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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 334 (1992), S. 141-146 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Regio- and Stereoselectivity of Nucleophilic Thiol Additions to PolyinesNucleophilic thiophenol additions to α,ω-diphenyl polyines Ph-(C≡C)n-Ph (n = 2-4) (1-3) take a regio- and stereoselective course. The well-defined, crystalline addition products bind the phenylthio group in terminal position of the aliphatic chain, the resulting C, C-double bonds of the mono-(4, 6, 8) and bis-addition products (5, 7, 9) are (Z)-configurated, as unequivocally proved by 13C-n.m.r. analysis.
    Additional Material: 2 Tab.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 318 (1976), S. 1031-1037 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Separation and Identification of the Isomers of Di-1,2-propyleneglycolThe structural isomers of di-1,2-propyleneglycol are separated by means of gaschromatography. The structural and stereoisomeric forms are distinguished and identified by n.m.r. spectroscopy (1H and 13C) and mass-spectrometry.
    Notes: Die vom Dipropylenglykol-(1,2) möglichen strukturisomeren Formen werden gaschromatographisch getrennt. Die Strukturisomere und Diastereomere werden mit Hilfe der 1H-NMR-Signale der Methylgruppen sowie durch 13C-NMR- und Massenspektroskopie unterschieden und zugeordnet.
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 334 (1992), S. 179-180 
    ISSN: 0941-1216
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Lanthanide-Complexes with Rapid Z/E-Isomerisation of the 3-Acetyltetramic Acid Ligand
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 319-324 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tautomeric 3-Acetyltetramic Acid Derivatives -1H/13C-n.m.r.-InvestigationThe molecular structure of 1,5,5-trimethyl-3-acetyltetramic acid (I) and its Schiffbases with ethylendiamin (II) and 1,3-diaminopropan-2-ol (III) is described by an equilibrium of four tautomers. The solvent dependence of the equilibrium is attributed to the strength of the intramolecular hydrogen bond. The higher proton affinity of the Schiff-bases (II and III) in comparison with the ketone (I) should be responsible for the faster equilibration of II and III.
    Additional Material: 2 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 470-474 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The diastereomers of 16 1,3-oxa-, 1,3-aza- and 1,3- thiaphospholanes were assigned by means of the coupling constants 2J(P—C—H) and 3J(P—C—CH3) and the linewidths of the 31P signals and 1H chemical shifts of CH3 groups. It is shown that the change in the 31P chemical shifts allows the estimation of the relative configuration in these compounds.
    Notes: Die Diastereomeren von 16 1,3 Oxa-, 1,3-Aza-und 1,3-Thiophospholanen wurden mit Hilfe der Kopplungs-konstanten 2J(P—C—H) und 3J(P—C—CH3), der Signalbreite der 31P-Signale und der 1H-chemischen Verschiebungen der CH3-Gruppen zugeordnet. Es wird gezeigt, daß auch die 31P-chemischen Verschiebungen eine Bestimmung der relativen Konfiguration dieser Verbindungen gestatten.
    Additional Material: 4 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 478-484 
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1H NMR chemical shifts of 18 methyl substituted cyclohexane-1,2-dicarboxylic anhydrides were determined. In compounds with asymmetric substitution vicinal coupling constants were measured. In the series of trans-anhydrides it can be deduced from the NMR data, that the 6-membered ring has a chair-like conformation. Additionally, in the series of the cis-anhydrides a twisted chair conformation is favoured for the most part.
    Notes: Die chemischen Verschiebungen der 1H-NMR-Spektren von 18 methylsubstituierten Cyclohexandicarbonsäure-(1,2)-anhydriden wurden bestimmt. Von den unsymmetrisch sub-stituierten Verbindungen wurden die vicinalen Kopplungskonstanten ermittelt. Bei den trans-Anhydriden lässtsich aus den NMR-Daten ableiten, dass der Sechsring in einer sesselähnlichen Form vorliegt. Auch bei den cis-Anhydriden sind in den meisten Fällen Konformationen mit verdrillter Sesselanordnung des Cyclohexans bevorzugt.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 594 (1991), S. 66-76 
    ISSN: 0044-2313
    Keywords: Organophosphorus compounds, bicyclic hydrophosphorylation, intramolecular ; methylenebisphosphines ; 1,3-diphosphorinances ; 1,5-diphosphabicyclo[3.3.1]nonanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,5-Diphosphabicyclo [3.3.1]nonane1,5-Diphosphabicyclo[3.3.1]nonane 8 has been obtained by free-radical cyclization of CH2=CHCH2(H)PCH2P(H)CH2CH=CH2 6 and 1-allyl-1,3-diphosphorinane 7. For the synthesis of 6 and 7 the chlorophosphine Cl2PCH2PCl2 1 is used as a starting material, which can be converted into Me2N(Cl)PCH2P(Cl)NMe2 3 by reaction with (Me2N)2PCH2P(NMe2)2 2. Treatment of 3 with two equivalents of allyl lithium and cleavage of the PN bonds in CH2=CHCH2(Me2N)PCH2P(NMe2)CH2CH=CH2 4 with diluted HCl affords CH2=CHCH2(H)(O)PCH2P(O)(H)CH2CH=CH2 5. Phenylsilane is used for the first time as a reducing agent to obtain a secundary phosphine like 6 from the secundary phosphine oxide (5). Prolonged heating increases the yield of the byproduct 7 in the mixture of 6 and 7. Reactions of the trivalent phosphorus in 8 with CS2, CH3I, POCl3, NO, sulfur, and KSeCN, respectively, delivers the corresponding derivatives 9-17. The compounds decribed are characterized by 1H, 13C, 31P, 77Se n.m.r., i.r., and m.s. data.
    Notes: 1,5-Diphosphabicyclo[3.3.1]nonan 8 wird durch radikalische Cyclisierung von CH2=CHCH2(H)PCH2P(H)CH2CH=CH2 6 und 1-Allyl-1,3-diphosphorinan 7 erhalten. Ausgangsmaterial für die Synthese von 6 und 7 ist Cl2PCH2PCl2 1, das mit (Me2N)2PCH2P(NMe2)22 quantitativ zu Me2N(Cl)PCH2P(Cl)NMe2 3 reagiert. Die Umsetzung von 3 mit zwei Äquivalenten Allyllithium zu CH2=CHCH2(Me2N)PCH2P(NMe2)CH2CH=CH2 4 und Abspaltung der Me2N-Schutzgruppen mit verdünnter Salzsäure liefert CH2=CHCH2(H)(O)PCH2P(O)(H)CH2CH=CH2 5. Dessen Reduktion zu 6 gelingt mit C6H5SiH3. Daneben entsteht 7, das durch längeres Erhitzen angereichert werden kann. Reaktionen des dreibindigen Phosphors in 8 mit CS2, CH3I, POCl3, NO, Schwefel und KSeCN führen zu den Derivaten 9-17. Die Verbindungen werden durch 1H-, 13C-, 31P- und 77Se-NMR-sowie IR- und MS-Daten charakterisiert.
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  • 8
    ISSN: 0044-2313
    Keywords: Chelating agent: CuII and NiII complex ; complexation ; relaxation times ; 13C-n. m. r. ; magnetic properties ; X-ray analysis ; structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Isomerization at the Complexation of 3-Acetyltetramic Acid: Structure and Magnetic Properties of the CuII- and NiII-Complex of 2,7-Bis (1′, 5′, 5′ -trimethylpyrrolidin-2′,4′ -dion-3′ -yl)-3,6-diazaocta-2,6-dien2,7-Bis(1′, 5′, 5′ -trimethylpyrrolidin-2′, 4′ -dion-3′ -yl)-3,6-diazaoctadien formes CuII and NiII complexes with different constitutions (because of the Z/E isomerization). Results of X-ray analysis of N,N′ -ethylenbis(1′, 5′, 5′ -trimethylpyrrolidin-2′, 4′ -dion-3′ -acetiminato)nickel(II) 1 respectively -copper(II) 2 shows, that the complexing agent in 1 occurs in the E-form, whereas the ligand of the CuII complex forms the Z-form. Magnetic susceptibility and shift effects of the 13C-NMR signals point to a weak paramagnetism of the NiII complex. ESR-spectra are obtained from 2 only. Furthermore, the CuII complex reduces the relaxation times T1 and T2 of 1H and 17O nuclei spins from water. From the temperature dependence of the shortening of the relaxation times an activation energy is calculated which describes the reorientation of the copper complex in the “water matrix”.
    Notes: 2,7-Bis(1′, 5′, 5′ -trimethylpyrrolidin-2′, 4′ -dion-3′ -yl)-3,6-diazaocta-2,6-dien bildet aufgrund der Z/E-Isomerisierung als Ligand CuII- und NiII- Komplexe unterschiedlicher Konstitution. Die Ergebnisse der Röntgenstrukturanalyse von N,N′ -Ethylen-bis- (1′, 5′, 5′ -trimethylpyrrolidin-2′, 4′ -dion-3′ -acetimina-to)-Nickel-(II) 1 bzw. -Kupfer-(II) 2 zeigen, daß bei 1 der Ligand in der E-Form hingegen beim Kupferkomplex in der Z-Form vorliegt. Die magnetische Suszeptibilität und die Verschiebungseffekte der Ligandensignale in den 13C-NMR-Spektren deuten einen schwachen Paramagnetismus des Nickelkomplexes an. EPR-Spektren konnten nur vom Kupferkomplex 2 erhalten werden. Des weiteren verkürzt 2 die Relaxationszeiten T1 und T2 der Kernspinzustände von 1H und 17O des Wassers. Aus der Temperaturabhängigkeit der Relaxationszeitverkürzung wird eine Aktivierungsenergie berechnet, die zur Beschreibung der Reorientierung des Kupferkomplexes in der „Wassermatrix“ dient.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 619 (1993), S. 989-992 
    ISSN: 0044-2313
    Keywords: Bicyclic organophosphorus compounds ; intramolecular hydrophosphorylation ; 1-phosphabicyclo[3.3.1]nonanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 5-Hydroxy-1-phosphabicyclo[3.3.1]nonaneA new approach to 1-phosphabicyclo[3.3.1]nonane compounds involves free-radical cyclization of 4-trimethylsilyloxy-4-phosphinomethyl-hepta-1.6-diene synthesized by the reaction of 2.2-diallyl-oxirane with KPH2 followed by trimethylsilylation. Trimethylsilyl groups are easily cleaved in boiling methanol forming 5-hydroxy-1-phosphabicyclo[3.3.1]nonanes. Silylated and desilylated bicyclic compounds are characterized by n.m.r. and i.r. data.
    Notes: Die Reaktion von 2,2-Diallyl-oxiran mit KPH2 zu 4-Hydroxy-4-phosphinomethyl-hepta-1,6-dien, das nach Bildung des Trimethylsilylethers radikalisch cyclisiert wird, stellt einen neuen Zugang zum 1-Phosphabicyclo[3.3.1]nonan-System dar. Die Titelverbindung wird durch Abspaltung der Trimethylsilylgruppe in siedendem Methanol gebildet. Die silylierten und entsilylierten bicyclischen Verbindungen werden durch NMR- und IR-Daten charakterisiert.
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  • 10
    ISSN: 0044-2313
    Keywords: γ-anti effect ; 1-phosphabicyclo 3.3.1 nonane derivatives ; pentacarbonylchromium complex ; structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: γ-Anti Effect in 1-Phosphabicyclo[3.3.1]nonane Derivatives with Substituents at Phosphorus. Synthesis and Structure of Pentacarbonyl(1-phosphabicyclo[3.3.1]nonane) ChromiumIn 1-phosphabicyclo[3.3.1]nonane derivatives of the composition C8H15P(X) the CC-conformation always dominates. Changes in the chemical shifts of the bridge-head carbon atom C(5) in the 13C-NMR spectrum are only originated by the electronic influence of the substituent X at the phosphorus centre. Based on a homogeneous interpretation of the electronic interactions and with regard to Pearsons's definition of electronegativity the electronegativities of substituents at the phosphorus atom X = Cr(CO)5, Fe(CO)4, and Ni(CO)3 are estimated. These groups are placed in antiperiplanar orientation to the carbon atom C(5).The molecular structure of (1-phosphabicyclo[3.3.1]-nonane) Cr(CO)5 3 was elucidated by X-ray diffraction analysis. The molecule features the 1-phosphabicyclononane ligand in the CC-conformation, which has a nearly undistorted Cr(CO)5 unit coordinated to the phosphorus atom (d Cr—P = 2.368(1) Å).
    Notes: Bei 1-Phosphabicyclo[3.3.1]nonan-Derivaten C8H15P(X) dominiert stets die CC-Konformation. Änderungen der chemischen Verschiebung des C(5)-Brückenkopfatoms im 13C-NMR-Spektrum werden alleine durch den elektronischen Einfluß des Substituenten X am Phosphoratom hervorgerufen. Auf der Grundlage einer einheitlichen Interpretation der elektronischen Wechselwirkungen und unter Anwendung des Elektronegativitätsbegriffs von Pearson konnte die Elektronegativität der in antiperiplanarer Position zu C(5) stehenden Phosphorsubstituenten X = Cr(CO)5, Fe(CO)4, Ni(CO)3 abgeschätzt werden.Die Molekülstruktur von (1-Phosphabicyclo[3.3.1]-nonan) Cr(CO)5 (3) wurde mittels Röntgenbeugung ermittelt. Das Molekül zeigt das Bild eines 1-Phosphabicyclo[3.3.1]nonans in der CC-Konformation, an dessen Phosphoratom eine nahezu unverzerrte Cr(CO)5 Einheit (d Cr—P = 2,368(1) Å) koordiniert ist.
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