Chlorthionitrenkomplexe des Wolframs Die Kristallstruktur von [WCl4(NSCl)]2

Chlorothionitrene Complexes of Tungsten. Crystal Structure of [WCl₄(NSCl)]₂ Tungsten hexachloride reacts with trithiazyl chloride, (NSCl)₃, yielding the chlorothionitrene complex [WCl₄(NSCl)]₂, from which AsPh₄[WCl₅(NSCl)] can be obtained by reaction with AsPh₄Cl. Both complexes are characterized by their i.r. spectra. The crystal structure of [WCl₄(NSCl)]₂ was determined and refined with X-ray diffraction data (1059 reflexes, R = 0.055). It crystallizes in the monoclinic space group P2₁/n with the lattice constants a = 1523, b = 904, c = 583 pm and β = 91.35°. In the unit cell there are two centrosymmetric [WCl₄(NSCl)]₂ molecules in which the W atoms are linked via two chloro bridges; short and long W? Cl distances (244 and 265 pm) alternate in the W₂Cl₂ ring, the NSCl groups are found in the trans positions to the longer W? Cl bonds. The WNS bond angle (175°) and short bond distances correspond to a formulation .     

Cyclo-S2N2-verbrückte Chlorthionitrenkomplexe von Molybdän und Wolfram. Die Kristallstruktur von μ-(S2N2)[MoCl4(NSCl)]2

Cyclo-S₂N₂ Bridged Chlorothionitrene Complexes of Molybdenum and Tungsten. Crystal Structure of μ-(S₂N₂)[MoCl₄(NSCl)]₂ Molybdenum pentachloride reacts with (NSCl)₃ in CH₂Cl₂ suspension giving a product mixture from which the complex μ-(S₂N₂)[MoCl₄(NSCl)]₂ can be extracted with CH₂Cl₂. It forms black crystals, whereas the corresponding tungsten compound forms copper-red crystals. μ-(S₂N₂)[WCl₄(NSCl)]₂ is obtained by abstraction of SCl₂ and chlorine from N(SCl)₂[WCl₅(NSCl)], which can be obtained from WCl₆ and N₂S₃Cl₂. According to their i.r. spectra both complexes μ-(S₂N₂)[MCl₄(NSCl)]₂ have the same molecular structure. The crystal structure of μ-(S₂N₂)[MoCl₄(NSCl)]₂ was determined and refined with X-ray diffraction data (1851 reflexions, R = 0.019). It crystallizes in the triclinic space group P1 with two molecules per unit cell. The lattice constants are a = 685, b = 735, c = 963 pm, α = 76.6°, β = 80.9°, γ = 87.0°. μ-(S₂N₂)[MoCl₄(NSCl)]₂ forms centrosymmetric molecules in which the Mo atoms of the MoCl₄(NSCl) units are linked via the N atoms of a planar N₂S₂ ring. The Mo atoms have coordination number 6, having the N atom of the chlorothionitrene ligand Mo in trans position to the N atom of the S₂N₂ ring.     

Synthese und Kristallstruktur von (AsPh4)2[Cl5WNSNWCl5]

Synthesis and Crystal Structure of (AsPh₄)₂[Cl₅WNSNWCl₅] . The chlorothionitrene complex [WCl₄(NSCl)]₂ reacts with excess tetraphenylarsonium chloride via the intermediate AsPh₄[Cl₅W(NSCl)] to yield the title compound. This was characterized by its i.r. spectrum and an X-ray crystal structure determination (4078 reflexions uncluding Friedel pairs, R = 0.059). (AsPh₄)₂[Cl₅WNSNWCl₅] crystallizes in the monoclinic system, a = 1110.5, b = 1714.6, c = 1521.7 pm, β = 107.24°, Z = 2. The space group is either P2₁/n with anions statistically disordered in two different positions or Pn with an apparent higher symmetry due to the presence of inversion twins. Bond distances and angles correspond to the formula      

Synthese,IR-Spektrum und Kristallstruktur von PPh4[OsCl4(NO)(NSCl)]

Synthesis, I.R. Spectrum, and Crystal Structure of PPh₄[OsCl₄(NO)(NSCl)] Molten trithiazyl chloride reacts with OsCl₃(NO) to yield a product mixture consisting mainly of S₄N₃[OsCl₄(NO)(NSCl)] and S₄N₃Cl. Extraction of this mixture with a solution of tetraphenylphosphonium chloride in dichloromethane affords green (PPh₄)₂[OsCl₅(NO)] · 2 CH₂Cl₂ and the red title compound. PPh₄[OsCl₄(NO)(NSCl)] was characterized by its IR spectrum and an X-ray crystal structure analysis (3001 independent observed reflexions, R = 0.048). Crystal data: monoclinic, space group P2₁/c, Z = 4, a = 1716, b = 1054, c = 1588 pm, β = 96.25°. The compound consists of PPh₄⊕ cations and [OsCl₄(NO)(NSCl)]? anions in which the nitrosyl and the chlorothionitrene ligands have a cis arrangement. Due to positional disorder the NO and NSCl groups are superimposed statistically in the structure model.     

[ReCl3(NSCl)2(CH3CN)]. Synthese,IR-Spektrum und Kristallstruktur

[ReCl₃(NSCl)₂(CH₃CN)]. Synthesis, I. R. Spectrum, and Crystal Structure Black, moisture sensitive crystals of the title compound are obtained from [ReCl₃(NSCl)₂]₂ and acetonitrile in dichloromethane. The complex is characterized by its i.r. spectrum and an X-ray crystal structure determination (2483 observed independent reflexions, R = 0.035). Crystal data: triclinic, space group P1 , Z = 2, a = 681.8, b = 899.9, c = 1104.0 pm, α = 110.50, β = 97.90 and γ = 101.34°. In the monomeric [ReCl₃(NSCl)₂(CH₃CN)] molecule the Re atom has a distorted octahedral coordination with meridional arrangement of the Cl atoms. The chlorothionitrene ligands have nearly linear ReNS groups with bond lengths that correspond to double bonds (ReN 178 and 179 pm); this agrees with the NReN bond angle of 100°.     

Chlorthionitrenkomplexe des Molybdäns

Chlorothionitrene Complexes of Molybdenum Molybdenum pentachloride reacts with trimer thiazylchloride, (NSCl)₃, forming the chlorothionitrene complex \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm Cl}_4 {\rm Mo} = \mathop {\rm N}\limits^ \oplus = \mathop {{\rm SCl}}\limits^ \ominus $\end{document}, in which the chlorothionitrene ligand is to be understood as (NSCl)^2? group. I reacts with phosphorylchloride forming the solvate Cl₃PO? Mo(Cl₄)(NSCl) ( II ) that can also be obtained directly from MoCl₅ · OPCl₃ and trithiazylchloride. II reacts with chloride ions giving the anionic chlorothionitrene complex [Cl₅Mo(NSCl)]? ( III ). Thermal decomposition of I leads to MoNCl₃ under SCl₂ cleavage, while reaction of I with chloride ions gives [MoNCl₄]?. Both reactions prove chlorothionitrene complexes to be excellent precursors for the syntheses of nitrido complexes. The complexes I—III have been characterized by IR spectroscopy.     

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.     

[ReCl2(NS)(NSCl)(Pyridin)2], ein Thionitrosyl-chlorthio-nitrenkomplex des Rheniums

[ReCl₂(NS)(NSCl)(Pyridine)₂], a Thionitrosyl-chlorothionitrene Complex of Rhenium The title compound was obtained by the reaction of pyridine with either [ReCl₃(NSCl)₂POCl₃] or [ReCl₃(NSCl)₂]₂ · (μ-N₂S₂) under the reducing action of dichloromethane. It is slightly soluble in CH₂Cl₂, from which it can be obtained in form of black crystals. The IR spectrum is reported. The crystal structure of [ReCl₂(NS)(NSCl)(Pyridine)₂] was determined by X-ray diffraction (R = 0.027 for 2105 observed reflexions). Crystal data: a = 1551.6, b = 694.9, c = 1513.2 pm, β = 96.50°, space group P2₁/c, Z = 4. In the monomer molecules, each rhenium atom has a distorted octahedral coordination of two cis-chlorine atoms, two cis-nitrogen atoms of the pyridine ligands and two cis-nitrogen atoms of the thionitrosyl and chloro thionitrene ligands. One of the pyridine groups is in trans position to the nearly linear thionitrosyl group (angle ReNS 176°) with distances ReN of 177 pm and NS of 152 pm. However, in the trans position of the chlorothionitrene group (angle ReNS 159°, distances ReN 189 pm, NS 149 pm) a chlorine atom is found.     

N(SCl)2 ⊕[MoCl5(NSCl)]⊖, ein Chlorthionitrenokomplex von Molybdän(VI)

N(SCl)₂^⊕ [MoCl₅(NSCl)]^?, a Chlorothionitrene Complex of Molybdenum (VI) . The title compound is formed together with MoCl₃(N₃S₂) by the reaction of MoCl₄ or MoCl₅ with (NSCl)₃ in CH₂Cl₂. The black, crystalline compound was characterized by its i.r. spectrum and an X-ray crystal structure determination. N(SCl)₂^⊕[MoCl₅(NSCl)]^? crystallizes in the monoclinic space group P2₁/n with four formula units per unit cell. The lattice constants are a = 716.3, b = 1627.4, c = 1178.9 pm and β = 100.90°. The [MoCl₅(NSCl)]^? ion posseses an almost linear Mo = N = S grouping with bond lengths that can be interpreted as double bonds. Crystal data for AsPh₄[MoCl₅(NSCl)] are reported.     

Funktionalisierte Alkinkomplexe von Wolfram(VI). Synthese und Kristallstrukturen von [WCl4(Et?Se?CC?Se?Et)(THF)] und [WCl4(Et?Te?CC?Te?Et)(THF)]

Functionalized Alkyne Complexes of Tungsten(VI). Syntheses and Crystal Structures of [WCl₄(Et? Se? C?C? Se? Et)(THF)] and [WCl₄(Et? Te? C?C? Te? Et)(THF)] The title compounds have been prepared by reactions of [WCl₄(SEt₂)₂] with the alkynes Et? X? C?C? X? Et (X = Se, Te) in CCl₄ solution and subsequent addition of tetrahydrofurane. Both complexes were characterized by crystal structure determinations. [WCl₄(Et? Se? C?C? Se? Et)(THF)]: Space group P2₁/n, Z = 4, structure determination with 2942 unique reflections, R = 0.038. Lattice dimensions at 20°C: a = 934.2, b = 1639.5, c = 1189.5 pm, β = 96.497°. [WCl₄(Et? Te? C?C? Te? Et)(THF)]: Space group P2₁/n, Z = 4, structure determination with 4097 unique reflections, R = 0.067, Lattice dimensions at ?70°C: a = 899.2, b = 1691.9, c = 1213.3 pm, β = 96.82°. The complexes have monomeric molecular structures with the oxygen atom of the THF molecules in trans-position to the side-on bound alkyne ligands.     

Zur Chemie der Chlorthionitrenkomplexe des Rheniums Die Kristallstruktur von [N(SCl)2]⊕ [Re2Cl9]⊖

Chemistry of Chlorothionitrene Complexes of Rhenium. Crystal Structure of [N(SCl)₂]⊕ [Re₂Cl₉]? By reaction of S₃N₂Cl₂ with ReCl₅ the chlorothionitrene complex [ReCl₃(NSCl)₂]₂ is obtained in good yield; it has a dimer structure with chloro bridges. By the same reaction in POCl₃ solution the solvate [ReCl₃(NSCl)₂OPCl₃] is obtained. Instead, when a molar ratio of ReCl₅ and S₃N₂Cl₂ of 2:1 is taken, the product is [N(SCl)₂][Re₂Cl₉]. [ReCl₄(NSCl)OPCl₃] and excess PPh₃ react to give the nitrido complex [ReNCl₂(PPh₃)₂]. The crystal structure of [N(SCl)₂][Re₂Cl₉] was determined and refined with X-ray diffraction data (1021 independent reflexions, R = 0.031). It crystalizes in the space group C2/c with four formula units per unit cell (a = 1197, b = 1288, c = 1144 pm, ß = 107.83°). The [N(SCl)₂]⊕ cations have exactly C₂ and approximately C_2v symmetry; the NS bond lengths of 162 pm and the bond angles SNS (133.6°) and NSCl (117.6°) deviate considerably from the values of known [N(SCl)₂]⊕ structures. The [Re₂Cl₉]? anion consists of two face sharing octahedra and has a Re—Re distance of 270 pm. I. r. spectra of all compounds are reported and discussed.     

Diphenyl-diacetylen-Komplexe von Molybdän(IV) und Wolfram(IV). Die Kristallstrukturen von PPh4[WCl5(Ph?CC?CC?Ph)] · CCI4 und von PPh4[WCl5(Ph?CC?C(Br)C(Br)?Ph)] · CCl4

Diphenyldiacetylene Complexes of Molybdenum (IV) and Tungsten (IV). Crystal Structures of PPh₄[WCl₅(Ph? C?C? C?C? Ph)] · CCl₄ and PPh₄[WCl₅(Ph? C?C? C(Br)?C(Br)? Ph)] · CCl₄ Syntheses and i.r. spectra of the following diphenyldiacetylene complexes are reported: [MoCl₄(Ph? C?C? C?C? Ph)]₂( 1 ), [WCl₄(Ph? C?C? C?C? Ph)]₂ ( 2 ), PPh₄[WCl₅(Ph? C?C? C?C? Ph)] · CCl₄ ( 3 ). 1 is formed in the reaction of MoCl₅ with excess diphenyldiacetylene. 2 is prepared from WCl₆ and excess diphenylacetylene with additional C₂Cl₄ as a reducing agent. Reaction of 2 with PPh₄Cl in CH₂Cl₂ solution in the presence of CCl₄ yields 3 . The complexes contain one of the acetylene functions bonded in a metallacyclopropene ring; the metal atoms are seven-coordinated. 2 reacts with bromine to from the dibromide [WCl₄(Ph? C?C? C(Br)? Ph)]₂ (4). In CH₂Cl₂ solution and in presence of ccl₄ 4 is turned into the ionic complex PPh₄[Ph? C?C? C(Br)? Ph] · CCl₄ (5) by PPh₄Cl. The complexes 3 and 5 are characterized by structural analyses on the basis of X-Ray diffraction data. 3 crystallized monoclinic in the space group p2₁/n with four formula units per unit cell (2623 observed, independent reflexions, R = 5.4%). 5 crystallized in the same space group, set P2₁/c, the unit cell containing four formula units (2537 observed, independent reflexions, R = 5.4%). Both complexes consist of tetraphenylphosphonium cations and anions, in which the tungsten atoms are coordinated by five chlorine and two carbon atoms, the latter bonding side-on, in an approximately symmetrical way. In addition the lattices contain one molecule CCl₄ per formula unit. The acetylene ligand causes a strong trans-effect. As a result the W? Cl bond lengths in trans-position are by 10 pm longer than those in cis-position. Bromination of the second acetylene function of 3 leads to addition in trans-position (5).     

Coordinatively unsaturated alkyne complexes: synthesis of mono and bis-alkyne complexes of tungsten (II)

[WBr₂(CO₄]_n reacts with alkynes to give complexes [WBr₂CO(RCCR)₂]₂ (1) (R = R′ = Me, Et, Ph; R = Me, R′ = Ph), which react with nucleophiles L{L = CNBu^t, PPh₃, or P(OMe)₃} to give monoalkyne derivatives (WBr₂(CO)(RCCR′)L₂](2). An intermediate bis-alkyne adduct [WBr₂CO(MeCCMe)₂(CNBu^t)] (3) was isolated in the reaction of [WBr₂CO(MeCCMe)₂]₂ with CNBu^t illustrating that cleavage of the dimer (1) is the first stage in these reactions.     

Komplexe des Rheniums mit planarer ReN2S2-Fünfringstruktur Synthesen und Kristallstrukturen von AsPh4[ReCl4(N2S2)] und PPh4[ReBr4(N2S2)]

Complexes of Rhenium with Planar ReN₂S₂ Rings. Syntheses and Crystal Structures of AsPh₄[ReCl₄(N₂S₂)] and PPh₄[ReBr₄(N₂S₂)] The complex [ReCl₄(N₂S₂)]^? can be obtained as PPh₄^⊕ or AsPh₄^⊕ salt by the action of S(NSiMe₃)₂ and of diphenylacetylene, respectively, on the chlorothionitrene complex [ReCl₄(NSCl)₂]^?. Another method of synthesis is the reaction of [ReCl₃(NSCl)₂(POCl₃)] with SbPh₃. [ReBr₃(N₂S₂)]₂ is obtained from excess Me₃SiBr and [ReCl₃(NSCl)₂(POCl₃)]. The anionic complex [ReBr₄(N₂S₂)]^? forms from either [ReCl₄(NSCl)₂]^? or [ReCl₄(N₂S₂)]^? with Me₃SiBr. All compounds are black, diamagnetic, and sensitive to moisture; the PPh₄^⊕ and AsPh₄^⊕ salts are soluble in CH₂Cl₂ and CH₂Br₂. The IR spectra are reported. The crystal structures of AsPh,₄[ReCl₄(N₂S₂)] and PPh₄[ReBr₄(N₂S₂)] were determined by X-ray diffraction. AsPh₄[ReCl₄(N₂S₂)]: space group P2/n, Z = 2, a = 1244.5, b = 1429.3, c = 791.1 pm, γ = 96.89° (1715 observed reflexions, R = 0.082). PPh₄[ReBr₄[ReBr₄(N₂S₂)]: space group P2₁/n, Z = 4, a = 961.7, b = 1397.4, c = 2205.7 pm, β = 102.10° (1787 observed reflexions, R = 0.073). In both compounds the [ReX₄(N₂S₂)]? anions have the same type of structure, the Re atoms forming part of planar ReN₂S₂ rings; the bond lengths are ReN 177 pm, NS 152 pm, and SS 259 for the chloro compound and ReN 184 pm, NS 153 pm, and SS 264 pm for the bromo compound. In AsPh₄[ReCl₄(N₂S₂)] the cations are stacked to form columns in the c-direction; in PPh₄[ReBr₄(N₂S₂)], there is considerable distortion form this packing principle.     

Dichloracetylen als stabiler Komplexligand Die Kristallstruktur von PPh4[WCl5(C2Cl2)] · 0,5 CCl4

Dichloro Acetylene as Complex Ligand. Crystal Structure of PPh₄[WCl₅(C₂Cl₂)] · 0.5 CCl₄ Tungsten hexachloride and dichloro acetylenediethyletherate react in boiling CCl₄ in presence of C₂Cl₄ as reducing agent forming [Et₂O · WCl₄(C₂Cl₂)]. In vacuo the complex looses ether giving the dichloro acetylene complex [WCl₄(C₂Cl₂)]₂ which is dimeric with chloro bridges. Both complexes react with tetraphenylphosphonium chloride to form PPh₄[WCl₅(C₂Cl₂)] which is equally prepared by ligand exchange of PPh₄[WCl₅(C₂I₂)] with silver chloride. All dichloro acetylene complexes are red to brown crystalline solids sensitive to moisture, and are thermally and mechanically very stable compared with the highly explosive dichloro acetylene. The compounds are characterized by their i.r. spectra; [Et₂O · WCl₄(C₂Cl₂)] was additionally investigated by ¹³C-nmr spectroscopy. PPh₄[WCl₅(C₂Cl₂)] · 0.5 CCl₄ formes dark brown crystals; according to the structural investigation by X-ray diffraction methods the compound crystallizes orthorhombic in the space group Pbca with 8 formula units per unit cell (1317 observed, independent reflexions, R = 0.049). The cell dimensions are a = 1702 pm, b = 1675 pm and c = 2228 pm. The compound consists of [WCl₅(C₂Cl₂)]? anions and PPh₄⊕ cations including CCl₄ molecules without bonding interactions. The tungsten atoms are seven-coordinated by five chlorine atoms and two carbon atoms. The dichloro acetylene ligand is bonded symmetrically side-on and has a C? C bond length of 128 pm. The W? C distances are 201 pm, the four equatorial Cl atoms have W? Cl bond lengths of 234 pm whereas the chlorine atom in trans-position to the W? C₂ group is situated in a distance of 244 pm.     

Heteromolecular insertion of EtNCX (X = O, S) and RCN (R = CH3, C6H5) into tungsten hexachloride

The interactions of tungsten hexachloride with EtNCX (X = O, S) and RCN (R = CH₃, C₆H₅) were studied. In the case of E = CH₃, heterocumulenes are inserted at the W-Cl bond, while in the case of R = C₆H₅, they were inserted at a multiple tungsten-nitrogen bond of an intermediate imido complex [WCl₄(NCPh)(CNCl₂Ph)]. The IR, MALDI TOFF mass spectroscopy, and elemental analysis data confirmed that these interactions yielded the products of heteromolecular insertion, namely, [WCl₄{(EtNCO)₂(MeCN)Cl}], [WCl₄(EtNCS)₂(MeCN)Cl], [WCl₄N(CCl₂Ph)C(=NEt)O}], and WCl₄N(CCl₂Ph)C(=NEt)S}], whose compositions and structures were determined by the nature of the organic nitrile radical.     

Tribrom-methylnitren-Komplexe des Wolframs Die Kristallstruktur von PPh3Me[WBr5(NCBr3)]

Tribromomethylnitrene Complexes of Tungsten. Crystal Structure of PPh₃Me[WBr₅(NCBr₃)] Tungsten hexabromide reacts with BrCN in boiling bromine under formation of the BrCN adduct of tribromomethylnitrene tungsten, [BrCN? WBr₄(NCBr₃)]. This reacts with triphenylmethylphosphonium bromide in dibromomethane forming the tribromomethylnitrene pentabromowolframate, PPh₃Me[WBr₅(NCBr₃)]. Both compounds form brown-black, moisture sensitive crystal powders that were characterized by their IR spectra. The crystal structure of PPh₃Me[WBr₅(NCBr₃)] was determined by X-ray diffraction (3 664 observed reflexions, R = 0.066). Crystal data: a = 1 401.6, b = 1 243.3, c = 884.6 pm, α = 90.82, β = 110.74, γ = 90.67°, space group P1 , Z = 2. The compound consists of PPh₃Me^⊕ cations and [WBr₅(NCBr₃)]^? anions in which the tungsten atoms have a distorted octahedral coordination by five bromine atoms and the N atom of the nitrene ligand. The WN bond length of the nitrene ligand (175 pm) corresponds approximately to a triple bond; the W?N? C group is linear and shows a strong trans effect.     

S4N3⊕[ReCl4(NSCl)2]⊖ Synthese und Kristallstruktur

S₄N₃^⊕[ReCl₄(NSCl)₂]^?. Synthesis and Crystal Structure S₄N₃^⊕[ReCl₄(NSCl)₂]^? is formed as a byproduct in the reaction of Re₂(CO)₁₀ with excess trithiazyl chloride. The compound is characterized by a crystal structure analysis by X-ray methods. S₄N₃[ReCl₄(NSCl)₂] crystallizes in the noncentrosymmetric space group P2₁2₁2₁ with four formula units per unit cell and the lattice dimensions a = 980, b = 1205, c = 1362 pm (2376 observed, independent reflexions; R = 0.076). The compound consists of the well known cyclic planar S₄N₃^⊕-cations and anions [ReCl₄(NSCl)₂]^?, in which the rhenium atom is coordinated octahedral by four Cl atoms and two cis-positioned NSCl ligands. The mean Re? N and N? S bond lengths (177 pm and 158 pm) correspond to double bonds. The bond lengths and angles are much like in the structure of AsPh₄[ReCl₄(NSCl)₂]; however the chlorine atoms of the NSCl ligands are turned to each other.     

Synthese und Kristallstrukturen der Wolfram(VI)-Alkin-Komplexe [W2(O)(OMe)6(Et?Se?CC?Se?Et)2] und Li[W(OMe)5(Et?Te?CC?Te?Et)]

Synthesis and Crystal Structures of the Tungsten(VI)-alkyne Complexes [W₂(O)(OMe)₆(Et? Se? C?C? Se? Et)₂] and Li[W(OMe)₅(Et? Te? C?C? Te? Et)] The title compounds have been prepared by reactions of lithium methanolate with [WCl₄(Et? Se? C?C? Se? Et)(THF)] and [WCl₄(Et? Te? C?C? Te? Et)(THF)], respectively, in diethylether suspensions. Both complexes were characterized by crystal structure determinations. [W₂(O)(OMe)₆(Et? Se? C?C? Se? Et)₂]: Space group P1 , Z = 2, structure determination with 4 320 observed unique reflections, R = 0.041. Lattice dimensions at ?70°C: a = 949.3, b = 1 225.3, c = 1 285.0 pm, α = 82.48°; γ = 82.44°; β = 81.44°. The tungsten atoms are bridged by three μ₂-O-atoms of the OMe groups; the alkyne ligands are coordinated side-on in a metallacyclopropene-like fashion. Li[W(OMe)₅(Et? Te? C?C? Te? Et)]: Space group P1 , Z = 2, structure determination with 9 381 observed unique reflections, R = 0.038. Lattice dimensions at ?70°C: a = 983.4, b = 1606.9, c = 1971.5 pm, α = 66.09°, β = 84.29°, γ = 79.83°. The lithium ions link the [W(OMe)₅(Et? Te? C?C? Te? Et)]^? anions to a trimeric ion ensemble via the O atoms of three OMe groups of each anion.