Die Pyridinaddukte der Goldhalogenide. 1. Darstellung und Struktur von [Hpy][AuCl4], AuCl3 · py, [AuCl2(py)2]Cl · H2O und [AuCl2(py)2][AuCl2]

Pyridine Adducts of the Gold Halides. 1. Synthesis and Structure of [Hpy][AuCl₄], AuC1₃ · py, [AuCl₂(py)₂]Cl · H₂O, and [AuCl₂(py)₂] [AuCl₂] HAuCl₄ reacts with pyridine in aqueous solution to form sparingly soluble [Hpy] [AuCl₄]. This goes into solution as [AuCl₂(py)₂]⁺ on adding an excess of pyridine. [Hpy][AuCl₄] decomposes above 195°C to HCl and AuCl₃ · py, which can also be obtained from NaAuCl₄ and pyridine. AuCl₂ · py is formed by the reaction of AuCl₂ · S(CH₂C₆H₄)₂ with pyridine in CHCl₃. According to the vibrational spectrum the complex is built up of trans[AuCl₂(py)₂]⁺ cations and [AuCl₂]^? anions. The IR spectra of [Hpy][AuCl₄], AuCl₃ · py, and [AuCl₂(py)₂]Cl · H₂O are discussed and assigned with respect to the crystal structures. [Hpy][AuCl₄] crystallizes monoclinic in the space group C2/m. In its structure alternating layers of [Hpy]⁺ cations and [AuCl₄]^? anions are observed. The monoclinic AuCl₃ · py (space group C2/c) consists of molecular complexes, wherein the gold atom is surrounded by three Cl atoms and one pyridine molecule in a square planar arrangement. The coordination is completed to an elongated octahedron by two more distant Cl atoms of neighbouring complexes. [AuCl₂(py)₂]Cl · H₂O crystallizes in the monoclinic space group P2₁/n. It forms planar trans[AuCl₂(py)₂]⁺ cations, weakly coordinated with an additional Cl^? ion and one H₂O molecule. The Au? Cl bond lengths in the complexes under investigation are in the range of 227 to 229 pm, the Au? N distances are between 197 and 199 pm.     

Ag/CuI-Mischbesetzung in den Kristallstrukturen der Kupfer(II)-cyanoargentate Cu(NH3)(py)Ag3-xCux(CN)5 · py

Ag/Cu^I Mixed Occupancy in the Crystal Structures of the Copper(II) Cyanoargentates Cu(NH₃)(py)Ag_3?xCu_x(CN)₅ · py From pyridine and ammonia containing Cu^II solutions, to which K[Ag(CN)₂] and in part KCu(CN)₂/KCN has been added, we obtained single crystals of mixed-valent copper compounds of variable composition Cu(NH₃)-(py)Ag_3-xCu_x(CN)₅ · py. The phases corresponding to x = 0.39(1) ( I ) and to x = 1.243(6) ( II ) were characterized by X-ray structure analysis. They are isomorphous and crystallize with Z = 4 in the monoclinic space group P2₁/c. The lattice constants for I [and II , resp.] are: a = 923.8(2) [901.4(2)], b = 1226.8(2) [1227.3(2)], c = 1809.8(4) [1783.5(2)] pm, β = 91.41(3) [91.02(1)]°. The Cu^II cation shows trigonal bipyramidal [CuN₅] coordination, with the neutral ligands in axial positions (mean value Cu? N for II : 201 pm), three N atoms of cyano bridges in equatorial ones (Cu? N: 206 pm). One of these bridges stems from a trigonal unit [AgCN(NC)₂], the central atom of which is substituted by Cu^I to an extent of 39% in I , and completely in II . The two other bridges originate from two [Ag(CN)₂]^? groups, of which the more bent one may be partially occupied by Cu^I as well (24% in II ). The units mentioned are connected into meshes of elongated hexagons and further into puckered layers within the (010) plane, interpenetrating each other in pairs. A threedimensional linking of layers occurs by the trigonal Ag/Cu^I species forming centrosymmetric dimers, in which the metal coordination is completed to tetrahedral by a C-atom of the corresponding neighbouring group and short metal-metal distances of 279.1(3) pm in I and 264.1(1) pm in II appear. Details and relations are discussed.     

Pentaazadienido-Komplexe von Zink,Cadmium und Quecksilber Die Kristallstruktur von [Cd(EtOC6H4-N5-C6H4OEt)2(py)2] und [Hg(tol-N5-tol)2(py)]

Pentaazadienido Complexes of Zinc, Cadmium, and Mercury. The Crystal Structure of [Cd(EtOC₆H₄-N₅-C₆H₄OEt)₂(py)₂] and [Hg(tol-N₅-tol)₂(py)] The pentaazadienido complexes [M(EtOC₆H₄N₅C₆H₄OEt)₂] (M = Zn ( 1 ), Cd ( 2 )) are formed by the reaction of [M(NH₃)₄]²⁺ with [EtOC₆H₄N₅C₆H₄OEt]^? in aqueous ammonia. 2 crystallizes from pyridine as [Cd(EtOC₆H₄N₅C₆H₄OEt)₂py₂] ( 3 ) with the triclinic space group P1 and a = 937.2(2); b = 1422.7(2); c = 2085.5(2) pm; α = 75.28(1)°; β = 94.74(1)°; γ = 99.75(1)°; Z = 2. The central Cd²⁺ ion of 3 exhibits an octahedral coordination by two pyridine ligands in cis arrangement and two (N1, N3)-²⁺ chelating pentaazadienide ions. The reaction of [HgI₄]² with the 1,5-di(tolyl)pentaazadienide anion in aqueous ammonia affords [Hg(p-tol-N₅-tol)₂] ( 4 ), which crystallizes from pyridine in form of [Hg(tol-N₅-tol)₂py] ( 5 ) with the space group P1 and a = 1176.2(4); b = 1203.1(3); c = 1295.6(5) pm; α = 100.77(3)°; β = 110.08(3)°; γ = 94.29(2)°; Z = 2. In 5 the Hg²⁺ cation is threefold coordinated by two monodentate (N3)-η¹ pentaazadienid anions and one pyridine ligand. Within the N₅ chains of the pentaazadienid anions of 3 and 5 localized N? N double bonds are found in the positions N1? N2 and N4? N5 with distances between 125 and 129 pm.     

Pyridin‐Komplexe von Seltenerd‐Trichloriden. Synthese und Kristallstrukturen von [YCl3(Py)4] und [LnCl3(Py)4] · 0,5 Py mit Ln = La und Er

Pyridine Complexes of Rare Earth Element Trichlorides. Syntheses and Crystal Structures of [YCl₃(py)₄] and [LnCl₃(py)₄] · 0.5 py with Ln = La and Er The pyridine complexes [YCl₃(py)₄] ( 1 ), [LaCl₃(py)₄] · 0.5 py ( 2 · 0.5 py), and [ErCl₃(py)₄] · 0.5 py ( 3 · 0.5 py) have been prepared from the diacetone‐alcohol complexes [LnCl₃(DAA)₂] or directly from the metal trichlorides with excess pyridine to give colourless, only sparingly moisture sensitive crystals. They were characterized by IR spectroscopy and by crystal structure determinations. 1 : Space group Pbca, Z = 16, lattice dimensions at –80 °C: a = 1647.4(1), b = 1743.1(1), c = 3190.5(1) pm, R₁ = 0.031. 2 · 0,5 Py: Space group P2₁/n, Z = 4, lattice dimensions at –80 °C: a = 978.9(1), b = 1704.5(1), c = 1589.5(1) pm, β = 103.61(1)°, R₁ = 0.0281. 3 · 0,5 Py: Space group P2₁/n, Z = 4, lattice dimensions at –80 °C: a = 970.1(1), b = 1706.4(1), c = 1566.1(1) pm, β = 103.46(1)°, R₁ = 0.0232. All complexes realize monomeric molecular structures with the metal atom in a distorted pentagonal‐bipyramidal coordination. One of the chlorine atoms and the four pyridine molecules are in the equatorial plane.     

Pyridinium‐Chlorometallate von Lanthanoid‐Elementen. Die Kristallstrukturen von [HPy]2[LnCl5(Py)] mit Ln = Eu,Er, Yb und von [H(Py)2][YbCl4(Py)2] · Py

Pyridinium Chlorometallates of Lanthanoid Elements. Crystal Structures of [HPy]₂[LnCl₅(Py)] mit Ln = Eu, Er, Yb und von [H(Py)₂][YbCl₄(Py)₂] · Py The pyridinium chlorometallates [HPy]₂[LnCl₅(Py)] with Ln = Eu, Er and Yb, as well as [H(Py)₂][YbCl₄(Py)₂]·Py have been obtained by the reaction of diacetone alcohol with solutions of the corresponding metal trichlorides in pyridine at 100 °C. According to the crystal structure determinations the anions [LnCl₅(Py)]^2— are linked by bifurcated Cl···H···Cl bridges with the protons of the [HPy]⁺ cations forming chains along [001]. The anions of [H(Py)₂][YbCl₄(Py)₂]·Py form discrete octahedrons with trans‐positions of the pyridine ligands. [HPy]₂[EuCl₅(Py)] ( 1a ): Space group Pnma, Z = 4, lattice dimensions at —80 °C: a = 1874.4(2), b = 1490.2(2), c = 741.5(1) pm, R₁ = 0.0466. [HPy]₂[ErCl₅(Py)] ( 1b ): Space group Pnma, Z = 4, lattice dimensions at —80 °C: a = 1864.3(1), b = 1480.7(2), c = 739.7(1) pm, R₁ = 0.0314. [HPy]₂[YbCl₅(Py)] ( 1c ): Space group Pnma, Z = 4, lattice dimensions at —80 °C: a = 1858.9(2), b = 1479.0(1), c = 736.8(1) pm, R₁ = 0.0306. [H(Py)₂][YbCl₄(Py)₂]·Py ( 2 ·Py): Space group Ia, Z = 4, lattice dimensions at —80 °C: a = 1865.5(1), b = 827.5(1), c = 1873.4(1) pm, ß = 103.97(1)°, R₁ = 0.0258.     

Trichloropalladate(II) Complexes with Pyridine Ligands – Molecular Structure and Conformational Analysis of [K(18C6)][PdCl3(py)]

[K(18C6)]₂[Pd₂Cl₆] ( 1 ) (18C6 = 18‐crown‐6) was found to react with pyridines in a strictly stoichiometric ratio 1 : 2 in methylene chloride or nitromethane to yield trichloropalladate(II) complexes [K(18C6)][PdCl₃(py*)] (py* = py, 2a ; 4‐Bnpy, 2b ; 4‐tBupy, 2c ; Bn = benzyl; tBu = tert‐butyl). The reaction of 1 with pyrimidine (pyrm) in a 1 : 1 ratio led to the formation of the pyrimidine‐bridged bis(trichloropalladate) complex [K(18C6)]₂[(PdCl₃)₂(μ‐pyrm)] ( 3 ). The identities of the complexes were confirmed by means of NMR spectroscopy (¹H, ¹³C) and microanalysis. The X‐ray structure analysis of 2a reveals square‐planar coordination of the Pd atom in the [PdCl₃(py)]^? anion. The pyridine plane forms with the complex plane an angle of 55.8(2)°. In the [K(18C6)]⁺ cation the K⁺ lies outside the mean plane of the crown ether (defined by the 6 O atoms) by 0.816(1) Å. There are tight K···Cl contacts between the cation and the anion (K···Cl1 3.340(2) Å, K···Cl2 3.166(2) Å). To gain an insight into the conformation of the [PdCl₃(py)]^? anion, DFT calculations were performed showing that the equilibrium structure ( 6eq ) has an angle between the pyridine ligand and the complex plane of 35.3°. Rotation of the pyridine ligand around the Pd–N vector exhibited two transition states where the pyridine ligand lies either in the complex plane ( 6TS _pla, 0.87 kcal/mol above 6eq ) or is perpendicular to it ( 6TS _per, 3.76 kcal/mol above 6eq ). Based on an energy decomposition analysis the conformation of the anion is discussed in terms of repulsive steric interactions and of stabilizing σ and π orbital interactions between the PdCl₃^? moiety and the pyridine ligand.     

Nickel(II) and copper(II) complexes of ONS ligands formed from 2-hydroxyacetophenone and S-alkyldithiocarbazates and the X-ray crystal structure of the [Ni(Ap-SMe)py] complex (Ap-SMe = anion of the 2-hydroxyacetophenone Schiff base of S-methyl-dithiocarbazate)

Summary New nickel(II) and copper(II) complexes of general formulae [M(Ap-SR)] and [Ap-SR)B] (Ap-SR = dianionic forms of the Schiff bases of 2-hydroxyacetophenone and S-alkyl esters of dithiocarbazic acid; M = Ni^II or Cu^II; R = Me or CH₂Ph; B = py, phen or dipy have been synthesized and characterized by a variety of physicochemical techniques. Magnetic and spectroscopic data support an oxygen-bridged binuclear structure for the [M(Ap-SR)] complexes. The [M(Ap-SR)py] complexes are four-coordinate and square planar, whereas the [M(Ap-SR)B] complexes (B = phen or dipy) are five-coordinate and probably trigonal bipyramidal. The [Cu(Ap-SR)B] complexes (B = py, phen or dipy) obey the Curie-Weiss law over the 298-93 K range.The structure of the [Ni(Ap-SMe)py] complex has been determined by X-ray crystallography. It has an approximately square-planar structure in which the doubly-deprotonated Schiff base is coordinated to the Ni^II ion via the azomethine N atom, the phenolic O atom and the thiolato S atom. The fourth coordination position around the Ni^II ion is occupied by the N of the pyridine ligand.     

Die Pyridinaddukte der Goldhalogenide. 2. Darstellung,Eigenschaften und Kristallstruktur von AuCl · NC5H5 und Aul · NC5H5

Pyridine Adducts of the Gold Halides. 2. Synthesis, Properties, and Crystal Structure of AuCl · NC₅H₅ and AuI · NC₅H₅ AuCl · py is formed by the reaction of AuCl · S(CH₂C₆H₅)₂ with pyridine in absolute Ethanol. AuI · py can be obtained from AuI and pyridine in toluene. Both compounds are sensitive to light and thermically instable. AuI · py decomposes already above ?30°C. AuCl · py crystallizes monoclinic with 16 formula units in the space group C2/c, AuI · py is orthorhombic with the space group Pnnm and 8 formula units per unit cell. The structures of the adducts are built up by linear Au(py)₂ and AuX₂ groups, which are linked together to tetranuclear, chainlike complexes AuX₂? Au(py)₂? Au(py)₂? AuX₂ by weak gold-gold bonds. (AuI · py)₄ forms a linear Au₄ chain and possesses nearly the symmetry D_2h. The shortest Au-Au distance being 299.0 pm. In the centrosymmetrical (AuCl · py)₄ an Au₄-zig-zag chain with Au? Au distances of 324.9 and 341.6 pm is observed. The gold-ligand bond lengths are: AuCl · py: Au? Cl = 228 pm, Au? N = 209 pm; AuI · py: Au? I = 254.4, Au? N = 202 pm. The IR spectra and the luminescence properties are discussed.     

Untersuchungen über Iodoferrate: Die Kristallstrukturen von Fe(THE)6(FeI3THF)2 · THF und Fe(Ch2O)6(FeI4)2 · I2(THF = C4H8O)

Investigations about Iodoferrates: The Crystal Structures of Fe(thf)₆(FeI₃thf)₂ · thf and Fe(CH₂O)₆(FeI₄)2 · I₂(thf = C₄H₈O) The crystal structures of FeI₂ · 3 thf (i.e. Fe(thf)₆(FeI₃thf)₂ · thf) ( 1 ) and Fe(CH₂O)₆(FeI₄)₂ · I₂ ( 2 ) were determined from single crystal X-ray data. 1 crystallizes in the cubic space group Pa3, a = 1759.8 pm, Z = 4, 2 in the monoclinic space group P2₁/n, a = 997.4, b = 1669.4, c = 1082.6 pm, β = 93.11°, Z = 2. The structure of 1 is composed of octahedral Fe(thf)₆²⁺ cations and distorted tetrahedral [FeI₃(thf)]-anions (Fe? I distance 261.1 pm). In 2 two tetrahedral tetraiodoferrate (III) anions are linked by an iodine molecule. The Fe? I distance was found to be 253.9 pm (mean, the I? I distance between FeI₄^? and I₂ 356.1 pm. The decomposititon of 1 in vacuum at elevated temperatures and the resulting formation of 2 from 1 are discussed.     

Halogencyane als Liganden Darstellung und Kristallstruktur des [Fe(NCBr)6](FeBr4)2 · 2 BrCN

Halogencyanogens as Ligands. Preparation and Crystal Structure of [Fe(NCBr)₆](FeBr₄)₂ · 2 BrCN Hexa(bromocyanogen)iron(II) bistetrabromoferrate(III) bromocyanogen(1/2) may be prepared by reaction of FeBr₂ and BrCN. It crystallizes triclinically in the space group P1 with a = 1249.3, b = 823.5, c = 962.2 pm, α = 89.58°, β = 77.72°, γ = 87.79° and Z = 1 formula unit. The salt-like compound is built up by nearly octahedral, only bromocyanogen molecules as ligands containing cations [Fe(NCBr)₆]²⁺, nearly tetrahedral anions [FeBr₄]^? and additional BrCN molecules. The packing of the ions may be compared with the CdCl₂ type. Short Br ?Br contacts between the coordinated BrCN molecules and Br^? ions connect the building units to a ribbon along [111 ] which contains the solvating BrCN molecules, too.     

Synthese,Eigenschaften und Struktur von Amin-Addukten der Lithium-tris[bis(trimethylsilyl)methyl]zinkate

Synthesis, Properties, and Structure of the Amine Adducts of Lithium Tris[bis(trimethylsilyl)methyl]zincates . Bis[bis(trimethylsilyl)methyl]zinc and the aliphatic amine 1,3,5-trimethyl-1,3,5-triazinane (tmta) yield in n-pentane the 1:1 adduct, the tmta molecule bonds as an unidentate ligand to the zinc atom. Bis[bis(trimethylsilyl)methyl]zinc · tmta crystallizes in the triclinic space group P1 with {a = 897.7(3); b = 1 114.4(4); c = 1 627.6(6) pm; α = 90.52(1); β = 103.26(1); γ = 102.09(1)°; Z = 2}. The central C₂ZnN moiety displays a nearly T-shaped configuration with a CZnC angle of 157° and Zn? C bond lengths of 199 pm. The Zn? N distances of 239 pm are remarkably long and resemble the loose coordination of this amine; a nearly complete dissociation of this complex is also observed in benzene. The addition of aliphatic amines such as tmta or tmeda to an equimolar etheral solution of lithium bis(trimethylsilyl)methanide and bis[bis(trimethylsilyl)methyl]zinc leads to the formation of the amine adducts of lithium tris[bis(trimethylsilyl)methyl]zincate. Lithium tris[bis(trimethylsilyl)methyl]zincate · tmeda · 2 Et₂O crystallizes in the orthorhombic space group Pbca with {a = 1 920.2(4); b = 2 243.7(5); c = 2 390.9(5) pm; Z = 8}. In the solid state solvent separated ions are observed; the lithium cation is distorted tetrahedrally surrounded by the two nitrogen atoms of the tmeda ligand and the oxygen atoms of both the diethylether molecules. The zinc atom is trigonal planar coordinated; the long Zn? C bonds with a value of 209 pm can be attributed to the steric and electrostatic repulsion of the three carbanionic bis(trimethylsilyl)methyl substituents.     

Reaktionen silylierter Phosphanimine mit Iodmonochlorid und Iodtrichlorid. Die Kristallstrukturen von [Me3SiNPMe3 · ICl], [Ph3PNCl · ICl] und [Me3PN(H)PMe3] [ICl2]2

Reactions of Silylated Phosphorane Imines with Iodine Monochloride and Iodine Trichloride. The Crystal Structures of [Me₃SiNPMe₃ · ICl], [Ph₃PNCl · ICl], and [Me₃PN(H)PMe₃][ICl₂]₂ The donor-acceptor complex [Me₃SiNPMe₃ · ICl] has been prepared from Me₃SiNPMe₃ and ICl in acetonitrile solution forming yellow-orange crystals. [Ph₃PNCl · ICl] can be prepared by the reaction of Me₃SiNPPh₃ with ICl₃ in dichloromethane solution forming pale yellow crystals. [Me₃PN(H)PMe₃][ICl₂]₂ is formed in a small amount by a slow reaction of Me₃SiNPMe₃ with ICl₃ in CCl₄ suspension in the presence of traces of moisture. All samples are characterized by IR spectroscopy and by X-ray structure analyses. [Me₃SiNPMe₃ · ICl] (1) : Space group Iba2, Z = 8, structure solution with 1 727 observed unique reflections, R = 0.051. Lattice dimensions at ?60°C: a = 1 510.7, b = 1 862.8, c = 988.9 pm. 1 has a molecular structure in which the N atom of the phosphorane imine is connected with the iodine atom of the ICl molecule in a linear arrangement N? I? Cl. Bond lengths N? I = 222.7 pm, I? Cl = 265.1 pm. [Ph₃PNCl · ICl] (2) : Space group Pna2₁, Z = 4, structure solution with 1 530 observed unique reflections, R = 0.030. Lattice dimensions at 20°C: a = 1 522.8, b = 1 408.3, c = 865.8 pm. 2 has a molecular structure in which the N atom of the N chlorophosphorane imine is connected with the iodine atom of the ICl molecule in a linear arrangement. Bond lengths N? Cl = 174.4 pm, N? I = 229.5 pm, I? Cl = 251.2 pm. [Me₃PN(H)PMe₃][ICl₂]₂ (3) : Space group P2₁/c, Z = 4, structure solution with 1 989 observed unique reflections, R = 0.029. Lattice dimensions at ?50°C: a = 1 223.1, b = 1 090.2, c = 1 482.8 pm, β = 112.21°. 3 consists of [Me₃PN(H)PMe₃]²⁺ ions and ICl₂^? anions. The PNP bond angle of the dication amounts to 134.4° with PN distances of 165.6 and 166.1 pm, approximately according to double bonds.     

Syntheses,structures and properties of isonicotinamidium,thionicotinamidium, 2- and 3-(hydroxymethyl)pyridinium nitrates

New salts containing cations of selected pyridine derivatives of the composition [pyH]NO₃, where py is 2-pyridylmethanol (2-(hydroxymethyl)pyridine, 2pm), 3-pyridylmethanol (3-(hydroxymethyl) pyridine, 3pm), isonicotinamide (4-(aminocarbonyl)-pyridine, inia) and thionicotinamide (4-(aminothiocarbonyl)pyridine, tnia) were synthesised using two methods. By the first method, the above salts were obtained from reaction mixtures prepared from Fe(NO₃)₃ · 9H₂O and the appropriate pyridine derivative py in ethanol without the addition of acids. The protons required for protonation of the given pyridine derivatives are formed by the protolytic reaction of [Fe(H₂O)₆]³⁺, which acts as a cationic Brønstedt acid. These cations are present in the solid state of Fe(NO₃)₃ · 9H₂O as well as in its solutions. Under the second procedure, the salts were prepared by a direct reaction of the selected pyridine derivative py with a diluted solution of HNO₃. The first method affords crystals with lower yields but the second method produces microcrystals with higher yields. All the compounds were characterised by elemental analysis, infrared and NMR spectroscopic analyses and [3pmH]NO₃ and [2pmH]NO₃ by X-ray structure analysis also. [3pmH]NO₃ crystallises in the monoclinic and [2pmH]NO₃ in the triclinic system.     

Einkristallzüchtung und Röntgenstrukturanalyse von CoSO4 · Pyrazin · 6 H2O (I) und (CoSO4)2 · Pyrazin · 12 H2O (II)

Crystal Growth and Structure of CoSO₄ · Pyrazine · 6 H₂O (I) and (CoSO₄)₂ · Pyrazine · 12 H₂O (II) Single crystals of μ-pyrazino-bis[pentaquacobalt(II)]-sulfate-dihydrate CoSO₄(pz) · 6 H₂O and Tetraqua-μ-pyrazino-cobalt(II)sulfate-dihydrate (CoSO₄)₂(pz) · 12 H₂O were grown by using gel methods and investigated by X-ray analysis. CoSO₄(pz) · 6 H₂O (I) shows monoclinic symmetry, space group C2/c; a = 1006.4(4) pm, b = 1026.9(4) pm, c = 1261.5(2) pm; β = 104.01(4)°; Z = 4. (CoSO₄)₂(pz) · 12 H₂O (II) shows orthorhombic symmetry, space group Pbam; a = 1262.3(4) pm, b = 1231.3(4) pm, c = 684.1(2) pm; Z = 2. CoSO₄ and Pyrazine crystallize in a polymeric (I) as well as in a dimeric (II) compound. In the polymeric compound the molecules are bonded by pyrazine to form alternating linear chains. The dimer is a dinuclear complex with a bridging pyrazine molecule.     

Reaktionen koordinierter Liganden. IX [1]. Reaktionen und Molekülstruktur von Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphan-P2)eisen(0) – einem Monosubstitutionsprodukt des Pentacarbonyleisens mit äquatorialem Phosphanliganden

Die Struktur von Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphan-P²)-eisen(0) ( I ) wurde röntgenographisch bestimmt. I kristallisiert in der Raumgruppe P1 . Es weist trigonal bipyramidale Koordination am Fe-Atom auf. Der Phosphanligand befindet sich in äquatorialer Position mit einem Fe? P? ;Abstand von 226,2(1) pm. Der mittlere Abstand Fe? C für die axial gebundenen CO-Gruppen beträgt 178,8(3) pm und unterscheidet sich nicht signifikant von dem für die äquatorial gebundenen CO-Gruppen. Die P? P? Abstände im Triphosphanliganden unterscheiden sich um 1,9 pm [225,6(2) und 223,7(1) pm]. Mit PtCl₂ bildet I einen Komplex ( III ) der Zusammensetzung (CO)₄FePPh(PPh₂)₂PtCl₂, in dem die terminalen Phosphoratome an das Platin koordiniert sind und einen viergliedrigen Ring bilden. Beim Erhitzen lagert sich I unter Wanderung der Fe(CO)₄-Einheit von der medialen in die terminale Position der Triphosphankette in den isomeren Komplex II um. Die Bestrahlung von I mit UV-Licht liefert als Hauptprodukte Ph₂P? PPh₂ und (CO)₄Fe? PPhH? PPh₂. Reactions of Coordinated Ligands. IX. Reactions and Molecular Structure of Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphane-P²)iron(0) – a Monosubstitution Product of Pentacarbonyliron with an Equatorial Phosphane Ligand The structure of tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphane-P²)iron(0) (I) was determined by X-ray analysis. The molecule displays a trigonal-bipyramidal coordination geometry at the iron atom with the phosphane ligand in an equatorial position and an Fe? P distance of 226.2(1) pm. The average Fe? C axial distance of 178.8(3) pm is not significantly different from that of 178.0(5) pm for the average Fe? C equatorial distance. A difference of 1.9 pm is observed between the two P? P distances [225.6(2) and 223.7(1) pm]. With PtCl₂ I yields a complex of composition (CO)₄FePPh(Ph₂P)₂PtCl₂ (III) in which the terminal phosphorus atoms of I are coordinated to platinum forming a four membered ring system. On heating, complex II , an isomer of I , is formed by migration of the Fe(CO)₄-unit from the medial to the terminal position within the triphosphane chain. Irradiation of I with UV light affords Ph₂P? PPh₂ and Fe(CO)₄? PPhH? PPh₂ as main products.     

Polysulfonylamine. XXXVII. Darstellung von Quecksilberdimesylamiden. Kristall- und Molekülstrukturen von Hg[N(SO2CH3)2]2, Hg[{N(SO2CH3)2}2(DMSO)2] und Hg[{N(SO2CH3)2}2(HMPA)]

Polysulfonyl Amines. XXXVII. Preparation of Mercury Dimesylamides. Crystal and Molecular Structures of Hg[N(SO₂CH₃)₂]₂, Hg[{N(SO₂CH₃)₂}₂(DMSO)₂], and Hg[{N(SO₂CH₃)₂}₂(HMPA)] Hg[N(SO₂CH₃)₂]₂ ( 1 ) and Hg₂[N(SO₂CH₃)₂]₂ ( 2 a ) are formed as colourless, sparingly soluble precipitates when solutions of Hg(NO₃)₂ or Hg₂(NO₃)₂ in dilute nitric acid are added to an aqueous HN(SO₂CH₃)₂ solution. By a similar reaction, Hg₂[N(SO₂C₆H₄ ? Cl? 4)₂]₂ is obtained. 1 forms isolable complexes of composition Hg[N(SO₂CH₃)₂]₂ · 2 L with L = dimethyl sulfoxide (complex 3 a ), acetonitrile, dimethyl formamide, pyridine or 1,10-phenanthroline and a (1/1) complex Hg[N(SO₂CH₃)₂]₂ · HMPA ( 4 ) with hexamethyl phosphoramide. Attempted complexation of 2 a with some of these ligands induced formation of Hg⁰ and the corresponding Hg^II complexes. Crystallographic data (at -95°C) are for 1: space group 14₁/a, a = 990.7(2), c = 2897.7(8) pm, V = 2.844 nm³, Z = 8, D_x = 2.545Mgm^?3; for 4a: space group P1 , a = 767.8(2), b = 859.2(2), c = 925.2(2)pm α = 68.44(2), β = 86.68(2), γ = 76.24(2)°, V = 0.551nm³, Z = 1, D_x = 2.113 Mgm^?3; for 4: space group P2₁/c, a = 1041.3(3), b = 1545.4(3), c = 1542.5(3) pm, β = 100.30(2)°, V = 2.474nm³, Z = 4, D_x = 1.944Mgm³. The three compounds form molecular crystals. The molecular structures contain a linear or approximately linear, covalent NHgN moiety; the Hg? N distances and N? Hg? N angles are 206.7(4) pm and 176.3(2)° for 1, 207.2(2) pm and 180.0° for 3a, 205.7(4)/206.7(4) pm and 170.5(1)° for 4. In the complexes 3a and 4, the 0-ligands are bonded to the Hg atoms perpendicularly to the N? Hg? N axes, leading in 3a to a square-planar trans-(N₂O₂) coordination with Hg? 0 261.2(2) pm and N? Hg? O 92.3(1)/87.7(1)°, in 4 to a slightly distorted T-shaped (N₂O) geometry with Hg? 0 246.2(4)pm and N? Hg? 0 96.7(1)/92.0(1)°. In all three structures, the primary coordination is extended to a severely distorted (N₂O₄) hexacoordination by the appropriate number of secondary, inter- and/or intramolecular Hg…?0 inter-actions (0 atoms from sulfonyl groups, Hg…?O distances in the range 280—300pm). The intramolecular Hg…?O interactions give rise to nearly planar four-membered [HgNSO] rings. The molecule of 1 has a two-fold axis through the bisector of the N? Hg? N angle, the molecule of 3a an inversion center at the Hg atom. The molecule of 4 has no symmetry.     

Nitrido-Azido-Komplexe des Molybdän(VI): Synthese und Kristallstruktur von [MoN(N3)2(terpy)]+ [MoN(N3)4]−·MoN(N3)3 (terpy)

Nitrido-Azido-Complexes of Molybdenum(VI). Synthesis and Crystal Structure of [MoN(N₃)₂(terpy)]⁺[MoN(N₃)₄] ^? · MoN(N₃)₃(terpy) (CH₃)₃SiN₃ reacts with Mo(CO)₃(terpy) in CH₃CN yielding red crystals of [MoN(N₃)₂(terpy)]⁺[MoN(N₃)₄] ^?· MoN(N₃)₃(terpy) (space group P1 , a = 1039.3 pm, b = 1384.6 pm, c = 1685.4 pm, α = 112.4°, β = 108.1°, γ = 88.3°, Z = 2, R = 0.035 for 4376 independent reflections). The structure consists of three different mononuclear complexes. In the neutral complex MoN(N₃)₃(terpy) Mo exhibits the coordination number 7 in form of a distorted pentagonal bipyramid, with the terpyridine ligand and two azido groups in the equatorial plane. The axial positions are occupied by the nitrido ligand and another azido group. The triply bonded nitrido nitrogen atom (Mo1? N1 = 165.6 pm) causes a strong trans effect resulting in a long distance of 245.7 pm to N_α of the trans bonded azido group. The cationic complex [MoN(N₃)₂(terpy)]⁺ derives from MoN(N₃)₃-(terpy) by abstraction of the trans bonded azido group. For the molybdenum atom remains the coordination number 6 in form of the rarely found pentagonal pyramid. In the anion [MoN(N₃)₄]^? the molybdenum atom exhibits the coordination number 5 in form of a tetragonal pyramid with the nitrido ligand in the apex. The square basic plane is formed by the N_α atoms of the azido groups.     

Synthese und Struktur von Lithium-tris(trimethylsilyl)silanid · 1,5 DME

Synthesis and Structure of Lithium Tris(trimethylsilyl)silanide · 1,5 DME Lithium tris(trimethylsilyl)silanide · 1,5 DME 2a synthesized from tetrakis(trimethylsilyl)silane 1 [6] and methyllithium in 1,2-dimethoxyethane , crystallizes in the monoclinic space group P2₁/c with following dimensions of the unit cell determined at a temperature of measurement of ?120 ± 2°C: a = 1 072.9(3); b = 1 408.3(4); c = 1 775.1(5) pm; β = 107.74(2)°; 4 formula units (Z = 2). An X-ray structure determination (R_w = 0.040) shows the compound to be built up from two [lithium tris(trimethylsilyl)silanide] moieties which are connected via a bridging DME molecule. Two remaining sites of each four-coordinate lithium atom are occupied by a chelating DME ligand. The Li? Si distance of 263 pm is considerably longer than the sum of covalent radii; further characteristic mean bond lengths and angles are: Si? Si 234, Li? O 200, O? C 144, O?O (biß) 264 pm; Si? Si? Si 104°, Li? Si? Si 107° to 126°; O? Li? O (inside the chelate ring) 83°. Unfortunately, di(tert-butyl)bis(trimethylsilyl)silane 17 prepared from di(tert-butyl)dichlorsilane 15 , chlorotrimethylsilane and lithium, does not react with alkyllithium compounds to give the analogous silanide.     

Synthese von Nitrenkomplexen mit N-Trimethylsilylanilin. II. Charakterisierung und Kristallstruktur der Rhenium(V)-phenylnitren-Komplexe mer-[Re(NPh)Cl3(NH2Ph)(Ph3P)] und trans-[Re(NPh)(OMe)Cl2(Ph3P)2]

Synthesis of Phenylnitrene Complexes with N-Trimethylsilylaniline. II. Characterization and Crystal Structure of the Rhenium(V) Complexes mer-[Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] and trans-[Re(NPh)(OMe)Cl₂(Ph₃P)₂] Reaction of [ReOCl₃(Ph₃P)₂] with N-trimethylsilylaniline yields mer-[Re(NPh)Cl₃(Ph₃P)₂], which reacts under air with excess of N-trimethylsilylaniline to form [Re(NPh)Cl₃ · (NH₂Ph)(Ph₃P)]. Crystallization from CH₂Cl₂/MeOH affords [Re(NPh)(OMe)Cl₂(Ph₃P)₂] as an additional product. [Re(NPh)Cl₃(NH₂Ph)(Ph₃P)] crystallizes in the monoclinic space group P2₁/n with a = 1 192.3(3); b = 1 918.9(3); c = 1 266.3(3) pm; β = 101.71(1)°; Z = 4. The rhenium atom has a distorted octahedral environment with the Cl atoms in meridional positions. The phenyl nitrene ligand is coordinated with an almost linear arrangement Re? N1? C40 = 166.8(6)° and with a bond distance Re?N = 170.5(6) pm. [Re(NPh)(OMe)Cl₂(Ph₃P)₂] · 1/2CH₂Cl₂ crystallizes in the triclinic space group P1 : a = 1 103.1(4); b = 1 227.9(4); c = 1 711.3(5) pm; α = 70.48(3)°; β = 72.71(3)°; γ = 80.03(3)°; Z = 2. The rhenium atom exhibits a distorted octahedral coordination with the Cl atoms and the phosphine ligands in trans positions. As a consequence of the competition of the nitrene ligand and the trans-coordinated methoxy group the Re?;N bond length is slightly lengthened to 173.2(7) pm, while the Re? O bond length of 193.4(6) pm is short. The bond angles Re? N? C70 and Re? O? C80 are 173.3(7)° and 139.1(7)°, respectively.