ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • ASTROPHYSICS
  • Analytical Chemistry and Spectroscopy
  • 1965-1969  (28)
  • 1
    Electronic Resource
    Electronic Resource
    Deceptive simplicity in NMR spectra of oriented molecules (1969)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 1 (1969), S. 93-99 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The theory for deceptive simplicity in the NMR spectra of oriented molecules is discussed in terms of degeneracy of subspectra. The conditions for the degeneracy of AB, AB2 and AA′BB′ spectra leading to deceptive simplicity in the spectra of the type ABX, AB2X, AA′BB′X and AA′XX′ are reported.It is shown that the conditions for deceptive simplicity are easily fulfilled for ABX, AA′BB′X and AA′XX′ cases. It is further demonstrated that deceptive simplicity is not so common in AB2X spectra.The proton spectra of partially oriented 2,4,5-trichloronitrobenzene (AB) and 2,6-dibromo-pyridine (AB2) are use to illustrate degeneracy and those of p-chloro- and p-bromo-fluorobenzenes are reported to demonstrate deceptive simplicity.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270010202
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Studies in nuclear magnetic resonance - IXFor Part VIII see Ref. 1.. Rotational barriers in substituted N,N-dimethylbenzamides (1969)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 1 (1969), S. 109-123 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The barriers to rotation about the C—N bond in eighteen substituted N,N-dimethylbenzamides have been determined by complete line shape analysis of the NMR spectra of the N,N-dimethyl protons. The barriers have been correlated with the substituent constants σ and σ+. It has been shown that polar solvents increase the barrier in N,N-dimethylbenzamide.Acid catalysis of rotation about the amide C—N bond in N-(p-N,N-dimethylcarboxamidobenzyl)-pyridinium bromide has been investigated. 18O exchange studies show that catalysis is due to N-protonation rather than the formation of a tetrahedral intermediate. The rate of rotation is a function of the Hammett acidity function, H0, and the water activity, and it is shown that proton exchange between the N- and O-protonated species involves the intermediacy of a water molecule.The differences in chemical shifts for the non-equivalent N, N-dimethyl groups of the benzamides are also a function of the substituents. Possible explanations of this phenomenon are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270010204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Determination des taux de deuteriation de molecules organiques par resonance magnetique nucleaire (1969)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 1 (1969), S. 191-202 
    Details
    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 accuracy of several methods for deuterium content determination in organic molecules are tabulated. The sample-substitution (using one or two NMR sample tubes) and internal standard (inter- or intra-molecular) processes are discussed and compared. These methods are applied to some examples and the NMR results are confirmed by mass spectrometry.
    Notes: Les précisions de différentes méthodes de détermination du taux de deutériation de molécules organiques par RMN sont évaluées. On compare successivement les méthodes de changement de tube-échantillon et les méthodes utilisant un étalon interne. Ces méthodes sont ensuite appliquées au dosage du deutérium dans plusieurs molécules et les résultats sont comparés à des mesures de spectrographie de masse.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270010304
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Carbon-proton coupling constants in α-chlorostyrene-α-13C (1969)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 1 (1969), S. 209-212 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The two stereochemically distinct two-bond carbon-13- hydrogen coupling constants J(13C—CH), for α-chlorostyrene-α-13C have been shown to be of similar magnitude but opposite sign (-6.3 and +5.6 Hz). A simple additivity relationship which adequately reproduces all the reported J(13C—CH) values for chloroethylenes has been found.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270010306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    ‘Mass spectrometry of vitamin B6: Different forms of the vitamin, its metabolites, antimetabolites, and analogs’ (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 151-166 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectra of the different forms of vitamin B6, some metabolites and antimetabolites, and some analogs are reported. The free bases are suitable for study, but the 5-phosphates are not sufficiently volatile. The hydrochloride salts dissociate thermally in the inlet system into the free base and HCl and give the spectrum of the free base with the spectrum of HCL superimposed on it. The compounds studied are: pyridoxol, pyridoxamine and pyridoxal, which are different forms of vitamin B6; 4-pyridoxic acid and its lactone, 5-pyridoxic acid lactone, isopyridoxal, 5-formyl-3-hydroxy-2-methylpyridine-4-carboxylic acid, and 3-hydroxy-2-methylpyridine-4,5-dicarboxylic acid, which are vitamin B6 metabolites; α4-and α5-deoxypyridoxol, 3-deoxypyridoxol, and 4- and 5- norpyridoxol, which are antimetabolites and analogs of vitamin B6.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The fragmentation of organic molecules under electron-IMPACT - IIPart I, J. Chem. Soc. 34 (1968).. The mass spectra of tetronic acid and some of its derivatives (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 743-759 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectra of tetronic acid and of a number of its derivatives are recorded and discussed. Where necessary, the composition of the fragment ions has been checked by high resolution mass measurements. Fragmentation of the molecular ion is explained in terms of the rupture of a bond attached to C-4, and the predominant routes for many of the compounds can be explained on the basis of two schemes, the first involving preliminary ketonisation of the molecular ion, followed by elimination of carbon monoxide, the second involving rupture of the C-4—R3 bond prior to elimination of carbon monoxide. Special structural features, however, provide alternative routes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010602
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ethylene and carbon monoxide eliminations in the ionic fragmentation of metal acetylacetonates (1969)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1969), S. 1171-1173 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210021113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Rearrangement ions in the mass spectrum of methyl vinyl sulphoxide (1969)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 2 (1969), S. 425-426 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210020410
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The oxygen rearrangement of aromatic and unsaturated esters under electron-impact - I: General regularities of the rearrangement (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 899-905 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some esters of γ, δ-unsaturated or β-arylsubstituted acids undergo a peculiar transformation under electron-impact including an elimination of the alcohol residue as a radical R. with the following loss of the ketene molecule. One of the oxygen atoms of the carbonyl group enters an ion which is formed from an unsaturated part of the molecule. The possible mechanism of this reaction and the influence of structural modifications on the course of this process are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010613
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Pyrolysis and mass spectra of some aromatic-imides (1968)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 1 (1968), S. 915-917 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electron-impact induced loss of CO2 from phthalanil and 4-phthalimidobiphenyl is paralleled by the formation of large amounts of CO2 on pyrolysis. CO is also a major pyrolysis product, but the loss of CO from these compounds under electron-impact is not an important fragmentation process.The mass spectra of meta and para-chlorophthalanils show prominent [M — CO2] peaks but the corresponding peak for the ortho isomer is of relatively low intensity. CO and CO2 are the principal gaseous products of the thermal decomposition of o-chlorophthalanil.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210010617
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...