Zum chemischen Transport von Yttriumtrichlorid mit Aluminiumtrichlorid

Chemical Transport of Yttrium Trichloride by Aluminium Trichloride Yttrium trichloride is transported by gaseous aluminium trichloride in the temperature range of 300°C to 700°C from hot to cold. It is followed a gaseous complex YAl₄Cl_15,g and the enthalpy of formation as well as the standard entropy of the complex from the dependence of the transport rate on the temperature and the initial pressure of Al₂Cl_6,g.     

Darstellung von Schwermetallchalkogenid-Einkristallen durch chemischen Transport mit Aluminiumchlorid

Zusammenfassung Durch chemischen Transport mit wasseerfr. AlCl₃ als Transportmittel konnten folgende Schwermetallsulfide und-selenide in Form von Einkristallen erhalten werden: Cr₂S₃, Cr₃S₄, Cr₅S₆, Cr₇S₈, CrS, Cr₂Se₃, Cr₇Se₈, CoS₂, CoS, (Co), NiS₂, NiS, ZnCr₂S₄, CdCr₂S₄, MnCr₂S₄, ZnCr₂Se₄, CdCr₂Se₄, HgCr₂Se₄, CuCr₂Se₄, NiCr₂S₄, Ni_0,95Cr_0,05S, Ni_0,83Cr_0,17S, Ni_0,75Cr_0,25S. Der Mechanismus des Transports mit AlCl₃ und die Darstellung größerer Einkristalle werden diskutiert.

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Growing of chalcogenide single crystals by chemical transport with aluminium chloride

Single crystals of the following compounds have been grown by chemical transport with anhydrous aluminium chloride as transporting agent: Cr₂S₃, Cr₃S₄, Cr₅S₆, Cr₇S₈, CrS, Cr₂Se₃, Cr₇Se₈, CoS₂, CoS, (Co), NiS₂, NiS, ZnCr₂S₄, CdCr₂S₄, MnCr₂S₄, ZnCr₂Se₄, CdCr₂Se₄, HgCr₂Se₄, CuCr₂Se₄, NiCr₂S₄, Ni_0,95Cr_0,05S, Ni_0,83Cr_0,17S, Ni_0,75Cr_0,25S. The growing of larger crystals and the mechanism of the transport with AlCl₃ are discussed.

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Cs. Lovász, Teil der Dissertation, Universität Köln 1969.

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K.-H. Bertram, Teil der diplomarbeit, Universität Köln 1970.     

Darstellung und Untersuchung von Phosphinkomplexen mit Aluminiumtrichlorid und Aluminiumtriäthyl

Synthesis and Investigation of Complexes of Phosphines with AlCl₃ and AlEt₃ (t.-Bu)₃P and (Me₃Si)₃P form similar adducts with AlCl₃ and AlEt₃ (t.-Bu = ? C(CH₃), Me = ? CH₃, Et = ? C₂H₅). Analogous compounds are formed by reaction of (t.-Bu)₂PSiMe₃ with AlCl₃ and AlEt₃, and of (Me₃Ge)₃P and (Me₃Sn)₃ with AlEt₃. The i.r., Raman, ¹H-n.m.r. and ³¹P-n.m.r. spectroscopic data are reported and discussed.     

Zum chemischen Transport von Vanadiummonophosphid mit lod

Chemical transport of vanadiummonophosphide with iodine Well shaped crystals of vanadiummonophosphide can be grown by CVT using iodine as transport agent (e. g. → 900°C). As a result of thermodynamical calculations the evaporation and deposition of VP should be expressed by the following exothermic equilibrium At higher temperatures and low concentrations of Iodine, combined with desorption of moisture from the walls of the silica ampules endothermic deposition of VP according to has been observed. Assuming Δ_BH°₂₉₈(VP_s) = ?61 [kcal/mol] a satisfying agreement between thermodynamical calculations and experimental results can be reached.     

Beiträge zum chemischen Transport oxidischer Metallverbindungen. III. Der Transport von NiO und MgO über ihre Metallchloride

Transport effect of HCl on NiO and MgO according to between T₂ = 1000°C and T₁ = 800°C was calculated by the model of diffusion in dependence of total pressure; for comparison, the classical transport of α-Fe₂O₃ was analogously treated. By experimental determination of the transport rates at total pressures from 0.009 to 6 atm hitherto not considered influences of the amount and surface of the starting material, and of the transport time were found. These effects are explained by a (not in detail defined) term of ?sorption”? of the transport gas onto the powder of the starting material. For an explanation of the transport rates estimations of the diffusion coefficients of the gas pairs FeCl₃–HCl and NiCl₂–HCl were performed and the vapour pressure diagrams of NiCl₂ and MgCl₂ evaluated.     

Zum chemischen Transport von SiAs mit Iod — Experimente und Modellrechnungen

On the Chemical Transport of SiAs using Iodine — Experiments and Thermochemical Calculations Using iodine as transport agent siliconarsenide migrates in a temperature gradient. The direction of the migration depends on the chosen temperature and the concentration of the transport agent. The transport rates were measured for various transport agent concentrations (0.0002 ? C(I₂) ≥ 0,02 mmol/cm³) and for various mean transport temperatures (650 ? T? ? 1 000°C). For low temperatures (e.g. T₁ = 750°C→T₂ = 850°C), low iodine concentrations (e.g. C(I₂) = 0.001 mmol/cm³) and in the presence of H₂O (from wall of silica ampoule) the following exothermic reaction is responsible for the deposition of SiAs-crystals in the sink region:

• SiAs_s + 4HI_g = SiI_4,g + 2H_2,g + 1/4As_4,g

In case of higher temperatures (e.g. T₂ = 1 050°C→T₁ = 950°C) and higher iodine concentrations (e.g. C(I₂) = 0.02 mmol/cm³) SiI_4,g is the transport agent. According to model calculations the following endothermic reaction is responsible for the migration of SiAs to the region of the lower temperature:

• SiAs_s + SiI_4,g = 2SiI_2,g + 1/4As_4,g

The heterogeneous and homogenous equilibria will be discussed and an explanation of the non equilibrium transport behaviour of SiAs is given. Thermochemical data of SiAs are characterized by the quartzmembrane zero manometer technique and further verified by model calculations.     

Zum chemischen Transport von Fe2O3 mit Tellurtetrachlorid

Chemical Transport of Fe₂O₃ by TeCl₄ The behaviour of the transport of Fe₂O₃ by TeCl₄ is calculated by the aid of the solubulities in the gas phase. TeOCl₂ existing in the gas phase is the essential species for the transport of oxygen. According to the calculations a reversion of the transport direction appears in the temperature range of about 800°C, which was confirmed experimentally. Stoichiometric single crystals of α-Fe₂O₃ were obtained showing in most cases rhombic plates of maximum dimensions 15° 10 · 1 mm.     

Zum chemischen Transport von Wolfram mit HgBr2 – Experimente und Modellrechnungen

On the Chemical Transport of Tungsten using HgBr₂ – Experiments and Thermochemical Calculations Using HgBr₂ as transport agent tungsten migrates in a temperature gradient from the region of higher temperature to the lower temperature (e.g. 1 000 → 900°C). The transport rates were measured for various transport agent concentrations (0.64 ? C(HgBr₂) ? 11.74 mg/cm³; T? = 950°C) and for various mean transport temperatures (800 ? T? ? 1 040°C). Under these conditions tungsten crystals were observed in the sink region. To observe the influence of tungsten dioxide (contamination of the tungsten powder) on the transport behaviour of tungsten, experiments with W/WO₂ as starting materials were performed. According to model calculations the following endothermic reactions are important for the migration of tungsten: In the presence of H₂O or WO₂ other equilibria play a role, too. Using a special “transport balance” we observed a delay of deposition of tungsten (e.g. T? = 800°C; 15 h delay of deposition) with W and W/WO₂ as starting materials. The heterogeneous and homogeneous equilibria will be discussed and an explanation for the non equilibrium transport behaviour of tungsten will be given.     

Über Chalkogenolate. 79. Untersuchungen über N-Hydroxydithiocarbamidsäure 1. Darstellung und Eigenschaften von N-Hydroxydithiocarbamaten und von Hydroxylammoniumdithiocarbamat

On Chalcogenolates. 79. Studies on N-Hydroxy Dithiocarbamic Acid. 1. Preparation and Properties of N-Hydroxy Dithiocarbamates and of Hydroxylammonium Dithiocarbamate In the presence of the corresponding hydroxide the reactions between hydroxylamine and carbon disulfide lead to N-hydroxy dithiocarbamates and [H₃NOH][S₂C? NH₂], respectively. The unstable compounds have been characterized by different methods.     

Über Chalkogenolate. 144. Darstellung und Eigenschaften von Alkalimetall-t-butyl-carbonaten,Neue Untersuchungen über Trimethylsilylcarbonate

On Chalcogenolates. 144. Synthesis and Properties of Alkali Metal t-Butyl Carbonates. Reinvestigations of Trimethylsilyl Carbonates The t-butyl carbonates M[O₂C? OC(CH₃)₃], where M = Li, Na, K, Rb, Cs, have been prepared by reaction of the corresponding t-butoxide with CO₂ and characterized by means of diverse methods. The equivalent conductivities of the [O₂C? OC(CH₃)₃]^? ion in aqueous solution have been determined and the Stokes radius, the radius of the hydrated ion, and the diffusion coefficient were calculated. The dissociation constant of t-butyl carbonic acid in water at 25°C is K_a = (1.63 ± 0.03)· 10^?8. The thermodynamic data of dissociation were calculated. New data of trimethylsilyl carbonates [O₂C? OSi(CH₃)₃]^? are given.     

Über Chalkogenolate. 99. Untersuchungen über Monothiocarbamidsäure 1. Darstellung und Eigenschaften von Monothiocarbamaten

On Chalcogenolates. 99. Studies on Monothiocarbamic Acid. 1. Synthesis and Properties of Monothiocarbamates The monothiocarbamates , and Ba[SOC? NH₂]₂ have been prepared and characterized by means of infrared, electron absorption, and mass spectra. The existence of the free monothiocarbamic acid was ascertained.     

Über Chalkogenolate. 108. Untersuchungen über Perthiocyansäure 1. Darstellung und Eigenschaften von Perthiocyanaten

On Chalcogenolates. 108. Studies on Perthiocyanic Acid. 1. Synthesis and Properties of Perthiocyanates The perthiocyanates have been prepared by different techniques. The compounds were characterized by means of diverse methods.     

Über Chalkogenolate. LIV. Untersuchungen über Thioameisensäuren 2. Darstellung und Eigenschaften von Dithioformiaten

K[HCS₂] was prepared by interaction of chloroform with K₂S. Rb[HCS₂] and Cs[HCS₂] were formed by reaction of trimeric dithioformic acid with alcoholates (X-ray data see ?Inhaltsübersicht”?). The dithioformates T1[HCS₂], In[HCS₂]₃, and M[HCS₂]₂ with M = Pb, Zn, Cd, Hg, and M[HCS₂] with M = [(C₆H₅)₄P], [(C₆H₅)₄As], [(C₂H₅)₄N], (C₆H₅)₃Sn have been prepared. The prepared compounds are investigated by different methods.     

Über Chalkogenolate. 121. Untersuchungen über N-Cyanomonothiocarbimidsäure 1. Darstellung und Eigenschaften von Alkalimetall-N-cyanomonothiocarbimaten

On Chalcogenolates. 121. Studies on N-Cyanomonothiocarbimic Acid. 1. Synthesis and Properties of Alkali Metal N-Cyanomonothiocarbimates The hitherto unknown N-cyanomonothiocarbimates M₂[SOC?N? CN] · H₂O, where M = Na, K, Rb, Cs, have been prepared by reaction of the corresponding alkali metal salt of cyanamide with COS. N-Cyanomonothiocarbimates react with sulfur to form the ion, which gives with an acid and with CH₃I the methyl compound . The reaction of the latter compound with H₂O₂ yields . All compounds have been characterized by means of diverse methods.     

Untersuchungen über die reaktionsfähigkeit von chrom und titan mit pyrrolidindithiocarbaminat

The dependence of the reactivity with pyrrolidinedithio-carbamate of titanium on pH and the presence of other ions, and of chromium^III on the state of binding of the chromium^III ion and on pH have been investigated. The results of this investigation provide an explanation of the hitherto very variable accounts of the reactivity of titanium and chromium with disubstituted dithiocarbamates.

Résumé

Les auteurs étudient l'influence du pH et de la la présence d'autres ions sur le pyrrolidinedithiocarbamate de titane et l'influence du pH et de l'état sous lequel se trouve le chrome (III) en solution sur le pyrrolidinedithiocarbamate de chrome (III). Les résultats obtenus permettent d'expliquer les différences rencontrées quant aux réactions du chrome et du titane avec les dithiocarbamates bisubstitués.     

Untersuchungen über N-Methoxyguanidin 1. Darstellung und spektroskopische Charakterisierung

Studies on N-Methoxyguanidine. 1. Synthesis and Spectroscopic Characterization The hitherto unknown title compound has been isolated as a free base. The infrared, nuclear magnetic resonance, and mass spectra are reported. The amino protones are involved in rapid interchange processes. The activation values of the interchanges have been approximately determined from temperature dependent ¹H-n.m.r. experiments. The related tautomeric structures are discussed.     

Umsetzungen einiger Schwefel-Fluor-Verbindungen mit Verbindungen von übergangsmetallen; Darstellung und spektroskopische Untersuchung von Sulfito-Komplexen mit MnII,Mo0 und W0

Reactions of some Sulfur-Fluorine Compounds with Compounds of Transition Metals; Synthesis and Spectroscopic Investigation of Sulfito Complexes, involving Mn^II, Mo⁰, and W⁰ In the oxidative addition reactions of sulfuryl fluoride ( 1 ) and of methanesulphonic acid fluoride ( 2 ) with η²-ethylene-bis(triphenylphosphine)platinum(0) the novel ionic binuclear tetrakis(triphenylphosphine)-(μ-fluoro)-(μ-peroxo)-platinum(II)-fluorosulfonate and -methylsulfonate complexes 3 a and 3 b were formed. O,O-Sulfito-manganese(II) tricarbonyl 5 a and the binuclear μ-disulfito-dimanganese decacarbonyl complex 6 a were obtained in the reaction of disulfuryl difluoride ( 4 ) with the carbonyl metalate complex, Na⁺[Mn(CO)₅]^?. In this redox reaction several further products (e.g., CO, SO₂F₂ ( 1 ) and Mn₂(CO)₁₀) were formed and were determined quantitatively. In the presence of acetonitrile the acetonitrile-O,O-sulfito-manganese(II) tricarbonyl complex 5 b was isolated. The new binuclear complexes, bis(η⁵-cyclopentadienyl)-μ-disulfito-dimetalhexacarbonyls ( 6 b : metal = Mo⁰ and 6 c : metal = W⁰) were obtained in the reaction of 4 with the carbonyl metalates Na⁺[CpM(CO)₃]^? (M?Mo¹, W¹; Cp = cyclopentadienyl). Further products (e.g., CO, SO₂F₂ ( 1 ) and [CpM(CO)₃]₂, M?Mo, W) were formed and were determined quantitatively. The validity of the concept of hard and soft acids and bases (HSAB-concept) and of the 18-valence-electron rule (18-VE-rule) could not be confirmed in all cases. The characterization of 3a, 3b, Sb, 6b and 6c was based on their IR and NMR spectra, and in one case, on the mass spectra ( 5b ). For 3a and 3b the dynamic behaviour at room temperature in CD₂Cl₂ and CD₃OD was studied by ³¹P-NMR spectroscopy. The results are interpreted in terms of exchange processes in solution between the coordinated μ-fluoride and the solvent ligand or the uncoordinated anion. 5a and 6a and the by-products (e.g., CO and SO₂F₂ ( l )), which were formed in the redox reactions, were identified by their infrared spectra.