Investigation of the phase barograms and diagrams of the GeI4-I2, GeI4-BiI3 and GeI4-HgI2 systems

The phase barograms of the systems GeI₄-I₂, GeI₄-BiI₃ and GeI₄-HgI₂ were determined by total pressure measurements in a membrane zero manometer and the resulting phase diagrams were compared with those obtained by DTA measurements. All the systems were single eutectics.

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Zusammenfassung Durch Gesamtdruckmessungen mittels eines Membrannullmanometers wurden Phasenbarogramme der Systeme GeI₄-I₂, GeI₄-BiI₃ und GeI₄-HgI₂ ermittelt und die resultierenden Phasendiagramme mit den an Hand von DTA-Messungen erhaltenen verglichen. Alle diese Systeme besitzen einen eutektischen Punkt.

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Dedicated to Prof. Dr. H. J. Seifert on the occasion of his 60^th birthday

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We express our thanks to Mrs. Dr. U. Stahlberg, who carried out the analyses at the MS 7 in the ZFW Dresden     

31P-KERNRESONANZUNTERSUCHUNGEN VON P4S9 UND P4S10

Abstract

The preparation of P₄P₉ from P₄S₃ and sulfur in decalin is described. The ³¹P nmr spectra of P₄S₉ and P₄S₁₀ are presented and discussed.

Die Darstellung von P₄S₃ aus P₄S₃ und Schwefel in Dekalin wird beschrieben. Die ³¹P-NMR-Spektren von P₄S₉ und P₄S₁₀ sind angegeben und interpretiert.     

Statistische Modellrechnungen an den Molekülen CH4, SiH4, GeH4, SnH4 und PbH4 nach der Einzentrenmethode

Zusammenfassung Mit einem Einzentren-Ansatz werden Bindungsabstände und Gesamtenergien der Moleküle CH₄, SiH₄, GeH₄, SnH₄ und PbH₄ berechnet. Die statistische Betrachtungsweise der Elektronen nach Gombás und Ladányi [1] wird mit der Edelgas-Modellvorstellung nach Hartmann und Gliemann [2] verknüpft. Die Ergebnisse liegen in guter Übereinstimmung mit den vorliegenden experimentellen Daten. Bindungsabstand und Gesamtenergie des Moleküls PbH₄ werden erstmals berechnet.

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Statistical OCE-calculations on the molecules CH₄, SiH₄, GeH₄, SnH₄ and PbH₄

OCE-calculations are reported for ground state energies and bond distances of the hydrides CH₄, SiH₄, GeH₄, SnH₄ and PbH₄. The statistical atom model (Gombás and Ladányi [1]) is connected with the noble gas model (Hartmann and Gliemann [2]). The results are in good agreement with known experimental values. Bond distance and ground state energy of PbH₄ are presented for the first time.

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Wir danken der DFG für die finanzielle Unterstützung dieser Arbeit.     

Barium-orthotellurat,BaH4TeO6

Zusammenfassung Bei der Umsetzung von Kaliumtellurat mit BaCl₂ fällt primär BaH₄TeO₆, welches bei 250°C 1 1/2 Mole Wasser abgibt und erst bei über 375°C in das wasserfreie BaTeO₄ übergeht. Vergleiche der Pulverdiagramme dieser Bariumtellurate untereinander und mit denen von BaSeO₄ und BaSO₄ werden angestellt.

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BaH₄TeO₆ is precipitated when barium chloride is added to a solution of potassium tellurate. This compound looses 1 1/2 moles water when heated to 250°C, and forms BaTeO₄ above 375°C. TheDebye-Scherrer powder diagrams of these barium tellurates are compared with each other, and with those of BaSeO₄ and BaSO₄.

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Mit 3 Abbildungen

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Frau Professor Dr.Erika Cremer anläßlich ihres Geburtstages 1965 in Verehrung gewidmet.     

Die Kristallstruktur von Ir4Ge5

Zusammenfassung Mittels Fourier- und Differenz-Fourier-Synthesen wird eine Struktur für Ir₄Ge₅ errechnet. Der Aufbau, der einem Abkömmling des TiSi₂-Typs mit starkem Unterschuß desB-Elements entspricht, ist durch Stapelung in Richtung derc-Achse gemäßn=4 charakterisiert.

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By means of Fourier- and difference Fourier-synthesis a crystal structure for Ir₄Ge₅ was calculated. The crystal structure of Ir₄Ge₅, a derivative of the TiSi₂-type structure with a strong deficiency of theB-element, is characterized by a 4-fold stacking of the subcell in thec-direction.

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Mit 1 Abbildung

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Herrn Professor Dr.J. W. Breitenbach zum 60. Geburtstag gewidmet.     

Zum Substitutionsverhalten von Imidazolidin-4-thionen

The reaction of imidazolidine-4-thiones [1, 6 (R=H)] with acyl chlorides and arylsulfonyl chlorides under various conditions to 3-acyl-imidazolidin-4-thiones and 3-arylsulfonyl-imidazolidin-4-thiones are described. 3-Alkyl-imidazolidine-4-thiones are synthesized in the same way. 1-Phenylcarbamoyl-imidazolidine-4-thiones (8, 9) are obtained by reacting1 and6 (R=H) with phenyl isocyanate. By oxidation with KMnO₄ in absol. acetone2 (R=COC₅H₁₁) is converted into 3-hexanoyl-2,2,5,5-tetramethyl-imidazolidine-4-one (10).

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Herrn Dr. phil.Günther W. Ibing zum 65. Geburtstag gewidmet.

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89. Mitt.:F. Asinger, A. Saus, E. Fichtner undW. Leuchtenberger, Mh. Chem.106, 1461 (1975).

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K. Hentschel, Teil der Dissertation, Technische Hochschule Aachen, Inst. f. Techn. Chem. u. Petrolchemie, 1974.     

Kristallographische Daten und IR-Spektrum von AlVO4

The unit cell parameters of AlVO₄ have been determined from powder diagrams. The compound pertains to the triclinic system and is isostructural wi7h FeVO₄. The infrared spectra of AlVO₄ and FeVO₄ and of a series of solid solutions in the system AlVO₄/FeVO₄ has also been recorded and discussed.

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Mit 2 Abbildungen

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20. Mitt. der Reihe Orthovanadate und verwandte Verbindungen. 19. Mitt.:E. J. Baran, Z. anorg. allg. Chem., im Druck; 18. Mitt.:E. J. Baran, J. Less-Common Met.46, 343 (1976).     

Distribution of ligands in polynuclear palladium complexes: DFT study of isomerism of Pd4(L)4(RCO2)4 (L = CO,CH2, NO) complexes

Structural isomerism of the Pd₄(L)₄(RCO₂)₄ (L = CO, CH₂, NO; R = CC1₃, CF₃, CH₃) complexes was studied in the framework of the density functional theory (DFT). Among the Pd₄(CO)₄(RCO₂)₄ and Pd₄(CH₂)4(RCO₂)₄ complexes the most stable were the isomers with alternate coordination of pairs of carbonyl and carboxylate ligands on the sides of a planar rectangular metal core. The isomers with the pairwise coordination of NO/RCO₂ on one side of the metal core are the most stable between the Pd₄(NO)₄(RCO₂)₄ complexes. The features of mutual coordination of ligands in polynuclear complexes of palladium are clarified using the obtained results.

     

Ni[P(OPh)3]4 Catalyzed Transfer Hydrogenation Using Hcoonh4

Ni[P(OPh)₃]₄ was found to catalyze the transfer hydrogenation of various organic functional groups using HCOONH₄.

     

Study of hydrothermally synthesized LiFePO4 with different morphology

Monodispersed LiFePO₄ particles with different morphology have been successfully obtained through hydrothermal method using same starting materials. The morphology of the as-synthesized LiFePO₄ particles were dependent on feeding sequence of starting materials. Different dissolution rate of solid phase in precursor prepared by reversing feeding sequence lead to different morphology. The half-cell using as-obtained LiFePO₄ with different morphology were assembled to investigate electrochemical performance. The results show that LiFePO₄ with nanorods morphology displays a higher initial discharge capacity and excellent cycle retention than the sample with microplates morphology.

     

Zum Reaktionsverhalten der Imidazolidin-thione-(4)

Zusammenfassung Imidazolidin-thione-(4) setzen sich mit H₂O₂ in Methylalkohol oder in basischem Milieu mit sehr guten Ausbeuten zu Imidazolidin-onen-(4) um. Einige bisher unbekannte Verbindungen dieses Typs werden beschrieben. Am Beispiel des 2.2.5.5-Tetramethyl-imidazolidin-thion-(4) bzw.-on-(4) wird gezeigt, daß bei durchgreifender Reduktion mit LiAlH₄ das einheitliche, durch Ringsprengung zwischen Position 1 und 2 bedingte 1-[N-Isopropyl]-2.2-dimethyläthylendiamin entsteht. Die Struktur dieses Amins wird bewiesen. 2.2.5.5-Tetramethylimidazolidin-thion-(4) bildet mit anorganischen Silber-, Kupfer- und Cadmium salzen die entsprechenden Imidazolin-(3)-mercaptide-(4).Durch Austauschreaktion mit Carbonylverbindungen lassen sich die Substituenten der Imidazolidin-thione-(4) in 2-Stellung gegen andere Substituenten austauschen.

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Imidazolidine-thiones-(4) react with H₂O₂ in methyl alcohol or in basic solution to give the corresponding imidazolin-ones-(4) in very good yields. Some new chemical compounds of that type are described. On reduction of 2.2.5.5-tetramethylimidazolidin-thione-(4) and-one-(4), as examples, with LiAlH₄ only 1-[N-isopropyl]-2.2-dimethylethylendiamine is formed, demonstrating that the heterocyclic ring is cleaved between the positions 1 and 2. The structur of the open chain diamine is proved. With anorganic, water-soluble salts of Ag, Cu and Cd the corresponding imidazoline-(3)-mercaptides-(4) are formed.By treating the imidazolidine-thiones-(4) with ketones or aldehydes the substituents on the C-(2)-position can be exchanged.

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58. Mitt.:F. Asinger, W. Schäfer, H. Meisel, H. Kersten undA. Saus, Mh. Chem.98, 338 (1967).

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Hilde Kersten, Teil der Dissertation, Techn. Hochschule Aachen 1965.

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

Die Verwendung von Klathraten der Komplexsalze vom Typ Ni(SCN)2(4-MePy)4 zur Trennung vonCis-Trans-Azobenzolgemischen

Zusammenfassung Zur Trennung voncis- undtrans-Azobenzol wurden Klathrate des Typs Ni(SCN)₂(4-Methylpyridin)₄·0,7(4-Methylpyridin) erfolgreich als Adsorbentien in chromatographischen Säulen verwendet.Die thermische und photochemischecis-trans-Isomerisierung dieser Verbindungen (bei Zimmertemp.) wurden als mögliche Fehlerquellen bei der quantitativen Auswertung der Trennergebnisse untersucht.

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The application of clathrates formed from complex salts of the Ni(SCN)₂(4-methylpyridine)₄ type to the separation of mixtures of cis- and trans-azobenzenes

The clathrates of Ni(SCN)₂(4-methylpyridine)₄·0,7(4-methylpyridine) type have been successfully applied as sorbents in chromatographic columns to the separation of geometric isomers ofcis- andtrans-azobenzenes.Thermal and photochemicalcis-trans-isomerization of these compounds (at room temperature) have been studied as possible source of errors in the quantitative evaluation of separation results.

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Mit 3 Abbildungen

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Herrn Prof. Dr.H. Nowotny gewidmet.     

THE P4 MOLECULE AND P4H+ ION

Abstract

Experimental findings as well as quantum chemical calculations indicate that the P₄ molecule has a remarkably low nucleophilicity. The P₄H₊ ion is predicted to have a ‘proton at apex’ configuration whereas a proton in the centre seems to be metastable. The influence of d orbitals on the stability of P₄ against 2 P₂ and 1/2 P₈, the photoelectron spectrum, and the valence electron density is discussed.     

Mesogenicity of 4-alkanoyl-4′-alkyloxybiphenyl derivatives

Abstract

Phase transitions of 4-alkanoyl-4′-alkyloxybiphenyl were studied by differential scanning calorimetry and optical microscopy. 4-Acetyl-4′-alkyloxybiphenyl homologues (number of carbon atoms, of n, 4′-alkyloxy group is 4–10) showed S_E phases with good thermal stability, while 4-propionyl-4′-alkyloxybiphenyl homologues (n = 4–10) and 4-pentanoyl-4′-decyloxybiphenyl showed S_A phases with good thermal stability. Moreover changes in the thermal stability by substitution of bulky Br, Cl or CH₃ substituents into the alkanoyl groups were studied for the previously mentioned three homologues. The substitution at the α-position of the alkanoyl group was found to strikingly lower the thermal stability.     

Synthesis,Crystal Structure,and Characterization of Na7Cu4(AsO4)5

Abstract

Sodium copper (II) arsenate Na₇Cu₄(AsO₄)₅ has been grown by conventional high-temperature, solid-state methods in molten-salt media. It was characterized by single crystal X-ray diffraction (XRD), thermal analysis (DTA–TGA), scanning electron microscopy (SEM), semiquantitative energy dispersive spectroscopy analysis (EDS), and vibrational spectroscopy. Na₇Cu₄(AsO₄)₅ exhibits a three-dimensional framework built up of CuO₅, CuO₄, and AsO₄ polyhedra, with intersecting channels in which the Na⁺ cations are located. The three-dimensional cohesion of the framework results from Cu–O–As bridges. CuO₅ and CuO₄ polyhedra are elongated due to the Jahn–Teller effect, whereas AsO₄ tetrahedra are almost regular. This new structural model is validated by the charge distribution (CD) analysis. The infrared and Raman spectra confirmed the presence of AsO₄ tetrahedra.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables and figures.]     

Zur Säurestärke von Tetrafluoro-orthoperjodsäure,HOJOF4

Zusammenfassung Mit Hilfe eines Näherungsverfahrens konnte die Säurestärke von HOJOF₄ in Eisessig aus Leitfähigkeitsmessungen bestimmt werden. Der Wert für die Dissoziationskonstante,K _Diss. ^HOJOF ₄=10^–5,0 zeigt, daß Tetrafluoro-orthoperjodsäure neben HClO₄ die stärkste in Eisessig vermessene Säure ist. Sie ist stärker als HBr und H₂SO₄.

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Acidity of tetrafluoro-orthoperiodic acid, HOJOF₄

Using an approximation method, the dissociation constant of HOJOF₄ in glacial acetic acid could be derived from conductivity measurements. The value,K _Diss. ^HOJOF ₄=10^–5.0, shows tetrafluoro-orthoperiodic acid, next to HOClO₄ to be the strongest acid in glacial acidic acid, stronger than HBr and H₂SO₄.

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Mit 2 Abbildungen

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Herrn Prof. Dr.Hans Nowotny gewidmet.     

Viscosity of molten NaCI,NaBF4 and KBF4

Abstract

The viscosities of molten NaBF₄ and KBF₄ were determined over a 120°C interval and the viscosity of molten NaCl was redetermined over a 200°C interval by use of an oscillating cup viscometer. The viscosities of all three samples followed an Arrhenius type temperature dependence. The measured viscosity for NaCl agreed better with predicted values and the trend established by the other sodium and potassium halides than did previous determinations. The Batchinskii free volume concept of viscosity held for the sodium and potassium halides and the two MBF₄ salts. An equation based upon a hard-sphere model predicted viscosity values in agreement with experimental values for the alkali metal halides and KBF₄ but was not suitable for NaBF₄.     

2, 4-bis(4-methoxyphenyl)-1, 3, 2, 4-dithiadiphosphetane 2, 4-disulfide,lr, as a new activation reagent in preparation of peptides,amides and esters

Abstract

2, 4-Bis(4-methoxyphenyl)-1, 3, 2, 4-dithiadiphosphetane 2, 4-disulfide, LR, is easily prepared by refluxing P₄S₁₀ in anisole for two hours produces the title compound in high yield.     

Low temperature absorption spectra of TcO 4 − and ReO 4 − in KClO4

The low temperature spectra of TcO ₄ ^– and ReO ₄ ^– both show two band systems with pronounced vibrational structures. The bands are identified as¹ A ₁¹ T ₂ transitions. No other bands are observed with certainty. It seems likely that the KClO₄ crystals contain KReO₄ crystallites. They are therefore not pure mixed crystals. It is concluded that the virtual orbital (2e) used in the construction of the low lying states resembles an atomic nd orbital more and more when going from n=3, Mn to n=5, Re.

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Zusammenfassung Die Tieftemperaturspektren von TcO ₄ ^– und ReO ₄ ^– zeigen beide zwei Bandensysteme mit ausgeprägten Schwingungsstrukturen. Die Banden werden als ¹ A ₁¹ T ₂-Übergänge identifiziert. Keine anderen Banden werden mit Sicherheit beobachtet. Es scheint wahrscheinlich, daß die KClO₄-Kristalle KReO₄-Kristallite enthalten und deswegen keine reinen Mischkristalle sind. Es wird geschlossen, daß das virtuelle Orbital (2e), welches zur Konstruktion der tiefliegenden Zustände gebraucht wird, in der Reihe n=3, Mn bis n=5, Re immer weitgehender einem nd-Atomorbital ähnelt.

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Nachwuchsstipendiat, Schweizerischer Nationalfonds.     

Nanocomposite of CeVO4/BiVO4 Loaded on Reduced Graphene Oxide for the Photocatalytic Degradation of Methyl Orange

A facile procedure, involving one-pot synthesis of CeVO₄/BiVO₄ and in-situ reduction of graphene oxide (GO), has been used to prepare CeVO₄/BiVO₄/rGO nanocomposites. Different ratios of the CeVO₄–BiVO₄ were prepared to afford composites represented as CBVG3, CBVG5, and CBVG7. The ternary nanocomposite materials were characterized by using powder X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), photoluminescence and UV–vis spectroscopic techniques. Photocatalytic efficiency of the as-prepared ternary nanocomposites was investigated through the photo degradation of methyl orange under a visible light irradiation at 470 nm. The photocatalytic performance was enhanced by loading the CeVO₄/BiVO₄ nanoparticles on reduced graphene oxide (rGO), given MO degradation rate of 57, 65, 80, and 90% for BVG, CBVG3, CBVG5, and CBVG7, respectively after exposure to visible light for 120 min. Effects of experimental process parameters including initial dye concentration, catalysts loading and effect of different modification regimes were studied using CBVG7, which exhibited the highest efficiency. The improvement in the photocatalytic efficiency may be attributed to increased surface area of the nanocomposites, enhanced light absorption capacity and improved charge separation. The study showed a one-pot synthesis route to prepare promising CeVO₄/BiVO₄/GO nanocomposites for the photo-enhanced degradation of dye contaminants.