Bestimmung von freiem Chlor im Chlorcyan

Zusammenfassung Es wird eine Methode zur Bestimmung von freiem Chlor in verflüssigtem Chlorcyan beschrieben. Die Chlorcyanprobe wird verdampft und der Dampf wird durch eine Lösung von Kaliumiodid in einem wäßrigen pH-7-Puffergemisch geleitet. Dadurch wird die Fähigkeit des Chlorcyans, Iodid-Ionen zu oxidieren, unterbunden, nur das freie Chlor oxidiert die Iodid-Ionen zu Iod, welches mit Natriumthiosulfat titriert werden kann. Die Standardabweichungen sind im Bereich ± 0,0049 bis ± 0,013 (0,1–2,0% Cl₂ in ClCN).

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Determination of free chlorine in cyanogen chloride

Summary A method is provided for determining free chlorine in liquefied cyanogen chloride. The cyanogen chloride sample is vaporized, and the vapour is passed through potassium iodide dissolved in an aqueous pH-7-buffer solution. In this way cyanogen chloride is not able to oxidize iodide ions. Only free chlorine oxidizes the iodide ions to iodine, the latter being titratable by sodium thiosulphate. Standard deviations are in the range of ±0.0049 to ±0.013 (0.1–2.0% Cl₂ in ClCN).

     

Tetrafluordiazabuten-Derivate aus Chlorcyan

Cyanogenchloride reacts in liquid hydrogenfluoride with fluorides of some aliphatic hydrocarbons to yield derivatives of 2,4,4,4-tetrafluoro-1,3-diazabut-2-ene. The mechanism of its formation is explained in terms of an intermediate fluorinated linear dimerization product of cyanogenchloride. Reactions of the N-trifluoromethylgroup are reported.     

Zum Chemischer Transport ternärer Übergangsmetall‐ und Erdalkaliwolframate MWO4 mit Chlor

On the Chemical Vapor Transport of Ternary Transition Metal‐ and Earth Alkaline Tungstates MWO₄ with Chlorine The chemical vapor transport of transition metal tungstates MWO₄ (M=Mn, Co, Ni, Cu, Zn, Cd) was investigated in dependence on mean transport temperature (923 K to 1223 K) and amount of transport agent Cl₂. All tungstates migrate in a temperature gradient ΔT = 100 K from the region of higher temperature to the lower temperature with migration rates of 0.5 to 8 mg/h depending on experimental conditions. The transport behaviour was determined by continuous measurement of mass change during the transport experiments. The results were compared to thermo chemical calculations and the influence of moisture content discussed in detail. MgWO₄ migrates under the influence of Cl₂ in a temperature gradient 1273 K to 1173 K (migration rate 0.7 mg/h), CaWO₄ and SrWO₄ in a temperature gradient 1423 K to 1323 K (migration rate <0.1 mg/h).     

Bestimmung von Chlor und Brom

Ohne Zusammenfassung     

Über die Cycloaddition von Dithiocyan und Trithiocyan mit Hexafluoraceton und Folgeprodukte aus der Spaltung der Schwefel-Schwefel-Bindung mit elementarem Chlor im Dithiocyan-Hexafluoraceton-Addukt

Cycloaddition of Dithiocyanogen and Trithiocyanogen with Hexafluoroacetone and Products of the Cleavage of the Sulfur-Sulfur Bond in Dithiocyan-Hexafluoroacetone Adduct by Elemental Chlorine The reaction of dithiocyanogen and trithiocyanogen with hexafluoroacetone (HFA) leads to the cycloaddition products (SCN)₂ · 4 HFA 1 and S(SCN)₂ · 4 HFA 2 . These are the first reactions of (SCN)₂ and S(SCN)₂ without cleavage of the S—S bonds. Elemental chlorine cleaves in 1 the S? S bond and 3 is formed. In 3 the chlorine atom can be replaced by the rests —CN 4 , (C₆H₁₁)₂N— 5 , and n-C₄H₉– 6. 6 eliminates one molecule of HFA by warming up and the four-membered ring 7 is formed. The compounds were characterized on the basis of mass and nmr spectra.     

Herstellung von Aryl-isothiocyanaten aus Arylaminen und Bis-diäthylthiocarbamoylsulfiden

The preparation of aryl-isothiocyanates from aryl-amines and bis-diethylthiocarbamoyl sulfides is reported and mechanisms are proposed for these reactions of thiocarbamoyl derivatives.     

Die Reaktion von Halogenboranen mit Chlorcyan,Bromcyan und Isocyaniddichloriden

Zusammenfassung BCl₃, BBr₃ und C₆H₅BCl₂ reagieren mit ClCN und BrCN zu hochhalogenierten Bis(methylenaminoboranen). Isocyaniddichloride vom Typ RNCCl₂ (R=C₆H₅ und C₂H₅) bilden mit BCl₃ und BBr₃ Addukte. Die IR-Spektren der Cyclodiborazanderivate werden zugeordnet. BF₃ reagiert nicht.

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BCl₃, BBr₃ and C₆H₅BCl₂ react with ClCN and BrCN to yeald bis(methyleneaminoboranes). C₆H₅NCCl₂ and C₂H₅NCCl₂ give adducts with BCl₃ and BBr₃. Frequencies in the IR-spectra of the cyclodiborazane derivatives are assigned. No reactions are observed with BF₃.

     

Chlor, Brom und Jod

Ohne Zusammenfassung