Über Chalkogenolate. 158. Reaktion von N-Methylthioformamid mit Kohlenstoffdisulfid 2. Oxydation von N-Methyl-N-thioformyldithiocarbamaten und S-Methylester der N-Methyl-N-thioformyldithiocarbamidsäure

On Chalcogenolates. 158. Reaction of N-Methyl Thioformamide with Carbon Disulfide. 2. Oxidation of N-Methyl N-Thioformyl Dithiocarbamates and S-Methyl Ester of N-Methyl N-Thioformyl Dithiocarbamic Acid The oxidation of N-methyl N-thioformyl dithiocarbamates with iodine forms the hitherto unknown N-methyl-1,2,4-dithiazole-3,5-dithione . The S-methyl ester of N-methyl N-thioformyl dithiocarbamic acid H? CS? NCH₃? CS? SCH₃ has been prepared by reaction of potassium N-methyl N-thioformyl dithiocarbamate with methyl iodide as well as by reaction of the S-methyl ester of N-methyl N-formyl dithiocarbamic acid with Lawesson reagent. Both compounds have been characterized by means of chemical and diverse spectroscopic methods.     

Über Chalkogenolate. 154. Reaktion von N-Methylformamid mit Kohlenstoffdisulfid 1. Darstellung und Eigenschaften von N-Methyl-N-formyl-dithiocarbamaten

On Chalcogenolates. 154. Reaction of N-Methyl Formamide with Carbon Disulfide. 1. Synthesis and Properties of N-Methyl N-Formyl Dithiocarbamates N-Methyl formamide reacts with carbon disulfide in the presence of sodium hydride, potassium hydroxide, and barium hydroxide to form the corresponding N-methyl N-formyl dithiocarbamate. The prepared compounds have been characterized with chemical and thermal methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

Über Chalkogenolate. 153. Untersuchungen über Derivate der N-Thioformyldithiocarbamidsäure 3. Ester der N-Thioformyldithiocarbamidsäure und Oxydation von N-Thioformyldithiocarbamaten

On Chalcogenolates. 153. Studies on Derivatives of N-Thioformyl Dithiocarbamic Acid. 3. Esters of N-Thioformyl Dithiocarbamic Acid and Oxidation of N-Thioformyl Dithiocarbamates The esters of N-thioformyl dithiocarbamic acid have been prepared by reaction of tetra-n-butylammonium N-thioformyl dithiocarbamate with the corresponding alkyl iodide. Also the reaction of S-methyl N-formyl dithiocarbamate with Lawesson reagent forms the methyl ester of N-thioformyl dithiocarbamic acid. The oxidation of N-thioformyl dithiocarbamates with iodine yields 1,2,4-dithiazole-3-thione All compounds have been characterized by means of chemical and diverse spectroscopic methods. A new method to prepare 5-phenyl 1,2,4-dithiazole-3-thione is given.     

Über Chalkogenolate. 101. Untersuchungen über Halbester der Monothiokohlensäure. 1. Darstellung und Eigenschaften von Oxoxanthaten

On Chalcogenolates. 101. Studies on Hemiesters of Monothiocarbonic Acid. 1. Preparation and Properties of Oxoxanthates Alkyl oxoxanthates of alkali metals have been prepared by reaction of COS with the corresponding alkoxides. The reaction of ethyl oxoxanthate with methyl iodide leads to S-methyl-O-ethyl ester of monothiocarbonic acid. The oxidation of [SOC? OC₂H₅]^? ions with iodine forms bis(ethoxycarbonyl)-disulfide (S? CO? OC₂H₅)₂. The prepared compounds have been characterized with chemical and thermoanalytical methods as well as by means of electron absorption spectra, infrared spectra, ¹H-NMR spectra, and mass spectra.     

Über Chalkogenolate. 156. Reaktion von N-Methylformamid mit Kohlenstoffdisulfid 3. Alkylester der N-Methyl-N-formyldithiocarbamidsäure

On Chalcogenolates. 156. Reaction of N-Methyl Formamide with Carbon Disulfide. 3. Alkyl Esters of N-Methyl N-Formyl Dithiocarbamic Acid The hitherto unknown esters of N-methyl N-formyl dithiocarbamic acid H? CO? NCH₃? CS? SR, where R = CH₃ and C₂H₅, have been characterized by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

Zur Zersetzung von Tetrathiowolframaten und Bildung von Nonathiotriwolframaten

Decomposition of Tetrathiotungstates and Formation of Nonathiotritungstates The tetrathiotungstates have been prepared by reaction of [NH₄]₂WS₄ with [R₄X]Y (Y = OH, Cl or I). The tetrathiotungstates decompose under variable conditions to form [R₄X]₂W₃S₉. The thiotungstates [R₄X]₂WS₄ and [R₄X]₂W₃S₉ have been characterized by chemical and thermoanalytical methods as well as by infrared, electron absorption, ¹H-NMR, and mass spectra. The decomposition of [R₄N]₂WS₄ has been studied kinetically. A mechanism of the formation of W₃S₉^2? is suggested.     

Über Chalkogenolate. 162. Umsetzungen von Hydrazin mit Kohlenstoffdisulfid. 1. Darstellung und Eigenschaften von 1,2-Hydrazin-bis(dithioformiaten)

On Chalcogenolates. 162. Reactions of Hydrazine with Carbon Disulfide. 1. Synthesis and Properties of 1,2-Hydrazine-bis (dithioformates) The prepared 1,2-hydrazine-bis(dithioformates) have been characterized with chemical methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

Über Chalkogenolate. 126. Untersuchungen über N-Cyanformamidinodithiocarbimidsäure 2. Thermisches Verhalten von Kalium-N-cyanformamidinodithiocarbimat in Lösung

On Chalcogenolates. 126. Studies on N-Cyanformamidino Dithiocarbimic Acid. 2. Thermal Behaviour of Potassium N-Cyanformamidino Dithiocarbimate in Solution The thermal treatment of K₂[S₂C?N? C(NH₂)?N? CN] in methanolic solution yields . The semi-hydrate has been isolated. It reacts with acid to form The reaction with H₃CI gives The compounds have been characterized by means of electron absorption, ¹H- and ¹³C-N.M.R., infrared, and mass spectra.     

Über Chalkogenolate. 155. Reaktion von N-Methylformamid mit Kohlenstoffdisulfid 2. N-Methyl-N-formyldithiocarbamidsäure und Oxydation von N-Methyl-N-formyldithiocarbamaten

On Chalcogenolates. 155. Reaction of N-Methyl Formamide with Carbon Disulfide. 2. N-Methyl N-Formyl Dithiocarbamic Acid and Oxidation of N-Methyl N-Formyl Dithiocarbamates The reaction of a solution of K[S₂C? NCH₃? CO? H] in acetone-d₆ with gaseous HCl at ?78°C forms unstable H? CO? NCH₃? CS? SH. The existence of this acid in solution has been demonstrated by nuclear magnetic resonance spectra. The oxidation of N-methyl N-formyl dithiocarbamates with iodine yields N,N′-dimethyl N,N′-diformyl thiuram disulfide (H? CO? NCH₃? CS? S? )₂, which has been characterized by means of diverse spectroscopic 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.     

Thermische Zerfallsreaktionen von Nitroverbindungen in Stosswellen. II: Dissoziation von Nitroäthan

A shock wave study of the thermal decomposition of nitroethane in excess Ar at temperatures 900 < T < 1350 K and total concentrations of 4,5 · 10^?6 < [Ar] < 3 · 10^?4 mol cm^?3 showed that the C? N-bond fission is the primary reaction step. This unimolecular reaction could be observed in its transition region near the high pressure limit. The derived rate constants are k_∞ = 10^15.9 exp (–57 kcal mol^?1/RT) s^?1 for the high pressure and k₀/[Ar] = 10^18.0 exp (-36 kcal mol^?1/RT) cm³ mol^?1 s^?1 (at T ? 1100–1200 K) for the low pressure limit. The observed concentration profiles of C₂H₅NO₂ and NO₂ permitted to conclude on the subsequent decomposition of the ethyl radical This reaction was found to be in the fall-off range under the applied conditions.     

Über Chalkogenolate. 151. Untersuchungen über Derivate der N-Thioformyldithiocarbamidsäure. 1. Darstellung und Eigenschaften von N-Thioformyldithiocarbamaten

On Chalcogenolates. 151. Studies on Derivatives of N-Thioformyl Dithiocarbamic Acid. 1. Synthesis and Properties of N-Thioformyl Dithiocarbamates The N-thioformyl dithiocarbamates M[S₂C? NH? CS? H], where M = K, Rb, Cs, Tl, NH₄, [N(ⁿC₄H₉)₄], Na[S₂C? NH? CS? H] · 0.5 H₂O, and Ba[S₂C? NH? CS? H]₂ · 3 HO? CH₂? CH₂? OCH₃ have been prepared by use of partial different procedures. The compounds were characterized with chemical and thermal methods as well as by means of electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra. Attempts to synthesize N-thioformyl dithiocarbamic acid were not successful.     

Über Chalkogenolate. 146. Asymmetrische Derivate der Kohlensäure mit Elementen der IV. Hauptgruppe. Notiz über Silbermonomethylcarbonat

On Chalcogenolates. 146. Asymmetric Derivatives of Carbonic Acid with main Group IV Elements. Notice of Silver Monomethyl Carbonate The esters of carbonic acid have been prepared by different methods. The compounds were characterized by means of infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra. Synthesis and properties of unstable Ag[O₂C? OCH₃] are described. The infrared spectrum is given.     

Über Chalkogenolate. 92. Untersuchungen über Trithioallophansäure 1. Alkalimetalltrithioallophanate

On Chalcogenolates. 92. Studies on Trithioallophanic Acid 1. Trithioallophanates of Alkali Metals The trithioallophanates have been prepared by reaction of H₂S with the corresponding dithiocarbimate. The compounds have been characterized by different methods. In aqueous solution the equivalent conductivites of [S₂C? NH? CS? NH₂]^? have been determined by means of conductivity measurements. The Stokes radius of the ion, the radius of the hydrated ion, and its diffusion coefficient were calculated.     

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. 165. Umsetzungen von Hydrazin mit Kohlenstoffdisulfid. 4. Salze des S-Methylesters der N-Dithiomethylendithiocarbazidsäure

On Chalcogenolates. 165. Reactions of Hydrazine with Carbon Disulfide. 4. Salts of the S-Methyl Ester of N-Dithiomethylene-dithiocarbazic Acid The S-methyl ester of dithiocarbazic acid reacts with carbon disulfide in the presence of sodium or potassium hydride at ?15°C to yield the hitherto unknown salts of the S-methyl ester of N-dithiomethylene-dithiocarbazic acid. The prepared compounds , have been studied with chemical methods as well as with electron absorption, infrared, nuclear magnetic resonance (¹H and ¹³C), and mass spectra.     

Über Oberflächenverbindungen von Übergangsmetallen. VIII. Die Komplexbildung von koordinativ ungesättigtem Oberflächen-Chrom (II) mit Oxiden des Stickstoffs

On Surface Compounds of Transition Metals. VIII. Complex Formation of a Coordinatively Unsaturated Cr^II Surface Compound with Nitrogen Oxides N₂O forms with surface-Cr(II) a relatively unstable light blue compound of the stoichiometry 1:1, while addition of NO results in formation of a very stable dark brown, diamagnetic surface complex . By reaction with O₂ this complex undergoes — depending on reaction temperature — either replacement of NO unter reoxidation of the metal (→Cr(VI)) or/and reaction of the ligand (→NO₂). Direct reaction of NO₂ with results in the same products as stepwise addition of NO and 1/2 O₂. reacts with HCl/ROH under formation of the soluble, paramagnetic kation [Cr(NO)(ROH)_n]²⁺, which is formulated as [Cr(II)(NO)]²⁺ ? [Cr(I)(NO⁺)]²⁺ accordingly to the e.s.r. spectra.     

Absolute rate constants for reactions of free radicals in the high-temperature photolysis of formamide vapor. II. Amino radicals

The rotating-sector method has been applied to the photoinitiated radical-chain decomposition of formamide at 300°C to measure the rate constant for the bimolecular disappearance of NH₂ radicals. The decomposition is propagated by the reactions (1) (2) Conditions were chosen so that reaction (1) was rate controlling and NH₂ the terminating radical. A flow system was employed with C₂F₆ as a carrier gas at a pressure of 300 Tort, and the chain reaction was initiated by the photolysis of either formamide or NH₃. A value of 4.7(±2.0) × 10¹⁰ (M ·sec)^?1 was estimated for the termination reaction (3) and a value of 8.4 × 10⁶ (M ·sec)^?1 for reaction (1) in the same system, both at 300°C.     

Zur Kristallchemie der Oxoplumbate(II). III. Synthese und Aufbau von PbAl2O4 und PbGa2O4

Solid State Chemistry of Lead Monoxide Compounds. III. Synthesis and Structure of PbAl₂O₄ and PbGa₂O₄ Single crystals of PbAl₂O₄ and PbGa₂O₄ were prepared and investigated by single crystal work. They crystallize triclinic, space group P1. PbAl₂O₄ and PbGa₂O₄ belong to the family of stuffed tridymit structures. Pb²⁺ is coordinated by three O^2? ions in a trigonal pyramidal manner. MO₄ Tetrahedra form six-membered rings which are linked with other similar rings in three dimensions.     

Beiträge zum thermischen Verhalten von Oxoniobaten der Übergangsmetalle. V. Zum Chemischen Transport von NiNb2O6 mit Cl2 und NH4Cl. Experimente und Modellrechnungen

Contributions on the Thermal Behaviour of Oxoniobates of the Transition Metals. V. Chemical Vapour Transport of NiNb₂O₆ with Cl₂ or NH₄Cl. Experiments and Calculations Well shaped crystals of NiNb₂O₆ were obtained by CVT using Cl₂ (added as PtCl₂) or NH₄Cl as transport agents (1020°C → 960°C). As a result of thermodynamic calculations the migration of NiNb₂O₆ in the temperature gradient in the presence of Cl₂ can be expressed by the heterogenous endothermic equilibrium (1). Assuming Δ_BH(NiNb₂O_{6, s}) = ?524.4 kcal/mol a satisfying agreement between thermodynamical calculation and experimental results can be reached. NH₄Cl is less suitable as transport agent, because Ni²⁺ is partly reduced to the metal by NH₃. The additionally H₂O produced by this reduction leads to a less favourable equilibrium position of (2) and to low deposition rates. .