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  • 1980-1984  (11)
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 84 (1980), S. 3638-3646 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 2255-2277 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thioketyls, 5. Isotropic ESR Parameters in Thio- and SelenoketylsThe preparation of aliphatic and aromatic thio- and selenoketones and of some of their D-, 13C-, and 77Se derivatives is described. Most of these compounds yield persistent radical anions on one-electron electroreduction, which are studied by ESR spectroscopy.  -  The 13C coupling constants allow the conclusion that in thio- and selenoketyls the spin density is mainly located at the central carbon atom.  -  The observed temperature dependence of the coupling constants is in agreement with a planar geometry of the thioketyl molecule.
    Notes: Die Darstellung aliphatischer und aromatischer Thio- und Selenoketone sowie einiger ihrer D-, 13C- und 77Se-angereicherten Derivate wird beschrieben.  -  Bei der elektrochemischen Einelektronen-Reduktion liefern die meisten Vertreter persistente Radikalanionen, die ESR-spektroskopisch untersucht werden. Die gemessenen isotropen 13C-Kopplungskonstanten erlauben den Schluß, daß in der Thio- bzw. Selenoketyl-Gruppe die Spinpopulation am zentralen C-Atom am größten ist.  -  Die beobachtete Temperaturabhängigkeit der Kopplungskonstanten ist mit einer planaren Geometrie des Thioketyl-Moleküls in Einklang.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 2221-2228 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thioketyls, 8. Radical Anions of α-Thioxoketones (“Monothiosemidiones”)Radical anions (“monothiosemidiones”) 5 are obtained by in-situ electroreduction of α-thioxoketones. Conclusions about the spin density distribution are drawn from their ESR spectra. The unpaired electron is mainly located in the central CO—CS group. - Only 5a-g exhibit proton hfs splittings, and that for the protons of the thiobenzoyl but not of the benzoyl group. 13C-satellites of the CS- and CH3-carbon atoms are observed in the spectra of 5h-j. From the latter π-spin populations of the thiocarbonyl carbon atom of 0.82 (5h) and 0.54 (5j), respectively, are calculated.
    Notes: Durch in-situ-Elektroreduktion werden α-Thioxoketone in die Radikalanionen („Monothiosemidione“) 5 übergeführt. Aus deren ESR-Spektren lassen sich Rückschlüsse über die Aufenthaltswahrscheinlichkeit des ungepaarten Elektrons ziehen. Die zentrale CO—CS-Gruppe enthält den überwiegenden Teil der Spindichte. - Nur bei 5a-g treten meßbare Protonen-HFS-Aufspaltungen auf, und zwar für die Protonen der Thiobenzoyl- nicht aber der Benzoylgruppen. Bei 5h-j beobachtet man 13C-Satelliten der CS- und CH3-Kohlenstoffatome. Aus letzteren erhält man π-Spinpopulationen am Thiocarbonyl-C-Atom von 0.82 (5h) bzw. 0.54 (5j).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1983 (1983), S. 1116-1132 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: α-Oxo- and α-Thioxothioamides from Methyl KetonesMixtures of α-(chloro)sulfenyl chlorides 5 and trisulfides 6 are obtained from the reaction of thionyl chloride with methyl ketones in the presence of pyridine. From these mixtures as well as from the pure trisulfides 6, with amines the α-oxothioamides 1-4 are formed with good yields. Thionation of the thioamides 1 and 2 yields the deeply coloured α-thioxothioamides 16 and 17, the structure of which has been especially characterized by X-ray structure analyses.
    Notes: Bei der Reaktion von Methylketonen mit Thionylchlorid in Gegenwart von Pyridin entstehen Gemische aus α-(Chlor)sulfenylchloriden 5 und Trisulfiden 6, die - ebenso wie die reinen Trisulfide 6 - mit Aminen hohe Ausbeuten an α-Oxothioamiden 1-4 liefern. - Schwefelung der Thioamide 1 und 2 ergibt die tieffarbigen α-Thioxothioamide 16 und 17, deren Struktur insbesondere durch Röntgenstrukturanalysen charakterisiert wird.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1983 (1983), S. 1694-1711 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of New Vicinal Tricarbonyl Compounds and Some of Their Sulfur AnaloguesMesoxalamides 5, benzoylglyoxylamides 19, and pivaloylglyoxylamides 26 are prepared from the corresponding malonamides 4, benzoylacetamides 17 and pivaloylacetamides 24, respectively, by suitable oxidation reactions. Some of the sulfur analogues of 5, 19, and 26, including the first stable 2-thiomesoxalic acid derivative 11b, are also obtained. The spectroscopic properties of the compounds are discussed.
    Notes: Durch geeignete Oxidationsreaktionen gelingt die Überführung der Malonamide 4 in Mesoxalamide 5, der Benzoylacetamide 17 in Benzoylglyoxylamide 19 und der Pivaloylacetamide 24 in Pivaloylglyoxylamide 26. Auch Schwefelanaloga von 5, 19 und 26, darunter das erste stabile 2-Thiomesoxalsäurederivat 11b sind zugänglich. Die spektroskopischen Eigenschaften der dargestellten Verbindungen werden diskutiert.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 66 (1983), S. 801-808 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The He(Iα) photoelectron (PE.) spectra of a series of substituted 1,2-dithietes have been recorded and assigned with respect to the orbital sequence derived from an STO-3G model calculation and by correlation with the PE. spectra of related compounds. The results provide additional support for the presence of a closed, four-membered ring moiety in all the 1,2-dithietes investigated. In all cases the two highest occupied molecular orbitals are b2(π)= HOMO, a2(π), with exception of 3,4-bis(trifluoromethyl)-1,2-dithiete where the sequence b2(π), a2(π) or a2(π), b2(π) is uncertain.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electroreduction of Organic Compounds, 1.  -  Condensation Reactions of Acetonitrile with the Aid of Electrogenerated BasesElectrochemical reduction of alkyl benzoates in dry acetonitrile yields benzoylacetonitrile (2). Methyl 3-cyano-2-hydroxy-2-phenylpropionate (7) is obtained from methyl phenylglyoxalate (5) under the same conditions.  -  Analogously β-dialkylaminocinnamonitriles 9 can be obtained from N,N-dialkylthiobenzamides 8. N,N-Dimethylbenzamide (10) yields β-dimethylamino-cinnammonitrile (9a) on electoreduction in the presence of azobenzene as a probase by catalytical generation of acetonitrile anions.
    Notes: Die elektrochemische Reduktion von Benzoesäureestern in wasserfreiem Acetonitril liefert Benzoylacetonitril (2). Aus Phenylglyoxylsäure-methylester (5) entsteht unter gleichen Bedingungen 3-Cyan-2-hydroxy-2-phenylpropionsäure-methylester (7).  -  Analog können aus N,N-Dialkylthiobenzamiden 8 β-Dialkylaminozimtsäurenitrile 9 erhalten werden. Aus N,N-Dimethylbenzamid (10) entsteht β-Dimethylaminozimtsäurenitril (9a) bei der Elektroreduktion in Gegenwart von Azobenzol als Probase durch die katalytische Erzeugung von Acetonitrilanionen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electroreduction of Organic Compounds, 21).  -  Preparation of Dithioacetals by Electroreductive Alkylation of Alkyl DithiocarboxylatesAlkyl dithiobenzoates 1 and O-methyl thiobenzoate (7) yield the benzaldehyde dithioacetals 2 or monothioacetals 8, respectively, by electroreduction in the presence of alkyl halides. The S-acylal 3b is formed from ethyl dithiobenzoate 1b in the presence of acetic anhydride.  -  The dithioacetals 5 and the ketene dithioacetals 6 are obtained by co-electroreduction of methyl dithiopropionate (4) with alkyl halides.  -  Conclusions about the reaction mechanism are drawn from voltammetric measurements.
    Notes: Dithiobenzoesäureester 1 und Thiobenzoesäure-O-methylester (7) liefern bei der Elektroreduktion in Gegenwart von Alkylhalogeniden die Benzaldehyd-dithioacetale 2 bzw. -monothioacetale 8; in Gegenwart von Acetanhydrid entsteht aus dem Ethylester 1b das S-Acylal 3b.  -  Die Koelektroreduktion von Dithiopropionsäure-methylester (4) mit Alkylhalogeniden ergibt neben den Dithioacetalen 5 die Keten-dithioacetale 6.  -  Aus voltammetrischen Messungen werden Rückschlüsse auf den Reaktionsmechanismus gezogen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 10-19 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Diaryl and Aryl tert-Butyl α-ThioxoketonesThe preparation of the α-haloketones 6, 13-16, 19, and 20 is reported. 13 or its precursor, the acyloin 9, respectively, is conveniently obtained by a Seebach synthesis.  -  Reaction of the haloketones with tetraethylammonium thiosulfate (21) yields the Bunte salts 22-27 which form the thioketones 28-33 on cleavage with aqueous alkali. 29 is stable as a crystalline, blue monomer in contrast with other aromatic α-thioxoketones. This ist also true for the aromatic-aliphatic derivatives 30 and 31 as well as their isomers 32 and 33 which do not dimerize.
    Notes: Die Darstellung der α-Halogenketone 6, 13-16, 19 und 20 wird beschrieben. 13, bzw. seine Vorstufe 9, ist am besten durch eine Seebach-Synthese zugänglich.  -  Durch Umsetzung mit Tetraethylammonium-thiosulfat (21) erhält man aus den Halogenketonen die Bunte-Salze 22-27, die nach Spaltung mit Alkali die Thioketone 28-33 liefern. 29 ist im Gegensatz zu anderen aromatischen α-Thioxoketonen als kristallisiertes blaues Monomeres beständig. Auch die aromatisch-aliphatischen Vertreter 30 und 31 sowie ihre Isomeren 32 und 33 dimerisieren nicht.
    Type of Medium: Electronic Resource
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