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  • 1975-1979  (516)
  • 1890-1899
  • 1840-1849
  • 1975  (516)
  • 1896
  • Analytical Chemistry and Spectroscopy  (516)
  • 101
    Electronic Resource
    Electronic Resource
    News and events (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. A19 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040416
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  • 102
    Electronic Resource
    Electronic Resource
    X-ray diffraction procedures for polycrystalline and amorphous materials. Harold P. Klug and Leroy E. Alexander, John Wiley & Sons, New York, 1974, pp. 960. $37.50 (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. A18 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040415
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  • 103
    Electronic Resource
    Electronic Resource
    Determination of a binary calibration curve with one or two standard specimens in X-ray flourescence analysis (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 11-13 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Two simple approximate formulae have been derived for binary calibration curves. These formulae contain one or two constants, which can be determined experimentally with one or two standard specimens, respectively. These formulae can be applied within a wide range around the composition of the standard specimen. These approximations can be used both in X-ray and in isotope excited fluorescence analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040104
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  • 104
    Electronic Resource
    Electronic Resource
    Note on the accuracy involved in the use of effective mass absorptiobn coefficients in X-ray fluorescence analysis with polychromatic radiation (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 108-113 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The question as to whether the multiple least squares regression of X-ray fluorescence analytical data used in an earlier paper and based on an equation derived for excitation by monochromatic radiation can be considered as valid with sufficient accuracy in an experimental system using polychromatic radiation as source of excitation was examined. The results of computer simulation of the process of X-ray fluorescence show that although definite differences in the intensities of fluorescent radiation arise as a result of the substitution of polychromatic primary radiation for a monochromatic source, the flexibility of the particular equation used for regression eliminates such deviations by incorporating them in the experimental regression coefficients. The overall accuracy of the regression was found to be satisfactory by any practical criteria.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040305
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  • 105
    Electronic Resource
    Electronic Resource
    Chemical state analysis of vanadium by high resolution X-ray spectroscopy (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 117-118 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The chemical shift of V Kβ1, 3 and width of V Kα1 were measured with a two crystal X-Ray spectrometer. It was found that V Kβ1, 3 shift and V Kα1width can be utilized for identification of the vanadium oxidation state. Applications to vanadium containing catalysts and several perovskite structure compounds are discussed.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040307
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  • 106
    Electronic Resource
    Electronic Resource
    X-ray mass absorption coefficient measurements for aluminium in the range 1.9 to 9.9 Å (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 119-122 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: X-ray mass absorption coefficients for aluminium have been measured for nine wavelengths in the range 1.9 to 9.9 Å. The values obtained disagree with many published compendia of mass absorption coefficients, but agree well with some published experimental values.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040308
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  • 107
    Electronic Resource
    Electronic Resource
    Energy dispersion quantitative X-ray microanalysis on a scanning electron microscopeEDX = energy dispersion X-ray microanalysis; WDX = wavelength dispersion X-ray microanalysis; EPMA = electron probe microanalyser; SEM = scanning electron microscope; FWHM = full width at half maximum. (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 99-107 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: In this work quantitative measurements performed by EDX on SEM, abd by WDX on EPMA are compared. The commerical SEM has been improved by the addition of a beam regulation and an anticontamination device. The spectra are detected by a Si(Li) detector (FWHM = 180 eV) and digitalized by an analog-to -digital converter. The spectra obtained are treated by an on-line minicomputer PDF 11/05 included in a NS 880 system. A teminal byilt-in magnetic tape cassette functions as a storage device for the computer. The dialogue between the system and the operator and programmation are possible through a keyboard and a visualization screen. The programs used include: spectrun smoothing, background subtaction selected area totalizing and spectrum stripping. The count rate is maintained at the order of 3000 counts per second to avoid pulse pile up and dead time losses. The experimental intensities are then corrected through a ZAF method by the profgram C ø R on an IBM 360. Binary alloys TiA1, FeA1, ZrNi, NbA1 and TiZr have been studied by K and L lines at different values of the excitation voltage. Alloys MgA1, FeMn and TiVCr Presenting overlapping peaks, and a glass, have also been analysed. The errors, advantages and limits of the method are discussed: in a homgeneous bulk material the minimum detectable limit calculated by C(DL)A = 3IB½ CA/IA is of the order of 0.03 wt % with WDX and 0.2 Wt % with EDX for 100 seconds counting time. It could be improved by increasing the counting time and by using better electronics. The precision of the result is comparable to that obtained by WDX. With EDX on SEM the rapid and simultaneous quentitative micro analysis of all the elements of 11 〈 Z ≤ 92 can be performed with good precision. This method is very interesting for thin targets and dispersion of precipitates.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040304
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  • 108
    Electronic Resource
    Electronic Resource
    A design to minimize exposure to scattered X-ray radiation (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. 202-204 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A design is described which conforms to OSHA recommendations for good radiation protection procedures. This design can be used on most units where X-ray optics are exposed to the atmosphere. It proves sufficient and should make most nonvacuum X-ray units comply with today's recommended dosage levels. A survey of our instrument gave results well below the maximum permissible level of 2.5 milliröntgen per hour for scattered radiation at a distance five centimeters from the housing surface. The detected scattered radiation was in the range of 0.03 milliröntgen per hour, which is within the limits of normal background radiation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040411
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  • 109
    Electronic Resource
    Electronic Resource
    Course (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 4 (1975), S. A18 
    Details
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/xrs.1300040413
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  • 110
    Electronic Resource
    Electronic Resource
    Lanthanide-induced shifts of diastereotopic groups (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 240-243 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The chemical shift differences of diastereotopic protons in aliphatic acyclic alcohols, mostly of the type R—CH2—CR′R″—(CH2)nOH, have been investigated. Fairly small amounts of Eu(dpm)3 cause the spectra of these materials to simplify dramatically; indeed, even diastereotopic protons rather far removed form the hydroxyl group give discrete signals in the presence of the shift reagent. Large shift differences were realized in the γ-protons (n = 1) and the δ-protons (n = 2), particularly if R is bulky and R' and R″ have different steric requirements. Semi-quantitative conformational preferences can be determined from the data obtained.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070508
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  • 111
    Electronic Resource
    Electronic Resource
    13C NMR study of the enol forms of β-diketones (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 237-239 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra of a series of β-diketones in the enol form with various β-substituents have been studied. An additive influence of the β-substituents on the chemical shifts of the carbon atoms in the hydrogen bonded chelate ring has been found. It is shown that the α- and β-carbon chemical shifts can be calculated by means of a set of increments for arbitrary combinations of the X and Y substituents. Analysis of the experimental data enables the conclusions to be drawn that enol-enolic tautomerism with different populations of the forms (A) and (B) is absent in β-diketones and that the carbon chemical shift changes are caused by electron density redistribution in the hydrogen bonded chelate ring (C).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070507
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  • 112
    Electronic Resource
    Electronic Resource
    Interactions intramoleculaires: XXIIPartie XXI: Réf. 1. - Constantes de couplage, équilibres conformationnels et interactions gauches avec un groupement t-butyle (molécules cyclohexéniques deutériées) (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 226-236 
    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 NMR parameters are determined for a series of disubstituted (R = CH3, (CH3)3C; X = COOCH3, CN) and specifically deuterated cyclohexenes. The 3 J(HH), 3J(HD), 4J(HH) and 5 J(HH) coupling constants are used to evaluate the conformational equilibria. Three of the five compounds with an allylic t-butyl substituent, are conformationally heterogeneous; these equilibria, and those between stereoisomers are used for an analysis of this phenomenon, carried out within the framework of the hypothesis of additivity of conformational free energies and gauche interactions.
    Notes: Les paramètres RMN d'une série de cyclohexènes disubstitués (R = CH3, (CH3)3C; X = COOCH3, CN) et spécifiquement deutériés sont déterminés. A partir des valeurs des constantes de couplage 3J(HH), 3J(HD), 4J(HH) et 5J(HH), les équilibres conformationnels sont évalués. Trois des cinq composés ayant un groupement t-butyle en position allylique sont conformationnellement hétérogènes; les équilibres correspondants et les équilibres entre stéréoisomères permettent une analyse de ce phénomène dans le cadre de l'hypothèse de l'additivité des enthalpies libres conformationnelles et des interactions gauches.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070506
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  • 113
    Electronic Resource
    Electronic Resource
    Long range 13C—1H coupling constants IVSee Ref. 1. - methoxy-, amino- and hydroxypyridines (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 244-246 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: One bond and long range 13C—1H coupling constants for some methoxy-, amino- and hydroxypyridines are described. An unambiguous assignment of carbon-13 resonances is carried out based on the analysis of the fine splitting caused by long range couplings. J values for compounds other than 2- and 4-hydroxy-pyridines are explainable in terms of the values previouly obtained for cyano- and methylpyridines. The hydroxypyridine-pyridone tautomerism affects 2J(Hα), i.e. 2J associated with the α proton. This effect can be used to differentiate pyridones from hydroxypyridines.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070509
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  • 114
    Electronic Resource
    Electronic Resource
    Masthead (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975) 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070601
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  • 115
    Electronic Resource
    Electronic Resource
    Vicinal interproton couplings through two heteroatoms. II - Coupling 3J(H—N—O—H) occurring in m-Nitrophenylhydroxylamines (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 247-248 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectra of certain arylhydroxylamines in DMSO-d6 show a vicinal coupling through nitrogen and oxygen. The assignment of OH and NH signals was made using a 15N labelled derivative.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070510
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  • 116
    Electronic Resource
    Electronic Resource
    Verification of the correlation between geometric parameters of molecules and the parameters of their 1H NMR spectra (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 313-314 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The dihedral and bond direction angles between all pairs of vicinal protons of the arabinofuranose residue were calculated from the coordinatees of the hydrogen atoms found by an X-ray study of 3-O-acetyl-β-L-arabinofuranose 1,2,5-orthobenzoate. The values found were compared with those calculated with the help of correlation equations previously proposed by Karplus and recently by the authors, linking the values of those angles with the spin-spin coupling constants of vicinal protons [3J(H,H′)]. It has been found that the best agreement between the angles found crystallographically and calculated from the 1H NMR data can be achieved using the equation which includes bond direction angles and the sum of the chemical shifts of the protons involved.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070704
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  • 117
    Electronic Resource
    Electronic Resource
    Constantes de couplage de vinylallènes (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 315-319 
    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: In order to define the influence of an allenic type conjugation, the NMR spectra of vinylallene and of some of its methyl derivatives are analysed The signs of the coupling constants are also determined. These compounds are characterised by a planar s-trans structure of the two noncumulated double bonds. A discussion of the parameters, and especially of the methyl replacement effects, evidences the importance of the π type contributions. The theoretical calculations of the coupling constants by the methods of finite perturbation CNDO and INDO corroborate this interpretation.
    Notes: Afin de préciser l'influence d'une conjugaison de type allénique les spectres RMN du vinylallène et de plusieurs de ses dérivés méthylés ont été analysés et les signes des constantes de couplage ont été déterminés. Ces composés présentent une structure s-trans plane des deux doubles liaisons non cumulées. Une discussion des paramètres et no amment de l'influence des substitutions méthylées fait ressortir une forte prédominance des contributions de type π. Cette interprétation est corroborée par les calculs théoriques des constantes de couplages, effectués par la méthode de perturbations finies CNDO et INDO.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070705
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  • 118
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    Electronic Resource
    NMR study of 4-membered rings. VIIIPart VII: C. Cistaro, G. Fronza, R. Mondelli, S. Bradamante and G. A. Pagani, J. Magn. Resonance 17, 219 (1975). - The sign of the four-bond couplings in adducts of cyclopentenone with vic-dichloroethylenes (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 320-325 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton spectra of the four stereoisomers prepared by photocycloaddition of 2-cyclopentenone to cis and trans dichloroethylene have been analysed using tickling and INDOR techniques in order to obtain the sign of the cross-ring four-bond coupling constants in the cyclobutane ring. These parameters are correlated with the relative orientation of the protons involved. The complete NMR analysis of the seven-spin system of the cycloadduct endo-7-phenoxybicyclo[3.2.0]hept-2-en-6-one has been carried out and all the four-bond coupling constants have been obtained and discussed. The sign of the cross-ring coupling in the cyclobutanone ring has been determined.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070706
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  • 119
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    Electronic Resource
    Etude par RMN du carbone des systèmes C=N: imines, phénylhydrazones, semicarbazones, amidines, iminoéthers (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 326-330 
    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: A carbon-13 NMR study of compounds containing C=N or conjugated C—N bonds (iminoethers, saturated and unsaturated aliphatic imines, amidines, oximes, phenylhydrazones, semicarbazones) is presented. The influence of the Z/E isomerism, the substituents and the steric effects on the chemical shifts are discussed.
    Notes: Ce travail présente une étude par RMN de carbone-13 de composés comportant une double liaison C=N simple et conjuguée (iminoéthers, imines aliphatiques, imines éthyléniques, amidines, oximes, phénylhydrazones, semicarbazones). L'influence de la stéréoisomérie Z/E, des substituants et le rǒle de l'effet stérique sur le déplacement chimique sont discutés.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070707
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  • 120
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    Solvent effects of pyridine on the NMR spectra of carboxylic acids. I - study of the acrylic, trans-crotonic and 3-butenoic acids (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 331-333 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton magnetic resonance spectral parameters of acrylic, trans-crotonic and 3-butenoic acids, their methyl esters and the corresponding alcohols (COOH substituted by CH2OH) have been measured for 5% (w/v) solutions in carbon tetrachloride and in pyridine-d5 at 33·5 °C. The total solvent effect of pyridine on the shifts of the skeleton protons of the acid was found to consist of three different effects independently measured from the reference samples.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070708
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  • 121
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    Etude théorique des déplacements chimiques du phosphore en RMN (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 334-338 
    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: Phosphorus chemical shifts have been evaluated by means of the perturbation theory using CNDO/S wave functions in phosphine, phosphite, phosphonate and phosphate derivatives. The necessity of introducing 3d orbitals of phosphorus and of using Zeff3d as an adjustable parameter for each family of compounds is shown. Calculated values agree with experimental ones.
    Notes: La méthode des perturbations est appliquée aux fonctions d'onde CNDO/S pour calculer les déplacements chimiques du phosphore de quelques phosphines, phosphites, phosphonates et phosphates. Nous montrons la nécessité d'introduire les orbitales 3d du phosphore et de considérer Zeff3d comme un paramètre à déterminer pour chaque famille de composés. Les valeurs calculées sont alors en bon accord avecl' expérience.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070709
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  • 122
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    Carbon-13 chemical shifts and 13C—15N coupling constants of 3,4-dihydroisoquinoline-15N, its 15N-oxide and their conjugate acids (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 349-350 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On protonation of 3,4-dihydroisoquinoline-15N 1J(13C - 1, 15N) is increased by a factor of five and 1J(13C - 3, 15N) changes its sign, while on protonation of 3,4-dihydroisoquinoline-15N-oxide the coupling constants, including the relatively large 1J(13C - 1, 15N), remain practically constant, although significant alterations of the 13C chemical shifts take place.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070712
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  • 123
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    Stereochemical aspects of proton chemical shifts. III - Configurational assignments in pentacyclic systems without recourse to a karplus equation (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 345-348 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that in contrast to the use of coupling constants, chemical shift criteria may lead to unambiguous structural elucidations in pseudorotational frameworks (pentacycles, heptacycles, etc.).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070711
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  • 124
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    Carbon-13 NMR spectra of coumarin and methoxycoumarins - a reinvestigation of charge density/Chemical Shift RelationsApplications of Carbon Resonance Spectroscopy: XX. For part XIX see U. Ewers, H. Günther and L. Jaenicke, Angew. Chem. 87, 356 (1975); Angew. Chem. Intern. Ed. Engl. 14, 354, (1975). (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 339-344 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The carbon-13 NMR spectra of coumarin, 6-, 7-, 8-methoxycoumarin, and 5,7-, 7,8-, 5,8- and 6,7-dimethoxycoumarin have been measured and assigned. It is shown that substituent induced chemical shifts S(δ) in the mono- and disubstituted systems correlate well with the HMO atom-atom polarisibilities πij of the parent compound: Si(δi) = 80.13 πij with a standard deviation of 1.42 ppm and a correlation factor of 0.994. Correlations between δ(13C) values and charge densities calculated by various semi-empirical methods are less successful.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070710
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    NMR studies on benzaldehydes. IIIFor Part II, see Ref. 12. - Rotational isomerism and torsional barriers in stable protonated o- and m-substituted benzaldehydes (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 351-354 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton and carbon-13 NMR spectroscopy have been used to obtain the torsional barrier in some protonated ortho and meta substituted benzaldehydes, and the relative populations of the O-cis and O-trans rotamers have been determined. The results are compared with earlier data on free benzaldehydes.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070713
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  • 126
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    Erratum (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. A1 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070716
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  • 127
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    Long range HH couplings and bond fixation in 2-pyrones (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 355-357 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have determined the magnitudes of all possible four-, five- and six-bond HH couplings in four 2-pyrone derivatives. Substituents exert a negligible effect on the couplings. The allylic couplings are position-specific (J34 = 1·2; J45 ≤ 0·2; J56 = 0.8) and the observed pattern of alternating magnitudes is indicative of π-bond fixation. The allylic couplings can be translated into π-bond orders which agree well with results of recently published SCF-MO calculations on 2-pyrone. Finally, comparison of long range coupling constant data for 4,6-dimethyl-2-pyrone with those for related cyclic anhydrides and trans-1,3-pentadiene further supports the picture of 2-pyrone as a slightly perturbed butadiene, in agreement with extensive chemical and physical evidence.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270070714
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  • 128
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    Three chlorinated bipyridine compounds: Quantum calculations and their relationship to the molecular structure and physicochemical properties of the molecules considered (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 358-360 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Cl35 nuclear quadrupole resonances were measured for three chlorinated bipyridine compounds. The number of resonances obtained is explained in terms of the position of one ring of the compound with respect to the other. Quantum chemical calculationsDetails of the computer programs used are available from the author on request. confirm the explanation given.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070715
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  • 129
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    Forthcoming papers (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. A5 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070717
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  • 130
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975) 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070801
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  • 131
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    Carbon-13 NMR spectra of some polychloro hydrocarbons and related compounds (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 361-365 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Data derived from the carbon-13 NMR spectra of 37 organic polychloro compounds allow one to identify readily the —CHCl2, —CCl2— and —CH2Cl groups, the 13C signals of which are registered in the shift ranges of 67 to 78 (80), 85 to 96 and 38 to 55 (59) ppm (from TMS), respectively, and have the distinctive one bond spin-spin coupling constants 1J(C—H) 170 to 184 Hz (for the —CHCl2 groups) and 147 to 158 Hz (for the —CH2Cl groups). The —CCl2CH2CH2Cl fragment features characteristic diamagnetic shieldings of the —CCl2— and —CH2Cl that may be related to increased electron density on both of these groups.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070802
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  • 132
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    Carbon-13 NMR Spectra of some aryl substituted ferrocenes (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 372-375 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The carbon-13 spectra of some para and meta substituted phenylferrocenes have been analysed. The substituent-caused shifts are discussed and compared with similarly substituted biphenyls. Correlations with Hammett parameters and with the reactivity parameters of Swain and Lupton have been attempted.
    Additional Material: 6 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270070804
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  • 133
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    Exemple d'une transposition dyotropique à l'état solide Mise en evidence par RMN haute résolution (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 376-378 
    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 analysis of 250 MHz spectra of 2,3,6-tribromo-4-methyl-cyclohexanones gives the precise value of the J(H—H) coupling constants of these products. The validity of the assignments has been checked by computer simulation of the spectra. The results obtained have been interpreted in terms of geometric deformations.
    Notes: L'analyse des spectres RMN à 250 MHz de tribromo-2,3,6 méthyl-4 cyclohexanones a permis de déterminer avec précision les constantes de couplage J(H—H) de ces composés. La validité des attributions a été contrôlé en reconstituant les spectres par calcul électronique. Les résultats observés ont été interprétés en terme de déformation géométrique.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070805
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  • 134
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    Etudes configurationnelles et conformationnelles de quelques chlorures de désoxy-6 β-L-héxopyrannosyle chlorosulfonyles et de leurs glycosides de méthyle (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 366-371 
    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: A total analysis of the NMR spectra of 6-deoxy-L-hexopyranoses in the α-configuration and of the corresponding β-anomers was carried out. The parameters obtained are characteristic of a 1C (L) chair conformation, having the anomeric substituent in an axial orientation for the methyl α-fuco-, α-rhamno- and α-chinovopyranosides and for the α-fuco- and α-rhamnopyranosyl chlorides. The structure is also of a 1C (L) chair type for the methyl β-fuco- and β-chinovopyranosides; the geometry is the same for the β-fuco- and β-rhamnopyranosyl chlorides despite the anomeric effect of a chlorine atom. However, the NMR parameters of the β-chinovopyranosyl chloride are not explicable on the basis of a chair conformation with an equatorial chlorine or a boat structure.
    Notes: Une analyse complète des spectres RMN de désoxy-6 L-hexopyrannoses de configuration α et des anomères β correspondants est réalisée. L'ensemble des paramètres obtenus confirme l'existence d'une structure chaise 1C (L) présentant une disposition axiale du substituant anomère dans le cas des α-fuco-, α-rhamno- et α-chinovopyrannosides de méthyle et des chlorures de α-fuco- et α-rhamnopyrannosyle. La structure reste de type chaise 1C (L) dans le cas des β-fuco- et β-chinovopyrannosides de méthyle. Il en est de même en dépit de I'effect anomère dû à I'atome de chlore, pour les chlorures de β-fuco-et β-rhamnopyrannosyle. Par contre les paramètres RMN du chlorure de β-chinovopyrannosyle ne semblent interprétables ni sur la base d'une géométrie chaise à chlore équatorial ni par une structure bateau.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070803
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  • 135
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    NMR study of organosilicon compounds. IIIPart II, see Ref. 1. - Silicon-29, nitrogen-14, carbon-13 and proton NMR spectra of silylakylamines (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 379-385 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 29Si, 14N 13C and 1H NMR data are presented for a series of homologous (methylethoxysilyl)alkylamines of the type (CH3)3-n(C2H5O)nSi(CH2)mNH2(n=o to 3; m = 1 to 4). The measured 13C and 1H chemical shifts correlate with the total net charges QA on the corressponding atoms, estimated by the Del Re method. 14N and 29Si chemical shifts which do not show simple linear relationships to the charges are found to correlate with the relative basicities of the compounds. The influence of the remote substituent (—NH2 and others) on the 29Si chemical shifts is shown to depend on the number and nature of substituents directly on the silicon atom. Argyments for d-orbital participation in the Si—O bounds are given. The chemical shifts of 29Si, 14N and 13C nuclei are not consistent with the fromation of intramolecular ‘long bonds’ between the solicon and nitrogen atoms in aliphatic silymethylamines.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070806
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  • 136
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    1H and 13C NMR study of α-acetylenic PIII and PIV derivatives. Signs and magnitudes of J(P—C) and J(P—H) (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 392-400 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: All J(P—H) and J(P—C) values, including signs, have been obtained in acetylenic and propynylic phosphorus derivatives, R2P(X)—C≡C—H and R2P(X)—C≡C—CH3 (X = oxygen, lone pair and R = C6H5, N(CH3)2, OC2H5, N(C6H5)2, Cl) from 1H and 13C NMR spectra. In PIV derivatives the following signs are obtained: 1J(P—C)+, 2J(P—C)+, 3J(P—C)+, 3J(P—H)+, 4J(P—H)—. Linear relations are observed between 1J(P—C), 2J(P—C) and 3J(P—C) versus 3J(P—H), indicating that these coupling constants are mainly dependent on the Fermi contact term, though the other terms of the Ramsey theory do not seem to be negligible for 1J(P—C) and 2J(P—C).In PIII derivatives these signs are: 1J(P—C)- and +, 2J(P—C)+, 3J(P—C)-, 3J(P—H)-, 4J(P—H)+. Only 3J(P—C) and 3J(P—H) reflect a small contribution of the Fermi contact term while in 1J(P—C) and 2J(P—C) this contribution seems to be negligible relative to the orbital and/or spin dipolar coupling mechanisms.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070808
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  • 137
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    Influence de la substitution sur la structure de la benzophenone. X. - Etude conformationnelle de benzaldehydes, acetophénones et benzophénones substitués par complexation avec les lanthanides (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 386-391 
    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: Low temperature 1H NMR was unsuccessful in conformational analysis of substituted benzophenones. However, induced lanthanide chemical shifts study permitted us to check satisfactorily the results obtained by Rayleigh depolarised light scattering and dipole moment studies on meta and ortho substituted benzophenones. The existence in solution, of a conformational equilibrium in these cases is confirmed.
    Notes: La résonance magnétique nucléaire du proton à basse température s'est révélée peu fructueuse dans l'étude conformationnelle des benzophénones substituées. Cependant, l'analyse des déplacements induits par les lanthanides nous a permis de recouper de façon très satisfaisante les résultats obtenus par diffusion Rayleigh dépolarisée et dipolemétrie pour les benzophénones meta et ortho substituées. L'existence en solution d'un équilibre conformationnel pour ces composés est confirmée.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070807
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  • 138
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    An NMR study of some N-arylaminopropenylylidenearylammonium salts (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 401-404 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation, characterisation and 1H NMR spectra of some N-arylaminopropenylylidenearylammonium salts are reported. The NMR data show that in DMSO the cations exist as conjugated amino-imines, generally as the ‘all-trans’ geometrical isomer. An exception is found in the case of the 4-nitrophenyl derivative which produces a mixture of the ‘all-trans’ and ‘cis-trans’ isomers with slow exchange between them at room temperature. The relative stability of the ‘all-trans’ isomer increases as the salt becomes more ionic. By varying the temperature, pH and nature of the anion it is found that exchange of the N—H protons on the cation controls the appearance of spin-spin coupling between the N—H and 1,3-propene protons.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070809
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  • 139
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    Determination of relative signs of 13C—13C coupling constants in doubly labelled compounds (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 405-406 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Analysis of the noise decoupled 13C spectra of doubly 13C labelled compounds where the two labelled carbons are identical, makes the determination of reltive signs of 13C—13C coupling constants possible in a very simple way. The involved carbon form AA'X or AA'B spin systems.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070810
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  • 140
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975) 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070901
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  • 141
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    Solvent effects upon the proton NMR linewidth in dimethylformamide (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 409-410 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The NMR linewidth of the formyl proton in dimethylformamide has been studied in the neat liquid and twelve organic solvents. It varies by more than one order of magnitude which is referred to solvent viscosity changes and to the protonation of dimethylformamide. The data do not allow the distinction between N- and O-protonation without further knowledge of the solvent dependence of either the nitrogen-14 spin lattice relaxation time or the spin-spin coupling 2J(NH).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270070902
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  • 142
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    Study of rotation barriers in N,N-dimethylnicotinamide and quaternary salt derivatives by proton NMR. A correlation of rotation barriers of N,N-dimethylamides with carbon-13 chemical shifts (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 422-425 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rotational barrier in the N,N-dimethylamide group is studied by proton NMR for N,N-dimethylnicotinamide and two quaternary salts in aqueous solution. The carbon-13 NMR spectra of a number of aromatic N,N-dimethylamides are discussed. A roughly linear correlation is found between the ΔG≠ values of the rotation barriers and the chemical shifts of the carbon atom substituted by the amide group.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070906
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  • 143
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    13C-NMR-Spektren von MonoterpenenSiehe Lit. 1. (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 426-432 
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    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 13C NMR spectra of nearly 100 monoterpenes show that they are very useful for the characterisation of these compounds. This method is especially valuable for the elucidation of stereochemical problems. With the exception of a few cases the observed chemical shifts follow the common rules. The problems with measurements using shift reagents are discussed.
    Notes: Die 13C-NMR-Spektren von fast 100 Monoterpenen zeigen, daß sie zur Charakterisierung derartiger Verbindungen sehr brauchbar sind. Besonders wertvoll ist diese Methode zur Klärung stereochemischer Probleme. Bis auf wenige Fälle folgen die beobachteten chemischen Verschiebungen den allgemeinen Regeln. Die Probleme der Messungen mit Verschiebungsreagenzien werden diskutiert.
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    URL: http://dx.doi.org/10.1002/mrc.1270070907
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  • 144
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    Equilibre conformationnel du fluoro-1 chloro-2 cyclohexane cis (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 442-444 
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    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 conformational equilibrium and kinetics of ring inversion are studied using essentially the fluorine lineshape. A new method for the calculation of the thermodynamic activation parameters is presented.
    Notes: L'équilibre conformational et la cinétique de l'inversion du cycle sont étudiés essentiellement à partir de la forma de raie du fluor. Une nouvelle méthode de calcul des grandeurs thermodynamiques d'activation est présentée.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070909
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  • 145
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    Carbon-13 NMR study of enamines and enamino ketones. A direct observation of the conformation of the 2-methylcyclohexanone enamine tautomers (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 433-441 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The carbon-13 spectra of a series of cyclohexanone, cyclopentanone and 2-methylcyclohexanone enamines are reported. The influence of the amino component was studied in a series of enamino ketones. The spectra reflect the amount of p-π overlap in the molecules and their conformation. Differences between 5-and 6-membered carbonyl components are evaluated.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070908
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  • 146
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    Azolides. VII - Restricted rotation in N-acylindoles and carbazoles. Anisotropy effect of the carbonyl group (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 445-450 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The barrier to internal rotation about the N—C bond and the E/Z configuration of some N-acetyl and N-formylindole derivatives have been determined and discussed in terms of electronic and steric effects. The barriers to internal rotation have been determined for certain N-acetylcarbazoles and some new N-formyl derivatives of carbazole. Experimental proof is also given, showing that contrary to the provisions of the classical model of carbonyl anisotropy, the protons (α and peri positions) next to the oxygen of the acyl group are displaced to high frequencies. This result allows one to determine the preferred configuration of N-acetyl derivatives of perimidine and 1H-naphtho[1,8-de]triazine.
    Additional Material: 7 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270070910
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  • 147
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    The 1H NMR spectra of quinoline, quinoline N-oxide, the quinolinium ion and of their monomethyl derivatives (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 451-454 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1H chemical shifts of quinoline, quinoline N-oxide and the quinolinium ion were obtained by complete analysis of their NMR spectra and interpreted critically in an attempt to quantify the possible different effects acting on the shielding constant of protons in these systems. Semi-empirical SCF calculations of electron charge densities and ring current contributions were also performed. It was found that the same effects that act on the shielding of protons directly bonded to the heterocyclic system also act, in an attenuated form, on the proton chemical shift of methyl groups in monomethyl derivatives. Vicinal coupling constants were rationalised in terms of π-electron bond order and electro-negativity of neighbouring atoms.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070911
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  • 148
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    Silicon-29 and carbon-13 NMR studies of organosilicon chemistry. II - The Methylethoxysilanes MenSi(OEt)4-n (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 460-464 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Silicon-29, carbon-13 and oxygen-17 NMR data are reported for the methylethoxysilanes, MenSi(OEt)4-n with n = C to 3. The values of 1J(SiC) vary greatly, in a manner which appears to be inconsistent with an effect of s-character variation alone. The chemical shifts are discussed in terms of possible π-bonding. Silicon-29 and carbon-13 spin-lattice relaxation times and nuclear Overhauser effects are also reported and discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270070913
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  • 149
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    Structure and protonation study of the imidazo [1,2-a]-pyrimidine system in 1H nuclear magnetic resonance (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 455-459 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H NMR spectra of imidazo [1,2-a]pyrimidine derivatives have been analysed to study the aromatic character and protonation behaviour of this system. By employing the ‘ring currentn’ model and calculations based on the coupled Hartree-Fock method it can be deduced that a large π-electron delocalisation exists in this heterocyclic system and affects the screening constant of the protons. Charge density schemes obtained by SCF techniques agree with the reactivity behaviour of these molecules.A detailed study of protonation carried out by following the 1H NMR spectra both in trifluoroacetic acid and in aqueous hydrochloric acid shows that the most probable site of protonation is N-1, but leaves open the possibility of a rapid exchange of one proton between N-1 and N-8.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270070912
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  • 150
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975) 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071001
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  • 151
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    Effect of methyl substituents on the NMR spectra of aromatic protons of some nitrobenzene derivatives (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 465-466 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton NMR spectra were recorded and analysed for 1-bromo-4-nitrobenzene, 2-bromo-5-nitroluene, 3-bromo-6-nitrotoluene and 2-bromo-5-nitro-p-xylene, as well as for the corresponding compounds having p-CH3C6H4S in place of Br. Chemical shifts and coupling constants generally agree with expected values; however, a deshielding effect of the methyl group on aromatic protons was observed in one case.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270070914
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  • 152
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    Influence of chemical exchange on the temperature dependence of Eu(fod)3-induced shifts (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 467-469 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Temperature dependences of the paramagnetic shifts induced by Eu(fod)3 in 1H NMR spectra of ethylene oxide in carbon disulphide solution are obtained in the temperature range from +40 to - 100°C at 100 MHz and from +30 to -60°C at 60 MHz. The influence of chemical exchange leads to a decrease of the observed paramagnetic shifts with decreasing temperature. It is shown that a modified Swift and Connick equation can be used to describe the observed dependences. Upper limits of the mean lifetimes of the Eu(fod)3-ethylene oxide adduct are τp 〈 1·7 × 10-8 s at 14 °C and τp 〈 1 × 10-8 s at 20 °C, respectively. The corresponding activation energy is equal to Va = 13·7 kcal/mol.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071002
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  • 153
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    31P-NMR-Daten heterocyclischer phosphine. Diastereomerenzuordnung an 1,3-Oxa-, 1,3-Aza- und 1,3-thiaphospholanen (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 470-474 
    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 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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    URL: http://dx.doi.org/10.1002/mrc.1270071003
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  • 154
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    Substituent effects on 13C—13C coupling constants and chemical shifts in 13C labelled polycyclic aromatic hydroxy compounds (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 475-477 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of an hydroxy substituent on 13C—13C coupling constants and 13C chemical shifts have been measured in 1-hydroxynaphthalene-2-13C and 1-hydroxypyrene-1-13C. The changes observed in the 13C—13C couplings show the effect of a substituent attached directly to the labelled carbon or to a carbon ortho to this. In both situations the effect is a decrease in the numerical magnitude of most of the long range 13C—13C coupling constants.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270071004
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  • 155
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    1H-NMR-Spektroskopische Untersuchungen zur Konformation von Cyclohexandicarbonsäure-(1,2)-anhydriden (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 478-484 
    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: 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.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/mrc.1270071005
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  • 156
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    Carbon-13 NMR spectra of all-trans-N-retinylidene-n-butylamine as an analogue of the Schiff's base linkage-compound in visual pigment (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 485-487 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 NMR spectra have been obtained for all-trans-N-retinylidene-n-butylamine as an analogue of the Schiff's base linkage compound in visual pigment. The chemical shift changes on going from all-trans-retinal1 to all-trans-N-retinylidene-n-butylamine are observed. These changes indicate the collapse of the bond alternation in conjugated polyene carbons, whereas N-protonation in all-trans-N-retinylidene-n-butylamine does not affect the bond alternation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071006
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  • 157
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    Proton magnetic resonance studies of compounds with bridgehead nitrogen: XXVIIIFor Part XXVII, see Ref. 1. - Stereochemical studies with perhydropyrido[1,2-c] [1,6,3]dioxazocines and 2-alkylperhydropyrido[1,2-c] [1,3,6]oxdiazocines (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 488-495 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of perhydropyrido[1,2-c][1,6,3]dioxazocines and 2-alkylperhydropyrido[1,2-c][1,3,6]oxdiazocines have been prepared. 6-p-Nitrophenyl-3,4-dimethylperhydropyrido[1,2-c][1,6,3]-dioxazodioxazocine is shown to adopt the cis fused ring conformation in solution with the nitrogen lone pair axial with respect to the piperidine ring. The 2-alkylperhydropyrido[1,2-c][1,3,6]oxdiazocines adopt a similar cis fused ring conformation and with increasing steric requirement of the 2-alkyl substituent the 8-membered ring increasingly favours the chair-chair conformation, rather than the chair-boat conformation favoured by the 2-methyl substituted compound.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071007
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  • 158
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    The 250 MHz 1H NMR spectrum of cinnoline (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 504-507 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton NMR spectrum of cinnoline has been measured at high field (250 MHz) and analysed as an H-8-de-coupled ABCXY and H-4-decoupled ABCX system. Inter-ring H—H couplings have been determined and discussed in relation to theoretical values obtained using INDO calculations.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071009
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  • 159
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    Carbon-13 NMR spectroscopy of the biological pigments luteoskyrin and rugulosin and some polyhydroxyanthraquinone analogues (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 496-503 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bianthraquinonic biological pigments luteoskyrin and rugulosin and five polyhydroxyanthraquinone derivatives are studied by carbon-13 NMR in DMSO solution. Peak assignment for the fourteen carbon atoms of these compounds is achieved by proton spin decoupling and by investigating the effect of ionisation of the hydroxyl groups upon the carbon chemical shifts. Carbon chemical shifts in the planar hydroxyanthraquinones can be rationalised in terms of conjugation and intramolecular hydrogen bonding. The latter is responsible for the relative acidity of the hydroxyl groups in the analogues, and for the different conformations proposed for luteoskyrin and rugulosin. Tautomeric equilibria occur in DMSO and water-DMSO solutions for the anionic species [LS]2- and [RG]2-. This can account for the binding of luteoskyrin and rugulosin to nucleic acids.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071008
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  • 160
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    Synthesis and structure assignments of cis- and trans-2-(diethylaminomethyl)cyclohexanols (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 508-511 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of cis- and trans-2-(diethylaminomethyl)-cyclohexanols and their structural assignments by NMR using the shift reagent Eu(dpm)3 are described. The correlation of the induced shifts with the equation Δν = K(3 cos2θ - 1)r-3, assuming an Eu—O distance of 2·4 Å and θ less than 30°, suggests that the interactions are pseudocontact. The values of K are 452 and 420 for the two cyclohexanols, respectively.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071010
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  • 161
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    1H NMR spectra of E and Z pyridine-2-carbaldehyde 2′-pyridylhydrazone and related compounds (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 512-519 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Proton magnetic resonance spectra at 100 MHz are reported for the E- and Z-isomers of pyridine-2-carbaldehyd 2′- pyridylhydrazone in carbon tetrachloride, d6-dimethylsulphoxide and d6-benzene solutions, and for various monomethylated derivatives in d6-dimethylsulphoxide. The spectral parameters obtained by analysis with the help of LAOCOON 3 are discussed in terms of solvent effects and the chemical shift changes consequent upon isomerisation are evaluated. Some conclusions are reached concerning the preferred conformations of the E- and Z-isomers of pyridine-2-carbaldehyde 2′-pyridylhydrazone.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071011
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  • 162
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    Parameter errors in LAOCOON 3 calculations (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 520-523 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Some model calculations with LAOCOON 3 have been used to show that the mean error in the calculated coupling constants is linearly related to the root mean square error in the transition frequencies. On the basis of this linearity it is shown that the ‘probable’ error parameter of LAOCOON 3 should be increased by a factor of 2·5 to give more realistic errors.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071012
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  • 163
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    On the mechanism of reaction of tert-butoxyl radicals with dialkylphosphitesIssued as NRCC No. 14748. (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 527-528 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It has been shown by ESR spectroscopy that the title reaction involves abstraction of hydrogen from the phosphite, since at -10°C the reaction has a kinetic deuterium isotope effect, kH/kD, or ∼3. The rate constant for hydrogen abstraction is c. 2 × 104 M-1 s-1. There is no significant addition of alkoxyl radicals to the phosphite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071014
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  • 164
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    Application des mesures de couplages 15N—H à la détermination de configurations d'oximesInteractions spin-spin nucléaires XII. Parties XI, voir Réf. 1. (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 524-526 
    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: Several 15N enriched oximes of heterocyclic aldehydes have been prepared in syn and anti forms. The less stable form may be obtained by UV irradiation of the other one. The geminal 15N—H coupling in the R—CH=15N—OH fragment allows an immediate and unambiguous assignment of the configuration to be made, being 13 to 16 Hz and 2 to 3 Hz for the anti and syn forms, respectively. Whereas oximes 1 to 4 are preferentially in the anti form, the N-methylpyridinium aldoxime iodides (2-PAM, 3-PAM, 4-PAM) are found to be syn in the stable form and not anti as previously thought. This reassignment is of special interest, since 2-PAM (8), which is an excellent antidote against alkyl phosphate nerve poisoning, has been used to study the geometry of the acetylcholinesterase active site of the enzyme.
    Notes: Plusieurs oximes, enrichies en 15N, d'aldéhydes hétérocycliques ont été préparées dans les formes syn et anti. La forme la moins stable peut être obtenue par irradiation UV de l'autre. Le couplage géminal 15N—H dans le fragment R—CH=15N—OH permet une attribution non ambiguë de la configuration; il est de 13 à 16 Hz et de 2 à 3 Hz pour les formes anti et syn, respectivement. Les oximes 1 à 4 sont préférentiellement anti, alors que la forme stable des oximes des aldéhydes de N-méthyl pyridinium (8 à 11) est syn et non pas anti comme cela avait été admis. Cette réattribution présente un intérêt spécial puisque 2-PAM (8), qui est un excellent antidote réactivant l'acétylcholinestérase inhibée par phosphorylation, a été utilisée pour étudier la géometrie du site actif de l'enzyme.
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975) 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071101
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  • 166
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    Détermination de la forme la plus stable de l'ortho-dichlorofluorure de benzyle par RMN en phase nématique (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 633-634 
    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 value of direct couplings in o-dichlorobenzylfluoride, obtained from nematic phase NMR, lead to the conclusion that the most stable form is such that the fluorine atom is in a plane perpendicular to the benzene ring. However, the complete intepretation of these couplings in terms of geometrical parameters tends to indicate a modification of orientation with internal rotation of CH2F.
    Notes: La valeur des couplages directs dans l'ortho-dichlorofluorure de benzyle, obtenus par RMN en phase nématique, permet d'affirmer que la position la plus stable du CH2F est telle que le fluor se trouve dans un plan perpendiculaire au cycle benzénique. L'interprétation complète de ces couplages en fonction de la géométrie de la molécule laisse cependant supposer une modification de l'orientation intervenant en même temps que la rotation du groupement CH2F.
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    URL: http://dx.doi.org/10.1002/mrc.1270071216
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  • 167
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    29Si and 13C NMR studies of organosilicon chemistry. VThe previous paper in this series is Ref. 1. - Sugar derivatives (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 635-636 
    Details
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 29Si spectra have been obtained for four trimethylsilylated hexopyranoside sugars, and the resonance due to the CH2OSiMe3 group at position 5 has been assigned by experiments involving gated decoupling at a single 1H frequency.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/mrc.1270071217
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  • 168
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    Forthcoming papers (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. A5 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1270071219
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  • 169
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    RMN du carbone-13 en serie cyclopropanique. Effets de substituants (1975)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 7 (1975), S. 637-638 
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    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Substituent effects on chemical shifts of cyclopropane derivatives are investigated by 13C NMR. When we introduce pairwise corrections in empirical correlations, the theoretical chemical shifts of trisubstituted cyclopropanes are in good agreement with experimental values.
    Notes: Les effets de substituants sur les déplacements chimiques de dérivés cyclopropaniques ont été étudiés par RMN du carbone-13. Les déplacements chimiques théoriques de cyclopropanes trisubstitués sont en bon accord avec les valeurs expérimentales lorsqu'on introduit dans les corrélations des paramètres d'interaction du second ordre.
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    URL: http://dx.doi.org/10.1002/mrc.1270071218
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    Biographical note (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. vii 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100113
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  • 171
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975) 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100301
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  • 172
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    Stereospecific 1,3 and 1,4 dehydration reactions in the mass spectra of podocarpan-12- and -14-OLS†Part 9 in the series “Mass Spectra of Diterpenes”. For Part 8, see Ref.1. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 162-177 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Specific deuterium labelling revealed that podocarpan-12α- and -14α-01, representing conformationally well defined cyclohexanols, eliminate water mainly by stereospecific 1,3 reactions involving cis tertiary hydrogens on electron-impact. Dehydration of podocarpan-12ß-0l, which also involves a cis tertiary hydrogen, occurs almost exclusively by a 1,4 reaction. Subsequent decomposition of the various [M - 18]+· ions was found to lead to different products, thus explaining some of the intensity differences encountered in the lower parts of the spectra of the epimeric podocarpan-12-ols and -14-ols.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100303
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  • 173
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    ZUM MECHANISMUS MASSENSPEKTROMETRISCHER FRAGMENTIERUNGSREAKTIONEN BEI A/B-CIS- VERKNüPFTEN 3α-HYDROXYSTEROIDEN MIT UND OHNE 11-KETOGRUPPE (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 200-214 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass spectra of steroids containing a carbonyl group in position 11 and a 3α-hydroxy group in a cis connected A/B ring system are characterised by very strong [M - 72]+· key ions and may therefore be clearly differentiated from the spectra of their isomers. The mechanism of this fragmentation reaction was investigated by deuterium labelling and the DADI technique. The 3α-hydroxy group is eliminated together with the 9α-H atom. Next a hydrogen atom is transferred from the A ring to the B/C/D ring system. This causes the cleavage of the C-3—C-4 bond and expulsion of C atoms 1 to 4 as butadiene. In 3α-hydroxy-5α-androstanes possessing no 11-keto group an analogous [M - 18]+. fragment is fromed, followed by the elimination of ethylene originating mostly from C-1 and C-2.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100306
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  • 174
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    Biographical note (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. vii 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100310
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  • 175
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    A test of the concept of ‘charge localisation’ in methionine (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 250-258 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A previous re-investigation of methionine has shown that the [C2H5S]+ ion is generated via rather complicated routes from the molecular ion. This has been interpreted as evidence against charge localisation in the fragmentation of the title compound. Deuterium labelling, high resolution mass measurements and metastable transitions have revealed, however, that the formation of the [C2H5S]+ ion is not in contradiction with the predicting capabilities of the concept of charge localisation.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100403
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  • 176
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    Mass spectroscopy of hydroxamic acids: Fragmentation by the loss of the hydroxylamino oxygen (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 259-262 
    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 three dihydroxamic acids have shown in each case prominent [M - 16]+· and [M - 32]+· ions. The spectrum of biosynthetically labeled rhodotorulic acid indicates that these ions arise from the sequential, specific loss of the hydroxylamino oxygens.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100404
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  • 177
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    Studies in mass spectrometry. I - Common intermediates in the fragmentation of isomeric compounds under electron-impact (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 81-88 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the particular case where a specific ion [c]+· is generated with different internal energy, the variation of Z(E) = [(f)+]/[(c)+·] vs energy of the electron beam is discussed in relation to the P(Ei) and k(Ei) functions which describe the decay process [c]+· → [f]+. Qualitative application to seven isomeric hydrocarbons suggests that, among these isomers, two pairs might rearrange to a common intermediate before fragmentation occurs. It is found that in such cases the curves Z = f(E) for a given fragmentation are not superimposable but parallel, as suggested by theoretical considerations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100202
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  • 178
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    ETUDE EN SPECTROMETRIE DE MASSE DE PHOSPHONATES ENYNIQUES ET DE β-CETOPHOSPHONATES-γ, δ-ETHYLENIQUES (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 122-140 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The mass spectrometric study of acetylenic dialkylphosphonates (I) and of γ, δ-éthylenic-β-ketophosphonates (II) is characterised by rearrangement processes of the phosphorylated group and cleavage of the phosphorus-carbon bond. The fragmentation patterns of compounds II were identical to those found for I by loss of water.
    Notes: L'étude des processus de rupture en spectrométrie de masse de dialcoylphosphonates ényniques (I) et de β-cétophosphonates-γ, δ-éthylénique (II) sont caractérisés par des réarrangements au niveau du groupement phosphoré et des ruptures au niveau de la liaison phosphore-carbone. Les composés II conduisent à des schémas identiques à ceux de I par perte d'une molécule d'eau.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100206
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  • 179
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    Redistribution reactions in the ion source of a mass spectrometer of complexes of titanium (iv), tin (iv) and germanium (iv) with 8-quinolinolato and halo or ethoxy ligands (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 146-154 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The relative intensities of peaks in the mass spectra of the compounds MX4-noxn (oxH = 8-quinolinol; n = 2; M = Ti; X = F, Cl, Br or OEt; M = Sn; X = F, Cl, Br or I; M = Ge; X = Cl or Br; n = 1; M = Ti; X = OEt) depend on the insertion temperature and the residence time of the sample in the mass spectrometer. In most cases ions which cannot arise by fragmentation of the respective molecular ions are observed. These ions arise from the ionisation and fragmentation of species which are due to redistribution reactions in the mass spectrometer. The fragmentation pattern of the compounds MX2ox2 (X = halogen), mainly involving loss of ligand radicals, is related to the common oxidation states of the metals and reflects the metal-halogen bond strength. The molecular ions of the compounds Ti(OEt)4-noxn (n = 0, 1 or 2) fragment by loss of intact ligand radicals.
    Additional Material: 8 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100208
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  • 180
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    Editorial announcement (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 161-161 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100302
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  • 181
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    Transposition des cycles satures en spectrometrie de masse II-Ethylene acetals derives de cyclopentanones et de cyclohexanonesEquipe de recherches associées au C. N. R. S. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 178-195 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The detailed study of the mass spectra of cyclopentanone and cyclohexanone acetals produces new evidences for the rearrangement of the corresponding molecular ions. The rearrangement was quantitatively studied with the help of a simple model. The influence of different structural features is discussed.
    Notes: L'étude détaillée des spectres de masse des éthyléne acétals dérivés de cyclopentanones et de cyclohexanones apporte de nouveaux arguments en faveur d'une transposition de l'ion moléculaire. Un modèle simplifié permettant l'étude quantitiative de ce réarrangement est proposé. L'influence de divers facteurs structuraux sur ce réarrangement est discutée.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210100304
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  • 182
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    Erratum (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. iii 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100309
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  • 183
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    Masthead (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975) 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100401
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  • 184
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    Electron-impact-induced rearrangements in the mass spectra of phosphinyl stabilized triphenylphosphonium ylides (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 241-249 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Examination of the mass spectra of some methyl and phenyl phosphonate stabilized triphenylphosphonium ylides revealed that these compounds are quite stable to electron-impact and provided valuable structural information. They exhibit strong molecular and [M - H]+ ions, and fragment ions which are characteristic for the phosphonium or the phosphonate portion of the molecules. Numerous rearrangement ions were detected, however, the most prominent of which involves the migration of a phosphonate phenyl to the ylide carbon, leading to the base peak (m/e 352) in the spectrum of diphenyl triphenylphosphoranylidenemethylphosphonate. The mechanism of these fragmentations has been studied with the aid of high resolution analysis and deuterium labeled analogs whose preparation is reported.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100402
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  • 185
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    Mass spectrometry of p-toluenesulfonamides: Useful amine identification derivativesResearch supported jointly by the Chemical Carcinogenesis Program of the National Cancer Institute and the US Atomic Energy Commission under contract with the Union Carbide Corporation. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 473-479 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The mass spectral fragmentation patterns of p-toluenesulfonamides have been determined and have been found useful for identification of naturally occurring amines.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100610
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  • 186
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    Electron-impact-induced rearrangements of organic ions VIFor Part 1, see Ref. 1.Unimolecular reactions of isomeric[C8H9]+ions (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 494-502 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Metastable ion spectra and deuterium labelling have been used to investigate a series of gaseous [C8H9]+ ions of isomeric structures. The similarity of the intensities of their metastable loss of hydrogen, acetylene and ethylene molecules and metastable reactions of specifically labelled ions, suggests that the [C8H9]+ reacting ions, formed initially with different structures, isomerise to a common structure or mixture of structures via deep-seated rearrangement reactions which render all hydrogen atoms equivalent. The isomerisation process involved is controlled by a conversion of a vinyl bond into an allyl-type bond, thus destroying the aromatic moiety.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100703
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  • 187
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    Fragmentation d'azoles sous l'impact electronique VI-indazole (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 558-560 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular ion isomerisation precedes the fragmentation of indazole upon electron-impact.
    Notes: Une ismérisation des ions molécularies précéde la fragmentation de l'indazole sous l'impact.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100711
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  • 188
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    Forthcoming meeting (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. vii 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210100713
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  • 189
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    The significance of field ionisation kinetics to ion structure: Isomerisation and decompostition of [C4H8]+· radical ionsWe follow our own suggestion14 in referring to the technique through which kinetics of ion decomposition can be determined in the picosecond and nanosecond timeframes as “field ionisation kinetics (FIK).” (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 563-578 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of formation of [C3H5]+[M — CH3]+, [C3H4]+·[M — CH4]+· and [C2H4]+·[M — C2H4]+· from but-1-ene, cis- and trans-but-2-ene, 2-methylpropene, cyclobutane and methylcyclopropance following field ionisation have been determined as a function of time 20 (or 30) picoseconds to 1 nanosecond and at two points in the microsecond time-frame. The results are consistent with the supposition that at the shortest accessible times (20 to 30 picoseconds) the structure of the [C4H8]+· molecular ion qualitatively resembles that of its neutral precursor, but suggest that prior to decomposition within nanoseconds the various molecular ions (excepting cyclobutane where the processes are slower) attain a common structure or mixture of structures. Reaction pathways of the presumed known ion structures are delineated from the nature of decompostion at the shortest times.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210100802
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  • 190
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    ETUDE DE LA FRAGMENTATION DE N-ARYL ET DE N-ALKYL AMINOCETONES EN SPECTROMETRIE DE MASSE (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 669-678 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Comparison of the chemical ionisation and elctron-impact mass spectra of alkyl and aryl aminoketones has bee carried out. This has revealed the particular stabilization of the N-aryl grops in all cases.
    Notes: La comparison des spectres de masse en ionisation chimique et électronique d'alkyl et d'aryl aminocétones a étéréalisée. Elle a surtout permis de mettre en évidence dans tous les cas, la stabilisation particulière du groupe N-aryl.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210100812
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  • 191
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    Molecular weight determination by cationisation (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 660-668 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In General cationised molecules are more stable than redical molecular ions or protonated molecules. The fragmentation of the polar molecules resulting from a cationsation by for instance alkali ions, has a higher activation energy than splitting off fuctional groups after a protonation. Cationisation is therefore an intersting tool for the determination of molecular weights. Three different methods for achiving a cationisation are described and discussed: (1) field-indiced cationisation at low anode temperatures using a heterogenous reaction of the molecules in the gas phase with molecules of a salt in the adsorption layer on the field anode; (2) a largely thermally induced catisation at high emitter temperatures and low electric fields; (3) a cationisation, causing less thermal excitation to the molecules, using the field desorption technique.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210100811
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  • 192
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    The negative ion mass spectra of mixtures of sulphur and organic compounds. II - the formation of [C5H5 + Sn]- from the mixture of sulphur and ferrocene (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 698-701 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The negative ion mass spectra of ferrocene and of a mixture of ferrocene with sulphur were studied. In the spectrum of the mixture, characteristic peaks of [C5H5 + Sn]- (n = 1, 2, 3 etc.) were observed. The structures of these ions are discussed.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210100903
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  • 193
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    Mass spectral study of cyclic alkaneboronates of sugar phosphates. Evidence of interaction between the phosphate group and boron under electron-impact conditionsSupported by NIH grant NS-05159. (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 1007-1020 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclic butane- and methaneboronic esters of dimethylphosphates of glucose, galactose, mannose, fructose and methyl gluconate have been examined by mass spectrometry. High resolution information and deuterium labeling of all six carbons of glucose, as well as of the methylphosphate groups, permits elucidation of the origin of various ions, which can be grouped according to their probable mechanism of formation. In each case, the intensity of the [M - R]+ ion can be rationalized, in stereochemical terms, by the ease with which incipient positive charge on boron can be stabilized by the phosphate group. This interaction also gives rise to rearrangement ions containing a B—O—P linkage. Other effects of structure on fragmentation pattern are discussed. Retention of specific portions of the glucose skeleton in ions with clearly defined label shift behavior, as well as the preservation of intact sugar moieties in intense [M - R]+ ions, suggests applications for stable isotope analyses. These are discussed in terms of their advantages over silicon-containing derivatives.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/oms.1210101111
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  • 194
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    The mass spectrometric behaviour of dimethylcyclosiloxanes (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 1035-1045 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The fragmentations of [(CH3)2SiO]n, (Dn), where n = 4, 5, 6, 7, 8, 9, 10, 12 and 15 are reported. The behaviour of these compounds under electron-impact is governed by the size of the siloxane ring. Rings smaller than D6 have base peaks corresponding to [M - 15]+ ions; larger rings all show base peaks of m/e 73 [Si(CH3)3]+. A transannular mechanism previously applied only to D5 and D6 is extended and modified to account for the behaviour of larger rings. A ring con-traction mechanism is proposed which leads to the formation of smaller rings and doubly charged ions. A new transannular mechanism is proposed to account for the production of [M - 177]+ and [M - 193]+ ions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101114
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  • 195
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    The reactive states of ions: Octatrienes and dimethyl substituted cyclohexadienes (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 1075-1083 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The principal decomposition routes of molecular ions of cis, cis, cis-2,4,6-octatriene, cis, cis, trans-2,4,6-octatriene, trans, cis, trans-2,4,6-octatriene, trans-5,6-dimethyl-1,3-cyclohexadiene and cis-5,6-dimethyl-1,3-cyclohexadiene were studied using ion kinetic spectroscopy. The loss of radicals from [M]+· appears to proceed via a ground state, while loss of a neutral molecule appears to involve either complete equilibration of structure within the system or both ground state and excited state pathways.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101205
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  • 196
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    Electron impact studies. CIPart C: J. H. Bowie and B. J. Stapleton, submitted for publication. - negative ion mass spectra of the carbonyl group. The Aryl—CH2—CO- and Aryl—(CH2)2—CO- systems (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 1117-1124 
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    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fragmentations of the molecular anions of m- and p-nitrophenyl-CH2—CO—R yield nitrobenzyl anions in the ion source when R = Ph, but the corresponding ion from the system where R = Me is only formed after collision activation. o- and p-Nitrophenyl parent anions undergo β-cleavage to the carbonyl centre to produce nitrobenzyl anions. Pronounced rearrangement peaks are noted in the spectra of o-nitrophenyl- compounds. Labelling studies indicate the identity of the eliminated species, but the mechanisms of the rearrangements are complex.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101209
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  • 197
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    An intermolecular methyl transfer during field desorption mass spectrometry. Identification of the [M + 14] peak in choline chloride (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 1147-1151 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Choline chloride, bromide and iodide all contain a peak at m/e 118 [M + 14] in their field desorption mass spectra. Comparison with choline(methyl-d9) chloride demonstrates that this peak arises from an intermolecular transfer of a methyl group. Partial exchange of hydroxyl hydrogen on choline chloride does not displace the m/e 118 peak, suggesting that this hydrogen is lost during methyl transfer. The structure of the [M + 14] species should then correspond to choline methyl ether.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101213
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  • 198
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    Beurteilungskriterien für Klassifikatoren zur automatischen Spektreninterpretation (pattern recognition) (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 874-884 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: In recent years numerous methods of pattern recognition have been tested for automatic interpretation of physicochemical data. Classifiers have been used successfully, especially with low resolution mass spectra. However, judgement of spectral classifiers (‘percentage of correctly classified spectra’) was often mathematically insufficiently defined. In this paper basic principles of the probability theory and information theory are used to derive objective criteria for binary classifiers. A classifier is an algorithm that uses a pattern vector (mass spectrum) and a priori probabilities for the classes (chemical structures) to which this vector belongs; the classification results are a posteriori probabilities for the classes. Predictive abilities for both classes or the information gain are suitable, objective criteria, to compare classifiers. Mathematical formulae are given and explained by examples from mass spectrometry.
    Notes: In den Letzten Jahren wurden zahlreiche Verfahren der Zeichenerkennung für die automatische Interpretation von chemisch-physikalischen Daten erprobt. Gute Erfolge wurden insbesondere mit Klassiufikatoren für niedrig aufgelöste Massenspektren erzielt. Die Angaben über die Güte der Spektrenklassifikatoren (‘Prozenstsatz richtig klassifizierter Spektren’) waren jedoch oft mathematisch unzureichend definiert. In dieser Arbeit werden mit Hilfe grundlegender Prinzipien der Wahrscheinlichkeitsrechnung und der Informationstheorie objektive Beurteuilungskriterien für binäre Klassifikatoren abgeleitet. Ein Klassifikator ist eine Rechenvorschrift, um aus einem Merkmalsvektor (Massenspektrum) und den a priori-Wahrscheinlichkeiten der Klassenzugehörigkeiten (chemischen Strukturen) für diesen Merkmalsvektor die a posteriori-Wahrscheinlichkeiten zu berechnen. Für den Vergleich der Güte von Klassifikatoren sind die Klassifizierungsfähigkeiten für die einzelnen Klassen oder der Informationsgewinn geeignet. Die angegebenen Formeln werden durch Beispiele aus der Massenspektrometrie erläutert.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101011
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  • 199
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    Electron-impact-induced fragmentation of some isomeric cyclopropyl picolyl and pyridyl ketones (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 913-918 
    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 fragmentation of three cyclopropyl picolyl ketones and three cyclopropyl pyridyl ketones has been studied with the aid of deuterium labeling, high resolution mass measurements and metastable mode operation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101016
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  • 200
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    Fragmentation d'azoles sous l'impact electronique. X - etude de rearrangements cycliques en serie alkylamino-1,2,4-triazole (1975)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 10 (1975), S. 946-957 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: In situ generation of the individual tautomers by fragmentation reactions in the mass spectrometer is shown to provide a means of studying rearrangements of the type involved in prototropic equilibria. C-aminotriazole was generated in different tautomeric forms by ethylene elimination from the N-ethyl compounds and the tautomers were shown to equilibrate prior to further fragmentation. Ethylene elimination was shown by characterising the energy partitioning associated with the metastable ion reactions to occur via a four centred transition state from two ethylamino-triazole isomers and via a five centred transition state from the third. These mechanistic conclusions were supported by characterising frequency factors through measurements of kinetic isotope effects. Propene elimination from the corresponding propylaminotriazoles was studied by analogous methods. Energy partitioning and kinetic isotope effect studies were in agreement with a stepwise elimination of propene, or with a five centred β-hydrogen transfer mechanism.
    Notes: La formation in situ de tautomères individuels par des réactions de fragmentation dans le spectromètre de masse constitue une méthode de réarrangements tels que les équilibres prototropiques. Le C-aminotriazole est généré en ses différentes formes tautomères par élimination d'éthylène à partir des composés N-éthylés et ces tautomères sont isomérisés en une structure commune avant fragmentation. L'élimination d'éthylène se déroule via un état de transition à quatre centres pour deux éthylaminotriazoles isomères et via un état de transition à cinq centres pour le troisième comme le montrent les termes de partition d'énergie associés aux réactions aux réactions d'ions métastables. Ces conclusions mécanistiques sont étayées par l'étude d'effects isotopiques (méthode de caractérisation de facteurs de fréquence). L'élimination de propène à partir de propylaminotriazoles est abordée par des méthodes analogues. Les termes de partition d'énergie et l'étude d'effets isotopiques primaires sont en accord avec une élimination non concertée de propène ou avec un mécanisme de transfert de l'hydrogène β via un complexe transitoire à cinq centres.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210101105
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