Sr2(OLi2Sr4)[CrN4]2, ein Nitridochromat(VI)‐Oxid mit Sauerstoff in tetragonal‐bipyramidaler Koordination durch Lithium und Strontium

Sr₂(OLi₂Sr₄)[CrN₄]₂, a Nitridochromate(VI)‐Oxide with Oxygen in Tetragonal‐Bipyramidal Coordination by Lithium and Strontium Green gleaming crystals of Sr₂(OLi₂Sr₄)[CrN₄]₂ were prepared by reaction of Li, Sr and CrN/Cr₂N (approximate 1 : 1 mixture) with flowing nitrogen at 900 °C (molar overall composition Li : Sr : Cr = 6 : 1 : ∼3). The oxygen content results from a leak in the gas supply. The crystal structure was determined by single crystal methods (triclinic; P1; a = 615.87(9) pm, b = 682.50(10) pm, c = 754.30(8) pm, α = 82.302(14)°, β = 75.197(10)°, γ = 70.133(13)°; Z = 1) and contains distorted tetragonal bipyramids (OLi₂Sr₄)⁸⁺ and [Cr^VIN₄]^6–‐tetrahedra besides Sr²⁺.     

LiSr2[ReN4] und LiBa2[ReN4] – isotype Nitridorhenate(VII)

LiSr₂[ReN₄] and LiBa₂[ReN₄] – isotypic Nitridorhenates(VII) The quaternary nitridorhenates(VII) LiAE₂[ReN₄] (AE = Sr, Ba) were synthesized by reaction of the metals with molecular nitrogen at 850–900 °C. The plate‐like, nearly colourless crystals were investigated by X‐ray single crystal methods and were identified as isotypic phases: LiSr₂[ReN₄] (LiBa₂[ReN₄]); monoclinic, P2₁/m; a = 614.64(8) pm (651.04(12) pm), b = 585.97(6) pm (b = 598.86(9) pm), c = 689.70(17) pm (737.43(5) pm), β = 106.375(4)° (108.535(2)°); Z = 2. Crystals of the strontium compound were systematically twinned along [001]. In the crystal structures of the quaternary compounds the alkaline earth‐ and nitride‐ ions are arranged in the motif of the InNi₂‐type structure. Strontium and barium are in a trigonal prismatic coordination by nitrogen (Sr–N: 261.0(7)–284.3(4) pm; Ba–N: 278.0(7)–303.0(6) pm). One half of the tetrahedral voids within the partial structure formed by stacking of trigonal prismatic rod layers is occupied by rhenium (formation of [Re^VIIN₄]^5–‐tetrahedra; Re–N: 181.0(6)–184.5(8) pm), lithium takes the positions of the remaining tetrahedral sites (Li–N: 2 × 198(1) pm, 224(2) pm and 228(2) pm for the strontium phase). In the barium compound the lithium positions show a larger shift from the tetrahedral centres towards a tetrahedral plane (Li–N: 2 × 195(1) pm, 213(2) pm and 304(2) pm).     

Synthesis and Structure of Ba[ZrN2] and Ba2[NbN3]

Ba₃N₂ reacts at 950°C under pure N₂ with Zr to yield dark red, air-sensitive Ba[ZrN₂]. This new compound crystallizes in the tetragonal space group P4/nmm with a = 416.10(2), c = 839.2(1) pm and Z = 2. The crystal structure was solved and refined using X-ray and neutron powder diffraction data. In the nitrido zirconate [ZrN₂]^2? the Zr atoms exhibit a square-pyramidal coordination by five N atoms at distances of 201(3) and 220.2(2) pm. The pyramids share all the edges in the basal plane to form layers parallel to (001) with their apices alternately pointing up and down. The Ba²⁺ cations are integrated into these layers at the levels of the pyramidal apices. The structure can be interpreted as a stuffed PbFCl type. Ba₂[NbN₃] is formed by the reaction of Ba₃N₂ and NbN or of Ba and Nb at 1 000°C under N₂. Isostructural to Ba₂[TaN₃] it crystallizes in the monoclinic space group C2/c with a = 613.2(3), b = 1 176.8(3), c = 1 322.9(4) pm, β = 91.65(2)°, Z = 8. The nitrido niobate anions form chains of corner sharing NbN₄ tetrahedra with distances Nb? N between 188(1) and 199.9(9) pm.     

Li4Sr2[Cr2N6]: Ein Hexanitridodichromat(V)

Li₄Sr₂[Cr₂N₆]: A Hexanitridodichromate(V) The quaternary hexanitridodichromate(V) Li₄Sr₂[Cr₂N₆] was obtained by reaction of the metals with flowing nitrogen at 900 °C as black‐shining crystals with a platy habit. The crystal structure was determined by X‐ray single crystal methods (orthorhombic, Pbca; a = 914.0 pm, b = 735.4 pm, c = 1053.6 pm; Z = 4). The compound contains isolated complex anions [Cr₂N₆]^8— consisting of two tetrahedra CrN₄ sharing a common edge. The distance Cr—Cr in the complex anion is 249.7 pm. The analysis of the Electron Localization Function (ELF) indicates bonding interactions Cr—Cr. Strontium is in a sixfold (distorted octahedral), Lithium in a distorted tetrahedral ([3+1]) coordination by nitrogen. According to measurements of the magnetic susceptibility the compound is diamagnetic.     

[CoN2]/[CN2]‐Substitution in a Crystalline Phase with Composition Close to Sr6[CoN2]2[CN2]

Sr₆[CoN₂]₂[CN₂] was prepared from Sr₂N, carbon, cobalt, and NaN₃ as nitrogen source. The crystal structure (I4/mmm (no. 139), a = 383.55(10) pm, c = 1237.8(4) pm) represents a Na₂[HgO₂] type arrangement with both linear [Co^IN₂]^5– and smaller [CN₂]^2– ions mutually occupying the [HgO₂] position.     

(A19N7)[In4]2 (A = Ca,Sr) and (Ca4N)[In2]: Synthesis,Crystal Structures,Physical Properties,and Chemical Bonding

Single phase powders of (A₁₉N₇)[In₄]₂ (A = Ca, Sr) and (Ca₄N)[In₂] were prepared by reaction of melt beads of the metallic components with nitrogen. The crystal structure of (Ca₁₉N₇)[In₄]₂ was refined based on neutron and X‐ray powder diffraction data. The crystal structure of (Sr₁₉N₇)[In₄]₂ was solved from the X‐ray powder pattern. The structure refinements in combination with results from chemical analyses ascertain the compositions. The compounds (A₁₉N₇)[In₄]₂ (A = Ca, Sr) are isotypes of (Ca₁₉N₇)[Ag₄]₂; (Ca₁₉N₇)[In₄]₂ is probably identical to the earlier reported (Ca_18.5N₇)[In₄]₂. The crystal structure of the isotypes (A₁₉N₇)[In₄]₂ (A = Ca, Sr; cubic, , Ca: a = 1471.65(3) pm; Sr: a = 1561.0(1) pm) contains isolated [In₄] tetrahedra embedded in a framework of edge‐ and vertex‐sharing (A₆N) octahedra. Six of these octahedra are condensed by edge‐sharing around one central A²⁺ ion to form “superoctahedra” (A₁₉N₆) which are connected three‐dimensionally via further octahedra by corner‐sharing. The crystal structure of (Ca₄N)[In₂] (tetragonal, I4₁/amd, a = 491.14(4) pm, c = 2907.7(3) pm) consists of alternating layers of perovskite type slabs of vertex‐sharing octahedra (Ca₂Ca_4/2N) and parallel arranged infinite zigzag chains equation/tex2gif-stack-1.gif[In₂]. In the sense of Zintl‐type counting the compounds (A²⁺)₁₉(N^3?)₇[(In^2.125?)₄]₂ present an electron excess, (Ca²⁺)₄(N^3?)[(In^2.5?)₂] is electron deficient. Metallic properties are supported by electrical resistivity and magnetic susceptibility measurements. The analysis of the electronic structures gives evidence for the existence of homoatomic interactions In–In and significant heteroatomic metal–metal interactions Ca–In which favor the deviations of the title compounds from the (8 – N) rule.     

Pniktogenidostannate(IV) mit isolierten Tetraeder‐Anionen: Neue Vertreter (E1)4(E2)2[Sn(E15)4] (mit E1 = Na,K; E2 = Ca,Sr, Ba; E15 = P,As, Sb,Bi) vom Na6[ZnO4]‐Typ und die Überstrukturvariante von K4Sr2[SnAs4]

Pnictogenidostannates(IV) with Discrete Tetrahedral Anions: New Representatives (E1)₄(E2)₂[Sn(E15)₄] (with E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) of the Na₆[ZnO₄] Type and the Superstructure Variant of K₄Sr₂[SnAs₄] The silvery to dark metallic lustrous compounds (E1)₄(E2)₂[Sn(E15)₄] (E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) were prepared from melts of stoichiometric mixtures of the elements. They crystallize in the Na₆[ZnO₄]‐type structure (hexagonal, space group: P6₃mc, Z = 2; Na₄Ca₂[SnP₄]: a = 938.94(7), c = 710.09(8) pm; K₄Sr₂[SnAs₄]: a = 1045.0(2), c = 767.0(1) pm; K₄Ba₂[SnP₄]: a = 1029.1(6), c = 780.2(4) pm; K₄Ba₂[SnAs₄]: a = 1051.3(1), c = 795.79(7) pm; K₄Ba₂[SnSb₄]: a = 1116.9(2), c = 829.2(1) pm; K₄Ba₂[SnBi₄]: a = 1139.5(2), c = 832.0(2) pm). The anionic partial structure consists of tetrahedra [Sn(E15)₄]^8– orientated all in the same direction along [001]. In the cationic partial structure one of the two cation positions is occupied statistically by alkali and alkaline earth metal atoms. Up to now only for K₄Sr₂[SnAs₄] a second modification could be isolated, forming a superstructure type with three times the unit cell volume (hexagonal, space group: P6₃cm, Z = 6; a = 1801.3(2), c = 767.00(9) pm) and an ordered cationic partial structure.     

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).     

Sr5Ge2N6 – A Nitridogermanate with Edge‐sharing Double Tetrahedra

The new nitridogermanate Sr₅Ge₂N₆ was obtained as a coarsely crystalline product by Na‐flux technique employing a reaction of Sr, Na, NaN₃ and GeO₂ in weld shut tantalum‐tubes at temperatures up to 760 °C. The crystal structure was determined by single‐crystal X‐ray methods: (Sr₅Ge₂N₆, space group C2/c (no. 15), a = 1040.8(2), b = 652.08(13), c = 1356.5(3) pm, β = 100.29(3)°, V = 905.8(3)·10⁶ pm³, Z = 4, 1240 observed reflections, 61 parameters, R1 = 0.031). In the solid, there are edge‐sharing [Ge₂N₆]¹⁰⁻ double tetrahedra surrounded by Sr²⁺ ions. Sr₅Ge₂N₆ was found to be isotypic with Ca₅Si₂N₆.     

Darstellung von Tetramethylammoniumazidsulfit und Tetramethylammoniumcyanat‐Schwefeldioxid‐Addukt, [(CH3)4N]+[SO2N3]–, [(CH3)4N]+ [SO2OCN]– und Kristallstruktur von [(CH3)4N]+[SO2N3]–

Preparation of Tetramethylammonium Azidosulfite and Tetramethylammonium Cyanate Sulfur Dioxide‐Adduct, [(CH₃)₄N]⁺[SO₂N₃]^–, [(CH₃)₄N]⁺[SO₂OCN]^– and Crystal Structure of [(CH₃)₄N]⁺[SO₂N₃]^– Tetramethylammonium azide forms with sulfur dioxide an azidosulfite salt. It is characterized by NMR and vibrational spectroscopy and the crystal structure analysis. [(CH₃)₄N]⁺[SO₂N₃]^– crystallizes in the monoclinic space group P2₁/c with a = 551.3(1) pm, b = 1095.2(1) pm, c = 1465.0(1) pm, β = 100.63(1)°, and four formula units in the unit cell. The crystal structure possesses a strong S–N interaction between the N^3– anions and the SO₂ molecules. The S–N distance of 200.5(2) pm is longer than a covalent single S–N bond. The structure is compared with ab initio calculated data. Furthermore an adduct of tetrametylammonium cyanate and sulfur dioxide is reported. It is characterised by NMR and vibrational spectroscopy. The structure is calculated by ab initio methods.     

Sr[ReO4]2: The First Single Crystals of an Anhydrous Alkaline-Earth Metal Meta-Perrhenate

Colorless single crystals of Sr[ReO₄]₂ were obtained from halide melts at 1123 K in open corundum crucibles. X-ray diffraction revealed that Sr[ReO₄]₂ crystallizes in the monoclinic space group P2₁/n with the lattice parameters a = 627.31(4) pm, b = 1004.56(7) pm, c = 1271.25(9) pm and β = 97.118(3)° for Z = 4. The crystal structure contains a unique Sr²⁺-cation site surrounded by eight crystallographically different oxygen atoms forming distorted bicapped trigonal prisms. All corners of these [SrO₈]^14– polyhedra (d(Sr–O) = 259–268 pm) are shared with tetrahedral meta-perrhenate units [ReO₄]^– (d(Re–O) = 166–173 pm) formed from two crystallographically different Re⁷⁺ cations surrounded by four O^2– anions each, building up the three-dimensional mosaic-like structure of Sr[ReO₄]₂. Single-crystal Raman data confirm the presence of two different kinds of symmetry-free meta-perrhenate units [ReO₄]^– and match well with results known from literature.     

Sr13□NbAs11 and Eu13□NbAs11 – Defect Variants of the Ca14AlSb11 Structure with asymmetric [As3]7− anions

The novel compounds Sr₁₃NbAs₁₁ and Eu₁₃NbAs₁₁ have been synthesized from SrAs, Eu₅As₄, Sr, Nb and As in niobium ampoules at 1173–1273 K. The tetragonal tI 200 phases are defect variants of the Ca₁₄AlSb₁₁ structure (space group I4₁/acd (no. 142); Sr₁₃□NbAs₁₁: a = 1649.8(2) and c = 2214.1(3); Eu₁₃□NbAs₁₁: a = 1632.9(8) and c = 2197.3(8) pm; Z = 8). The structures are built from the cations Sr²⁺, and Eu²⁺, respectively, and from the anions [NbAs₄]^7?, As^3?, and the linear polyanion [As₃]^7?. This polyanion (isosteric to I₃^?) is asymmetric with d(As? As) = 273.0 and 346.0 pm (Sr) and 274.7 and 335.6 pm (Eu), respectively. The bond lengths in the tetrahedral anions are d(Nb? As) = 250.8 and 251.1 pm. The complete structural arrangement is related to that of Cu₂O by forming two interpenetrating networks. The oxygen atoms are substituted by niobium centered As₄ tetrahedra, and the Cu atoms are substituted by As₆ octahedra (centered by Sr, Eu). The central As atoms of the polyanions connect the nets. Both As networks are enveloped by the remaining cations forming cubes, tetragonal antiprisms and capped trigonal prisms.     

Synthese und Struktur der Komplexe [(n‐Bu)4N]2[{(THF)Cl4Re≡N}2PdCl2], [Ph4P]2[(THF)Cl4Re≡N‐PdCl(μ‐Cl)]2 und [(n‐Bu)4N]2[Pd3Cl8]

Synthesis and Crystal Structure of the Complexes [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂PdCl₂], [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ and [(n‐Bu)₄N]₂[Pd₃Cl₈] The threenuclear complex [(n‐Bu)₄N]₂[{(THF)Cl₄Re≡N}₂ PdCl₂] ( 1 ) is obtained in THF by the reaction of PdCl₂(NCC₆H₅)₂ with [(n‐Bu)₄N][ReNCl₄] in the molar ration 1:2. It forms orange crystals with the composition 1· THF crystallizing in the monoclinic space group C2/c with a = 2973.3(2); b = 1486.63(7); c = 1662.67(8)pm; β = 120.036(5)° and Z = 4. If the reaction is carried out with PdCl₂ instead of PdCl₂(NCC₆H₅)₂, orange crystals of hitherto unknown [(n‐Bu)₄N]₂[Pd₃Cl₈] ( 3 ) are obtained besides some crystals of 1· THF. 3 crystallizes with the space group P1¯ and a = 1141.50(8), b = 1401.2(1), c = 1665.9(1)pm, α = 67.529(8)°, β = 81.960(9)°, γ = 66.813(8)° and Z = 2. In the centrosymmetric complex anion [{(THF)Cl₄Re≡N}₂PdCl₂]^2— a linear PdCl₂ moiety is connected in trans arrangement with two complex fragments [(THF)Cl₄Re≡N]^— via asymmetric nitrido bridges Re≡N‐Pd. For Pd(II) thereby results a square‐planar coordination PdCl₂N₂. The linear nitrido bridges are characterized by distances Re‐N = 163.8(7)pm and Pd‐N = 194.1(7)pm. The crystal structure of 3 contains two symmetry independent, planar complexes [Pd₃Cl₈]^2— with the symmetry 1¯, in which the Pd atoms are connected by slightly asymmetric chloro bridges. By the reaction of equimolar amounts of [Ph₄P][ReNCl₄] and PdCl₂(NCC₆H₅)₂ in THF brown crystals of the heterometallic complex, [Ph₄P]₂[(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂ ( 2 ) result. 2 crystallizes in the monoclinic space group P2₁/n with a = 979.55(9); b = 2221.5(1); c = 1523.1(2)pm; β = 100.33(1)° and Z = 2. In the central unit ClPd(μ‐Cl)₂PdCl of the centrosymmetric anionic complex [(THF)Cl₄Re≡N‐PdCl(μ‐Cl)]₂^2— the coordination of the Pd atoms is completed by two nitrido bridges Re≡N‐Pd to nitrido complex fragments [(THF)Cl₄Re≡N]^— forming a square‐planar arrangement for Pd(II). The distances in the linear nitrido bridges are Re‐N = 163.8(9)pm and Pd‐N = 191.5(9)pm.     

Synthese und Struktur von (PPh4)3[Re2NCl10]

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

Neue Phosphaniminato‐Komplexe von Molybdän und Wolfram. Die Kristallstrukturen von [(μ‐S2N2){MoCl4(NPPh3)}2], [Mo(NPPh3)4][BF4]2, [W(S)2(NPPh3)2] und [Ph3PNH2]+[SCN]–

New Phosphoraneiminato Complexes of Molybdenum and Tungsten. Crystal Structures of [(μ‐S₂N₂){MoCl₄(NPPh₃)}₂], [Mo(NPPh₃)₄][BF₄]₂, [W(S)₂(NPPh₃)₂], and [Ph₃PNH₂]⁺[SCN]^– The binuclear molybdenum(V)phosphoraneiminato complex [(μ‐S₂N₂){Mo^VCl₄(NPPh₃)}₂] ( 1 ) has been prepared by the reaction of the chlorothionitreno complex [Mo^VICl₄(NSCl)]₂ with Me₃SiNPPh₃ in dichloromethane forming green crystals. The temperature dependent magnetic susceptibility in the range of 2–30 K shows ideal behaviour according to the Curie law with a magnetic moment of 1.60 B.M. According to the crystal structure determination 1 forms centrosymmetric molecules in which the molybdenum atoms are connected by the nitrogen atoms of the S₂N₂ molecule. In trans‐position to it the nitrogen atoms of the phosphoraneiminato groups (NPPh₃^–) are coordinated with Mo–N bond lengths of 171(1) pm. The tetrakis(phosphoraneiminato) complex [Mo(NPPh₃)₄]‐ [BF₄]₂ ( 2 ) has been obtained as colourless crystal needles by the reaction of MoN(NPPh₃)₃ with boron trifluoride etherate in toluene solution. In the dication the molybdenum atom is tetrahedrally coordinated by the nitrogen atoms of the (NPPh₃^–) groups with Mo–N bond lengths of 179,8–181,0(3) pm. The dithio‐bis(phosphoraneiminato) tungsten complex [W(S)₂(NPPh₃)₂] ( 3 ) is formed as yellow crystals as well as [Ph₃PNH₂]⁺[SCN]^– ( 4 ) from the reaction of WN(NPPh₃)₃ with carbon disulfide in tetrahydrofurane in the presence of traces of water. 3 has a monomeric molecular structure with tetrahedrally coordinated tungsten atom with bond lengths W–S of 214.5(5) pm and W–N of 179(1) pm. In the structure of 4 the thiocyanate ions are associated by hydrogen bonds of the NH₂ group of the [Ph₃PNH₂]⁺ ion to give a zigzag chain. 1 : Space group Pbca, Z = 4, lattice constants at –80 °C: a = 1647.9(3), b = 1460.8(2), c = 1810.4(4) pm; R₁ = 0.0981. 2 : Space group P1, Z = 2, lattice constants at –80 °C: a = 1162.5(1), b = 1238.0(1), c = 2346.2(2) pm; α = 103.14(1)°, β = 90.13(1)°, γ = 97.66(1)°; R₁ = 0.0423. 3 : Space group Fdd2, Z = 8, lattice constants at –80 °C: a = 3310.1(4), b = 2059.7(2), c = 966,7(1) pm; R₁ = 0.0696. 4 : Space group P2₁2₁2₁, Z = 4, lattice constants at –80 °C: a = 1118.4(1), b = 1206.7(1), c = 1279.9(1) pm; R₁ = 0.0311.     

(Sr2N)H: Untersuchungen zur Redox‐Intercalation von Wasserstoff in Sr2N

(Sr₂N)H: On the Redox-Intercalation of Hydrogen into Sr₂N Strontium-nitride-hydride is obtained as brown-yellow single phase powder by reaction of strontium-subnitride (Sr₂N) with hydrogen (200 bar, 620 K) and subsequent treatment under vacuum (10⁻⁶ bar, 870 K). The structure determination was carried out by a combination of X-ray and neutron diffraction experiments on a deuterated sample. The elemental composition of the ternary compound was confirmed by means of chemical analyses. (Sr₂N)D crystallizes in the space group with a = 381.91(2) pm and c = 1887.61(2) pm. Strontium (Sr²⁺) in the crystal structure of (Sr₂N)D is arranged with an only slightly distorted ccp-motif. Nitrogen (N³⁻) and deuterium (D⁻) occupy the octahedral voids of the Sr²⁺-matrix in an ordered manner resulting in an alternating sequence of layers (anti-α-NaFeO₂-type structure).     

Synthese und Kristallstrukturen der Nitrido‐Chloro‐Molybdate [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 und [Li(12‐Krone‐4)(NMoCl4)]2 · 2 CH2Cl2

Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ and [Li(12‐Crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ Both the title compounds as well as [Li(12‐crown‐4)₂]⁺MoNCl₄^– were made from MoNCl₃ and the chlorides MgCl₂ and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R₁ = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl₄(THF)]^– ions. [Li(12‐crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R₁ = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]₂²⁺, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li₂O₂ four‐membered ring. The two N≡MoCl₄^– counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm.     

Phosphaniminato‐Komplexe des Hafniums. Die Kristallstrukturen von [Hf(NPPh3)4] · 3 THF und [Hf(NPPh3)2Cl2(HNPPh3)2]

Phosphoraneiminato Complexes of Hafnium. Crystal Structures of [Hf(NPPh₃)₄] · 3 THF and [Hf(NPPh₃)₂Cl₂(HNPPh₃)₂] The phosphoraneiminato complexes [Hf(NPPh₃)₄] · 3 THF ( 1 · 3 THF) and [Hf(NPPh₃)₂Cl₂(HNPPh₃)₂] ( 2 ) have been prepared as colourless, moisture sensitive single crystals by reactions of hafnium tetrachloride with [CsNPPh₃]₄ · 2 toluene in tetrahydrofurane solutions by application of different ratios of the educts. Both complexes are characterized by IR spectroscopy and X‐ray crystal structure determinations. 1 · 3 THF: space group P 1, Z = 4, lattice dimensions at 193 K: a = 2007.6(1); b = 2064.2(1); c = 2115.9(1) pm; α = 109.193(4)°; β = 111.285(4)°; γ = 96.879(4)°; R₁ = 0.0506. 1 forms monomeric molecules with tetrahedral coordination of the nitrogen‐atoms of the (NPPh₃^–)‐groups towards the Hafnium atom. The HfN distances of 200.9 pm in average correspond with double bonds. 2 : space group P 1, Z = 4, lattice dimensions at 193 K: a = 1444.0(1); b = 1928.1(1); c = 2455.8(2) pm; α = 67.273(8)°; β = 87.445(8)°; γ = 87.082(8)°; R₁ = 0.0312. 2 has a monomeric molecular structure with octahedral coordination of the hafnium atom. The chlorine atoms are in trans position to one another, whereas the nitrogen atoms of the phosphoraneiminato groups (NPPh₃^–) are in trans position towards the nitrogen atoms ot the phosphorane imine molecules (HNPPh₃). The HfN bond lengths of the (NPPh₃^–) groups of 199.7 pm in average correspond with double bonds, whereas the HfN distances of the HNPPh₃ molecules with bond lengths of 230.2 pm in average are of donor‐acceptor type.     

Rb7[SiO4][VO4]: ein Ortho‐Silicat‐Vanadat(V)

Rb₇[SiO₄][VO₄]: an Ortho‐Silicate‐Vanadate(V) Rb₇[SiO₄][VO₄] has been obtained from a redox reaction between CdO and vanadium metal in the presence of Rb₂O and SiO₂ at 600 °C in an Ag container as yellow‐greenish transparent single crystals. The crystal structure determination (IPDS data: P2₁/c, a = 637.6(1) pm, b = 1039.7(1) pm, c = 2076.8(4) pm, β = 93.21(2)°, Z = 4, wR2 = 0.1319) reveals the presence of isolated complex anions, [SiO₄]^4— and [VO₄]^3—.     

The Quasi‐Binary Acetonitriletriide Sr3[C2N]2

The first quasi‐binary acetonitriletriide Sr₃[C₂N]₂ has been synthesised and characterised. The nearly colourless crystals were obtained from the reaction of Sr metal, graphite, and elemental N₂, generated by decomposition of Sr(N₃)₂, in a sealed Ni ampoule with the aid of an alkali metal flux. The structure of this compound was analysed via single‐crystal X‐ray diffraction and the identity of the [C₂N]^3? anion was confirmed by Raman spectroscopy and further investigated by quantum‐chemical methods. Computed interatomic distances within the [C₂N]^3? anion strikingly match the obtained experimental data.