Kristallstruktur und Phasenumwandlungen von As(CH3)4I

Crystal Structure and Phase Transitions of As(CH₃)₄I The crystal structure of α-As(CH₃)₄I at room temperature was determined using single crystal data: cubic, space group Pa3 , a = 1 198.0(2) pm. Therefore α-As(CH₃)₄I displays a novel crystal structure, which is not comparable to known AB-Typ structures with respect to the arrangement of anions and the baricenters of the complex cations. Differential thermal analysis showed three phase transitions at 103, 175 and 215°C. The lattice parameters of the high temperature phases (temperature dependent Guinier measurements) are: β-As(CH₃)₄I (tetragonal): a = 845.2(2) pm, c = 615.0(2) pm; γ-As(CH₃)₄I (hexagonal): a = 737.7(2) pm, c = 1 082.2(3) pm; and to δ-As(CH₃)₄I (hexagonal): a = 705.8(2) pm, c = 1 147(1) pm. β-and γ-As[(CH₃)]₄I are isotypic to N(CH₃)₄Cl and As(CH₃)₄Br, respectively.     

Struktur und Eigenschaften von Doppelhalogeniden von substituiertem Ammonium und Quecksilber(II). VI [1]. Die Kristallstruktur von (CH3NH3)2HgBr4 und (CH3NH3)2HgI4

Structure and Properties of Double Halogenides of Substituted Ammonium and Mercury(II). VI. Crystal Structure of (CH₃NH₃)₂HgBr₄ and (CH₃NH₃)₂HgI₄ The compounds (CH₃NH₃)₂HgBr₄ and (CH₃NH₃)₂HgI₄ were prepared from stoichiometric mixtures of the methylammonium halogenides and the mercury(II) halogenides in methanol by evaporation. X-ray structure determination revealed for (CH₃NH₃)₂HgBr₄ monoclinic symmetry, space group P2₁/c and orthorhombic symmetry, space group Pbca for (CH₃NH₃)₂HgI₄. Both compounds are built from isolated, slightly deformed tetrahedra. The Hg? Br distances range from 2.586(3) Å to 2.598(2) Å, the Br? Hg? Br angles from 105.36(8)° to 112.26(8)°. The observed distances in the HgI₄ tetrahedra are in the range 2.751(1) and 2.803(1) Å, the I? Hg? I angles between 106.25(3)° and 115.68(4)°. The tetrahedra are linked together by hydrogen bonds between the methylammonium group and the halogen atoms.     

Synthese und Struktur von (Ph3PAu)3Mn(CO)4

Synthesis and Structure of (Ph₃PAu)₃Mn(CO)₄ Photolysis of (Ph₃PAu)Mn(CO)₅, Ph₃PAuN₃ and Ph₃PAuNCO yields (Ph₃PAu)₃Mn(CO)₄ ( 1 ). 1 crystallizes in the monoclinic space group P2₁/n with a = 1 031.3(1); b = 3 095.2(3), c = 3 386.3(3) pm; β = 97.58(3)°; Z = 8. The crystal structure contains two symmetry independent clusters 1 of the same geometry. Their inner core MnAu₃ forms a rhombus with distances Mn? Au of about the same lengths between 258.4(4) and 262.0(4) pm. The distances Au? Au range from 276.6(2) to 281.3(2) pm. The bonding in 1 is discussed and compared with those of (Ph₃PAu)₃Co(CO)₃ having the same total number of electrons but a tetrahedral framework.     

IR- und Elektronen-Spektrum von K3Nd(PO4)2

The infrared spectrum of crystalline K₃Nd(PO₄)₂ is reported and discussed with the aid of a factor group analysis. The electronic spectrum of the solid, in the region of the hypersensitive transitions of the Nd(III) ion, is also presented and analyzed.     

Ein Gemisch von 4-Allyl- und 3-Allyldioxybenzol

Ohne Zusammenfassung     

Die Kristallstruktur von Ce4As3 und Pr4As3

Ohne Zusammenfassung     

Die gaschromatographische Trennung von 3- und 4-Methylpenten-(1)

Ohne Zusammenfassung     

Darstellung und Kristallstruktur von Cs4SnO3

Preparation and Crystal Structure of Cs₄SnO₃ Crystals of Cs₄SnO₃ were synthesized by reaction of SnO with elemental Cs. The compound crystallizes with the triclinic spacegroup P1 with lattice constants a = 737.61(9) pm, b = 1171.3(1) pm, c = 1199.2(1) pm, α = 66.08(3)°, β = 80.88(2)°, γ = 82.28(3)° and Z = 4. The crystal structure exhibits isolated stannate(II) ions [Sn^IIO₃]^4– of ψ-tetrahedral form. Whereas a new structure type is present, there is a close relationship with the structures of the Cs stanntates and plumbates(IV).     

Darstellung und Kristallstruktur von Cs2Mn(PO3)4

Synthesis and Crystal Structure of Cs₂Mn(PO₃)₄ On heating mixtures of Cs₂CO₃, MnO and H₃PO₄ with Cs:Mn:P = 3:1:5 at 500°C Cs₂Mn(PO₃)₄ is formed. The by-product (CsPO₃)_n may be removed by leaching with water. The x-ray structure determination (P2₁/n; a = 797.62(3), b = 1324.91(6), c = 1154.62(8) pm; β = 101.97(1)°; Z = 4) proves the title compound to contain an infinite chain of corner sharing tetrahedra.     

Struktur und ausgewählte Reaktionen von ReCl4(PPh3)2

ReCl₄(PPh₃)₂ – Reactions and Structure The compounds ReCl₄(PPh₃)₂ and Re₂OCl₃(C₂H₅COO)₂(PPh₃)₂ resulting from the reaction of ReOCl₃(PPh₃)₂ with PPh₃ in boiling propionic acid and HCl atmosphere were characterized by their VIS-spectra and structural data. Ligand exchange reactions with acetylacetone gave ReCl₂(acac)₂ as well as ReCl₂(acac)(PPh₃)₂. Crystallographic data see “Inhaltsübersicht”.     

Jodometrische Titration von Perbromat (Bestimmung von BrO 4 − und BrO 3 − nebeneinander)

Perbromate is reduced to bromate by iodide in weakly alkaline solution (pH 7–9) at 100° C. The formation of iodine in the hot solution is prevented by addition of an excess of arsenite, which is finally titrated with a I₂-solution for the determination of BrO ₄ ^? . The total BrO ₃ ^? content is then determinated by titration of the acidified solution with thiosulphate. From both titrations the initial content of BrO ₃ ^? is obtained. Both methods are simple and accurate. A direct method for the determination of BrO ₃ ^? in solutions containing BrO ₄ ^? is also described.     

Synthese und Kristallstrukturen von Quecksilber(II)-iodid-Komplexen mit 3- und 4-pyridylmethylamino- sowie 4-pyridylmethoxy-substituierten Cyclophosphazen-Liganden

Synthesis and Crystal Structures of Mercury(II) Iodide Complexes with 3- and 4-Pyridylmethylamino- and 4-Pyridylmethoxy Substituted Cyclophosphazene Ligands Multifunctional cyclophosphazene ligands with 2-, 3-, and 4-pyridylalkylamino- or 4-pyridylmethoxy groups, N₃P₃(OC₆H₅)₅(NHCH₂(C₅H₄N-2)) ( 1 ), N₃P₃(OC₆H₅)₅ · (NHCH₂(C₅H₄N-3)) ( 2 ), N₃P₃(OC₆H₅)₅(NHCH₂(C₅H₄N-4)) ( 3 ) and N₃P₃(OC₆H₅)₅(OCH₂(C₅H₄N-4)) ( 4 ) are accessible through reactions of monochlorpentaphenoxycyclotriphosphaza-1,3,5-trien with aminomethylpyridine or pyridyl methanolate. 1 does not react with mercury(II) iodide whereas 2–4 yield the metal complexes 2 a , 3 a , and 4 a by interactions of the pyridyl nitrogen atoms. The X-ray single crystal structure analyses of these compounds shows that 2 a and 4 a are dimers, whereas 3 a is a HgI₂ polymer with syndiotacticaly arranged ligands.     

Synthese und Struktur von Re4(μ3-Te)4(TeBr2)4Br8

Synthesis and Structure of Re₄(μ₃-Te)₄(TeBr₂)₄Br₈ Re₄(μ₃-Te)₄(TeBr₂)₄Br₈ is obtained from the elements at 550°C in an evacuated glass ampoule. The diamagnetic compound forms air-stable, metallic lustre black crystals crystallizing in the tetragonal space group I4 with a = 1120.2(2), c = 1393.5(3) pm, and Z = 2. The crystal structure is built up by isolated cluster molecules Re₄(μ₃-Te)₄(TeBr₂)₄Br₈ occupying the centres 4 at 1/2, 1/2, 0 and 0, 0, 1/2. The inner sceleton is formed by a Re₄Te₄ heterocubane unit with short Re? Re distances of 277 and 283 pm, which can be discussed as single bonds. Each Re atom coordinates in addition two Br^? ligands and one TeBr₂ molecule. For Re therefore results the oxidation state +IV. Reaction of Re₄(μ₃-Te)₄(TeBr₂)₄Br₈ with I₂ yields (TeI₄)₄.     

Die Kristall- und MolekularStruktur von Antimontetrachloridazid (SbCl4N3)2

Antimony tetrachloride azide (SbCl₄N₃)₂ crystallizes in the monoclinic space group P2₁/n; the lattice parameters are: a = 8.051, b = 9.353, c = 10.124 Å; β = 93.75°; Z = 2. The crystal structure was solved with the aid of a Patterson synthesis and was refined by the method of least-squares to R = 4.9% for the 922 observed reflexions. The structure is built up from centrosymmetrical (SbCl₄N₃)₂ molecules (idealized point symmetry 2/m) which are arranged in the way of a body centered lattice. The linear azido groups are inclined against the planar (Sb–αN)₂ ring of the molecule by an angle of 24°. Each Sb atom is coordinated by two N and four Cl atoms in a distorted octahedral arrangement.     

Azidokomplexe von Mangan(II) und Cobalt(II) Die Kristallstrukturen von (PPh4)2[Mn(N3)4] und (PPh4)2[Co(N3)3Cl]

Azido Complexes of Manganese(II) and Cobalt(II). Crystal Structures of (PPh₄)₂[Mn(N₃)₄] and PPh₄₂[Co(N₃)₃Cl] (PPh₄)₂[Mn(N₃)₄] and (PPh₄)₂[Co(N₃)₃Cl] were obtained as light-brown and green blue, nonexplosive crystalline compounds, respectively. They are only slightly sensitive to moisture and were obtained from the tetrachloro complexes (PPh₄)₂MCl₄ by reactions with silver azide in dichloromethane. The compounds were characterized by thier i.r. spectra and by crystal structure analyses. Both crystallized in the monoclinic space group C2/c, Z = 4, but they are not isotypic. (PPh₄)₂[Mn(N₃)₄]: structure determination with 711 independent reflexions, R = 0.097; a = 2249.1, b = 1499.6, c = 1370.3 pm, β = 104.86°. (PPh₄)₂[Co(N₃)Cl]: 2753 reflexions, R = 0.075; a = 1119.7, b = 1899.2, c = 2115.4 pm, β = 90.47°. The structures consist of PPh₄⁺ ions and of anions that are situated on twofold crystallographic rotation axes. The anions show positional disorder, statistically assuming two different orientations with probabilities of 50% each; in the case of [Co(N₃)₃Cl]^2?, the Cl atom is superimposed statistically with an azido group, whereas the [Mn(N₃)₄]^2? ion is tilted by about 20° from the ideal position to two sides of the crystallographic axis. In both compounds the cation form layers and the anions are located between the layers.     

Zur Darstellung von Imidazolidin-thionen-(4) und Imidazolin-(3)-thionen-(5)

Zusammenfassung 2,2,5-Trisubstituierte Imidazolidin-thione-(4) lassen sich mittels Schwefels mit guten Ausbeuten zu Imidazolin-(3)-thionen-(5) dehydrieren. Hierüber sowie über einige Verbesserungen der bisher bekannten Synthesen für insbesondere 2,2,5-trisubstituierte Imidazolidin-thione-(4) wird berichtet.

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Dehydration of 2.2.5-trisubstituted imidazolidine-(4)-thiones with elementary sulfur gives in good yields 3-imidazoline-(5)-thiones. This reaction and improved methods of the well known syntheses of especially 2.2.5-trisubstituted imidazolidine-(4)-thiones are described.

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Mitt.:F. Asinger, W. Schäfer undH. Triem, Mh. Chem.97, 1510 (1966).

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Teil der Dissertation vonH. Meisel, Techn. Hochschule Aachen, 1963.

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Teil der Dipl.-Arbeit vonHilde Kersten, Techn. Hochschule Aachen, 1963, und Teil der Dissertation vonHilde Kersten, Techn. Hochschule Aachen, 1965.     

Synthese und Kristallstruktur von NaPr2F3(SO4)2

Synthesis and Crystal Strucure of NaPr₂F₃(SO₄)₂ Light green single crystals of NaPr₂F₃(SO₄)₂ have been obtained by the reaction of Pr₂(SO₄)₃ and NaF in sealed gold ampoules at 1050 °C. In the crystal structure (monoclinic, I2/a, Z = 4, a = 822.3(1), b = 692.12(7), c = 1419.9(2) pm, β = 95.88(2)°) Pr³⁺ is coordinated by four F^– ions and six oxygen atoms which belong to five SO₄^– ions. Thus, one of the latter acts as a bidentate ligand. The [PrO₆F₄] units are connected via three common fluoride ions to pairs with a Pr–Pr distance of 386 pm. Na⁺ is sevenfold coordinated by three fluorine and four oxygen atoms.