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  • 1
    Electronic Resource
    Electronic Resource
    Reduktive Arylierung von Vinyl-trifluoromethansulfonaten durch Friedel-Crafts-Reaktion (1987)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 120 (1987), S. 1255-1256 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reductive Arylation of Vinyl Trifluromethanesulfonates by Friedel-Crafts ReactionThe reaction of vinyl triflates 1 with benzene and toluene in the presence of aluminium trichloride gives alkyl-, alkenyl-, and 1,1-diarylalkanes 5, 6, 3, 9 depending on the structure of the substrate used. A mechanism for the reductive arylation is proposed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19871200724
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  • 2
    Electronic Resource
    Electronic Resource
    Über die stereoelektronischen Bedingungen der 1,2-Umlagerungen bei Vinylkationen (1984)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 2815-2824 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Stereoelectronic Requirements of 1,2-Rearrangements of Vinyl CationsThe triflates 8, 9, 12, 17, 19, and 23 have been synthesized to investigate their solvolysis products in absol. 2,2,2-trifluoroethanol (TFE) (Table 1). The kinetics of the solvolysis in 50% ethanol have been measured as well. The rate constants give a straight correlation line when we apply an approximate Taft's equation, from which we deduce that the solvolyses take place by a kc mechanism; one exception is 12, as it reacts with S-O bond cleavage. We also deduce that the value of ρ* does not depend on steric factors. Relations between structure and rearrangement of vinyl cations are discussed. Mechanisms for the formation of reaction products are proposed.
    Notes: Die Triflate 8, 9, 12, 17, 19 und 23 wurden synthetisiert, um die Produkte ihrer Solvolyse in absol. 2,2,2-Trifluorethanol (TFE) zu untersuchen (Tab. 1). Auch die Kinetik der Solvolysen in 50proz. Ethanol wurde bestimmt (Tab. 2). Die Solvolysegeschwindigkeiten ergeben eine Korrelationsgerade bei einer vereinfachten Taftschen Darstellung, woraus abgeleitet wird, daß die Solvolysen nach einem kc-Mechanismus erfolgen; eine Ausnahme ist 12, das durch S-O-Spaltung solvolysiert. Wir schließen daraus, daß ρ* von sterischen Effekten unabhängig ist. Es werden Beziehungen zwischen Struktur und Umlagerung bei Vinylkationen diskutiert und Mechanismen für die Bildung der Reaktionsprodukte vorgeschlagen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19841170904
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  • 3
    Electronic Resource
    Electronic Resource
    Darstellung, Temperaturverhalten und Kristallstruktur von BiF3 (1977)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 436 (1977), S. 105-112 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation, Temperature Behaviour, and Crystal Structure of BiF3Orthorhombic BiF3 was prepared from BiOCl and HF at 300°C through elimination of oxygen. Thermal analysis showed no transformation up to the melting point of 757°C. The orthorhombic structure of BiF3 can, however, transform into the structure of Tysonit in presence of a small amount of oxygen. The single-crystal X-ray structure determination (553 reflexions, R = 0.050) demonstrated that BiF3 is isostructural with the rare-earth trifluorides of the YF3 type (Pnma). The coordination polyhedron around Bi can be described in terms of a slightly distorted square-antiprisma (CN = 8).
    Notes: Orthorhombisches BiF3 wurde aus BiOCl und Fluorwasserstoff bei 300°C unter Ausschluß von Sauerstoff dargestellt. BiF3 zeigt bis zum Schmelzpunkt bei 757°C keine Phasen-umwandlung. Die orthorhombische BiF3-Struktur kann durch sehr geringe Sauerstoffgehalte in die Tysonitstruktur umgewandelt werden. Die Einkristall-Röntgenstrukturanalyse (553 Reflexe, R = 0,050) ergab, daß BiF3 isotyp mit den Selten-Erd-Trifluoriden vom YF3-Typ (Pnma) ist. Die Koordinationsverhältnisse um Bi können mit Hilfe eines leicht verzerrten quadratischen Antiprismas (KZ = 8) beschrieben werden.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19774360112
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  • 4
    Electronic Resource
    Electronic Resource
    Study on the System CoSeO4—NiSeO4—H2O at 30°C Crystal Structure of CoSeO4 · 5 H2O (1985)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 528 (1985), S. 183-190 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Das System CoSeO4-NiSeO4—H2O bei 30°C. Kristallstruktur des CoSeO4 · 5 H2OEs wird das System CoSeO4—NiSeO4—H2O bei 30°C untersucht. Die Kristallwerden aus wäßriger Lösung durch langsames Eindampfen erhalten. Die gefundenen Phasen sind CoSeO4 · 5 H2O und NiSeO4 · 6 H2O; CoSeO4 · 6 H2O wird dann gefunden, wenn die Kristallisation der Co-Verbindung in Gegenwart von Ni erfolgt. Diese drei Phasen zeigen einen begrenzten Ersatz des Metalls auf Grund von Röntgenpulverdaten. Die Kristallstruktur des CoSeO4 · 5 H2O ist triklin, a = 6.435(1), b = 10,703(2), c = 6,220(1) Å, α = 98,71(1), β = 109,60(2), γ = 75,54(1)°, P1, Z = 2. Verfeinerung bis zu R = 0,032 für alle beobachteten Reflexe. Die Kristallstruktur ist isostrukturell zu CuSO4 · 5 H2O und besteht aus Ketten von Co(H2O)4-Ionen parallel zu [110], die brückengebunden über die SeO4-Anionen sind. Das fünfte Wassermolekül wirkt als Puffer.
    Notes: A study of the system CoSeO4—NiSeO4—H2O at 30°C has been carried out. Crystals were obtained by slow evaporation from a water solution. The identified phases were CoSeO4 · 5 H2O and NiSeO4 · 6 H2O, but CoSeO4 · 6 H2O is identified when the crystallization of Co compound is carried out in presence of Ni. The three phases show a limited replacement of metal according to X-ray powder results. The crystal structure of CoSeO4 · 5 H2O has been solved, the come pound is triclinic, a = 6.435(1), b = 10.703(2), c = 6.220(1) Å, α = 98.71(1), β = 109.60(2), γ = 75.54(1)°, P1, Z = 2. Refinement was terminated at R = 0.035 for all observed reflections. The crystal structure is isostructural to CuSO4 · 5 H2O and consists of Co(H2O)4 ions chains parallel to [110] μ-linked by the SeO4. The fifth water molecule acts as buffer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19855280921
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  • 5
    Electronic Resource
    Electronic Resource
    Complexes of IIB Metal Halides with N,N-Diethylbenzenecarbothioamide crystal structure of [Hg{C6H5C(S)N(C2H5)2}I2]2 (1986)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 539 (1986), S. 219-228 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Komplexe von IIB Metall-halogeniden mit N,N-Diethylbenzocarbothioamiden. Kristallstruktur von [Hg{C6H5C(S)N(C2H5)2}I2]2Verschiedene Komplexe von N,N-Diethylbenzocarbothioamide (DEBCTA) mit MX2 (M = Zn, Cd oder Hg und X = Cl, Br oder I) wurden hergestellt und mittels Elementaranalyse, Molgewichtsbestimmung, IR, 1H-NMR-Spektren und konduktometrischen Messungen untersucht. Die Kristallstruktur von [Hg(DEBCTA)I2]2 wurde mit Hilfe von Röntgenbeugungsdaten ermittelt (2402 beobachtete unabhängige Reflexe, R = 0,097). [Hg(DEBCTA)I2]2 kristallisiert monoklin in der Raumgruppe P21/n mit zwei Formeleinheiten pro Elementarzelle; Gitterkonstanten a = 1383,9(2), b = 834,3(1), c = 1 418,1(2) pm, β = 101,03(1)°. Im dimeren Komplex sind die verzerrt-tetraedrisch koordinierten Hg-Atome von je einem S-Atom des Liganden, einem terminalen I-Atom und zwei verbrückenden I-Atomen umgeben.
    Notes: Complexes having the empirical formulae M(DEBCTA)2X2 (M = Zn or Cd, X = Br or I, DEBCTA = N,N-diethylbenzenecarbothioamide), Zn(DEBCTA)Cl2, Cd2(DEBCTA)Cl4 and Hg(DEBCTA)X2 (X = Cl, Br or I) were made by reaction of zinc, cadmium or mercury dihalides in ethanol or 1,2-dichloroethane. All complexes have been characterized by elemental analysis, conductance and molecular weight measurements and by infrared and 1H-NMR spectral studies. In addition, the structure of [Hg(DEBCTA)I2]2 has been determined by single-crystal X-ray crystallography and refined to a conventional R factor of 0.097. The compound crystallizes in the monoclinic space group P21/n with a = 1383.9(2), b = 834.3(1), c = 1418.2(2) pm, β = 101.03(1)° and Z = 2. The molecule was found to have a dimeric structure involving two asymmetrical iodine bridges in which the Hg atom lies a tetrahedral environment and the ligands lie mutually trans with respect to one another.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19865390823
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  • 6
    Electronic Resource
    Electronic Resource
    Pollucite- and Leucite-related Phases: A2BX5O12 and ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge) (1989)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 573 (1989), S. 223-230 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pollucit- und Leucit-verwandte Phasen: A2BX5O12 und ACX2O6 (A = K, Rb, Cs; B = Be, Mg, Fe, Co, Ni, Cu, Zn, Cd; C = B, Al, Ga, Fe, Cr; X = Si, Ge)Darstellung und kristallographische Daten von 29 neuen Phasen dieser Strukturfamilie werden angegeben. Ein Überblick über die gesamte Strukturfamilie, die bis jetzt 59 Phasen enthält, wird gegeben. Die Familie enthält wenigstens sieben Strukturvarianten, von denen zwei die Pollucit-, CsAlSi2O6, und Leucit-, KAlSi2O6, Struktur sind. Beziehungen zwischen der Kationengröße und dem Strukturtyp werden vorgestellt. Ungewöhnliche Variationen in den Größen der Einheitszelle als Funktion der Kationengröße werden diskutiert, und auf die mögliche Bedeutung für das „partially collapsed framework“-Konzept von Taylor und Henderson wird hingewiesen.
    Notes: Synthesis and crystallographic data on 29 new phases in this family are given. A survey of the crystal chemistry of the complete family, containing 59 phases to date, is presented. The family contains at least seven structural variations, two of which are the pollucite, CsAlSi2O6 and leucite, KAlSi2O6 structures. Correlations between cation size and structure type are presented. Unusual variations in unit cell dimensions as a function of cation size are discussed and the possible relevance of the „partially collapsed framework“ concept of Taylor and Henderson indicated.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19895730123
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  • 7
    Electronic Resource
    Electronic Resource
    Vinylkationen, 36. Solvolyse von Cycloalkylidenmethyl- und 1-Cyclopenten-1-yl-triflaten (1982)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 115 (1982), S. 772-782 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Vinyl Cations, 36. Solvolysis of Cycloalkylidenemethyl and 1-Cyclopenten-1-yl TriflatesCyclohexlidenemethyl triflate (2), cyclobutylidenemethyl triflate (5), 1-cyclopenten-1-yl triflate (7), bicyclo [3.1.0]hex-2-en-2-yl triflate (9), 1-cyclobutylideneethyl triflate (19), and 2-methyl-1-cyclopenten-1-yl triflate (29) were solvolyzed in solvents of various ionizing power and nucleophilicity and the solvolysis products were identified. The cyclobutylidenealkyl triflates solvolyze via a vinyl cation mechanism involving ion pairs with rearrangement to cyclopentene and cyclopentanone compounds. The 1-cyclopenten-1-yl triflates do not produce vinyl cation intermediates but give only the corresponding ketones via an O—S bond cleavage of the triflate group.
    Notes: Cyclohexylidenmethyl-triflat (2), Cyclobutylidenmethyl-triflat (5), 1-Cyclopenten-1-yl-triflat (7), Bicyclo[3.1.0]hex-2-en-2-yl-triflat (9), 1-Cyclobutylidenethyl-triflat (19) und 2-Methyl-1-cyclopenten-1-yl-triflat (29) wurden in Lösungsmitteln verschiedener Ionisierungsstärke und Nucleophilie solvolysiert und die Solvolyseprodukte aufgeklärt. Die Cyclobutylidenalkyl-triflate solvolysieren über Ionenpaarmechanismen (Vinylkationen) unter Umlagerung zu Cyclopenten- und Cyclopentanon-Derivaten. Die 1-Cyclopenten-1-yl-triflate reagieren nicht über Vinylkationen als Zwischenstufe, sondern unter O—S-Spaltung zu den entsprechenden Ketonen.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19821150238
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  • 8
    Electronic Resource
    Electronic Resource
    Selektivität bei der Umsetzung von Carbokationen mit Nucleophilen, 2. Solvolyse-Mechanismen bei 7-Norbornyl-trifluormethansulfonaten (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2557-2560 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Selectivity in the Reaction of Carbocations with Nucleophiles, 2. Solvolytic Mechanisms of 7-Norbornyl TrifluoromethanesulfonatesThe reactions of 7,7-bis(trifluoromethylsulfonyloxy)norbornane (4) with several metal cyanides in dipolar aprotic solvents are studied. The results obtained (Table 1) lead to the conclusion that the solvolysis of 7-substituted 7-norbornyl trifluoromethanesulfonates takes place either according to a kc mechanism or with fission of the S — O bond. In no instance is a C — O fission following an SN2 mechanism to be expected. - The selectivity of the reaction of the intermediate carbocations with nucleophiles cannot be explained by means of N+ correlations nor by the reactivity-selectivity relationship, but can be rationalized according to the HSAB principle.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851180632
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  • 9
    Electronic Resource
    Electronic Resource
    Über Struktur und Stereoselektivität von 2-Norbornen-7-yl-Radikalen und -Carbenoiden (1985)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4281-4284 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Structure and Stereoselectivity of 2-Norbornen-7-yl Radicals and CarbenoidsReduction of 7,7-diiodonorbornene (1) with Grignard reagents proceeds via the 7-iodo-2-norbornen-7-yl radical 2. From the observed syn-stereoselectivity, the absence of π-delocalization in 2 is inferred. This result agrees with the existence of an equilibrium mixture of two classical pyramidal structures (2a and 2b), in which the syn-isomer 2a predominates. The reaction of 1 with methyllithium takes place with anti-stereoselectivity; this fact proves that the anti-carbenoid 4b-M is more stable than the syn-isomer.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19851181035
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  • 10
    Electronic Resource
    Electronic Resource
    From Azole - Borane Adducts to Azaboles  -  Molecular Structure of an Imidazabole (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 343-346 
    Details
    ISSN: 0009-2940
    Keywords: Azole-borane adducts ; Azaboles ; Imidazabole ; X-ray analysis ; NMR, multinuclear ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Elimination of H2 from the imidazole - borane adduct 1 leads to a mixture of the imidazaboles 2 and 2′. The symmetrical isomer 2 (two H2BNC fragments) is isolated in pure state and characterized by an X-ray structure analysis (monoclinic, space group P21). 2-(Trimethylstannyl)thiazole (3a) and 1-methyl-5-(trimethylstannyl)-1,2,4-triazole (3b) react with triethylborane to form adducts 4 from which, in the presence of an excess of Et3B, tetraalkyltin is elimated to give the thiazabole 5a and the triazabole 5b, respectively. Multinuclear 1H-, 11B-, 13C-, 14N-, and 119Sn-NMR spectroscopy serve for following the reactions (compounds 3 to 5) and to characterize all final products.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19941270210
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