Spaltung von Disulfiden zu Arsen (III)‐mercaptiden

Abstract

Aliphatische und aromatische Disulfide werden in wäßrig-oder alkoholisch-alkalischer Lösung mit Alkaliarsenit reduzierend zu Thiolen gespalten. Diese setzen sich beim Ansäuern mit überschüssiger Arsen (III)-Verbindung zu gut kristallisierenden Arsen-trimercaptiden, As (SR)3, um, die sich wie „stabilisierter Formen” der freien Thiole verhalten. Aus den Trithioarseniten erhält man die Mercaptoverbindungen durch Hydrolyse mit Salzsäure-Eisessig in Gegenwart von Schwefelwasserstoff zurück. Die Beziehungen zwischen Arsen-mercaptiden, Disulfiden und freien Thiolen werden am Beispiel des 2.6-Dinitro-4-mercapto-phenols und seiner Methyläther genauer abgehandelt. Arsen-tris-phenylmercaptid hemmt das Wachstum von Staphylococcus aureus, Escherichia coli und Saccharomyces carlsbergensis total in einer Konzentration von 1.7–6.8·10−5 g/ccm

The Autoxidation of Triaryl Trithioarsenites, (ArS)3As: Evidence for Binding and Activation of Triplet Dioxygen by Arsenic(III)

“…This route, if followed, should be a minor one because trithioarsenites are stable in a neutral environment and unstable in alkaline or acidic solutions, 5,27 and because while the esters 6 and 7 decompose to As 2 O 3 and disulfide, their parent thiols, 4-chlorothiophenol and 4-nitrothiophenol, are not oxidized by air (Table I). 4 nitrothiophenol is not oxidized even in alkaline solutions.…”

The Oxidation of Trialkyl Trithioarsenites, (RS)3As, by Octasulfur/Triethylamine and Dioxygen

“…An excess of NaOH should be avoided because the trithioarsenites are not stable in alkaline solutions. 5,23 The trithioarsenites 4, 7, and 8 could not be studied because of their low solubilities.…”

On the direct reduction of arsonic acids to arsenoso compounds: mechanisms and preparations

“…The very fast reduction of arsonic acids with stoichiometric amounts of thiols to give RAs(SR') 2 and R'SSR' in the absence of added acid, 10,11,13,42 and of p-amino-substituted phenylarsonic acids by phenylhydrazine, 8 can be rationalized in the HSAB framework assuming four-centred transition states. 37 Finally, the puzzling reports on the reduction of alkylarsonic acids by SO 2 /H 2 O, mentioned in the introduction, may be explained by assuming that traces of I À (from the less volatile alkyl iodides used for their preparation) contaminated the starting material.…”