Synthese und Kristallstruktur von (PPh4)2[Mo2(S2)2Cl8] · 2 CH3CN und seine topotaktische Umwandlung zu (PPh4)2[Mo2(S2)2Cl8]

Synthesis and Crystal Structure of (PPh₄)₂[Mo₂(S₂)₂Cl₈] · 2 CH₃CN and its Topotactic Transformation to (PPh₄)₂[Mo₂(S₂)₂Cl₈] MoS₂Cl₃ was prepared from molybdenum and S₂Cl₂ at 200 °C. Its reaction with PPh₄Cl in acetonitrile yielded (PPh₄)₂[Mo₂(S₂)₂Cl₈] · 2 CH₃CN. In vacuum or upon warming, it loses the acetronitrile without degradation of the crystals. According to the X-ray crystal structure determinations both compounds, with and without acetonitrile, are triclinic. They contain the same [Cl₄Mo(μ-S₂)₂MoCl₄]^2– ions, in which the Mo atoms are joined by two disulfido groups and an Mo–Mo bond. Details of the crystal packings and their topotactic transformation are given.     

Disulfidoverbrückte Halogenokomplexe von Molybdän(V) Kristallstrukturen von (PPh3Me)2[Cl4Mo(μ-S2)2MoCl4] · 2 CH2Cl2 und (PPh4)2[Br4Mo(μ-S2)2MoBr4] · 3 CH2Br2

Disulfido-Bridged Halo Complexes of Molybdenum (V). Crystal Sructures of (PPh₃Me)₂ [Cl₄Mo (μ-S₂)₂MoCl₄]. 2 CH₂Cl₂ and (PPh₄)₂[Br₄Mo(μ-S₂)₂MoBr₄]. 3CH₂Br₂ . Mo(S₂)Cl₃ is prepared by an improved method; the i.r. spectrum is reported. In dichloro methane solution it reacts with (PPh₃Me)Cl forming the complex (PPh₃Me)₂[Cl₄Mo(μ-S₂)₂MoCl₄] · 2 CH₂Cl₂. The bromo complex (PPh₄)₂[Br₄Mo(μ-S₂)₂MoBr₄] · 3 CH₂Br₂ is obtained by reaction of MoBr₄ with S₇NH and subsequent treatment of the reaction mixture with PPh₄Br in CH₂Br₂ solution. Both complexes are characterized by i.r. spectra and structural analyses by X-ray methods. (PPh₃Me)₂[Cl₄Mo(μ-S₂)₂MoCl₄] · 2 CH₂Cl₂ crystallizes monoclinic in the space group P2₁/c with two formula units per unit cell (5268 observed independent reflexions, R = 4.0%). The lattice dimensions are: a = 1097 pm, b = 1510 pm, c = 1591 pm, β = 104.4°. (PPh₄)₂[Br₄Mo(μ-S₂)₂MoBr₄] · 3 CH₂Br₂ crystallizes triclinic in the space group P&1macr; with two formula units per unit cell and the lattice constants a = 1328 pm, b = 1573 pm, c = 1719 pm, α = 95.8°, β = 96.3°, γ = 74.1°. Both compounds are of ionical structure with PPh₃Me^⊕ and PPh₄^⊕ cations, respectively, and anions [X₄MO(μ-S₂)₂MoX₄]^2? very similar to each other. The molybdenum atoms are bridged by two disulfido ligands and are bonded directly with a bond length of 286 pm. The terminal halogen atoms add up to coordination number nine at the molybdenum.     

Synthese und Struktur des μ-Sulfido-μ-disulfido-octabromodiwolframat(V)-Ions [W2S3Br8]2−

Synthesis and Structure of μ-Sulfido-μ-disulfido-octabromoditungstate(V), [W₂S₃Br₈]^?2 Tungsten hexabromide reacts with H₂S in dichloromethane yielding a brown product which, by addition of tetraphenylphosphonium bromide in CH₂Cl₂, is converted to brown, crystalline (PPh₄)₂[Br₄W(μ-S)(μ-S₂)WBr₄] · CH₂Cl₂ · CH₂S. Its IR spectrum is reported, its crystal structure was determined by X-ray diffraction (2330 reflexions, R = 0.097). Crystal data: orthorhombic, Pnma, a = 1 766.5, b = 2 412.7, c = 1 416.3 pm, Z = 4. In the diamagnetic [W₂S₃Br₈]^2? ions the two W atoms are linked via a sulfido and a disulfido bridge and by a W? W bond.     

Synthesis and structure of an open-type trinuclear molybdenum cluster compound[Mo_3(μ_3-S)(μ-S)_2-(μ-OAc)(S_2CNC_4H_8)_3(O)_2]·0.5CH_2Cl_2·2H_2O

The title compound was prepared by the reaction of Mo_3S_4(dtp)_4(H_2O)[ctp=S_2P(OEt)_2]with NaOAc·3H_2O and C_4H_8NCS_2NH_4.Crystallographic data:[Mo_3(μ_3-S)(μ-S)_2(μ-OAc)-(S_2CNC_4H_8)_3(O)_2]·0.5CH_2CI_2·2H_2O,Mr=980.18,triclinic,space group P,α=12.360(3),b=16.653(6),c=9.206(2)A,α=101.97(2),β=108.32(2),γ=86.14(3)°.V=1759.6(9)A~3,Z=2,Dc=1.85 g/cm~3,F(000)=962,μ(Mo K_α)=16.53 cm~(-1).Final R=0.044 for 4301 reflections with I≥3σ(I).This compoundmay be regarded as a mixed-valent trinuclear molybdenum cluster{Mo_2(V)Mo(Ⅳ)(μ_3-S)(μ-S)_2-(μ-OAc)(S_2CNC_4H_8)_3(O)_2}.The Mo-Mo distances are 2.783(1),2.833(1)and 3.374(2)A in the Mo_3non-equilateral triangle and there exist only two Mo-Mo bonds.The cluster was obtained by oxi-dation and ligand substitution of{Mo_3(μ_3-S)(μ-S)_3[μ-S_2P(OEt_2)][S_2P(OEt)_2]_3(H_2O)}.     

Thiohalogeno-Verbindungen von Niob und Tantal: NbSCl3, TaSCl3, [NbSCl5]2−, [TaSCl5]2−, [NbSBr4]− Die Kristallstrukturen von (PPh4)2[NbSCl5] · 2 CH2Cl2 und NEt4[NbCl6]

Thiohalo Compounds of Niobium and Tantalum: NbSCl₃, TaSCl₃, [NbSCl₅]^2?, [TaSCl₅]^2?, [NbSBr₄]^?. Crystal Structures of (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ and NEt₄[NbCl₆] NbSCl₃ can be obtained from NbCl₅ by reaction with H₂S or bistrimethylsilyl sulfide in a suspension of CCl₄ or CH₂Cl₂, respectively; in the latter case the product contains a rest of trimethylsilyl groups. This also applies for TaSCl₃, NbSBr₃ and TaSBr₃, which are formed from the metal pentahalides and S(SiMe₃)₂. NEt₄[NbSCl₄] is formed together with NEt₄[NbCl₆] in the reaction of NbCl₅ with NEt₄SH in CH₂Cl₂. PPh₄[NbCl₆] reacts with S(SiMe₃)₂ in dichloromethane yielding (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂, whereas PPh₄[NbSBr₄] is obtained from PPh₄[NbBr₆] and S(SiMe₃) under the same conditions. (PPh₄)₂[TaSCl₅] · 2 CH₂Cl₂ was obtained from TaSCl₃ and PPh₄Cl in CH₂Cl₂. According to an X-ray crystal structure determination (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ crystallizes in the β-(AsPh₄)₂[UCl₆] · 2 CH₂Cl₂ type with positionally disordered, octahedral anions. Crystal data: a = 1 021.7, b = 1120.4, c = 1 243.3 pm, α = 70.77, β = 80.24, γ = 80.54°, space group P1 , Z = 2; 2462 unique observed reflexions, R = 0.036. NEt₄[NbCl₆] crystallizes isotypic to NEt₄[WCl₆], a = 723.5, b = 1 018.0, c = 1 174.6 pm, β = 100.07°, space group P2₁/n, Z = 2; 1 875 reflexions, R = 0.075.     

Darstellung von trans-[Mo6Cl8]Cl4Br22−ausgehend von kristallisierten [Mo6Cl8]Cl4(H2O)2 und die Kristallstruktur von [(C6H5)4As]2[Mo6Cl8]Cl4Br2

Preparation of trans-[Mo₆Cl₈]Cl₄Br₂^2? Starting from Crystalline [Mo₆Cl₈]Cl₄(H₂O)₂ and Crystal Structure of [(C₆H₅)₄As]₂[Mo₆Cl₈]Cl₄Br₂ The synthesis of the title compound is successful if the crystallized [(Mo₆Cl₈)Cl₄(H₂O)₂] containing the H₂O molecules in trans-position reacts with HBr + [(C₆H₅)₄As]Br in ethanol in a heterogeneous reaction. The X-ray structure investigation confirms the existence of discrete trans-Br-substituted cluster anions of composition [(Mo₆Cl₈)Cl₄Br₂]^2? in the crystal. The reaction in homogeneous solutions proceeds to Br-enriched compounds. [(C₆H₅)₄As]₂[(Mo₆Cl₈)Cl₄Br₂] crystallizes in the triclinic space group P¯1 with a = 11.071(2), b = 11.418(2), c = 12.813(2) Å, α = 116.10(2), β = 95.27(2) and γ = 94.41(2)° (?133°C). The crystal structure at ?133°C was determined from single crystal X-ray diffraction data (R₁ = 0.026). The [(Mo₆Cl₈)Cl₄Br₂]^2?-anions are not completely ordered but distributed statistically among the three positions which are possible within the limits of the ordered [Mo₆Cl₈]-cores (ratio 11:5:4). The frameworks of the anions consist of Mo₆ cluster units with (slightly distorted) octahedral arrangement of the metal atoms (d(Mo? Mo): 2.600(1) up to 2.614(1) Å), which are coordinated by the halogeno ligands in a square-pyramidal manner. The details of the structure will be discussed and compared with similar [(Mo₆X₈)Y₄] cluster units (X, Y ? Cl, Br).     

Nitrosylkomplexe des Molybdän(+II) Die Kristallstrukturen von [Mo(NO)Cl3 · POCl3]2 und von [AsPh4]2[Mo(NO)Cl5] · 2 CH2Cl2

Nitrosyl Complexes of Molybdenum (+II). Crystal Structures of [Mo(NO)Cl₃ · POCl₃]₂ and [AsPh₄]₂[Mo(NO)Cl₅] · 2 CH₂Cl₂ Solutions of MoCl₅ in POCl₃ react with NOCl forming the nitrosyl compound Mo(NO)Cl₃ · 2POCl₃ ( I ), which in CH₂Cl₂ cleaves off one solvate molecule, yielding the dimeric complex [Mo(NO)Cl₃ · POCl₃]₂ ( II ). Reaction with AsPh₄Cl in dichloro methane leads to the nitrosyl complexes AsPh₄[Mo(NO)Cl₄] · CH₂Cl₂ ( III ) and [AsPh₄]₂[Mo(NO)Cl₅] · 2CH₂Cl₂ ( IV ), respectively. The i.r. spectra are recorded and assigned. [Mo(NO)Cl₃ · POCl₃]₂ crystallizes monoclinic in the space group P2₁/c with two dimeric units per unit cell. The crystal structure was determined by X-ray diffraction methods (R = 0.040; 1391 observed, independent reflexions). Complex II is linked by chlorine bridges, forming a dimeric, centrosymmetric molecule of symmetry C_i. The N? O bond of the nitrosyl ligand is extremely short (108 pm), the Mo? N bond (181 pm) corresponds to a double bond. In trans position to the NO ligand, which is coordinated in linear array, there is the O atom of the solvate molecule POCl₃. [AsPh₄]₂[Mo(NO)Cl₅] · 2 CH₂Cl₂ crystallizes triclinic in the space group P1 with two units per unit cell (R = 0.039; 1967 observed, independent reflexions). The molybdenum atom is coordinated octahedrally by five Cl ligands and a nitrosyl group, as well coordinated in linear array (Mo? N? O 174°). The nitrosyl ligand exerts a significant trans-effect (r Mo? Cl_(trans) = 247 pm, r MoCl_4(eq)(average) = 239 pm).     

Über die Reaktion von 2,2-Dimethylpropylidinphosphan mit Molybdänpentachlorid; die Kristallstruktur von [Mo2Cl6(α,α′-Dipyridyl)3]

Reaction of 2,2-Dimethylpropylidynephosphine with Molybdenum Pentachloride; Crystal Structure of [Mo₂Cl₆(α,α′-dipyridyl)₃] 2,2-Dimethylpropylidynephosphine and molybdenum pentachloride dissolved in POCl₃ react with oxydation of the phosphorus and reduction of the molybdenum atom to give the alkyne complex [Mo₂Cl₄(μ-Cl)₂(μ-H₉C₄? C?C? C₄H₉)(OPCl₃)₂]. Addition of α,α′-dipyridyl or of methyltriphenylphosphonium chloride in dichloromethane results in a displacement of the ligands POCl₃ and H₉C₄? C?C? C₄H₉ from this complex and in the formation of [Mo₂Cl₆(dipy)₃] or [(H₅C₆? )₃P? CH₃]₃[Mo₂Cl₉]. Besides the latter compound small amounts of [(H₅C₆? )₃P? CH₃]₂[MoCl₆] can be isolated from the reaction mixture. [Mo₂Cl₆(dipy)₃] which has already been prepared by other methods crystallizes in the monoclinic space group P2₁/c with {a = 1612; b = 148; c = 1296 pm; γ 109.3°; Z = 4} at 20°C. As shown by a crystal structure determination the complex is built up from [MoCl₂(dipy)₂]⁺ cations and [MoCl₄(dipy)]^? anions. The molybdenum atoms are both octahedrally surrounded. With average values of 238 and 243 pm the Mo? Cl bond distances in the cation, where a cis-arrangement of the chlorine atoms is observed, and in the anion differ significantly from each other. [Mo₂Cl₆(dipy)₃] which has already been prepared by other methods crystallizes in the monoclinic space group P2₁/c with {a = 1612; b = 148; c = 1296 pm; γ = 109.3°; Z = 4} at 20°C. As shown by a crystal structure determination the complex is built up from [MoCl₂(dipy)₂]⁺ cations and [MoCl₄(dipy)]^? anions. The molybdenum atoms are both octahedrally surrounded. With average values of 238 and 243 pm the Mo? Cl bond distances in the cation, where a cis-arrangement of the chlorine atoms is observed, and in the anion differ significantly from each other.     

(PPh3Me)2[{MoCl4(NO)}2 (μ-S2N2)]; Synthese,IR-Spektrum und Kristallstruktur

(PPh₃Me)₂[{MoCl₄(NO)}₂(μ-S₂ N₂)]; Synthesis, I.R. Spectrum, and Crystal Structure The title compound is prepared by the reaction of (PPh₃Me)₂[MoCl₃(NO)₂]₂ with trithiazyl chloride in CH₂Cl₂ solution. It forms yellow, only slightly moisture sensitive crystals, which are characterized by their IR spectrum as well as by an X-ray structure determination. (PPh₃Me)₂[{MoCl₄(NO)}₂ (μ-S₂N₂)] crystallizes triclinic in the space group P1 with one formula unit in the unit cell (5952 independent, observed reflexions, R = 0.045). The lattice dimensions are at 20°C: a = 1021, b = 1143, c = 1243, pm; α = 64,15°, β = 68.24°, γ = 80.85°. The compound consists of PPh₃Me⊕ cations and anions [{MoCl₄(NO)}₂(μ-S₂N₂)]²?, in which the molybdenum atoms are bridged by the N-atoms of the planar S₂N₂ ring. In the trans-positions of these N-atoms the linear nitrosyl groups are coordinated via Mo ? N ? O .     

Synthese und Kristallstruktur von (PPh4)2[Mo2Cl10]

Synthesis and Crystal Structure of (PPh₄)₂[Mo₂Cl₁₀] The title compound is obtained in the reaction of [MoCl₄(Ph? C?C? Ph)]₂ with tetraphenylphosphonium chloride in dichloro methane, forming brown crystals. It is characterized by the i.r. spectrum and a crystal structure analysis by the aid of X-ray diffraction data. The complex crystallizes triclinic in the space group P1 with one formula unit per unit cell. The cell dimensions are a = 1122 pm, b = 1137 pm, c = 1283 pm; α = 63.4°, β = 69.1°, γ = 86.5°. The crystal structure determination (2959 observed, independent reflexions, R = 4.5%) shows the constants of the unit cell to consist of on centrosymmetric anion, two cations and one disordered molecule of dichloro methane. The distance Mo? Mo in the anion is 380 pm, which excludes direct magnetic interaction between the molybdenum atoms.     

Molybdänhalogenidcluster mit sechs terminalen Alkoholatliganden: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH und (C18H36N2O6Na2)2[Mo6Cl8(OC6H5)6]

Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6CH₃OH and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] . The reaction of Na₂[Mo₆Cl₈(OCH₃)₆] and 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6 CH₃OH ( 1 ), which is converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo₆Cl₈ⁱ(OR^a)₆]^2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo₆Cl₈(OC₆H₅)₆]^2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.     

Thiochlorowolframate von Wolfram(V) und -(VI). Die Kristallstrukturen von PPh4[WSCl4] und (PPh4)2[WS2Cl4] · 2 CH2Cl2

Thiochlorowolframates with Tungsten(V) and (VI). Crystal Structures of PPh₄[WSCl₄] and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂ Diamagnetic (NEt₄)₂[WSCl₄]₂, having tungsten atoms linked via sulfur atoms, is obtained by the reaction of WCl₅ with NEt₄SH as well as by the reduction of WSCl₄ with NEt₄I in dichloromethane. If the reduction is performed with PPh₄I, PPh₄[WSCl₄] with monomer anions is formed. Reaction of WCl₆ with H₂S in dichloromethane yields brown, insoluble WS₂Cl₂ which has terminal W?S groups and bridging W? S? W groups according to its IR spectrum. WS₂Cl₂ and PPh₄Cl react to afford PPh₄[WS₂Cl₃] · 2 CH₂Cl₂ and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂. IR spectra are reported. The crystal structures of PPh₄[WSCl₄] and (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂ were determined by X-ray diffraction. PPh₄[WSCl₄]: tetragonal, space group P4/n, Z = 2, a = 1292.3 pm, c = 763.2 pm; R = 0.054 for 898 observed reflexions. The [WSCl₄]^? ion has the structure of a square pyramid with a rather short W?S bond of 206 pm length. (PPh₄)₂[WS₂Cl₄] · 2 CH₂Cl₂: triclinic, space group P1 , a = 1017.7, b = 1114.5, c = 1243.4 pm, α = 70.61, β = 79.73, γ = 80.80°; R = 0.076 for 1804 reflexions. The [WS₂Cl₄]^2? has cis configuration; as it is situated on an inversion center it shows positional disorder.     

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.     

Synthese und Kristallstrukturen von (PPh4)2[In(S4)(S6)Cl] und (PPh4)2[In(S4)Cl3]

Synthesis and Crystal Structures of (PPh₄)₂[In(S₄)(S₆)Cl] and (PPh₄)₂[In(S₄)Cl₃] InCl and PPh₄Cl yield (PPh₄)₂[In₂Cl₆] in acetonitrile. This reacts with Na₂S₄ in presence of PPh₄Cl, forming (PPh₄)₂[In(S₄)(S₆)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh₄)₂[In(S₄)(S₆)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S₄ and S₆ groups being bonded in a chelate manner. The reaction of (PPh₄)₂[In₂Cl₆] and sulfur in acetonitrile yielded (PPh₄)₂[InCl₅] and (PPh₄)₂[In(S₄)Cl₃]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S₄ group occupying one axial and one equatorial position; the S₄ group shows positional disorder.     

(PPh4)[(ReO2S2)CuI] und (NEt4)2[(ReOS3)Cu3Cl4]: Fixierung der bisher nicht isolierten Ionen [ReO2S2]− und [ReOS3]− durch Ausnutzung der Stabilität der CuS2(Re)- und Cu3S3(Re)-Fragmente

(PPh₄)[(ReO₂S₂)CuI] and (NEt₄)₂[ReOS₃)Cu₃Cl₄]: Fixation of the up to now not Isolated Ions [ReO₂S₂]^? and [ReOS₃]^? Utilizing the Stability of the CuS₂(Re) and Cu₃S₃(Re) Fragments (PPh₄)[(ReO₂S₂)CuI] ( 1 ) and (NEt₄)₂[ReOS₃)Cu₃Cl₄] ( 2 ) containing the up to now not isolated oxothioperrhenate ions [ReO₂S₂]^? and [ReOS₃]^? as ligands, have been prepared by the reaction of (NEt₄)[ReS₄] with PPh₃ and CuI in acetone in the presence of (PPh₄)I (( 1 )) or with CuCl in CH₂Cl₂ in the presence of (NEt₄)Cl (( 2 )), respectively. 1 and 2 have been characterized by X-ray structure analysis, elemental analysis and spectroscopic studies (IR, UV/Vis). The electronic spectra show bands which can approximately be assigned to interesting low-energy charge-transfer-transitions of the type d(Cu) → d(Re). For crystal data see Inhaltsübersicht.     

Reaktionen von Uranpentabromid Die Kristallstrukturen von PPh4[UBr6], PPh4 [UBr6] · 2CCl4, (PPh4)2[UBr6] · 4CH3CN und (PPh4)2[UO2Br4] · 2CH2Cl2

Reactions of Uranium Pentabromide. Crystal Structures of PPh₄[UBr₆], PPh₄[UBr₆] · 2CCl₄, (PPh₄)₂[UBr₆] · 4CH₃CN, and (PPh₄)₂[UO₂Br₄] · 2CH₂Cl₂ PPh₄[UBr₆] and PPh₄[UBr₆] · 2CCl₄ were obtained from UBr₅ · CH₃CN and tetraphenylphosphonium bromide in dichloromethane, the latter being precipitated by CCl₄. Their crystal structures were determined by X-ray diffraction. PPh₄[UBr₆]: 2101 observed reflexions, R = 0.090, space group C2/c, Z = 4, a = 2315.5, b = 695.0, c = 1805.2 pm, β = 96.38°. PPh₄[UBr₆] · 2CCl₄: 2973 reflexions, R = 0.074, space group P2₁/c, Z = 4, a = 1111.5, b = 2114.2, c = 1718.7 pm, β = 95.42°. Hydrogen sulfide reduces uranium pentabromide to uranium tetrabromide. Upon evaporation, bromide is evolved from solutions of UBr₅ with 1 or more then 3 mol equivalents of acetonitrile in dichlormethane yielding UBr₄ · CH₃CN and UBr₄ · 3CH₃CN, respectively. These react with PPh₄Br in acetonitrile affording (PPh₄)₂[UBr₆] · 4CH₃CN, the crystal structure of which was determined: 2663 reflexions, R = 0.050, space group P2₁/c, Z = 2, a = 981.8, b = 2010.1, c = 1549.3 pm, β = 98.79°. By reduction of uranium pentabromide with tetraethylammonium hydrogen sulfide in dichloromethane (NEt₄)₂[U₂Br₁₀] was obtained; (PPh₄)₂[U₂Br₁₀] formed from UBr₄ and PPh₄Br in CH₂Cl₂. Both compounds are extremely sensitive towards moisture and oxygen. The crystal structure of the oxydation product of the latter compound, (PPh₄)₂[U0₂Br₄]· 2 CH₂Cl₂, was determined: 2163 reflexions, R = 0.083, space group C2/c, Z = 4, a = 2006.3, b = 1320.6, c = 2042,5 pm, β = 98.78°. Mean values for the UBr bond lengths in the octahedral anions are 266.2 pm for UBr₆-, 276.7 pm for UBr₆^2? and 282.5 pm for UO₂Br₄^2?     

Mo2O3Cl4(Pyridin)4 · CH2Cl2 Synthese,IR-Spektrum und Kristallstruktur

Mo₂O₃Cl₄(Pyridine)₄ · CH₂Cl₂. Synthesis, IR Spectrum, and Crystal Structure Reduction of MoO₂Cl₂(pyridine)₂ with triphenylphosphane in toluene and recrystallisation from CH₂Cl₂ yields brown crystal needles of the complex Mo₂O₃Cl₄(pyridine)₄ · CH₂Cl₂. The compound crystallizes monoclinic in the space group P2₁/c with four formula units per unit cell of the dimensions a = 1 234.6 pm; b = 1 593 pm, c = 1 522.3 pm and β = 105.66° A structural investigation by X-ray methods (3 276 independent observed reflexions, R = 0.033) reveals the molecule with two molybdenum atoms in a distorted octahedral coordination linked by an almost linear Mo? O? Mo bridge with bond distances of 167 and 168 pm, respectively. The chlorine atoms are located in trans-position to the oxygen atoms which have different trans effects: The Mo? Cl bond opposite the bridge (length 242 pm) is 8 pm shorter than the bond in trans position to the terminal oxo ligands. The pyridine nitrogen atoms are in trans position to each other and complete the coordination of the molybdenum atoms. The i.r. spectrum of the compound is reported.     

Eine neue Form von PdSCl: Der molekulare Komplex Tris(μ4‐disulfido)‐hexa‐μ2‐chloro‐hexapalladium(II) [Pd6(S2)3Cl6]

The Molecular Complex Tris(μ₄‐disulfido)‐hexa‐μ₂‐chloro‐hexapalladium [Pd₆(S₂)₃Cl₆] A new hexameric form of PdSCl have been obtained by reaction of Pd metal with sulfur in SCl₂ solution at 180 °C in a closed silica ampoule. The monoclinic crystal structure of β‐PdSCl (space group P2₁ /m; a = 7.766(2)Å; b = 11.941(2)Å; c = 9.136(3)Å; β = 110.57(3)°; Z =12) is built up by clusters [Pd₆(S₂)₃Cl₆] with nearly D_3h symmetry. In the molecular units six Pd atoms form a trigonal prism with three S₂ disulfide groups in front of the side faces. The fourfold coordination of the Pd atoms is completed by 6 Cl atoms forming μ₂ bridges.     

Chlorthionitrenkomplexe des Rheniums Die Kristallstruktur von AsPh4[ReCl4(NSCl)2] · CH2Cl2

Chlorothionitrene Complexes of Rhenium. Crystal Structure of AsPh₄[ReCl₄(NSCl)₂] · CH₂Cl₂ Rhenium pentachloride reacts in POCl₃ solution with (NSCl)₃ forming the chlorothionitrene complexes [(Cl₃PO)ReCl₄(NSCl)] ( I ) and [(Cl₃PO)ReCl₃(NSCl)₂] ( II ). I reacts with AsPh₄Cl in CH₂Cl₂ solution under abstraction of SCl₂ and POCl₃, yielding AsPh₄[ReNCl₄], while II forms the complex AsPh₄[ReCl₄(NSCl)₂] · CH₂Cl₂. The i.r. spectra of the compounds are discussed and assigned. The crystal structure of AsPh₄[ReCl₄(NSCl)₂] · CH₂Cl₂ was determined and refined with X-ray diffraction data (R = 0.031 for 2785 reflexions). It crystallizes in the space group Pī with two formula units per unit cell; the lattice constants are a = 1119, b = 1144, c = 1473 pm, α = 77.6, β = 70.8 and γ = 71.2°. The two NSCl ligands have cis arrangement with nearly linear Re?N?S groups, with interatomic distances corresponding to double bonds. The Re? Cl bonds are somewhat longer than usual and show no trans-effect; this is possibly due to Cl…?H? C bridges.     

Synthesis and crystal structure of tetraethylammonium-μ-trichloro-heptachloro-diaqua-trirhenate(III)-dihydrate,NEt4[Re3Cl10(H2O)2] · 2 H2O

NEt₄[Re₃Cl₁₀(H₂O)₂] · 2 H₂O ( 1 ) was obtained from hydrochloric acid solutions of ReCl₃ and tetraethylammonium chloride, NEt₄Cl, by isothermal evaporation as dark red crystals. 1 crystallizes in the orthorhombic crystal system, space group Pnma, Z = 4, with a = 1838,7(2), b = 1456.9(1), c = 972.08(7) pm, V_m = 391.81(6) cm³ · mol^?l. The crystal structure consists of [Re₃Cl₁₀(H₂O)₂]^? anions that are arranged in the fashion of a hexagonal closest-packing of spheres. These are held together by partially disordered NEt₄⁺ cations and are bound into a hydrogen bonding system with the crystal water.