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  • 1
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    (+)- and (-)-1,1,2,2-Tetrakis(2,6-dimethyl-4-methoxy- and 4-hydroxyphenyl)ethane. First examples of optically active sym-tetraarylethanes: syntheses, chiroptical properties and racemization (1982)
    American Chemical Society
    Details
    Publication Date: 1982-12-01
    Print ISSN: 0022-3263
    Electronic ISSN: 1520-6904
    Topics: Chemistry and Pharmacology
    Published by American Chemical Society
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    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    (+)- and (-)-1,1,2,2-Tetrakis(2,6-dimethyl-4-methoxy- and 4-hydroxyphenyl)ethane. First examples of optically active sym-tetraarylethanes: syntheses, chiroptical properties and racemization (1982)
    s.l. : American Chemical Society
    The @journal of organic chemistry 47 (1982), S. 5025-5027 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00146a041
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  • 3
    Electronic Resource
    Electronic Resource
    Editorial (1982)
    Springer
    Monatshefte für Chemie 113 (1982), S. 1-1 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00814330
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  • 4
    Electronic Resource
    Electronic Resource
    Optisch aktive, aromatische Spirane, 11. Mitt.: Synthese optisch aktiver mono- bis heptasubstituierter 5-Methyl- und 5-Ethyl-2,2′-spirobiindane und analoger Naphthalinderivate bekannter Chiralität und enantiomerer Reinheit (1981)
    Springer
    Monatshefte für Chemie 112 (1981), S. 801-823 
    Details
    ISSN: 1434-4475
    Keywords: Chirality function ; Circular dichroism ; Ligand parameters ; 5-Methyl and ethylindanes ; 1H-NMR spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Starting from optically active 5,5′-dimethyl, diethyl, and 5-ethyl-5′-methyl-2,2′-spirobiindane as well as from 5′-ethyl-spirobiindane-5-carboxylic ester of known enantiomeric purity and configuration 75 mono to polysubstituted 2,2′-spirobiindanes have been prepared. Amongst these are several compounds with rings anellated in the 6,7 (and 6′, 7′) positions, especially a spirohydrocarbon4 x with orthogonal naphthalene units the circular dichroism of which is reported and discussed. Several mono and disubstituted 5-methyl and ethylindanes (1,2) have been prepared as models for synthetic transformations in the spirobiindane series. From the molar rotations of symmetrically diacylated 5,5′-dimethyl and diethyl spirobiindanes (4a, 7b, 7c) empirical ligand parameters λ for acetyl and methoxycarbonyl were determined which gave much better results in the calculation of the rotations of appropriate spirobiindanes (with the “shortened polynomal Ansatz”) than the λ-values deduced previously from 5,5′-disubstituted spirobiindanes. The significance of these results is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00899783
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  • 5
    Electronic Resource
    Electronic Resource
    A recycling technique for the chromatographic separation of enantiomers and diastereomers on triacetylcellulose (1984)
    Springer
    Monatshefte für Chemie 115 (1984), S. 1113-1120 
    Details
    ISSN: 1434-4475
    Keywords: Enantiomeric purity ; Centro-, Axial- and Planarchiral Arenes and Metallocenes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird eine einfache und preisgünstige Anlage zur Racematspaltung und Trennung von Diastereomeren an Triacetylcellulose in Ethanol unter erhöhtem Druck beschrieben. Sie beinhaltet einen geschlossenen Lösungsmittelkreislauf (Pumpe — Säule — Detektor — Pumpe) und ermöglicht eine kontinuierliche Arbeitsweise bis zu etwa 16 Zyklen, ohne den Fluß unterbrechen oder die Fraktionen handhaben zu müssen. Diese offensichtlich universelle Methode, welche auch die Ermittlung enantiomerer Reinheiten erlaubt, wird an Hand von einigen zentro-, axial- und planarchiralen Arenen und Metallocenen vorgestellt.
    Notes: Abstract A simple and inexpensive equipment for the optical resolution of enantiomers (and separation of diastereomers) on triacetylcellulose in ethanol at elevated pressure is described. It involves a closed circuit of solvent (pump—column—detector—pump) allowing a continuous chromatography up to 16 cycles without stopping the flow or handling fractions. This useful and versatile method permitting also the determination of enantiomeric purities is illustrated by several examples of centro-, axial- and planarchiral arenes and metallocenes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00798778
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  • 6
    Electronic Resource
    Electronic Resource
    100 Jahre Monatshefte für Chemie (1980)
    Springer
    Monatshefte für Chemie 111 (1980), S. 1-1 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00938710
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  • 7
    Electronic Resource
    Electronic Resource
    Optisch aktives 1,3-Diferrocenyl-1,3-diphenyl-allen (1981)
    Springer
    Monatshefte für Chemie 112 (1981), S. 91-104 
    Details
    ISSN: 1434-4475
    Keywords: Chromatographic Resolution on Acetylcellulose ; Circular Dichroism ; 1,3-Diferrocenylbutadienes ; 1,3-Diferrocenylpropanes ; 1,3-Diferrocenylpropenes ; 1,3-Diferrocenylpropenols
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The title compound 2 was prepared by thermal dehydration of 1,3-diferrocenyl-1,3-diphenyl-propenol (24) with 70% yield.24 was accessible from 1,3-diferrocenyl-propanedione-1,3 (25) in two steps with 10% overall yield: Treatment of25 with phenyllithium gave 1,3-diferrocenyl-3-phenyl-propenone (8) which after repeated reaction with phenyllithium afforded24. Partial optical resolution of2 was achieved by chromatography on triacetyl cellulose in ethanol, whereby both (+)- and (−)-2 were obtained with different enantiomeric purities as could be deduced from the CD-spectra with Δε-values of +0.18 and −1.64, resp., at 480 nm. Attempts to prepare 1,3-diferrocenyl-allene and 1,3-diferrocenyl-1-phenyl-allene failed. In this context several 1,3-diferrocenyl-propenols,-propenones,-propenes,-propanones,-propanes and-butadienes were obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00906246
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  • 8
    Electronic Resource
    Electronic Resource
    The absolute chirality of (+)-12-Bromo-[2.2]metacyclophane-4-carbonitrile (1981)
    Springer
    Monatshefte für Chemie 112 (1981), S. 511-516 
    Details
    ISSN: 1434-4475
    Keywords: Bijvoet X-ray diffraction method ; Circular dichroism ; Exciton model ; Kinetic resolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die absolute Konfiguration von (+)-12-Brom-[2.2]metacyclophan-4-carbonitril [(+)-4 e] wurde mit Hilfe der anomalen Röntgenbeugung (Bijvoet-Methode) als(R) p (Fig. 1) ermittelt. Damit sind auch die Konfigurationen aller optisch aktiven 4-monosubstituierten, 4,14-homodisubstituierten sowie der 4,12- und 4,14-heterodisubstituierten [2.2]Metacyclophane bekannt, die mit (+)-4 e eindeutig chemisch korreliert sind. Dieses Ergebnis wird mit jenen verglichen, die mit Hilfe anderer Methoden zur Konfigurationsermittlung erhalten wurden.
    Notes: Abstract The absolute configuration of (+)-12-bromo-[2.2]metacyclophane-4-carbonitril [(+)-4 e] was determined by theBijvoet X-ray diffraction method as(R) p (Fig. 1). This result allows the unambigous assignment of the absolute chiralities of all optically active 4-monosubstituted, 4,14-homodisubstituted, 4,12- and 4,14-heterodisubstituted [2.2]metacyclophanes chemically correlated with (+)-4 e. The result is compared with those obtained by other methods for establishing the absolute configuration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00901830
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  • 9
    Electronic Resource
    Electronic Resource
    Die Kristallstruktur von 1,2-Diferrocenylethanen (1982)
    Springer
    Monatshefte für Chemie 113 (1982), S. 767-780 
    Details
    ISSN: 1434-4475
    Keywords: 1,2-Diferrocenylbutane (racemic and meso) ; 1,2-Diferrocenyl-1,2-diphenylethane (racemic and meso) ; Tetraferrocenylethane ; Conformations ; 13C-nmr spectroscopy ; X-ray crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract X-ray crystal structure analyses of stereoisomeric 1,2-dimethyl and diphenyl 1,2-diferrocenyl ethanes (1,2) as well as of 1,1,2,2-tetraferrocenyl ethane (3) showed that racemic (threo) and meso (erythro)2 adopt conformations with antiperiplanar arrangement of the ethane H-atoms (andC 2 andC i symmetry, resp.), whereas1 and3 prefer the synclinal (skew) conformations. In3 the torsional angle between the ethane H-atoms is increased to appr. 90°;3 represents a chiral structure withC 2 symmetry. For the conformation of tetraferrocenyl ethane (3) in solutionC 2 symmetry could be deduced from the13C-nmr. spectra. The conformations of the diferrocenyl ethanes are discussed and compared with those of corresponding alkyl and aryl ethanes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809018
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  • 10
    Electronic Resource
    Electronic Resource
    Ferrocene derivatives, part 6757Fe-NMR spectroscopy of ferrocenes (1983)
    Springer
    Monatshefte für Chemie 114 (1983), S. 495-499 
    Details
    ISSN: 1434-4475
    Keywords: 57Fe Shifts ; Hybridization influence on chemical shifts ; Ring tilting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 57Fe-NMR-Signale von 28 mono- und disubstituierten Ferrocenen mit natürlicher Häufigkeit an57Fe wurden gegen Ferrocen als innerem Standard gemessen. Die meisten Resonanzen sind zu höherer Frequenz verschoben. Die57Fe-Verschiebung reagiert sehr empfindlich auf Ringneigung, wie an [3]Ferrocenophanen gezeigt wurde. Substituenteneinflüsse auf die Verschiebung werden qualitativ diskutiert.
    Notes: Abstract 57Fe NMR-spectra of 28 mono and disubstituted ferrocenes with a natural abundance of57Fe have been measured relative to internal ferrocene. Most of the resonances appear at the high frequency side. The shielding influence of the various substituents is discussed qualitatively.57Fe shifts are very sensitive to ring tilting as occurring in [3]ferrocenophanes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00798447
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