = 12.341(1), b = 32.005(3), c = 19.929(3) Å, β = 99.75(2)°, V = 7758(7) ų, Z = 4 and the crystal structures of two modifications of the compound [Ph₄P]₄[Bi₆Br₂₂]. The α‐form, crystallises with triclinic symmetry in the S. G. P1 No. 2, a = 13.507(4) Å, b = 14.434(4) Å, c = 17.709(5) Å, α = 81.34(2)°, β = 72.42(2)°, γ = 72.53(2)°, V = 3132.7(1) ų, Z = 2. The high‐temperature β‐form, crystallises with triclinic symmetry in the S. G. P1 No. 2, a = 13.893(4) Å, b = 14.267(3) Å, c = 16.580(3), α = 100.13(2)°, β = 96.56(2)°, γ = 110.01(2)°, V = 2985.5(1) ų, Z = 2. Lattice parameters of [Ph₄P]₄[Bi₈Br₂₈] are also given. The thermal behaviour of the compounds and in addition the vibrational spectra of [Ph₄P]₃[Bi₂Br₉] · CH₃COCH₃ are presented and discussed.     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalysen von (n-Bu4N)2[ReBr5(NCS)] und (n-Bu4N)2[ReBr5(NCSe)]

Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of ( n -Bu₄N)₂[ReBr₅(NCS)] and ( n -Bu₄N)₂[ReBr₅(NCSe)] The X-ray structure determinations on single crystals of (n-Bu₄N)₂[ReBr₅(NCS)] ( 1 ) (monoclinic, space group P2₁/n, a = 10.9860(9), b = 11.6860(7), c = 35.551(3) Å, β = 91.960(9)°, Z = 4) and (n-Bu₄N)₂[ReBr₅(NCSe)] ( 2 ) (monoclinic, space group P2₁/n, a = 11.0208(15), b = 11.7418(16), c = 35.621(12) Å, β = 92.003(18)°, Z = 4) reveal that the thiocyanate and the selenocyanate group are bonded with the Re–N–C angle of 168.5° ( 1 ) and 169.9° ( 2 ). Based on the molecular parameters of the X-ray determinations the IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constants f_d(ReN) are 1.81 ( 1 ) and 1.75 mdyn/Å ( 2 ).     

Darstellung,Strukturen und EPR-Spektren der Rhenium(II)Thionitrosylkomplexe trans-[Re(NS)Cl3(MePh2P)2] und trans-[Re(NS)Br3(Me2PhP)2]

Preparation, Structures, and EPR Spectra of the Rhenium(II) Thionitrosyl Complexes trans -[Re(NS)Cl₃(MePh₂P)₂] and trans -[Re(NS)Br₃(Me₂PhP)₂] The paramagnetic rhenium(II) thionitrosyl compounds trans-[Re(NS)Cl₃(MePh₂P)₂] and trans-[Re(NS)Br₃(Me₂PhP)₂] are characterized by crystal structure diffraction and EPR spectroscopy. Trans-[Re(NS)Cl₃(MePh₂P)₂] is formed during the reduction of (a) [ReNCl₂(MePh₂P)₃] with disulphur dichloride or (b) of mer-[ReCl₃(MePh₂P)₃] with trithiazyl chloride. Trans-[Re(NS)Br₃(Me₂PhP)₂] is the final product of the ligand exchange reaction of mer-[Re(NS)Cl₂(Me₂PhP)₃] with bromine whereby the metal occurred to be simultaneusly oxidized. The crystal structure analyses show for trans-[Re(NS)Cl₃(MePh₂P)₂] (monoclinic, C2/c, a = 13.831(3) Å, b = 13.970(1) Å, c = 14.682(2) Å, β = 95.33(1), Z = 4) and trans-[Re(NS)Br₃(Me₂PhP)₂] (monoclinic, C2/c, a = 33.292(5) Å, b = 8.697(1) Å, c = 17.495(3) Å, β = 115.65(1), Z = 8) linear co-ordinated NS ligands (Re–N–S-angles 180° and 174.8°). The metal atom is octahedrally co-ordinated with the phosphine ligands in trans position to each other. X-band and Q-band EPR spectra of the rhenium(II) thionitrosyl complexes (5 d⁵ “low-spin” configuration, S = 1/2) are detected in the temperature range 295 ≥ T ≥ 130 K. They are characterized by well resolved ^185,187Re hyperfine patterns. The hyperfine parameters are used to get information about the spin-density distribution of the unpaired electron in the complexes under study.     

Zur Strukturchemie der Alkyl- und Arylhalogenoarsenate(III), [Me2As2Cl5]–, [RAsCl3]–, [R2As2Br6]2– (R = Me,Et, Ph) und [Ph2AsX2]– (X = Cl,Br)

Structural Chemistry of the Alkyl- and Arylhaloarsenates(III) [Me₂As₂Cl₅]^–, [RAsCl₃]^–, [R₂As₂Br₆]^2– (R = Me, Et, Ph) and [Ph₂AsX₂]^– (X = Cl, Br) The alkyl- and arylhaloarsenates(III) [Ph₄P][Me₂As₂Cl₅] ( 1 ), [Ph₄P][RAsCl₃] (R = Me, Et, Ph, 2 – 4 ), [Me₃PhN][PhAsCl₃] ( 5 ), [Ph₄P]₂[R₂As₂Br₆] (R = Me, Et, Ph, 6 – 8 ), [n-Pr₄N][Ph₂AsCl₂] ( 9 ) and [n-Bu₄N][Ph₂AsBr₂] ( 10 ) have been prepared and their structures established by X-ray diffraction. In contrast to the chloroarsenates(III) 2 – 5 , which all contain isolated ψ-trigonal bipyramidal anions [RAsCl₃]^–, the analogous bromoarsenates(III) 6 – 8 exhibit dimeric structures. Whereas the trans sited As–Cl distances in 2 and 3 are very similar a pronounced degree of asymmetry is apparent for the Cl–As–Cl three-centre bonds in 4 and 5 [2.396(1) and 2.602(1) Å in 5]. In 6 and 7 C_i symmetry related RAsBr₂ units are connected through long As…Br bonds [2.926(1) and 3.116(2) Å in 6 ]. The bromophenylarsenate(III) anion of 8 which contains two effectively undistorted ψ-trigonal bipyramids [PhAsBr₃]^– associated by weak As…Br interactions [3.117(2) Å]. In view of its very long bridging As…Cl distances the [Me₂As₂Cl₅]^– anion in 1 can, as 6 an 7 , be regarded as two MeAsCl₂ molecules weakly linked through a chloride ion.     

Kristallstrukturen und Normalkoordinatenanalyse der bindungsisomeren Pentachloroselenocyanatorhenate (IV)

Crystal Structure and Normal Coordinate Analysis of Linkage Isomeric Pentachloroselenocyanatorhenates (IV) The X-ray structure determinations on single crystals of (Ph₃PNPPh₃)₂[ReCl₅(NCSe)] ( 1 ) (monoclinic, space group P2₁/n, a = 10.806(2), b = 13.349(2), c = 46.071(4) Å, β = 94.947(9)°, Z = 4) and (Py₂CH₂)[ReCl₅(SeCN)] ( 2 ) (monoclinic, space group P2₁/n, a = 12.044(1), b = 9.838(1), c = 15.686(2) Å, β = 105.913(8)°, Z = 4) reveal, that the nearly linear selenocyanate group (178°) is coordinated via N with the Re–N–C angle of 172.7 ( 1 ) and via Se with the Re–Se–C angle of 107.4° ( 2 ). Based on the molecular parameters of the X-ray determinations the IR and Raman spectra, known from literature for both linkage isomers, have been assigned by normal coordinate analysis. The valence force constants are f_d(ReN) = 1.72 and f_d(ReSe) = 1.20 mdyn/Å.     

Synthese und Kristallstruktur von (Ph3PNPPh3)2[Cu(N3)4]

Inhaltsübersicht. Die Titelverbindung entsteht neben CuN₃ · PPh₃ bei der Einwirkung von Natriumazid auf CuCl₂ und Triphenylphosphan in siedendem Acetonitril bei Anwesenheit von 15-Krone-5 als Lösungsvermittler für NaN₃. (Ph₃PNPPh₃)₂[Cu(N₃)₄] bildet schwarze Kristalle, die wir durch das IR-Spektrum und durch eine röntgenographische Strukturanalyse charakterisiert haben. Raumgruppe Pbca, Z = 4, (4245 beobachtete unabhängige Reflexe, R = 7,2%), Gitter-abmessungen (20°C):a = 1980, 1;b = 1618,8; c = 2014,3 pm. Die Verbindung besteht aus Kationen [Ph₃PNPPh₃]⁺ und Anionen [Cu(N₃)₄]^2– der Symmetrie C_i, in denen das Cu-Atom planar von den α-N-Atomen der Azidgruppen mit Cu–N-Abständen von 197,2(4) und 189,5(4) pm umgeben ist. Synthesis and Crystal Structure of (Ph₃PNPPh₃)₂[Cu(N₃)₄] The title compound is prepared besides CuN₃ · PPh₃ by the reaction of sodium azide with CuCl₂ and PPh₃ in boiling acetonitrile in the presence of 15-crown-5. (Ph₃PNPPh₃)₂[Cu(N₃)4] forms black crystals, which have been characterized by their IR spectrum as well as by an X-ray structure determination. Space group Pbca, Z = 4 (4245 observed independent reflexions, R = 0.072), lattice dimensions (20°C): A = 1980.1; b = 1618.8; c = 2014.3 pm. The compound consists of Ph₃PNPPh₃⁺ cations and anions [Cu(N₃)₄]^2– with symmetry C₁, in which the copper atom is planarly surrounded by the four nitrogen atoms of the azide groups with bond lengths Cu–N of 197.2(4) and 189.5(4) pm, respectively.     

On Tetrachlorophosphonium Chlorometallates of Rhenium and Molybdenum: Syntheses,Crystal Structures,and Magnetism of [PCl4]2[Re2Cl10] and [PCl4]3[ReCl6]2, and the Magnetic Properties of [PCl4]2[Mo2Cl10]

MoCl₄, ReCl₄, and ReCl₅ react with PCl₅ in sealed glass ampoules at temperatures between 220° and 320° to [PCl₄]₂[Mo₂Cl₁₀] ( 1 ) [PCl₄]₂[Re₂Cl₁₀] ( 2 ), and [PCl₄]₃[ReCl₆]₂ ( 3 ). 2 crystallizes isotypically to the previously reported 1 and the respective titanium and tin containing analogues. The structure (triclinic, P1, Z = 1, a = 897.3(2), b = 946.0(2), c = 687.13(9) pm, α = 95.59(2)°, β = 95.80(2)°, γ = 101.07(2)°, V = 565.4(2) 10⁶ pm³) is built of tetrahedral [PCl₄]⁺ and edge sharing double octahedral [Re₂Cl₁₀]^2– ions and can be derived from a hexagonal closest packing of Cl^– ions with tetrahedral and octahedral holes partially filled by P(V) and Re(IV), respectively. 3 crystallizes isotypically to [PCl₄]₃[PCl₆][MCl₆] (M = Ti, Sn) (tetragonal, P 4₂/mbc, Z = 4, a = 1496.2(1), c = 1363.2(2) pm). Because no evidence was found for the presence of [PCl₆]^– ions, Re in 3 has to be of mixed valency with Re^IV and Re^V sharing the same crystallographic site. The structure can be derived from a cubic closest packing or alternatively from an only sparsely distorted body centered cubic arrangement of Cl^– ions which is rarely found for anion arrays. The tetrahedral and octahedral holes are partially filled by P^V and M^IV/V, respectively. Magnetic measurements show all three compounds to be paramagnetic and confirm the oxidation state IV for Mo and Re in 1 and 2 and the mixed valence (IV/V) for Re in 3 .     

New Ternary Hafniumhalides: Cs[Hf2Br9] and Rb[Hf2Br9]

The syntheses and crystal structures of two new ternary hafnium compounds, Cs[Hf₂Br₉] ( 1 ) and Rb[Hf₂Br₉] ( 2 ), are described. Both compounds are obtained in high yield from the chemical reaction of HfBr₄ and CsBr or RbBr, respectively, in the presence of a small amount of elemental Al at 450 °C in sealed silica tubes. They crystallize isostructurally in the monoclinic space group P2/n. The lattice parameters are a = 9.946(1) ( 1 ) and 9.9388(4) Å ( 2 ), b = 6.6580(9) ( 1 ) and 6.6695(3) Å ( 2 ), c = 12.930(2) ( 1 ) and 12.8435(6) Å ( 2 ), and β = 112.479(6)° ( 1 ) and 112.726(2)° ( 2 ). The crystals of the two compounds contain dinuclear tri‐μ‐bromido‐hexabromido‐dihafnate(–) complex anions, [Hf₂Br₉]^–, besides the alkali metal cations. The complex anions can be described as face‐sharing bioctahedral units.     

Direct Syntheses of Bis(tetraphenylphosphonium) and Bis(ethyltriphenylphosphonium) Hexabromo‐diselenates(II), [PPh4]2[Se2Br6] and [PEtPh3]2[Se2Br6]. The Crystal Structure of [PEtPh3]2[Se2Br6]

Brown crystals of [PPh₄]₂[Se₂Br₆] ( 1 ) and [PEtPh₃]₂[Se₂Br₆] ( 2 ) were obtained when selenium and bromine reacted in acetonitrile solution in the presence of tetraphenylphosphonium bromide and ethyltriphenylphosphonium bromide, respectively. The crystal structure of 2 has been determined by X‐ray methods and refined to R = 0.0420 for 4161 reflections. The crystals are monoclinic, space group P2₁/n with Z = 2 and a = 13.055(3) Å, b = 12.628(3) Å, c = 13.530(3) Å, β = 92.40(3)° (293(2) K). In the solid state structure of 2 the dinuclear hexabromo‐diselenate(II) anion is centrosymmetric and consists of two distorted almost square‐planar SeBr₄ units sharing a common edge through two bridging Br atoms. The terminal Se^II–Br bond distances are found to be 2.419(1) and 2.445(1) Å, the bridging μBr–Se^II bond distances 2.901(1) and 2.802(1) Å.     

Synthese,Struktur und Thermolyse von NH4[Re3Br10]

Synthesis, Structure and Thermolysis of NH₄[Re₃Br₁₀] NH₄[Re₃Br₁₀] crystallizes as dark brown single crystals upon slow cooling of a hot, saturated hydrobromic-acid solution of [Re₃Br₉(H₂O)₂] after the addition of NH₄Br. The crystal structure (monoclinic, C2/m (Nr. 12); Z = 4; a = 1461.6(7), b = 1 085.6(4), c = 1030.3(7) pm, β = 92.63(4)°, V_m = 245.9(4)cm³/mol; R = 0.097, R_w = 0.043) contains [Re₃Br₁₂]^? units that share two common edges. These chains run along [010] and are held together by NH₄⁺ ions. Each NH₄⁺ is surrounded by eight Br^? from four different chains. The first step of the thermal decomposition at 290°C is the disproportionation to ReBr₃ (ReCl₃ type), rhenium metal and (NH₄)₂[ReBr₆]. Secondly, the internal reduction of (NH₄)₂[ReBr₆] at 390°C to rhenium metal takes place.     

Darstellung,Schwingungsspektren und Normalkoordinatenanalyse von mer-[OsCl3I(NCS)]2− sowie Kristallstrukturanalyse von zwei Modifikationen des mer-(Ph4As)2[OsCl3I(NCS)2c]

Preparation, Vibrational Spectra, and Normal Cooordinate Analysis of mer-[OsCl₃I(NCS)₂^c]^2? and Crystal Structures of two Modifications of mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] By treatment of cis-/trans-[OsCl₄I₂]^2? or fac-[OsCl₃I₃]^2? with (SCN)₂ in dichloromethane mixtures of different linkage isomers are formed, from which mer-[OsCl₃I(NCS)]^2? has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. With tetraphenylarsonium ions mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] crystallizes in two different modifications. From acetone solution the high-temperature form α precipitates above ?10°C, the low-temperature form β below, ?65°C. The X-Ray structure determinations on single crystals of α-mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] (triclinic, space group P 1 , a = 10.245(5), b = 11.690(5), c = 22.027(5) Å, α = 83.650(5)°, β = 85.734(5)°, γ = 72.566(5)°, Z = 2) and β-mer-(Ph₄As)₂[OsCl₃I(NCS)₂^c] (triclinic, space group P 1 , a = 10.959(5), b = 11.122(5), c = 21.745(5) Å, α = 97.677(5)°, β = 92.339(5)°, γ = 104.712(5)°, Z = 2) reveal the ordering of the complex anions, which significantly differ in their geometry. The via N coordinated thiocyanate groups exhibit Os? N? C angles of 172.7° and 173.3° (α) and of 164.4° and 175.4° (β). Using the molecular parameters of the X-Ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salt of the complex anion are assigned by a normal coordinate analysis based on a modified valence force field. The valence force constants are f_d(OsN) = 1.66 and 1.64 mdyn/Å. Taking into account the trans influence a good agreement between observed and calculated frequencies is achieved.     

Darstellung,spektroskopische Charakterisierung und Normalkoordinatenanalyse von Nonabromoditechnetat(IV), [Tc2Br9]−

Preparation, Spectroscopic Characterization and Normal Coordinate Analysis of Nonabromoditechnetate(IV), [Tc₂Br₉]^? . On heating the tetraethylammonium salt (TEA)₂[Tc₂Br₆] with trifluoroacetic acid the face-sharing bioctahedral anion [Tc₂Br₉]^? is formed, which vibronic spectrum is assigned according to point group D_3h. Normal coordinate analysis, based on a general valence force field has been performed, resulting in a good agreement of calculated frequencies with the observed IR and Raman bands. Due to stronger bonding of the terminal as compared to the bridging ligands, the valence force constant f_d(TcBr_t) = 1.045 is significantly higher than f_d(TcBr_b) = 0.80 mdyn/Å.     

Synthesis and Thermal Behaviour of Compounds in the System [Ph4P]Cl/BiCl3 and the Crystal Structures of [Ph4P]3[Bi2Cl9] · 2 CH2Cl2 and [Ph4P]2[Bi2Cl8] · 2 CH3COCH3

Six polynuclear chlorobismuthates are formed in the reaction between BiCl₃ and Ph₄PCl by variation of the molar ratio of the educts, the solvents and the crystallisation methods: [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂, [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃, [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃, [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN, [Ph₄P]₄[Bi₆Cl₂₂], and [Ph₄P]₄[Bi₈Cl₂₈]. We report the crystal structure of [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ which crystallises with triclinic symmetry in the S. G. P1 No. 2, with the lattice parameters a = 13.080(3) Å, b = 14.369(3) Å, c = 21.397(4) Å, α = 96.83(1)°, β = 95.96(1)°, γ = 95.94(2)°, V = 3943.9(1) ų, Z = 2. The anion is formed from two face‐sharing BiCl₆‐octahedra. [Ph₄P]₂[Bi₂Cl₈] · 2 CH₃COCH₃ crystallises with monoclinic symmetry in the S. G. P2₁/n, No. 14, with the lattice parameters a = 14.045(5) Å, b = 12.921(4) Å, c = 17.098(3) Å, β = 111.10(2)°, V = 2894.8(2) ų, Z = 2. The anion is a bi‐octahedron of two square‐pyramids, joined by a common edge. The octahedral coordination is achieved with two acetone ligands. [Ph₄P]₄[Bi₄Cl₁₆] · 3 CH₃CN crystallises in the triclinic S. G., P1, No. 2, with the lattice parameters a = 14.245(9) Å, b = 17.318(6) Å, c = 24.475(8) Å, α = 104.66(3)°, β = 95.93(3)°, γ = 106.90(4)°, V = 5486(4) ų, Z = 2. Two Bi₂Cl₈ dimers in syn‐position form the cubic anion. Lattice parameters of [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ are also given. The solvated compounds are desolvated at approximately 100 °C. [Ph₄P]₃[Bi₂Cl₉] · 2 CH₂Cl₂ and [Ph₄P]₃[Bi₂Cl₉] · CH₃COCH₃ show the same sequence of phase transitions after desolvation. All compounds melt into a liquid in which some order is observed and transform on cooling into the glassy state.     

Synthesis,Crystal Structure,Vibrational Spectra,and Thermal Behaviour of [Ph4P]2[Bi2(μ‐Br)2Br6 (CH3COCH3)2]

[Ph₄P]₂[Bi₂Br₈(CH₃COCH₃)₂] ( 1 ) was obtained by the reaction of [Ph₄P]Br and BiBr₃ in acetone. Single crystals were grown by allowing a layer of n‐hexane to diffuse into the acetonic solution of 1 . The crystal structure was determined by means of X‐ray diffraction. 1 crystallises with monoclinic symmetry in the space group P2₁/n, No. 14 with the lattice parameters: a = 13.358(2), b = 12.637(2), c = 18.565(3) Å, β = 102.62(1)°, V = 3058.1(8) ų and Z = 4. The structure is characterised by the anion [Bi₂Br₈(CH₃COCH₃)₂]^2– which is embedded in a matrix of [Ph₄P]⁺ cations. The anion can be described as two edge‐sharing square pyramids with the apical bromide ions in anti‐position. Acetone co‐ordinates the bismuth atoms via oxygen atoms and increases the co‐ordination number of central bismuth atoms to six which results in the formation of a distorted bi‐octahedron. The distortion is due to the difference in terminal and bridging Bi–Br bond lengths. FT‐IR and Raman spectroscopic data are presented. In addition, the thermal behaviour of the compound was studied with the aid of TG/DSC coupled with MS revealing that acetone leaves the crystal in two steps. The compound melts at 203 °C and transforms into a glass on cooling.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.     

Azidokomplexe von Vanadium(IV) und Vanadium(V): (Ph4P)2[VOCl2(μ‐N3)]2 und (Ph4P)2[VOCl(μ‐N3)(N3)2]2

Azido Complexes of Vanadium(IV) and Vanadium(V): (Ph₄P)₂[VOCl₂(μ‐N₃)]₂ and (Ph₄P)₂[VOCl(μ‐N₃)(N₃)₂]₂ (Ph₄P)₂[VOCl₂(μ‐N₃)]₂ ( 1 ) was prepared by reaction of (Ph₄P)[VO₂Cl₂] with trimethylsilylazide in the molar ratio 1:2 in dichloromethane solution to give dark green, moisture sensitive, non‐explosive single crystals. The reaction is accompanied by the formation of the dark blue side‐product (Ph₄P)₂[VOCl(μ‐N₃)(N₃)₂]₂ ( 2a ), which can be obtained as the main product by application of a large excess of Me₃SiN₃. Dark blue needles of 2a crystallize spontaneously from the CH₂Cl₂ solution within one hour at 4 °C. After standing at 4 °C under its mother liquid within 24 hours a first‐order phase transition of 2a occurs forming dark blue prismatic single crystals of 2b . According to single crystal X‐ray structure determinations, 2a and 2b crystallize in the same type of space group , however, with different lattice dimensions. The vanadium(IV) complex 1 is characterized by X‐ray structure determination and by vibrational spectroscopy (IR, Raman) as well as by EPR spectroscopy, whereas 2b is characterized by IR spectroscopy. 1 : Space group P2₁/n, Z = 2, a = 1009.5(1), b = 1226.6(2), c = 1943.0(2) pm, β = 98.42(1)°, R₁ = 0.0672. The complex anion forms centrosymmetric units with V₂N₂‐four‐membered rings with a V···V distance of 335.6(1) pm and coordination number five on the vanadium(IV) atoms. 2a : Space group , Z = 1, a = 1089.0(2), b = 1097.1(2), c = 1310.1(2) pm, α = 92.99(1)°, β = 106.12(2)°, γ = 117.05(2)°, V = 1309.8(4) ų, d_calc. = 1.440 g·cm^?3, R₁ = 0.0384. The complex anion forms centrosymmetric units of symmetry C_i with V₂N₂ four‐membered rings and VN bond lengths of 200.4(3) and 234.4(2) pm, respectively. The non‐bonding V···V distance amounts to 356.2(1) pm. 2b : Space group , Z = 1, a = 1037.3(2), b = 1157.6(2), c = 1177.2(2) pm, α = 98.48(2)°, ° = 103.82(2)°, γ = 106.33(2)°, V = 1281.8(4) ų, d_calc. = 1.471 g·cm^?3, R₁ = 0.0724. The structure of the complex anion is similar to the anion of 2a with VN bond lengths of the four‐membered V₂N₂ ring of 203.3(4) and 235.2(4) pm, respectively, and a non‐bonding V···V distance of 357.5(1) pm.     

Synthese und Struktur von (PPh4)3[Re2NCl10]

Synthesis and Crystal Structure of (PPh₄)₃[Re₂NCl₁₀] The rhenium(V) nitrido complex (PPh₄)₃[Re₂NCl₁₀] ( 1 ) is obtained from the reaction of (PPh₄)[ReNCl₄] with 1, 3‐dioxan‐(2‐ylmethyl)diphenyl phosphine in CH₂Cl₂/CH₃CN in form of orange red crystals with the composition 1 ·2CH₂Cl₂ crystallizing in the triclinic space group P1¯ with a = 1210.7(2), b = 1232.5(1), c = 2756.3(5) pm, α = 99.68(1)°, β = 100.24(1)°, γ = 98.59(1)° and Z = 2. The crystal structure contains two symmetry independent, centrosymmetrical complex anions [Re₂NCl₁₀]^3‐ with a symmetrical nitrido bridge Re=N=Re and distances Re(1) ‐ N(1) = 181.34(5) and Re(2) ‐ N(2) = 181.51(4) pm.