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  • GEOPHYSICS  (2,353)
  • Inorganic Chemistry  (768)
  • 1970-1974  (3,121)
  • 1925-1929
  • 1973  (3,121)
Collection
Publisher
Years
  • 1970-1974  (3,121)
  • 1925-1929
Year
  • 1
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Directed Synthesis of Sulfinato-O and -S Complexes of some Transition Metals, VII. Sulfinato Complexes of Chromium(II), Manganese(II), Iron(II), Cobalt(II) and Nickel(II) with Mono- and Bidentate Nitrogen Ligands.The hitherto unknown, pseudooctahedral configurated bis(organosulfinato-O,O')dipyridine compounds of manganese(II), iron(II), cobalt(II) and nickel(II) 5a, b and 6a-8a are obtained by the reaction of the complexes (p-R-C6h4SO2)2M(OH2)2 1a, b and 2a-4a with pyridine according to equation (1). Linkage or stereo isomers cannot be detected.  -  White (p-CH3C6H4SO2)2Cr(OH2)2 (9) reacts with 2 moles of 2,2′-bipyridyl in water according to equation (2) to form the sulfinato-O complex 10, the corresponding manganese compound 1a adds only 1 mole of 2,2′-bipyridyl according to equation (3), yielding the sulfinato complex 11O,O'. In the case of 9 other solvents are not leading to linkage isomers. In contrast to this the sulfinato complex 11S, being linkage and structural isomeric to 11O,O' is obtained from 1a and 2,2′-bipyridyl in pyridine according to equation (4). The iron compound 2c reacts only in THF with 2 moles of 2,2-bipyridyl according to equation (5) to give the sulfinato complex 12O, which is in pyridine irreversibly converted into the S-isomer 12S according to equation (6). 12S can also be isolated from 2c and 2 moles of 2,2′-bipyridyl in pyridine according to equation (7). The newly prepared compounds are characterized on the basis of their i.r. and their electronic spectra as well as by magnetochemical investigations.
    Notes: Bei der Umsetzung der Komplexe (p-R C6H4SO2)2M(OH2)2 1a,b und 2a-4a mit Pyridin erhält man gemäß Gl. (1) die bisher unbekannten, pseudooktaedrisch konfigurierten Bis(organosulfinato-O,O')-dipyridin-Verbindungen von Mangan(II), Eisen(II), Kobalt(II) und Nickel(II) 5a, b und 6a-8a. Bindungs- oder Stereoisomere lassen sich nicht nachweisen.  -  Während (p-CH3C6H4SO2)2Cr(OH2)2 (9) in Wasser gemäß Gl. (2) 2 mol 2,2′-Bipyridyl unter Bildung des Sulfinato-O-Komplexes 10 aufnimmt, addiert die entsprechende Mangen-Verbindung 1a gemäß Gl. (3) nur 1 mol 2,2′-Bipyridyl, wobei der Sulfinato-Komplex 11O,O' entsteht. Andere Lösungsmittel führen bei 9 zu keinen Bindungsisomeren. Dagegen erhält man aus 1a und 2,2′-Bipyridyl in Pyridin entsprechend Gl. (4) den zu 11O,O' bindungs- und strukturisomeren Sulfinato-Komplex 11S. Die Eisen-Verbindung 2c setzt sich nur in THF mit 2 mol 2,2′-Bipyridyl gemäß Gl. (5) zum Sulfinato-O-Komplex 12O um, welcher in Pyridin irreversibel entsprechend Gl. (6) in das S-Isomere 12S übergeht 12S läßt sich gemäß Gl. (7) auch aus 2c und 2 mol 2,2′-Bipyridyl in Pyridin isolieren., Die neu dargestellten Verbindungen werden anhand ihrer IR- und Elektronenspektren, sowie durch magnetochemische Untersuchungen charakterisiert.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 288-311 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: X-Ray Structure Analysis of the 2 : 1-Cycloaddition Product of Diazomethane and 4-Methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadieneThe structure of 1-(4-methyl-1-pyrazolin-3-yl)-5,5-bis(trifluormethyl)-Δ2-1,2,3-triazoline (C8H9F6N5) (4a), which is the 2 : 1-cycloaddition product of diazomethane and 4-methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadiene, was solved by direct methods. Space group: Pbca; a = 19.839 Å, b = 12.985 Å, c = 8.826 Å 8 molecules per unit cell. The refinement by least squares methods yielded a final R index of 5.5% (for 1900 observed reflexions). The hydrogen atoms have been included into the refinement.The constitution of the molecule, which on chemical and physical ways could not unambigously be determined, has been evaluated. The binding situation is discussed and including hydrogen atoms a detailed conformational analysis is carried out. The crystal structure is discussed, too. It contains an interesting type of a hydrogen-bridge system.
    Notes: Die Lösung der Struktur des 1-(4-Methyl-1-pyrazolin-3-yl)-5,5-bis(trifluormethyl)-Δ2-1,2,3-triazolins (C8H9F6N5) (4a), dem 2 : 1-Cycloadditionsprodukt von Diazomethan und 4-Methyl-1,1-bis(trifluormethyl)-2-aza-1,3t-butadien erfolgte mit direkten Methoden. Raumgruppe: Pbca; a = 19.839 Å, b = 12.985 Å, c = 8.826 Å, mit 8 Molekülen pro Elementarzelle. Die Verfeinerung nach der Methode der kleinsten Quadrate konvergierte unter Einschluß der H-Atome bei einem R-Wert von 5.5% (für 1900 beobachtete Reflexe).DIE KONSTITUTION der Molekel, die auf chemisch-physikalischem Wege nicht eindeutig bestimmt werden konnte, wurde festgelegt. Es werden die Bindungsverhältnisse diskutiert und unter Einbeziehung der Wasserstoffatome eine detaillierte Konformationsanalyse durchgeführt. Gleichfalls wird auf die Kristallstruktur, die einen interessanten Typ eines Wasserstoffbrückensystems enthält, eingegangen.
    Additional Material: 11 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 332-338 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Hydrogenation of Δ2-5-IsoxazolonesThe Δ2-5-isoxazolones 1, 5, 8a-c, and 11a, b are opened under conditions of the catalytic reduction to yield β-enamino-β'-ketocarboxylic acids 6a, b. In a second step, the derivatives 8a-c, 11a, b form diazepines 10a-c and pyrazoles 12, 13 by intramolecular cyclization. The structures are elucidated on the basis of the n.m.r. and i.r. spectra.
    Notes: Die Δ2-5-Isoxazolone 1, 5, 8a-c und 11a, b werden bei der katalytischen Hydrierung unter reduktiver Ringöffnung zu β-Enamino-β'-ketocarbonsäuren 6a, b gespalten Dabei cyclisieren die Derivate 8a-c, 11a, b intramolekular zu den Diazepinen 10a-c und Pyrazolen 12, 13. Die Strukturen werden durch NMR- und IR-Spektren bewiesen.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 5
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Short-Life Radicals, IX1) Radical-Induced Decomposition of Esters of Peroxycarboxylic Acids: SH2 Reaction and Radical-Catalysed Fragmentation as Competing MechanismsThe radical decomposition of peresters RC(O)—O—OC(CH3,)3 R = C6H5, CH3, C(CH3)3 (1a-c) is induced very strongly by triethyltin hydride. A SH2 reaction and a radicalcatalysed fragmentation (a new type of reaction) are found to be competing mechanisms here. In both cases the stannyl radical is the attacking species. In the former reaction, splitting of the O—O bridge occurs with formation of the stannyl esters 3a-c. In the latter R· +CO2 ·OC(CH3) are formed, while the attacking radical is recovered. All products have been identified and quantitatively determined. From hall-life times and rate constants in the range of 21 -3O°, the following values have been calculated for the two competing reactions at 25° in the case of 1c: for the SH2 reaction ΔG+ = 22.7 kcal/mole, ΔS≠ = -19 e. u.; for the fragmentation ΔG≠ = -22.4 kcal/mole, ΔS+ = - 12 e. u. With 1a, the SH2 reaction dominates under all conditions. The importance of the competing catalysed fragmentation, however, increases greatly in the sequence 1a 〈 1b 〈 1c, and can become the main reaction. Dissociation energies and inductive effects of R, stereochemistry of transition states, temperature, and polarity of solvents are found to be of considerable influence.
    Notes: Der radikalische Zerfall von Perestern RC(O)—O—OC(CH3)3, R = C6H5, CH3, C(CH3)3 (1a-c) wird durch Triäthylzinnhydrid sehr stark induziert. Als konkurrierende Mechanismen werden eine SH2-Reaktion und, als neuartiger Reaktionstyp, eine radikal-katalysierte Fragmentierung beobachtet. In beiden ist das Stannyl-Radikal angreifendes Agens, in einem Fall unter Spaltung der O—O-Brücke und Bildung der Stannylester 3a-c, im anderen unter Bildung von R· +CO2 + ·OC(CH3)3 und Rückgewinnung des angreifenden Radikals. Entstehende Produkte werden qualitativ und quantitativ bestimmt. Für 1c ergibt sich aus Halbwertszeiten und Geschwindigkeitskonstanten im Bereich 21-30° für SH2-Reaktion bzw. Fragmentierung bei 25°: ΔG≠ = 22.7 kcal/mol, ΔS≠ = -19 e. u. bzw. 22.4 kcal/mol, -12 e. u. - Bei 1a überwiegt stets die SH2-Reaktion. In der Reihe 1a 〈 1b 〈 1c tritt jedoch die konkurrierende katalysierte Fragmentierung immer stärker hervor und kann zur Hauptreaktion werden. Dissoziationsenergien und induktive Effekte von R, die Stereochemie der Übergangszustände, Temperatur und Polarität des Lösungsmittels haben hierauf beträchtlichen Einfluß.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 471-483 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tautomerism of Heterocyclic Compounds, I. The Prototropic Tautomerism of “4-Quinazolylthioureas” and Related CompoundsThe prototropic tautomerism and hydrogen-bonding interactions of 4-quinazolylthioureas, -thioamides and a thiocarbamic acid ester are studied by spectroscopic methods (i. r. and n. m. r.). In case of thiocarbamic acid ester both tautomeric forms (10 and 11) can be isolated as crystalline solids.
    Notes: Die Tautomerieerscheinungen und Wasserstoffbrückenbeziehungen bei 4-Chinazolylthioharnstoffen, -thioamiden und einem -thiourethan werden IR- und NMR-spektroskopisch untersucht. Im Falle des Thiourethans können beide Tautomeren (10 und 11) in Substanz isoliert werden.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 497-504 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polyacetylenic Compounds, 2131) Novel Natural Sulphur Acetylenic CompoundsThe structures and configurations of four sulphur compounds isolated from Berkheya barbata (L. f.) Hutch. are established by synthesis of the two possible structure type (1 and 17)
    Notes: Die Konstitutionen und Konfigurationen von vier aus Berkheya barbata (L. f ) Hutch. isolierten Schwefel-Verbindungen werden durch Synthese der beiden möglichen Strukturtypen geklärt (1 und 17).
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973) 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 1-7 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On a [3 + 1] Cycloaddition, II. Reactions of 4,5-Dihydro-1,3,5-oxazaphosph(V)olen, VI4,5-Dihydro-1,3,5-oxazaphosph(V)oles 1 react with isonitriles to yield disubstituted 3-imino-4,4-bis(trifluoromethyl)-1-azetines 2 with elimination of phosphoric acid esters. The reaction should proceed via nitrile ylides.
    Notes: 4,5-Dihydro-1,3,5-oxazaphosph(V)ole 1 reagieren mit Isonitrilen zu disubstituierten 3-Imino-4,4-bis(trifluormethyl)-1-azetinen 2 unter Ehmmierung von Phosphorsäureester Eine Nitrilylid-Zwischenstufe wird angenommen.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 106 (1973), S. 882-887 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 17β-CyclobutenylsteroidsThe 21-mesylate derivative 1c of 3β,21-diacetoxy-5α-pregnan-20-one (1a) reacts with dimethyl(methylene)sulfonium oxide to give the aldehyde 2. Reduction of the aldehyde leads to the corresponding alcohol 3, which is easily dehydrated with ring expansion to the cyclobutenyl derivative 4a. After saponification and oxidation 17β-(1-cyclobuten-1-yl)-5α-androstan-3-one (5) is obtained.
    Notes: Ausgehend vom 3β,21-Diacetoxy-5α-pregnan-20-on (1a) gelangt man durch Umsetzung des 21-Mesylats 1c mit Dimethyl(methylen)sulfoniumoxid zum Aldehyd 2. Nach Reduktion zum Alkohol 3 erfolgt leicht Dehydratisierung unter Ringerweiterung zum Cyclobutenyl-Derivat 4a. Nach Verseifung und Oxidation erhält man das 17β-(1-Cyclobuten-1-yl)-5α-androstan-3-on (5).
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