Die Reaktion von Molybdänpentachlorid mit Trichlornitromethan; die Kristallstruktur von [MoOCl3 · POCl3]2

Reaction of Molybdenum Pentachloride with Trichloronitromethane. Crystal Structure of [MoOCl₃ · POCl₃]₂ An improved method for the preparation of MoO₂Cl₂ by the reaction of MoCl₅ with CCl₃NO₂ is reported. In the presence of the solvens POCl₃, molybdenum pentachloride reacts with trichloronitromethane forming the oxonitrosyl complex Mo(NO)OCl₃ · POCl₃. In CH₂Cl₂ solution this complex is decomposed forming [MoOCl₃ · POCl₃]₂. The crystal structure was solved by X-ray methods. [MoOCl₃ · POCl₃]₂ crystallizes monoclinic in the space group P2₁/c with two dimers in the unit cell (R = 0.07, 2327 independent reflexions). The complex dimerizes by symmetric chloro bridges; the oxoligand is in terminal position. The MoO bond length of 163 pm corresponds with a Mo?O triple bond. The POCl₃ molecule is coordinated in position trans to the oxoligand. The IR spectra are reported and assigned.     

Über die Reaktionen von N-Chloracetonimin mit Molybdänpentachlorid und Wolframhexachlorid Die Kristallstruktur von Me2CNH2[MoOCl4]

Reactions of N-Chloroacetoneimine with Molybdenum Pentachloride and Tungsten Hexachloride. Crystal Structure of Me₂C?NH₂[MoOCl₄] WCl₆ reacts with N-chloroacetoneimine under elimination of chlorine and formation of pentachloro-isopropylideneimino-tungsten(VI), Cl₅W?N?CMe₂, a brown-black crystal powder, which was characterized by i.r. spectroscopy. MoCl₅ reacts in a similar way, although only a product mixture can be obtained. Partial hydrolysis of this mixture yields isopropylideneiminium-tetrachlorooxomolybdate(V), Me₂C?NH₂⁺[MoOCl₄]^?, of which the crystal structure was determined (2323 unique observed reflexions, R = 0.049). Space group P2₁/c, Z = 4, a = 878.6, b = 907.2, c = 1252.2 pm, β = 91.29°. The compound consists of Me₂C?NH₂⁺ ions with a planar arrangement of the skeletal atoms and a CN bond length of 126.7 pm and of dimeric, centrosymmetric anions [MoOCl₄]₂^2? having Mo atoms linked via asymmetric chloro bridges (MoCl distances 238.4 and 307.6 pm). The longer Mo? Cl contacts are located in the trans-positions of the terminal oxoligands (MoO distance 164 pm).     

Über die Reaktion von Nb3Cl3 mit HCl

On the Reaction of Nb₃Cl₈ with HCl The greenish-blue gas phase which is formed at 500–600°C by reaction of Nb₃Cl₈ with HCl, is caused by an equilibrium reaction, in which small amounts of NbCl₅ and larger amounts of NbCl₄ are formed. This is shown by photometric measurements and by thermodynamic calculations.     

Über Chalkogenolate. 174. Reaktion von Acetamidin mit Kohlenstoffdisulfid 3. Kristallstruktur von Acetamidinium-N-acetimidoyldithiocarbamat [1]

On Chalcogenolates. 174. Reaction of Acetamidine with Carbon Disulfide. 3. Crystal Structure of Acetamidinium N-Acetimidoyl Dithiocarbamate The title compound [(H₂N)₂C? CH₃][S₂C? N?C(CH₃)? NH₂] crystallizes with Z = 4 in the monoclinic space group P2₁/n with cell dimensions a = 10.354(1), b = 6.798(1), c = 14.013(1) Å, β = 103.32(1)°. The crystal structure has been determined from single crystal X-ray data measured at 20°C and refined to a conventional R of 0.049 for 2 521 independent reflections (R_w = 0.052). The cation is associated with one anion by hydrogen bridges S…H? N and N…H? N forming an 8-membered ring system. The anion is not plane in contrast to hitherto known structures of dithiocarbamates.     

Die Reaktion von [Mo6Cl8]X4 mit N-Basen

Reaction of [Mo₆Cl₈]X₄ with N-Bases [Mo₆Cl₈]X₄ (X = Cl, Br, I) in ethanol solution by titration with Ag⁺ showed 4 labil X atoms. The displacement of X^? especially by F^? accelerates the titration decisively. Conductivity measurements in ethanol or acetone showed that [Mo₆Cl₈]X₄ at 25°C behave as weak 1:1-electrolytes. Solutions of [Mo₆Cl₈]X₄ in DMF heated up to 60°C and than lowered to 25°C showed that the compounds in this solvent behave as (potential) strong 2:1-valent electrolytes. From the following compounds the labil halides have been determined by titration with Ag⁺: [Mo₆Cl₈]X₄(Py)₂ (X = Cl, Br), [Mo₆Cl₈]X₄(bipy)₂ (X = Cl, Br, I), [Mo₆Cl₈]X₄(Phenpy)₂ (X = Cl, Br, I), (PyH)₂[Mo₆Cl₈]X₆ (X = Cl, Br); (bipyH)₂[Mo₆Cl₈]I₄Cl₂. Always 4 (respectively 6) labil halides have been observed; exception [Mo₆Cl₈]Cl₄(Py)₂ in acetone (2 labil Cl). Lattice constants and mole volumina for the adducts with pyridin and bipyridin have been determined. The adducts with bipyridin and phenylpyridin are isotypic. Conductivity measurements have been made in different solutions. The decomposition on the thermobalance showed that in [Mo₆Cl₈]Cl₄(Py)₂ the bond of pyridin is weak. The 2 pyridin molecules are evolved at the same time. However [Mo₆Cl₈]I₄(Bipy)₂ loses 1 bipyridin only. (PyH)₂[Mo₆Cl₈]X₆ formed during the first decomposition step the novel compounds (PyH) [Mo₆Cl₈]X₅ (X = Cl, Br). Both compounds are isotypic. They behave in ethanol solution as strong 1:1-valent electrolytes.     

Über die Reaktion von tertiären Vinylcarbinolen mit Isopropenyläther Eine neue Methode zur Herstellung von γ, δ-ungesättigten Ketonen

A novel acid-catalysed reaction of isopropenyl ether with tertiary vinyl carbinols giving γ, δ-unsaturated ketones in high yields is described. Methylheptenone, geranylacetone, farnesylacetone and analogous ketones were prepared by this convenient and efficient new method, which involves a Claisen-rearrangement step.     

Über die Reaktion von tertiären Vinylcarbinolen mit Vinyläthern Eine neue Methode Zur Herstellung von γ,δ-ungesättigten Aldehyden

A novel acid catalysed reaction of vinyl ethers with tertiary vinyl carbinols giving γ, δ-unsaturated aliphatic and alicyclic aldehydes in high yields is described. This new procedure for the utilization of the Claisen rearrangement reaction provides a convenient and efficient route to such aldehydes.     

Über die Reaktion von Alkalihexafluorosilicaten mit Aluminiumoxid

On Reactions of Alkali Hexafluorosilicates with Aluminum Oxides The reaction of Na- and K-hexafluorosilicates and α- or γ-Al₂O₃ has been investigated. Final reaction products are fluoroaluminates and alumosilicates. The reaction mechanism has been discussed. Influence of reaction parameters like time, temperature, layer thickness, and the effect of admixtures (fluorides, SiO₂) have been regarded. Tablet-reactions show the introduction of reaction by Si? F species.     

Über die Reaktion von Thiophosphoryltrichlorid mit Hexamethyldisilazan

On the Reaction of Thiophosphoryl Chloride with Hexamethyl Disilazane On the basis of a ³¹P n.m.r. spectroscopic study of the reaction of PSCl₃ with hexamethyl disilazane a method for the preparation of Me₃SiNHP(S)Cl₂( 1 ) and the diazadiphosphetidine 2 , [Me₃SiNHP(S)?NSiMe₃]₂ has been developed. These new crystalline compounds have been characterized by i.r., Raman, ³¹P n.m.r. and mass spectroscopy, and their thermal behaviour has been studied. The formation and constitution of 2 are discussed, and its ¹H and ²⁹Si n.m.r. spectra are reported.     

Über die Reaktion von W3O mit lod. Darstellung,Kristallstruktur und Eigenschaften von WOI3

On the Reaction of W₃O with Iodine: Preparation, Crystal Structure, and Properties of WOI₃ The novel tungsten oxide iodide WOI₃ is obtained from the reaction of the metalrich tungsten oxide W₃O (also known as ‘β-tungsten’) with iodine in a sealed glass tube placed in a temperature gradient (440–400°C). In the low-temperature region WOI₃ is formed as mouse-grey intergrown needle-like crystals. WOI₃ crystallizes in the tetragonal NbOCl₃ structure type, space group P4₂/mnm, with a = 12.346(2), c = 3.765(1) Å (20°C). The crystal structure at – 130°C was determined from single-crystal diffractometer data (R = 0.023). Results of magnetic susceptibility and vibrational spectroscopic measurements are given together with the mass spectrum of WOI₃ obtained on heating.     

Über die Reaktion von Phenolen mit N-substitutierten Maleinimiden

The Reaction of Phenols with N-substituted Maleinimides Phenoxysuccinimides are formed by the base catalysed addition of phenols to N-substituted maleinimides. In the presence of catalytic amounts of tertiary aliphatic amines yields as high as 90% are obtained. A series of adducts of mono-and di-phenols to mono- and bismaleinimides is described. Pure phenoxysuccinimides are stable compounds but the basic catalysts of their formation give rise to their decomposition into the phenolic component and oligomeric maleinimide. A nucleophilic reaction mechanism both for the formation and the decomposition is discussed. A new crosslinked addition polymer from a diphenol and a bismaleinimide with a surprisingly high heat stability is described.     

Darstellung von trans-[Mo6Cl8]Cl4Br22−ausgehend von kristallisierten [Mo6Cl8]Cl4(H2O)2 und die Kristallstruktur von [(C6H5)4As]2[Mo6Cl8]Cl4Br2

Preparation of trans-[Mo₆Cl₈]Cl₄Br₂^2? Starting from Crystalline [Mo₆Cl₈]Cl₄(H₂O)₂ and Crystal Structure of [(C₆H₅)₄As]₂[Mo₆Cl₈]Cl₄Br₂ The synthesis of the title compound is successful if the crystallized [(Mo₆Cl₈)Cl₄(H₂O)₂] containing the H₂O molecules in trans-position reacts with HBr + [(C₆H₅)₄As]Br in ethanol in a heterogeneous reaction. The X-ray structure investigation confirms the existence of discrete trans-Br-substituted cluster anions of composition [(Mo₆Cl₈)Cl₄Br₂]^2? in the crystal. The reaction in homogeneous solutions proceeds to Br-enriched compounds. [(C₆H₅)₄As]₂[(Mo₆Cl₈)Cl₄Br₂] crystallizes in the triclinic space group P¯1 with a = 11.071(2), b = 11.418(2), c = 12.813(2) Å, α = 116.10(2), β = 95.27(2) and γ = 94.41(2)° (?133°C). The crystal structure at ?133°C was determined from single crystal X-ray diffraction data (R₁ = 0.026). The [(Mo₆Cl₈)Cl₄Br₂]^2?-anions are not completely ordered but distributed statistically among the three positions which are possible within the limits of the ordered [Mo₆Cl₈]-cores (ratio 11:5:4). The frameworks of the anions consist of Mo₆ cluster units with (slightly distorted) octahedral arrangement of the metal atoms (d(Mo? Mo): 2.600(1) up to 2.614(1) Å), which are coordinated by the halogeno ligands in a square-pyramidal manner. The details of the structure will be discussed and compared with similar [(Mo₆X₈)Y₄] cluster units (X, Y ? Cl, Br).     

Thiochloroanionen von Molybdän(IV). Die Kristallstruktur von (NEt4)3[Mo3(μ3-S)(μ-S2)3Cl6]Cl · CH2Cl2 Kristallstruktur,EPR-Spektrum und magnetische Eigenschaften von (NEt4)2[Mo2(μ-S2)(μ-Cl)2Cl6]

Thiochloro Anions of Molybdenum (IV). Crystal Structure of (NEt₄)₃[Mo₃(μ₃-S)(μ-S₂)₃Cl₆]Cl μ CH₂Cl₂. Crystal Structure, Magnetic Properties, and EPR-Spectrum of (NEt₄)₂ [Mo₂(μ-S₂)(μ-Cl)₂Cl₆] From molybdenum pentachloride and tetraethylammonium hydrogensulfide in CH₂Cl₂ an insoluble product of composition (NEt₄)₂[Mo₂S₃Cl₉] was obtained along with a brown solution, from which (NEt₄)₂[Mo₂(S₂)Cl₈] was crystallized. The insoluble product and NEt₄Cl react in CH₂Cl₂ to yield, among others, (NEt₄)₃[Mo₃(S)(S₂)₃Cl₆]Cl · CH₂Cl₂. The latter crystallizes in the orthorhombic space group Pnma, a = 2495.8, b = 1501.2, c = 1295.6 pm, Z = 4. According to the crystal structure determination (3070 observed reflexions, R = 0.049) the [Mo₃(S)(S₂)₃Cl₆]^2? ion consists of an Mo₃ triangle with Mo? Mo bonds, each side of the triangle is bridged by disulfido groups and one sulfur atom is capped over the Mo₃ triangle; the single chloride ion is looseley associated to three S atoms. (NEt₄)₂[Mo₂(S₂)Cl₈] also crystallizes in the space group Pnma, a = 1425.6, b = 1129.9, c = 2004.7 pm, Z = 4; structure determination with 1703 observed reflexions, R = 0.061. In the [Mo₂(S₂)Cl₈]^2? ion the Mo atoms are bridged via one disulfido group and two chlorine atoms. There is a Mo? Mo bond, but according to the magnetic properties and the EPR spectrum each Mo atom still possesses one unpaired electron.     

Reaktion von 3-Dimethylamino-2,2-dimethyl-2H-azirin mit 6-Methyluracil; Kristallstruktur der Reaktionsprodukte

Reaction of 3-Dimethylamino-2,2-dimethyl-2H-azirine with 6-Methyluracil; Crystal Structure of the Products The reaction of 3-dimethylamino-2,2-dimethyl-2H-azirine ( 1 ) with 6-methyl-uracil ( 4 ) in 2-propanol at 80° yields the 4H-imidazoje derivative 5 as the main product. This reaction is similar to the previously reported ones with heterocyclic compounds containing the sequence NH? CO? NH? CO. In the presence of water, 5 is easily hydrolyzed to 6 . The structures of 5 and 6 have been established by X-ray crystallography.