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.     

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.     

Die Kristallstrukturen von [ReCl4(PhCCPh)]2 · 2 CH2Cl2 und von PPh4[ReOCl4]

Crystal Structures of [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂ and PPh₄[ReOCl₄] Single crystals of [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂ were obtained by chilling dilute solutions of the solvate [ReCl₄(PhC?CPh)POCl₃] in CH₂Cl₂. PPh₄[ReOCl₄] was formed by the reaction of the diphenyl acetylene complex [ReCl₅(PhC?CPh)] with PPh₄Cl · H₂O in CH₂Cl₂ solution. [ReCl₄(PhC?CPh)]₂ · 2 CH₂Cl₂: space group P2₁/c, Z = 2, 2244 observed independent reflexions, R = 0.038. Lattice parameters (19°C): a = 987.2 pm; b = 1533.9 pm; c = 1193.8 pm; β = 90.17° The compound forms centrosymmetrical dimeric molecules with ReCl₂Re bridges with Re? Cl distances of 241.2 and 267.6 pm. The longer Re? Cl bond is situated in trans-position to the equatorial, side-on coordinated diphenyl acetylene ligand with mean Re? C distances of 200 pm. PPh₄[ReOCl₄]: space group P4/n, Z = 2, 1487 observed, independent reflexions, R = 0.047. Lattice parameters (19°C): a = b = 1272.0 pm; c = 771.3 pm. The compound crystallizes in the AsPh₄[RuNCl₄] type; it consists of [ReOCl₄]^? anions and PPh₄⁺ cations. The anions are tetragonal with C_4v symmetry and bond lengths Re? O = 165.4 pm and Re? Cl = 232.6 pm; the bond angle OReCl is 106.7°.     

(PPh4)2[Cl2Re(N3S2)(μ‐NSN)(μ‐N≡ReCl3)]2 – ein Rhenium(VII)‐Komplex mit einer Nitrido‐, einer Dinitridosulfato(II)‐ und einer Rhena‐3,5‐dithia‐2,4,6‐triazino‐Funktion

(PPh₄)₂[Cl₂Re(N₃S₂)(μ‐NSN)(μ‐N≡ReCl₃)]₂ – a Rhenium(VII) Complex with a Nitrido, a Dinitridosulfato(II), and a Rhena‐3,5‐dithia‐2,4,6‐triazino Function The title compound has been prepared from PPh₄[Re^VIICl₄(NSCl)₂] with N(SiMe₃)₃ in dichloromethane solution to give red‐brown single crystals, which were suitable for a crystal structure determination. As a by‐product PPh₄[ReNCl₄] is formed. (PPh₄)₂[Cl₂Re^VII(N₃S₂)(μ‐NSN)(μ‐N≡Re^VIICl₃)]₂ ( 1 ): Space group P2₁/c, Z = 2, lattice dimensions at –80 °C: a = 1280.8(2), b = 1017.5(1), c = 2467.8(3) pm, β = 95.04(1)°, R = 0.049. The complex anion of 1 consists of a planar ReN₃S₂‐heterocycle which is connected with the second rhenium atom by a μ‐nitrido bridge as well as by a μ‐dinitridosulfato(II) ligand to form a planar Re₂(N)(NSN) six‐membered heterocycle. This [Cl₂Re(N₃S₂)(μ‐NSN)(μ‐N≡ReCl₃)]^– unit dimerizes via one of the N‐atoms of the (NSN)^4– ligand to give a centrosymmetric Re₂N₂ four‐membered ring.     

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.     

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.     

Thionitrosylkomplexe des Rutheniums. Die Kristallstruktur von (PPh4)2[{RuBr4(NS)}2(μ-N2S2)]

Thionitrosyl Complexes of Ruthenium. Crystal Structure of (PPh₄)₂[{RuBr₄(NS)}₂ (μ-N₂S₂)] Ruthenium trichloride reacts with trithiazyl chloride, yielding cis-RuCl₄ (NS)₂. With triphenylmethylphosphonium chloride this forms the complex [RuCl₄(NS)₂Cl]^? in which a chloride ion is bonded between the sulfur atoms in a chelate manner. With tetraphenylphosphonium bromide, RuCl₄(NS)₂ undergoes a redox reaction that affords (PPh₄)₂[{RuCl₄(NS)}₂(μ-N₂S₂)] which can be transformed to the title compound by the action of trimethylsilyl bromide. The i.r. spectra are reported. The crystal structure of (PPh₄)₂[{RuBr₄(NS)}₂(μ-N₂S₂)] · 4 CH₂X₂ (X ? Cl, Br) was determined with X-ray diffraction data (1534 observed reflexions, R = 0.085). Crystal data: monoclinic, space group P2₁/n, Z = 2, a = 1680.7, b = 1287.0, c = 1706.1 pm and β = 99.97°. The compound consists of tetraphenylphosphonium cations, CH₂Br₂ and CH₂Cl₂ molecules (statistically) and centrosymmetric anions [{RuBr₄(NS)}₂(μ-N₂S₂)]^2? in which the ruthenium atoms are linked via the nitrogen atoms of a planar N₂S₂ ring. In the corresponding trans-positions every Ru atom has a thionitrosyl ligand with a nearly arrangement Ru?N?S with RuN and NS bond lengths of 169 und 151 pm, respectively. Four bromine atoms complete the distorted octahedral coordination of each ruthenium atom. The bromine atoms that are coplanar with the N₂S₂ ring form rather short Br…?S contacts with a mean distance of 317 pm.     

S5N5⊕[RuCl3(CO)3]⊖ · 0,5 CH2Cl2 Synthese,IR-Spektrum und Kristallstruktur

S₅N₅^⊕[RuCl₃(CO)₃]^⊖ · 0.5 CH₂Cl₂. Synthesis, I.R. Spectrum and Crystal Structure S₅N₅[RuCl₃(CO)₃] · 0.5 CH₂Cl₂ is prepared from Ru₃(CO)₁₂ and trithiazylchloride in boiling dichloromethane; it forms red crystals, which are characterized by it's IR spectrum and by structural determination with X-ray methods. The compound crystallizes monoclinic in the space group C2/c with 8 formula units per unit cell. The lattice dimensions are a = 2047, b = 1064, c = 1637 pm, β = 96.1° (3487 independent, observed reflexions, R = 0.075). The structure consists of planar, cyclic S₅N₅^⊕ cations in the “azulene” conformation with bond lengths SN from 155 to 159 pm, and octahedral [RuCl₃(CO)₃]^⊖ anions with fac-geometry and bond lengths Ru Cl of 242 pm and Ru C of 185 to 190 pm.     

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.     

(PPh4)2[MoN(N3)3Cl]2; Synthese,IR-Spektrum und Kristallstruktur

(PPh₄)₂[MoN(N₃)₃Cl]₂; Synthesis, IR Spectrum, and Crystal Structure The title compound is formed in the reaction of molybdenum (II) benzoate with trimethylsilyl azide and PPh₄Cl in dichloro methane forming dark red single crystals. A PPh₃Me⊕ salt of the ion [MoN(N₃)₃Cl]₂^2? is obtained from (PPh₃Me)₂MoNCl₄] treated with silver azide in CH₂Cl₂ suspension. The solvent CH₂Cl₂ participates in both reactions as oxidizing agent. (PPh₄)₂[MoN(N₃)₃Cl₂ is characterized by a structural analysis based upon X-ray data: space group P1 , Z = 1, a = 1050.7 pm; b = 1185.4 pm; c = 1190.8 pm; α = 98.90°; β = 106.87°; γ = 103.97° (4505 independent, observed reflexions, R = 0.039). The compound consists of PPh₄⊕ cations and centrosymmetric anions [MoN(N₃)₃Cl₂^2? in which the molybdenum atoms are bridged by the N_α atoms of two azide groups; the resulting Mo? N bond lengths are 208 pm and 260 pm. In trans position to the long Mo? N bond the terminal nitrido ligand is situated, the Mo?N distance of 164 pm corresponds to a triple bond. Two terminal azido ligands and the chloro ligand are filling up the coordination sphere of the molybdenum atoms to a coordination number of six. The i.r. spectrum is reported and assigned.     

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.     

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.     

Cyclothiazenokomplexe von Molybdän(V) und (VI), sowie von Wolfram(VI) Die Kristallstruktur von (PPh4)2[MoCl3(N3S2)]2 · 2 CH2Cl2

Cyclothiazeno Complexes of Molybdenum(V), Molybdenum(VI), and Tungsten(VI). Crystal Structure of (PPh₄)₂[MoCl₃(N₃S₂)]₂ · 2 CH₂Cl₂ . From excess trithiazylchloride and molybdenum or tungsten hexacarbonyl, respectively, the cyclothiazeno complexes [MCl₃(N₃S₂)]₂(S₂N₂) are obtained. They possess metal atoms linked via a planar S₂N₂ ring. The corresponding bromo compounds [MBr₃(N₃S₂)]₂(S₂N₂) can be obtained in liquid bromine from S₄N₄ and MoBr₄ or WBr₆, respectively, or from S₄N₄ with the corresponding metal hexacarbonyls in the presence of bromine. Thermolysis of [WBr₃(N₃S₂)]₂(S₂N₂) yields [WBr₃(N₃S₂)]₂ which is dimerized via nitrogen bridges. When [MoCl₃(N₃S₂)]₂(S₂N₂) reacts with tetraphenylphosphonium chloride in dichloromethane, the S₂N₂ acts as reducing agent, and the paramagnetic molybdenum(V) complex (PPh₄)₂[MoCl₃(N₃S₂)]₂ · 2 CH₂Cl₂ is obtained (μ_eff = 1.2 B.M.). The i.r. spectra are reported. The crystal structure of (PPh₄)₂[MoCl₃(N₃S₂)]₂ · 2 CH₂Cl₂ was determined by X-ray diffraction (2524 independent reflexions, R = 0.052). It crystallizes in the space group P1 with the lattice con- stants a = 943.9, b = 1209.6, c = 1469.2 pm, α = 69.27, β = 72.20 and γ = 82.08°, Z = 1. There are tetraphenylphosphonium cations and centrosymmetric, dimeric anions [MoCl₃(N₃S₂)]₂^2?. The molybdenum atoms are part of six-membered cyclothiazeno rings MoN₃S₂ with MoN bond lengths of 177 and 197 pm; the N atom with the longer MoN bond is linked to the second Mo atom, so that a planar Mo₂N₂ ring results; this ring is nearly coplanar with the two MoN₃S₂ rings. Furthermore, each molybdenum atom is linked with three chlorine atoms with MoCl bond lengths of 240–242 pm, so that the Mo atoms possms a distorted octahedral coordination.     

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.     

Synthese und Kristallstruktur von SMe3 ⊕[MoBr4(SMe2)2]−

Synthesis and Crystal Structure of SMe₃^⊕ [MoBr₄(SMe₂)₂]^? . The title compound is obtained from MoBr₄ and excess dimethyl sulfide, forming red crystals which are only slightly sensitive to moisture. Whereas the intermediately formed adduct of MoBr₄ and SMe₂ is unstable, the stable adduct [Mo(NO)₂Br₂(SMe₂)₂] can be prepared from Mo(NO)₂Br₂ and SMe₂. According to the structural analysis by X-ray methods, SMe₃ ^⊕[MoBr₄(SMe₂)₂]^? crystallizes orthorhombic in the space group Imma with eight formula units per unit cell, the cell dimensions being a = 1578, b = 2820, c = 856 pm (1303 observed, independent reflexions). The compound consists of S(CH₃)₃^⊕ cations with S? C bond lengths of 180 pm and C? S? C bond angles of 102° and 103° resp., and anions [MoBr₄(SMe₂)₂]^?. The molybdenum atom is coordinated octahedral by four bromine atoms in equatorial positions and the two S atomes of the SMe₂ donor molecules in axial sites with Mo? S bond lengths of 254 pm.     

Synthese und Kristallstruktur von (PPh4)2[Mo2NCl9]2, einem μ-Nitridokomplex mit Molybdän(V), und -(VI)

Synthesis and Crystal Structure of (PPh₄)₂[Mo₂NCl₉]₂, a μ-Nitrido Complex with Molybdenum (V) and (VI) The title compound is formed as a by-product in the partial oxidation of Mo₂NCl₇ with chlorine in POCl₃ solution, when the reaction mixture is treated with PPh₄Cl. The crystals, which are sensitive to moisture, are black in reflectance and red in transmittance. A more effective synthesis is the direct reaction of PPh₄[MoNCl₄] with MoCl₅ in dichloro methane. (PPh₄)₂[Mo₂NCl₉]₂ was characterized by the i.r. spectrum and by a structural analysis with X-ray data. The compound crystallizes triclinic in the space group P1 with two formula units per unit cell (9225 independent observed reflexions, R = 0.058). The cell parameters are (20°C): a = 1144 pm, b = 1517 pm, c = 2000 pm, α = 79.8°, β = 80.1°, γ = 72.1°. (PPh₄)₂[Mo₂NCl₉]₂ consists of PPh₄⊕ cations and the anions [Mo₂NCl₉]₂^22?, which dimerize via chloro bridges with Mo? Cl bons lengths of 243 pm and 287 pm. In the [Mo₂NCl₉]₂^2? units the molybdenum atoms are linked by Mo^VI?N? Mo^V bridges (bond angles 179° and 174°, resp.) with Mo? N bond lengths of 167 pm and 212 pm.     

3-Chloro-1,2,3,4-tetraphenylcyclobutenyl-Ennea-chloro-μ-Oxo-di-Niobat(V),[C4Cl(Ph)4]⊕[Nb2OCl9]⊖ Synthese und Kristallstruktur

3-Chloro-1,2,3,4-tetraphenylcyclobutenyl-Ennea-chloro-μ-Oxo-di-Niobate(V), [C₄Cl(Ph)₄]^⊕[Nb₂OCl₉]^?. Synthesis and Crystal Structure The title compound yields from a one step reaction of niobium pentachloride and niobium oxide trichloride with diphenyl acetylene in dichloro methane, forming dark green crystals. The new complex is characterized by the i.r. spectrum and a crystal structure determination by X-ray methods. The compound crystallizes triclinic in the space group P1 with two formula units per unit cell (2253 independent observed reflexions, R = 4.7%). The lattice dimensions are a = 1199, b = 1034, c = 1453 pm; α = 87.0°, β = 108.6°, γ = 96.6°. The cyclobutenyl cation forms an almost planar C₄-ring with two pairs of neighbouring C? C bonds of 139 pm and 153 pm. The anion [Nb₂OCl₉]^? displays a nearly linear NbONb axis (bond angle 174°) in which the NbO bond lengths are 176 pm and 208 pm. Two anions are linked via asymmetric chloro bridges with Nb? Cl bond lengths of 248 pm and 270 pm to form a centrosymmetric dimer.     

Diiodacetylenkomplexe von Wolfram(IV). Die Kristallstruktur von PPh4[WCl5(C2l2)] · 0,5 CH2Cl2

Diiodoacetylene Complexes of Tungsten(IV). Crystal Structure of PPh₄[WCl₅(C₂I₂)] · 0.5 CH₂Cl₂ Tungsten hexachloride and diiodoacetylene react in CCl₄ solution forming [WCl₄(I? C?C? I)]₂ which has a dimer structure with chloro bridges. In CH₂Cl₂, it reacts with PPh₄Cl yielding PPh₄[WCl₅(I? C?C? I)] · 0.5 CH₂Cl₂. In both compounds the C₂I₂ ligands attain a marked increase in thermal stability by their side-one coordination to the tungsten atoms. The crystal structure of the PPh₄^⊕ salt was determined with X-ray diffraction data (3879 observed reflexions, R = 0.050). PPh₄[WCl₅(C₂I₂)] · 0.5 CH₂Cl₂ crystallizes in the space group P2₁/n with 8 formula units per unit cell. The lattice constants are a = 1723.0, b = 1681.2, c = 2214.6 pm and β = 94.38°. There are two crystallographically independent [WCl₅(C₂I₂)]^? ions which differ only slightly from one another. The C₂I₂ ligand has a staggered arrangement relative to the W? Cl groups, with C? C bond lengths of 127 pm. The infrared spectra are discussed.     

S5N5⊕[GaCl4]⊖ und S5N5⊕[Ga2Cl7]⊖. Synthesen,IR-Spektren und Kristallstrukturen

S₅N₅ ^⊕[GaCl₄]^? and S₅N₅ ^⊕[Ga₂Cl₇]^?. Synthesis, IR Spectra, and Crystal Structures . S₅N₅[GaCl₄] was obtained in high yields from gallium and trithiazyl chloride; depending on the solvent, different second products are formed: S₄N₄Cl[GaCl₄] in dichloromethane and S₃N₂Cl[GaCl₄] in carbon tetrachloride. These products can be separated due to their high solubility in CH₂Cl₂, S₅N₅[GaCl₄] being only slightly soluble. S₃N₂Cl[GaCl₄] can be converted to S₅N₅[GaCl₄] with additional (NSCl)₃. By the action of GaCl₃ on S₅N₅[GaCl₄], S₅N₅[Ga₂Cl₇] is formed. The IR spectra of the title compounds are reported; they differ considerably as well in number as in frequencies of the cation bands and show that the S₅N₅^⊕ ion has different structures depending on the anion. The crystal structures of both compounds were determined by X-ray diffraction. Crystal data: S₅N₅[GaCl₄], orthorhombic, a = 943.8, b = 1369.0, c = 2068.8 pm, space group Pnma, Z = 8 (1381 observed reflexions, R = 0.075); S₅N₅[Ga₂Cl₇], monoclinic, a = 847.5, b = 1298.2, c = 1654.0 pm, β = 93.51°, space group P2₁/n, Z = 4 (1359 observed reflexions, R = 0.065). S₅N₅[GaCl₄] is isotypic with S₅N₅[AlCl₄], showing a heartshaped S₅N₅^⊕ ion, but large ellipsoids of vibration suggest the presence of some kind of disorder (statical or dynamical). In S₅N₅[Ga₂Cl₇] the S₅N₅^⊕ has an azulene-like structure. In both cases the cations are planar, all S? N bond lengths being approximately equal.     

Chelatkomplexe von Rheniumtetrachlorid. Die Kristallstrukturen von ReCl4(DME) und ReCl4(DPPE) · Tolan

Chelate Complexes of Rhenium Tetrachloride. The Crystal Structures of ReCl₄(DME) and ReCl₄(DPPE) · Tolan Bright green crystals of ReCl₄(DME) have been prepared by the reaction of rhenium pentachloride with dimethoxyethane (DME) in dichloromethane. ReCl₄(DPPE) · tolan was obtained in form of red crystals by the reaction of the alkyne complex [ReCl₄(Ph? C?C? Ph)(POCl₃)] with bis(diphenylphosphino)ethane (DPPE) in dichloromethane. The complexes were characterized by X-ray structure determinations. ReCl₄(DME): Space group I4 2d, Z = 8, 829 observed unique reflexions, R = 0.022. Lattice dimensions at 19.5°C: a = b = 960.60(6), c = 2337.2(6) pm. The complex forms monomeric molecules with DME as chelating ligand; the Re? O bond lengths are 213.1 pm. The chlorine atoms, arranged in trans position to the chelating ligand, have slightly shorter Re? Cl bonds than the chlorine atoms in cis position (232,1 pm). ReCl₄(DPPE) · tolan: Space group P2₁/n, Z = 4,4313 observed unique reflexions, R = 0.040. Lattice dimensions at ?80°C: a = 1095.7(1), b = 1764.2(2), c = 1898.0(2) pm, β = 99.229(8)°. The compound consists in form of monomeric molecules [ReCl₄(DPPE)] and diphenylacetylene molecules, which are incorporated in the lattice. The two phenyl rings of the tolan molecules are twisted towards each other along the C? C axis with a dihedral angle of 21°. The DPPE molecules are bonded to the rhenium atom in a chelating fashion with medium Re? P lengths of 250.4 pm. The chlorine atoms, arranged in trans position to this ligand, with Re? Cl bond lengths of 234.5 pm are slightly longer than the Re? Cl bonds in cis position with 232.3 pm.