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  • 1
    ISSN: 0030-4921
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Various complexes of boron trifluoride and typical organo-phosphours compounds have been investigated using proton and fluorine resonance (at variable temperature) and boron and phosphorus resonance. In BF3, boron resonance is insensitive to the complex strength, but fluorine resonance suggests the possibility of various types of complexes on the phosphorus group or, additionally on the heteroatoms (e.g. oxygen, nitrogen) of the molecule. These complexes are probably σ type. Proton chemical shifts in the organo-phosphorus compounds follow the same trends as in similar complexes of amines, esters etc.; these perturbations may be mainly due to magnetic anisotropy effects; proton-phosphorus couplings conversely follow changes in phosphorus electronegativity.
    Notes: On a étudié, en résonance du proton et du fluor (à température variable) ainsi qu'en résonance du bore et du phosphore, un certain nombre de complexes entre BF3 et des composés organo-phosphorés typiques. En ce qui concerne BF3, la résonance de bore reste insensible à la force du complexe; par contre, la résonance du fluor suggéère l'existence de plusieurs types de complexes, soit sur le groupe phosphoré, soit sur les hétéroatomes (par example N, O) de la molécule. Ces complexes sont vraisemblablement de type σ pur. Le déplacement chimique des protons dans la molécule organo-phosphorée subit sensiblement les mêmes perturbations que dans les autres molécules complexables (amines, esters, etc.); ces perturbations peuvent provenir avant tout d'effets d'anisotropie magnétiques; par contre, les couplages proton-phophore suivent la modification de l'électronégativité de ce dernier.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 12 (1979), S. 77-82 
    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 2-dimethylaminocyclohexanols and the four trans-3-dimethylamino-2-decahydronaphtols are described. The gauche interactions allow precise estimation of chemical shifts for each carbon atom; thus, band attribution can be resolved without mistake. In the case of the cis and the trans diequatorial compounds, the conformational perturbations which we have suggested before are verified by our present measurements on the substituted carbon atoms. We also show effects on adjacent atoms, which were unobservable with the usual IR and 1H NMR techniques.
    Notes: Les spectres RMN du 13C de diméthylamino-2 cyclohexanols, des quatre diméthylamino-3 décahydronaphtols-2 trans et de leurs iodures d'ammonium quaternaires sont décrits. Le calcul des séplacements chimiques de chaque carbone en tenant compte des interactions gauches permet d'attribuer correctement chaque signal. Dans le cas des composés cis ou trans diéquatorial, on a pu non seulement vérifier des modifications conformationelles portant sur les carbones substitués, mais on a pu mettre également en évidence des effects portant sur les carbones voisins, effets que les méthodes IR et RMN du proton ne pouvaient pas permettre d'observer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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