Über ein spirocyclisches Pentaalkylphosphoran und Alkoxytetraalkylphosphoran,sowie über ein monocyclisches kovalentes Fluorotetraalkylphosphoran

Spirocyclic Pentaalkylphosphorane, Alkoxy tetraalkylphosphorane and a Monocyclic Covalent Fluorotetraalkylphosphorane Methylation of the spiro-phosphonium salt (CH₂)₄P(CH₂)₄⊕Cl? by CH₃Li at ?60°C affords the bicyclic pentaalkylphosphorane , a colourless distillable liquid of characteristic odour. The corresponding bicyclic methoxytetraalkylphosphorane is obtained from the same phosphonium salt with NaNH₃ followed by CH₃OH. The reaction is assumed to occur via the unstable bicyclic ylide. From 1-methyl-1-methylene-phospholane and NH₄F the liquid and distillable, covalent fluorotetraalkylphoshorane (CH₂)P(CH₃)₂F is formed. A complete ¹H-, ¹³C-, ¹⁹F- and ³¹P-NMR study has been carried out for these three compounds. Due to a pronounced fluxional behaviour, none of the fixed standard geometries (TBP, SP) can be assigned.     

1,4-Diaza-1,3-dien-Verbindungen elektronenarmer Übergangsmetalle σ-Donor- und π-Akzeptor-Komplexe des Zirconiums und Hafniums mit perphenylsubstituierten DAD-Liganden – ein Strukturvergleich

1,4-Diaza-1,3-diene Compounds of Early Transition Metals. σ-Donor and π-Acceptor Complexes of Zirconium and Hafnium with perphenyl-substituted DAD Ligands – a Comparison of Structures Reaction of 1,4- D i a za-1,3- d ienes (DAD) with the Lewis-acid ZrCl₄ affords σ-donor-complexes of composition ZrCl₄ · DAD. The X-ray analysis of the ( 2c ) (space group P1 , triclinic; a = 11.339(2), b = 11.845(2), c = 12.415(3) Å, α = 107.94(2), β = 107.26(2), γ = 104.73(2)°, Z = 2, R1 = 0.0266) shows that both N-atoms of the s-cis-configurated DAD-ligand occupy two corners of a distorted octahedron. There is only slight difference between the C?N bond lengths of the coordinated and noncoordinated ligand. In the homoleptic DAD-complexes of the type M(DAD)₃ [M = Zr ( 4b ), Hf ( 5b ), R = C₆H₄-4-Me] the DAD-ligands more act as π-acceptor ligands. X-ray analysis shows that the complexes [M = Zr ( 4b ), Hf ( 5b ), R = C₆H₄-4-Me] have the identical structure motive and crystallize in the triclinic space group P1 ( 4b : a = 14.904(1), b = 15.451(2), c = 19.584(4) Å, α = 112.08(1), β = 94.36(1), γ = 97.60(1)°, Z = 2, R1 = 0.0911; 5b a = 14.798(2), b = 18.226(2), c = 22.902(2) Å, α = 71.62(1), β = 72.38(1), γ = 87.27(1)°, Z = 2, R1 = 0.0644). The six N-atoms form a distorted octahedron in both complexes. The planarity of the five-membered rings and the almost similar C?N and C? C bond lengths are typical of the π-acceptor function of the diazadienes in 4b and 5b . The steric hindrance in 4b und 5b results in a dynamical behavior and a asymmetrical distortion at low temperatures as was observed by n.m.r.     

Neues über Oxouranate: Über α-Li6UO6. Mit einer Bemerkung über β-Li6UO6

New Investigations about Oxo Uranates: On α-Li₆UO₆. With a Remark about β-Li₆UO₆ The crystal structure of transparent, bright yellow single crystals of α-Li₆UO₆ has been determined. [a = 838.07(5), c = 738.34(7) pm; d_pyk = 4.02, d_x = 4.17 g · cm^?3; space group R3 ; Z = 3; R = 3.17%, R_w = 3.06%; 408 symmetry independent I₀(hkl); AgKα fourcircle diffractometer Philips PW 1100]. The structure is dominated by a threedimensional framwork of “hollow spaces”, built up by 12 O^2? (and 12 Li⁺). The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.     

Über die Darstellung und die Eigenschaften von σ-Organylwolframpentachloriden

Tungsten hexachloride reacts with dimethyl zinc or diphenyl zinc forming green methyl or phenyl tungsten pentachloride. However, tungsten hexachloride is reduced to tungsten tetrachloride on addition of zinc dialkyls with longer alkyl groups. Furthermore, alkyl tungsten pentachlorides can be prepared from tungsten hexachloride and tin tetraalkyls or boron trialkyls.     

Eine kinetische Studie über Ligandenverdrängungsreaktionen von π- Allyl-π-cyclopentadienyl-Metallkomplexen

The kinetics of the reactions of the complexes C₃H₅MC₅H₅ (M ? Ni, Pd) with tertiary phosphites P(OR)₃ to give M[P(OR)₃]₄ have been investigated. For M ? Ni and R ? C₂H₅, there results a third-order rate law whereas for M ? Pd and R ? C₆H₅ a second-order rate law is observed. Possible mechanistic implications of the kinetic data will be discussed.     

Über eine Ringerweiterungsreaktion an einem Barbitursäure-Derivat. 10. Mitteilung über Umamidierungsreaktionen

A Ring Enlargement Reaction with a Barbiturate The (6-membered) barbituric acid derivative 3 was synthesized and treated with KF/DMF/18-crown-6 to form the ring-enlarged 14-membered compound 8 in good yield.     

Über s-Triazinium-Salze und Additionsverbindungen des s-Triazins

Several unknown salts of s-triazine were prepared by different methods and the IR spectra of most of these salts were assigned. When s-triazine was reacted with HCl or HBr, mixtures were obtained which consisted of s-triazinium-monohalogenides and products with higher contents of hydrohalogenides. When s-triazine was reacted with HJ, a product C₃H₃N₃ · 3 HJ was obtained. The IR spectra of this compound and of the corresponding compound with DJ were taken to interprete the structure. Addition compounds of s-triazine with several ansolvo-acids were produced in which one or two ansolvo-acid molecules were bound to one molecule of s-triazine. The IR spectra of some of said addition compounds were assigned. Moreover, an adduct of bromine and s-triazine, C₃H₃N₃ · Br₂, was prepared.     

Über Silicid- und Germanidchalkogenide des Thoriums

On Thorium Silicide and Germanide Chalcogenides The compounds ThSiS, ThSiSe, ThSiTe, ThGeS, ThGeSe, and ThGeTe were synthetized from the elements at temperatures ranging from 800 to 1050°C. For structural X-ray investigation single crystals of the compound ThGeS were grown. ThGeS is tetragonal, space group I4/mmm with a = 3.9411(7), c = 17.1395(40) Å, and Z = 4. In order to refine the structure parameters intensity measurements were carried out by means of a four-circle single crystal diffractometer. By indexing the Debye-Scherrer diagrams the remaining ternary thorium chalcogenides were proved to be isostructural with ThGeS. This structure type is identical with the anti-Ti₂Bi-type structure and closely related to the PbFCl structure in the sense of a transposition structure. The interatomic distances, the relations to comparable structures and possible reasons for the formation of the anti-Ti₂Bi-type structure by ternary chalcogenides of the actinides are discussed.     

Über eine neue Modifikation des Na2C2

On a New Modification of Na₂C₂ On heating NaC₂H to temperatures between 80 °C and 150 °C in vacuum two coexisting modifications of Na₂C₂ are observed, as was shown by temperature dependent X‐ray powder diffraction. The known modification I (I4₁/acd, Z = 8) and a previously unknown modification II could be identified, which is isotypic to Li₂C₂ (Rb₂O₂ structure type, Immm, Z = 2). Modification II is also stable on cooling to room temperature, but a complete conversion of NaC₂H to Na₂C₂‐II could not be achieved up to now. Heating to temperatures above 150 °C leads to a complete conversion of Na₂C₂‐II to Na₂C₂‐I. According to MAPLE calculations Na₂C₂‐I represents the thermodynamically stable modification at room temperature.