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  • 11
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 12
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 55 (1990), S. 449-453 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
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  • 14
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1684-1695 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und Charakterisierung von Bis(thioacyl)tri- und -tetrasulfidenDurch Umsetzung von Dithiocarbonsäuren mit Schwefeldichlorid oder Dischwefeldichlorid werden einige Bis(thioacyl)tri- 1 und -tetrasulfide 2 dargestellt. Die aromatischen Bis(thioacyl)-sulfide (1, 2, R = Arylrest) sind thermisch stabile und nicht feuchtigkeitsempfindliche Kristalle. Die n →π*-Übergänge der Thiocarbonylgruppen in Bis(thioacyl)sulfiden [RC(S) - Sx - (S)CR, x = 1 - 4] sind von der Anzahl x der Schwefelatome abhängig. Ferner stimmt der merkliche Unterschied zwischen den n →π*-Übergängen (λmax) der Monosulfide vom Typ RC(S)S(S)CR und denen der Sulfide RC(S) - Sx - (S)CR (x = 2 - 4) mit dem Ergebnis von ab-initio-Molekül-Orbital-Berechnungen an Bis(thioformyl)sulfiden [HC(S) — Sx — (S)CH, x = 1 - 3] überein. Die Rechnungen zur Bestimmung der Ladungsverteilung und Grenzorbital-Elektronendichte sagen einen ladungskontrollierten Angriff von Nucleophilen oder Elektronen-Donoren auf den Sulfid-Schwefel voraus, während die Reaktion mit dem Thiocarbonyl-Schwefel der Grenzorbital-Kontrolle unterliegt.
    Notes: Bis(thioacyl) tri- 1 and tetrasulfides 2 have been prepared by the reaction of dithiocarboxylic acids with sulfur- or disulfur dichloride. The crystalline aromatic bis(thioacyl) sulfides (1, 2, R = aromatic) are stable towards heat and moisture. The n →π* transitions (λmax) of the thiocarbonyl groups of bis(thioacyl) sulfides [RC(S) — Sx — (S)CR, x = 1 - 4] are influenced by the number x of sulfur atoms. In addition, the remarkable difference in the n →π* transitions (λmax) between monosulfides [RC(S)S(S)CR] and polysulfides [RC(S) - Sx - (S)CR, x = 2 - 4] shows no contradiction with the results of the ab initio molecular-orbital calculation by employing bis(thioformyl) sulfides [HC(S) - Sx - (S)CH, x = 1 - 3] as model compounds. The results of the calculation of the charge distribution and the frontier-electron densities show that nucleophiles or electron-donating reagents attack the sulfide sulfur in a charge-controlled reaction and the thiocarbonyl sulfur in a frontier-orbital-controlled reaction.
    Additional Material: 6 Tab.
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1696-1708 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und einige Reaktionen von Selen- und Tellur-bis(dithiocarboxylaten)Durch Umsetzung von Piperidinium- oder Natrium-dithiocarboxylaten 1 mit Natrium-seleno-oder -telluropentathionaten wurden die Selen- 2 und Tellur-bis(dithiocarboxylate) 3 dargestellt. Die orangefarbenen oder roten Kristalle sind thermisch stabil und nicht feuchtigkeitsempfindlich. Durch Umsetzung von 2 oder 3 mit Halogenen oder N-Chlor- oder N-Bromsuccinimid wurden Haloselen- 4, 5 und Halotellur-dithiocarboxylate 6-8 mit guten Ausbeuten erhalten. Die n →πast;-Übergänge der Thiocarbonylgruppen in 2-8 treten bei kleineren Wellenlängen auf (hypsochrome Verschiebung) als die der entsprechenden Bis(thioacyl)-trisulfide sowie Dithio- und Thionselenolester.
    Notes: A number of selenium- 2 and tellurium bis(dithiocarboxylates) 3 have been prepared by the reaction of piperidinium or sodium dithiocarboxylates 1 with sodium seleno- and telluropentathionates. The orange or red products are stable towards heat and moisture. It was found that 2 and 3 react with halogens and N-chloro- and N-bromosuccinimide to give the corresponding haloselenium- 4, 5 and halotellurium dithiocarboxylates 6-8 in good yields. The n →π* transitions of the thiocarbonyl groups in 2-8 are observed in a region of shorter wavelengths (hypsochromic shift) than those of the corresponding bis(thioacyl) trisulfides and dithio- and thioneselenol esters.
    Additional Material: 4 Tab.
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  • 16
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1229-1244 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und einige Reaktionen von Bis(thioacyl)sulfidenDurch Umsetzung von Dithiocarbonsäuren mit Dicyclohexylcarbodiimid wurden die Bis-(thioacyl)sulfide 1, die nützliche und unter milden Reaktionsbedingungen einsetzbare Thioacylierungsmittel sind, dargestellt. Die aliphatischen Thioanhydride (1, R = Aliphaten) sind thermisch labile und feuchtigkeitsempfindliche purpurne öle, die bei Raumtemperatur zu den Dithietanen 5 dimerisieren, während die meisten aromatischen Derivate (1, R = Aromaten) tiefgrüne, einigermaßen stabile Kristalle bilden. Einige Reaktionen mit Nucleophilen werden diskutiert.
    Notes: Reaction of dithioic acids with dicyclohexylcarbodiimide has been found to give the corresponding bis(thioacyl) sulfides 1 in good yield, which are very useful thioacylating reagents under mild reaction conditions. Most of the aromatic thioanhydrides (1, R = aromatic) are fairly stable green crystals at room temperature, but the aliphatic ones (1, R = aliphatic) are unstable purple oils which dimerize at room temperature to give the dithietanes 5. The reactions with nucleophiles are discussed.
    Additional Material: 2 Ill.
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  • 17
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und einige Reaktionen von unsymmetrischen Acyl(thioacyl)sulfidenDurch Umsetzung von Piperidinium- oder Natrium-dithiocarboxylaten mit Acylchloriden oder durch Entschwefelung von Acyl(thioacyl)disulfiden mit Triphenylphosphan wurden einige un-symmetrische Acyl(thioacyl)sulfide [RC(S)S(O)CR'] dargestellt und charakterisiert. Die tiefblauen Öle oder hellgrünen Kristalle sind thermisch labil und feuchtigkeitsempfindlich. Die n →π-Übergänge der Thiocarbonylgruppe in 1 treten bei höheren Wellenlängen auf als die der entsprechenden symmetrischen Bis(thioacyl)sulfide [RC(S)S(S)CR']. Einige Reaktionen mit Nucleophilen werden diskutiert. Die Umwandlung von unsymmetrischen Acyl(thioacyl)sulfiden in symmetrische Bis(thioacyl)disulfide erfolgt in Gegenwart von Basen wie Lithium-ethanthiolat mit guten Ausbeuten.
    Notes: A number of unsymmetrical acyl thioacyl sulfides [RC(S)S(O)CR'] have been prepared and characterized by the reaction of piperidinium or sodium dithiocarboxylates with acyl chlorides or by desulfurization reaction of acyl thioacyl disulfides with triphenylphosphine. They are deep blue oils or light green crystals and very unstable thermally and for moisture. The n →π transitions of the thiocarbonyl group of 1 appear in higher wave length region than those of the corresponding symmetrical bis(thioacyl) sulfides [RC(S)S(S)CR']. Some reactions with nucleophiles are discussed. It was found that the symmetricallization reaction of these unsymmetrical acyl thioacyl sulfides occurs in the presence of base such as lithium ethanethiolate to give the symmetrical bis(thioacyl) disulfides in fair yield.
    Additional Material: 2 Ill.
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  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 102 (1990), S. 572-573 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 88 (1976), S. 844-844 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 20
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 9 (1996), S. 29-34 
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The relative reactivity of heteroatomic compounds (PhM; M = SeR, SnR3, TeR, I) towards BuLi was estimated by competitive experiments. The rates of exchange reactions in THF increase in the order I 〉 Te ≫ Sn ≫ Se with a ratio of 1000:300:15:1 at - 70 °C when R = Bu. Me3SnPh underwent exchange much faster than Bu3SnPh, suggesting that the exchange reaction was largely affected by steric hindrance. The evidence that Bu3SnPh and BuTePh react with BuLi at almost the same rate in the presence of HMPA and that the relative exchange rates of Li-Te/Li-Sn increase in less polar solvents such as Et2O and hexane indicates that coordination of solvents towards lithium plays an important role in exchange reactions. Relative activation parameters obtained from competitive reactions of PhTeBu and PhSnBu3 with BuLi showed that Li-Te exchange was favored over Li-Sn exchange by an enthalpy factor. Hammett treatment of Li-Te exchange of ArTeBu with BuLi in THF showed a substantially large positive reaction constant (ρ) of 3·4, indicating that the anion charge was largely distributed on the leaving group in the transition state.
    Additional Material: 4 Ill.
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