Synthese,Kristallstruktur und Festkörper‐NMR‐spektroskopische Untersuchung des Oxonitridosilicates BaSi6N8O

Synthesis, Crystal Structure and Solid‐State NMR Spectroscopic Investigation of the Oxonitridosilicate BaSi₆N₈O The phase‐pure oxonitridosilicate BaSi₆N₈O has been synthesized starting from BaCO₃ and silicon diimide Si(NH)₂ in a radiofrequency furnace at temperatures below 1630 °C as a coarsely crystalline colorless material. The structure has been determined by single‐crystal X‐ray diffraction analysis (BaSi₆N₈O, space group Imm2 (no. 44), a = 810.5(2), b = 967.8(2), c = 483.7(1) pm, V = 379.4(2)·10⁶ pm³, Z = 2, R1 = 0.014, 618 independent reflections, 44 parameters). The oxonitridosilicate comprises a three‐dimensional network structure of corner sharing SiN₄ and SiON₃ tetrahedra with Ba²⁺ located in the resulting voids. BaSi₆N₈O is isostructural with the oxonitridoalumosilicate (sialon) Sr₂Al_xSi_12?xN_16?xO_2+x (x ≈ 2) that previously has been described in the literature. Furthermore, the anionic network of BaSi₆N₈O derives from that of the homeotypic reduced nitridosilicate SrSi₆N₈ by a topotactic insertion of oxygen into the Si–Si single bonds. In the ²⁹Si MAS‐NMR spectrum two sharp isotropic signals have been observed at ?54.0 and ?56.3 ppm, respectively. With respect to their observed intensity ratio of 1 : 2.1(1) these two signals have to be attributed to the central atoms of SiON₃ and SiN₄ tetrahedra, respectively, which is in accordance with the X‐ray crystal structure determination (Si at Wyckoff positions 4d (SiON₃) and 8e (SiN₄)).     

Die neuen Schichtsilicate Ba3Si6O9N4 und Eu3Si6O9N4

The New Layer‐Silicates Ba₃Si₆O₉N₄ and Eu₃Si₆O₉N₄ The new oxonitridosilicate Ba₃Si₆O₉N₄ has been synthesized in a radiofrequency furnace starting from BaCO₃, amorphous SiO₂ and Si₃N₄. The reaction temperature was at about 1370 °C. The structure of the colorless compound has been determined by single‐crystal X‐ray diffraction analysis (Ba₃Si₆O₉N₄, space group P3 (no. 143), a = 724.9(1) pm, c = 678.4(2) pm, V = 308.69(9)· 10⁶ pm³, Z = 1, R1 = 0.0309, 1312 independent reflections, 68 refined parameters). The compound is built up of corner sharing SiO₂N₂ tetrahedra forming corrugated layers between which the Ba²⁺ ions are located. Substitution of barium by europium leads to the isotypic compound Eu₃Si₆O₉N₄. Because no single‐crystals could be obtained, a Rietveld refinement of the powder diffractogram was conducted for the structure refinement (Eu₃Si₆O₉N₄, space group P3 (no. 143), a = 711.49(1) pm, c = 656.64(2) pm, V = 287.866(8) ·10⁶ pm³, R_p = 0.0379, R_F² = 0.0638). The ²⁹Si MAS‐NMR spectrum of Ba₃Si₆O₉N₄ shows two resonances at ?64.1 and ?66.0 ppm confirming two different crystallographic Si sites.     

Synthese,Röntgenstrukturanalyse und Multikern‐NMR‐spektroskopische Untersuchung einiger intramolekular stickstoffstabilisierter Bor‐, Aluminium‐ und Galliumorganyle

Synthesis, X‐Ray Structure, and Multinuclear NMR Investigation of some intramolecularly Nitrogen stabilized Organoboron, ‐aluminum, and ‐gallium Compounds The intramolecularly nitrogen stabilized organoaluminum‐ and organoboron compounds Me₂Al(CH₂)₃NMe₂ ( 1 ), Me₂AlC₁₀H₆‐8‐NMe₂ ( 2 ), ⁱPr₂Al(CH₂)₃NEt₂ ( 3 ), (CH₂)₅Al(CH₂)₃NMe₂ ( 4 ), and (CH₂)₅B(CH₂)₃NMe₂ ( 5 ) are synthesized from Me₂AlCl and the corresponding organolithium compounds and from AlCl₃ or BCl₃, the lithium alkyl and ⁱPrMgCl or BrMg(CH₂)₅MgBr, respectively. AlCl₃ and GaCl₃ react with Li(CH₂)₃NMe₂ or LiCH₂CHMeCH₂NMe₂ forming Cl₂AlCH₂CHMeCH₂NMe₂ ( 6 ), Cl₂Al(CH₂)₃NMe₂ ( 8 ), and Cl₂Ga(CH₂)₃NMe₂ ( 9 ). The reaction of 6 and of 8 or 9 with BrMg(CH₂)₅MgBr and BrMg(CH₂)₆MgBr, respectively, yields (CH₂)₅AlCH₂CHMeCH₂NMe₂ ( 7 ), (CH₂)₆Al(CH₂)₃NMe₂ ( 10 ), and (CH₂)₆Ga(CH₂)₃NMe₂ ( 11 ). MeAlCl₂, made by the redistribution reaction of AlCl₃ with Me₂AlCl, reacts with 2 equivalents of Li(CH₂)₃NMe₂ yielding MeAl[(CH₂)₃NMe₂]₂ ( 12 ) and with MeN[(CH₂)₃MgCl]₂ under formation of MeAl[(CH₂)₃]₂NMe ( 13 ). MeAlCl₂, MeGaCl₂, or GaCl₃ accordingly react with one equivalent of organolithium reagent to give the intramolecularly nitrogen stabilized organoaluminum and organogallium chlorides MeClAl(CH₂)₃NMe₂ ( 14 ), MeClGa(CH₂)₃NMe₂ ( 15 ), MeClGaC₆H₄‐2‐CH₂NMe₂ ( 16 ) as well as Cl₂GaC₆H₄‐2‐CHMeNMe₂ ( 17 ). The compounds were characterized by elemental analyses, mass spectroscopy, ¹H, ¹¹B, ¹³C and ²⁷Al NMR investigations. Single crystal X‐ray structure analyses of 1 , 2 , 4 , 5 and 17 reveal the monomeric molecular structures with intramolecular nitrogen coordination.     

Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXVI [1] Synthese,Kristallstruktur und spektroskopische Charakterisierung von Palladium(II)‐diphosphat Pd2P2O7

Synthesis, Crystal Structure and Spectroscopical Characterization of Palladium(II)‐Diphosphate Pd₂P₂O₇ Pd₂P₂O₇ is synthesized by heating (T_max = 500 °C) stoichiometric amounts of PdO and phosphoric acid. Using chemical vapour transport experiments (850 °C → 750 °C, addition of PdCl₂) Pd₂P₂O₇ was crystallized. Pd₂P₂O₇ adopts its own structure type (C 2/c (No. 15), Z = 4, a = 13,151(2) Å, b = 5,172(1) Å, c = 8,139(1) Å, β = 97,52(1)°, 1160 independent reflections, 55 variables, R1 = 0,021 and wR2 = 0,050). Square‐planar [PdO₄]‐units are linked by diphosphate‐groups generating a 3D framework. Within this framework ribbons may be distinguished. Thus Pd₂P₂O₇ might be described as palladium(II)‐[diphosphatopalladate(II)]. The results of various spectroscopic measurements (IR, Raman, UV/VIS, ³¹P‐MAS‐NMR) are reported and discussed within the context of the crystal structure.     

Indenylvanadium(V)‐Verbindungen. Darstellung,Struktur und NMR‐spektroskopische Untersuchungen

Indenylvanadium(V) Compounds Synthesis, Structure, and NMR Spectroscopic Studies Syntheses of the indenylvanadium(V)compounds are described: ^tC₄H₉N = V(η⁵‐C₉H₇)Cl₂ ( 1 ), ^tC₄H₉N = V(η⁵‐C₉H₇)Br₂ ( 2 ), ^tC₄H₉N = V(η⁵‐C₉H₇)(O^tC₄H₉)Cl ( 3 ), ^tC₄H₉N = V(η¹‐C₉H₇)(O^tC₄H₉)₂ ( 4 ), ^tC₄H₉N = V(η¹‐C₉H₇)₂(O^tC₄H₉) ( 5 ), ^tC₄H₉N = V(η¹‐C₉H₇)(η⁵‐C₅H₅) · (O^tC₄H₉) ( 6 ), ^tC₄H₉N = V(η¹‐C₉H₇)(η⁵‐C₅H₅)(NH^tC₄H₉) ( 7 ). All compounds were totally characterized by spectroscopic methods (MS; ¹H, ¹³C, ⁵¹V NMR), 3 by single crystal X‐ray diffraction. For 6 the presence of the diastereomeres RR/SS and RS/SR was shown by NMR spectroscopy. The chlorovanadate (IV) complex [NHC₄H₉]₂⁺[(^tC₄H₉N)₇V₇ · (μ‐Cl)₁₄Cl₂]^2– has been obtained by decomposition of 1 in solution; the crystal structure indicates a wheel structure with hydrogen bonds between the tert‐butylammonium cations and the complex anion.     

Synthese,Kristallstruktur und spektroskopische Charakterisierung von Tetraphosphorhexaoxiddiselenid P4O6Se2

Synthesis, Crystal Structure, and Spectroscopic Characterization of Tetraphosphorus Hexaoxide Diselenide P₄O₆Se₂ P₄O₆Se₂ has been prepared by photochemical selenation of P₄O₆ with red selenium in CS₂ in presence of catalytical amounts of iodine. Isolation and single crystal growth were performed by fractional crystallization and subsequent sublimation. The compound crystallizes in the monoclinic space group P2₁/c (Nr. 14) with a = 11.473(2); b = 6.536(1); c = 11.796(2) Å; β = 90.06(1)°; Z = 4; R₁ = 0.030; wR² = 0.073. Within the limits of experimental error, the P₄O₆Se₂ molecules exhibit C_2v symmetry in the crystal. Bond lengths and angles within the molecule as well as the arrangement of the molecules within the crystal are discussed; IR-, Raman-, and ³¹P solution NMR data are reported.     

Synthese und Kristallstruktur von [(n‐Bu)4N][W6Cl18]

Synthesis and Crystal Structure of [(n‐Bu)₄N][W₆Cl₁₈] Single‐crystals of [(n‐Bu)₄N][W₆Cl₁₈] were obtained as thin needles by adding methanol to a solution of W₆Cl₁₈ and [(n‐Bu)₄N]Cl in tetrahydrofuran. The structure was determined by single‐crystal X‐ray diffraction at 210 K. [(n‐Bu)₄N][W₆Cl₁₈] crystallizes in the monoclinic space group C 2/c with Z = 8 and the lattice parameters a = 2175.6(1) pm, b = 1738.0(1) pm, c = 2160.36(9) pm, and β = 91.680(5) °. The crystal structure contains isolated [(W₆Cl₁₂ⁱ)Cl₆^a]^— clusters and [(n‐Bu)₄N]⁺ ions.     

LiLa5Si4N10O and LiPr5Si4N10O – Chain‐Type Oxonitridosilicates

The isotypic lithium rare‐earth oxonitridosilicates LiLn₅Si₄N₁₀O (Ln = La, Pr) were synthesized at temperatures of 1200 °C in weld shut tantalum ampoules employing liquid lithium as flux. Thereby, a silicate substructure with a low degree of condensation was obtained. LiLa₅Si₄N₁₀O crystallizes in space group P$\bar{1}$ [Z = 1, LiLa₅Si₄N₁₀O: a = 5.7462(11), b = 6.5620(13), c = 8.3732(17) Å, α = 103.54(3), β = 107.77(3), γ = 94.30(3), wR₂ = 0.0405, 1315 data, 96 parameters]. The nitridosilicate substructure consists of loop branched dreier single‐chains of vertex sharing SiN₄ tetrahedra. Lattice energy calculations (MAPLE) and EDX measurements confirmed the electrostatic bonding interactions and the chemical compositions. The ⁷Li solid‐state MAS NMR investigation is reported.     

Über die Synthese und spektroskopische Charakterisierung von Strontium‐ und Bariumtetrabromoferrat(III) und die Kristallstruktur von Ba(FeBr4)2

Preparation and Spectroscopic Characterization of Strontium and Barium Tetrabromoferrate(III) and the Crystal Structure of Ba(FeBr₄)₂ The synthesis of the hitherto unknown bromoferrates(III) of alkaline‐earth metals was carried out by heating mixtures of the metals or the binary bromides together with bromine at temperatures of 450 °C and pressures of up to 1500 bar in closed quartz ampoules. The attempts have been successful only with the larger cations of Sr and Ba. In the case of Be, Mg, and Ca only mixtures of the binary bromides with FeBr₃ could be received. By analysis of the Raman and electronic spectra the dark red compounds of Sr and Ba have been characterized as ternary tetrabromoferrates(III) containing tetrahedral FeBr₄ anions. The composition M(FeBr₄)₂ (M = Sr, Ba) has been determined by potentiometric and titrimetric analysis and thermal degradation by thermogravimetry. A single crystal structure determination of Ba(FeBr₄)₂ confirmed the spectroscopic assignments. The orthorhombic crystal structure (space group Pbca; a = 13.054(3) Å; b = 11.093(2) Å; c = 21.764(4) Å; Z = 8) consists of FeBr₄ and BaBr₉ polyhedra.     

Multianvil‐Synthese,Pulver‐Röntgenstrukturanalyse, 31P‐MAS‐NMR‐ und FTIR‐Spektroskopie sowie Materialeigenschaften von γ‐P3N5, einer Hochdruckphase von binärem Phosphor(V)‐nitrid mit verzerrt quadratischen PN5‐Pyramiden und PN4‐Tetraedern

Multianvil Synthesis, X‐ray Powder Diffraction Analysis, ³¹P‐MAS‐NMR, and FTIR Spektroscopy as well as Material Properties of γ‐P₃N₅, a High‐Pressure Polymorph of Binary Phosphorus(V) Nitride, Built up from Distorted PN₅ Square Pyramids and PN₄ Tetrahedra The high‐pressure phase γ‐P₃N₅ was synthesized at a pressure of 11 GPa and a temperature of 1500 °C in a multianvil apparatus. Partially crystalline P₃N₅ has been used as a starting material. The crystal structure was solved by direct methods on the basis of X‐ray powder diffraction data and it was refined by the Rietveld method (Imm2, a = 1287.21(4), b = 261.312(6), c = 440.03(2) pm, Z = 2, R_p = 0.073, wR_p = 0.094, R_F = 0.048). γ‐phosphorus nitride crystallizes in a three‐dimensional network structure built up from corner sharing PN₄ tetrahedra and trans‐edge sharing distorted PN₅ square pyramids. In the ³¹P‐MAS‐NMR spectrum two sharp isotropic resonances with an intensity ratio of 1 : 2.02(5) are observed at —11.95(3) and —101.72(7) ppm, respectively. The IR‐spectroscopic and thermal properties of γ‐P₃N₅ are described. Measurement of the Vickers hardness resulted in a value of 9.7(21) GPa for sintered polycrystalline γ‐P₃N₅, which is significantly higher than that for the partially crystalline normal pressure modification of P₃N₅ (5.1(7) GPa).     

Diselenadiphosphetandiselenide und Triselenadiphospholandiselenide – Synthese und Charakterisierung mittels 31P‐ und 77Se‐Festkörper‐NMRSpektroskopie

Diselenadiphosphetane Diselenides and Triselenadiphospholane Diselenides – Synthesis and Characterization by ³¹P and ⁷⁷Se Solid‐State NMR Spectroscopy 1,3‐Diselena‐2,4‐diphosphetane‐2,4‐diselenides (RPSe₂)₂ with R = Me, Et, t‐Bu, Ph, 4‐Me₂NC₆H₄, 4‐MeOC₆H₄ have been synthesized by different methods. The insoluble compounds were investigated by ³¹P and ⁷⁷Se solid‐state NMR and the purity of the compounds has been checked by their CP MAS sideband NMR spectra. The structure of the investigated compounds has been confirmed by the isotropic and anisotropic values of the chemical shifts and the ¹J_P–Se coupling constants. In addition, two new 1,2,4‐triselena‐3,5‐diphospholane‐3,5‐diselenides, (RPSe₂)₂Se (R = Me, Et), formed under similar synthesis conditions, were investigated. Their structure was derived from the ⁷⁷Se satellites of ³¹P solution spectra and from solid‐state spectra. For (t‐BuPSe₂)₂ the experimentally obtained principal values of phosphorus and selenium shielding tensors are compared with values from IGLO calculations (HF und SOS DFPT). The calculated orientations of the principal axes are discussed.     

Synthese und Kristallstruktur der Rhenium(VII)‐Nitridchloride ReNCl4 und ReNCl4·H2O

Syntheses and Crystal Structures of the Rhenium(VII) Nitride Chlorides ReNCl₄ and ReNCl₄·H₂O Rhenium(VII) nitride chloride, ReNCl₄ ( 1 ) is obtained in form of brown needles with metallic luster by the reaction of ReCl₅ with Cl₃VNCl at 140 °C under vacuum in a sealed glass ampoule. It crystallizes in the tetragonal space group I4 with the lattice parameters a = 826.7(4), c = 405.1(2) pm, and Z = 2. The square pyramidal molecules are connected by asymmetric nitrido bridges to form chains along the crystallographic c axis. The shorter Re‐N distance of 163.0(5) pm corresponds to a triple bond, while the pronounced longer distance of 242.0(5) pm can be interpreted with a weak donor bond. The reaction of ReCl₅ with VN at 170 °C under vacuum in a sealed glass ampoule yields red needles of ReNCl₄·H₂O ( 2 ). It crystallizes in the orthorhombic space group Pnma with a = 1075.4(2), b = 1108.5(2), c = 547.7(5) pm and Z = 4. The Re atoms exhibit a distorted octahedral coordination with the aqua ligand in trans position to the nitrido ligand. The Re‐N triple bond has a bond distance of 166.1(11) pm. The complexes are connected by hydrogen bridges O‐H···N to form chains.     

Synthese,Kristallstruktur und Eigenschaften von Vanadium(II)‐tetrachloroaluminat

Synthesis, Crystal Structure, and Properties of Vanadium(II) Tetrachloroaluminate The reaction of vanadium dichloride and aluminium trichloride yields vanadium(II) tetrachloroaluminate. Amber cuboid crystals can be obtained by slow cooling of the melt. V(AlCl₄)₂ crystallizes in the monoclinic space group I2/c (a = 1284.6(3), b = 776.3(2), c = 1163.5(2) pm, β = 92.376(10)°) and is therefore isotypic to Co(AlCl₄)₂. The structure contains chains build of VCl₆ octahedra and AlCl₄ tetrahedra sharing corners and edges with each other. The temperature dependence of the magnetic susceptibility follows Curie‐Weiss behaviour (μ = 3.88(2) μ_B, Θ = ?9(1) K) complying with the spin‐only paramagnetism expected of d³ ions.     

Synthese und Kristallstruktur von Ba6Lu4Zn10O22 mit [OBa6]-Oktaedern

On the Synthesis and Crystal Structure of Ba₆Lu₄Zn₁₀O₂₂ with [OBa₆] Octahedra Single crystals of Ba₆Lu₄Zn₁₀O₂₂ have been prepared by high temperature reactions and investigated by X-ray techniques. This compound is isotypic to Ba₃In₂Zn₅O₁₁ and the first member of the Rare Earth elements. Ba₆Lu₄Zn₁₀O₂₂ crystallizes with cubic symmetry, space group T-F4 3m, a = 13.452(1) Å and Z = 4. Zn²⁺ shows a tetrahedral, Lu³⁺ an octahedral and Ba²⁺ a three-fold capped trigonal prismatic coordination by O^2?. The ZnO₄ tetrahedra and LuO₆ octahedra are forming macro polyhedra of the type Zn₁₀O₂₀ and Lu₄O₁₆. A discussion is given for the Ba₆O₃₃ and Ba₆O₄₂ groups.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von (Ph4P)2[OsN(N3)5] und 15N‐NMR‐Verschiebungen von Nitridoosmaten(VI,VIII)

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of (Ph₄P)₂[OsN(N₃)₅] and ¹⁵N NMR Chemical Shifts of Nitridoosmates(VI, VIII) The treatment of (Ph₄P)[OsNCl₄] with NaN₃ yields (Ph₄P)₂[OsN(N₃)₅], which crystal structure has been determined by single crystal X‐ray diffraction analysis (monoclinic, space group P 2₁/a, a = 20.484(6), b = 11.168(1), c = 20.666(4) Å, β = 97.35(3)°, Z = 4). The IR and Raman vibrations were assigned by a normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are f_d(Os≡N) = 8.52, f_d(Os–N^α) = 1.99, f_d(N^α–N^β) = 12.42, f_d(N^β–N^γ) = 12.73 and for the azido ligand in trans‐position to the nitrido group f_d(Os–N^{α ·} ) = 1.84, f_d(N^{α ·} –N^{β ·} ) = 11.91, f_d(N^{β ·} –N^{γ ·} ) = 12.18 mdyn/Å. The ¹⁵N NMR spectra of various nitridoosmates reveal the chemical shifts δ(¹⁵N) for K[OsO₃¹⁵N] = 387.6, K₂[Os¹⁵NCl₅] = 446.7, (Ph₄P)[Os¹⁵NCl₄] = 352.9, [(n‐C₆H₁₃)₄N]₂[Os¹⁵N(N₃)₅] = 307.3 and for [(n‐Pr)₄N]₂[Os¹⁵N(¹⁵NCO)₅] = 483,7 (Os≡N), –417,7 (OsNCO_eq) und –392,8 ppm (OsNCO_ax).     

Polymorphie von Bis(dineopentoxyphosphorothioyl)diselenid – Korrelation von Röntgenstruktur und MAS‐NMR‐Daten

Polymorphism of Bis(dineopentoxyphosphorothioyl)diselenide – Correlation of X‐Ray Structure and MAS NMR Data The crystal structures of two polymorphs of the title compound were determined by single‐crystal X‐ray methods and refined both at room temperature and 250 K. A triclinic and a monoclinic phase were discovered and studied. Both modifications are centrosymmetrical layer structures. The numerically clearly significant differences were observed in unit cell volumes as well as in alternating disproportions of distances of atoms being chemically and crystallographically equivalent as a result of discontinuously distributed conformational changes along the single bonds. Phase transitions were not observed by cooling up to 240 K. Lowering temperatures single crystals of both phases decompose because of the considerable anisotropy of intermolecular interaction. The small differences of molecular structure produce slightly splitted ³¹P CP MAS NMR signals. A comparison of the chemical shifts from ¹³C CP MAS NMR spectra and from quantum‐chemical calculations leads to the conclusion that the inner rotation around CH₂–C_q bonds is not frozen in the solid state.     

Synthese und Kristallstruktur des ersten Oxonitridoborates — Sr3[B3O3N3]

Synthesis and Crystal Structure of the First Oxonitridoborate — Sr₃[B₃O₃N₃] The cyclotri(oxonitridoborate) Sr₃[B₃O₃N₃] was synthesized at 1450 °C as coarsely crystalline colourless crystals by the reaction of SrCO₃ with poly(boron amide imide) using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Sr₃[B₃O₃N₃], Z = 4, P2₁/n, a = 663.16(2), b = 786.06(2), c = 1175.90(3) pm, η = 92.393(1)°, R1= 0.0441, wR2 = 0.1075, 1081 independent reflections, 110 refined parameters). Besides Sr²⁺ there are hitherto unknown cyclic [B₃O₃N₃]^6— ions (B—N 143.7(10) — 149.1(9) pm, B—O 140.5(8) — 141.4(8) pm).     

Darstellung,Schwingungsspektrum und Kristallstruktur von (n‐Bu4N)2[(W6Cl)F] · 2 CH2Cl2 und 19F‐NMR‐spektroskopischer Nachweis der gemischten Clusteranionen [(W6Cl)FCl]2–, n = 1–6

Synthesis, Vibrational Spectra, and Crystal Structure of ( n ‐Bu₄N)₂[(W₆Cl )F ] · 2 CH₂Cl₂ and ¹⁹F NMR Spectroscopic Evidence of the Mixed Cluster Anions [(W₆Cl )F Cl ]^2–, n = 1–6 The reaction of (n‐Bu₄N)₂[(W₆Cl)Cl] with CF₃COOH in dichloromethane gives intermediately a mixture of the cluster anions [(W₆Cl)(CF₃COO)Cl]^2–, n = 1–6. By treatment with NH₄F the outer sphere coordinated trifluoracetato ligands are easily substituted and the components of the series [(W₆Cl)FCl], n = 1–6 are formed and characterized by their distinct ¹⁹F NMR chemical shifts. An X‐ray structure determination has been performed on a single crystal of (n‐Bu₄N)₂[(W₆Cl)F] · 2 CH₂Cl₂ (orthorhombic, space group Pbca, a = 15.628(4), b = 17.656(3), c = 20.687(4) Å, Z = 4). The low temperatur IR (60 K) and Raman (20 K) spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are f_d(WW) = 1.89, f_d(WF) = 2.43 and f_d(WCl) = 0.93 mdyn/Å.