Über die Reaktion von Trimethylamin mit Antimon(V)-chlorid

Inhaltsübersicht. Trimethylamin und Antimon(V)-chlorid bilden keinen Dornor-Acceptor Komplex. In Abhängigkeit vom Molverhältnis reagieren die Komponenten zu (CH₃)₃NCl⁺SbCl₆^– (I) bzw. zu (CH₃)₃NH+X^– und (CH₃)₂N=CH₃⁺X^– (X^– = SbCl₆^–, SbCI₄^–, Sb₃CI₁₄^3– und CI^–). I kann in (CH₃)₃NH⁺SbCl₆^– und (CH₃)₂N=CH₂+SbCl₆^– zerfallen. The Reaction of Trimethylamine with Antimony (V) Chloride Abstract. Trimethylamine and antimony(V) chloride forms no donor-acceptor-complex. In dependence of the molar ratio the compounds reacts to (CH₃)₃NCl⁺SbCl₆^– (I) resp. to (CH₃)₃NH+X^– and (CH₃)₂N=CH₃⁺X^– (X^– = SbCl₆^–, SbCI₄^–, Sb₃CI₁₄^3– and CI^–). I can decompose into (CH₃)₃NH⁺SbCl₆^– and (CH₃)₂N=CH₂+SbCl₆^–.     

Photocatalytic decarboxylative amidosulfonation enables direct transformation of carboxylic acids to sulfonamides

Sulfonamides feature prominently in organic synthesis, materials science and medicinal chemistry, where they play important roles as bioisosteric replacements of carboxylic acids and other carbonyls. Yet, a general synthetic platform for the direct conversion of carboxylic acids to a range of functionalized sulfonamides has remained elusive. Herein, we present a visible light-induced, dual catalytic platform that for the first time allows for a one-step access to sulfonamides and sulfonyl azides directly from carboxylic acids. The broad scope of the direct decarboxylative amidosulfonation (DDAS) platform is enabled by the efficient direct conversion of carboxylic acids to sulfinic acids that is catalyzed by acridine photocatalysts and interfaced with copper-catalyzed sulfur–nitrogen bond-forming cross-couplings with both electrophilic and nucleophilic reagents.

Sulfonamides are now accessible directly from carboxylic acids by a one-step, tricomponent decarboxylative amidosulfonation that provides the missing link between the two key functionalities.     

INFLUENCE OF pH AND OXYGEN ON 315 mμ INACTIVATION AND THYMINE DIMERIZATION IN MUTANTS OF BACTERIOPHAGE T4

Abstract— 1. Irradiation with 315 mμ light inactivates phage T4v-x C, and T4v^-x- , and forms thymine dimers in their DNA.
2. Both the rates of inactivation and of thymine dimerization depend upon pH and gaseous environment during irradiation. The U.V. sensitivities are: 1 (pH 7, N₂, 03, 2.2 (pH 3.5, Oz), 3.3 (pH 3–5, N₂; and the corresponding rates of thymine dimerization 1: 2.5: 5.2. The number of thymine dimers per lethal hit observed withT4v-x + are: 5.7 (pH 7, N₂, O₂, 5.4 (pH 3.5, O₂, 10.9 (pH 3.5, N₂); and forT4v-x-: 4.6, 3.4, and 7.1 with the same sequence of conditions.
3. Also the photoreactivable sectors depend upon the environmental conditions at 315 mp inactivation. In T4v-x f this sector amounts to about 50 per cent at pH 7, 18 per cent at pH 3.5, O., and 29 per cent at pH 3.5, N, respectively.
4. The molecular basis of these findings is discussed. It is concluded that, besides thymine dimer, at least one other lethal photoproduct (probably a photoproduct of cytosine) is involved in photoreactivation.     

Enhanced shot noise in tunneling through a stack of coupled quantum dots

We have investigated the noise properties of the tunneling current through vertically coupled self-assembled InAs quantum dots. We observe super-Poissonian shot noise at low temperatures. For increased temperature this effect is suppressed. The super-Poissonian noise is explained by capacitive coupling between different stacks of quantum dots.     

Universality of the automorphism group of the real line

We discuss the question, whether each automorphism group (of cardinality at most ) of a linear order is embeddable into the automorphism group of the real line. We show that the answer to this question is independent of the axioms of ZFC: the answer is positive, if we assume < and Souslin's hypothesis; the answer is negative, if we assume orV=L.