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  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 30 (1992), S. 320-326 
    ISSN: 0749-1581
    Keywords: 1H, 13C, 17O NMR spectra ; Disubstituted naphthalenes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 1H, 13C and 17O NMR spectra of several 4,1-disubstituted naphthalenes, viz. 4-substituted 1- acetylnaphthalenes (series 1), 4-substituted 1-nitronaphthalenes (series 2), 4-substituted 1-methoxynaphthalenes (series 3) and 4-substituted 1-naphthyl methyl sulphides (series 4), were measured. The 17O and 13C chemical shifts of these 4,1-disubstituted naphthalenes were compared with those of the corresponding 4,1-disubstituted benzenes and analysed using the dual substituted parameter (DSP) equation. It is concluded that in series 1, 2 and 4 the substituent effects from the 4-substituent to the C-1 carbon and the side-chain atoms are transmitted more effectively than those in the corresponding 4,1-disubstituted benzenes, whereas the transmission in series 3 is almost equal to that in the analogous benzene series, viz. 4-substituted anisoles. The reverse substituent effects displayed by the H-8 chemical shifts of series 1 and 2 and the existence of linear relationships between the chemical shifts of H-8 and the 17O chemical shifts of the oxygen of both the acetyl and nitro groups in series 1 and 2, respectively, are ascribed mainly to changes in the electron densities on the oxygen of the carbonyl and nitro groups affecting the diamagnetic screening of the proton.
    Additional Material: 12 Tab.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0749-1581
    Keywords: NMR ; 1H NMR ; 13C NMR ; diphenyl sulphides ; diphenyl sulphones ; π-polarization ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The proton and carbon NMR spectra of nine 2-substituted diphenyl sulphides (S-2-X), seven 3-substituted diphenyl sulphides (S-3-X), nine 2-substituted diphenyl sulphones (SO2-2-X), nine 3-substituted diphenyl sulphones (SO2-3-X) and nine 4-substituted-2′,6′-dimethyldiphenyl sulphides (Me2-S-4-X) were obtained. Correlations of the 1H and 13C chemical shifts were made with benzene substituent-induced chemical shifts (Lynch plots) and Hammett and dual-substituent parameters and the results were compared with those of 4-substituted diphenyl sulphides (S-4-X) and sulphones (SO2-4-X). The main conclusions are as follows: (i) the transmission of the substituent effects in substituted diphenyl sulphides decreases in the order S-4-X ≍ S-2-X 〉 Me2-S-4-X 〉 S-3-X; (ii) the inductive effects are transmitted to a larger extent than the resonance effects to the unsubstituted ring in 3-substituted diphenyl sulphides, while the reverse trend is observed in other substituted diphenyl sulphides; (iii) in 2-methoxy-, 2-chloro-, 2-bromo- and 2-nitrodiphenyl sulphides, an increase in the size of the substituent causes an upfield shift for H-6 ascribable to the repulsion between the lone pairs of electrons on the sulphur and the substituent and its influence on the conformation; (iv) the diminished transmission of substituent effects to the remote rings in 4-substituted 2′,6′-dimethyldiphenyl sulphides is probably due to the orthogonal orientation of the rings; and (v) the signal due to the H-6 of 2-substituted diphenyl sulphones suffers a downfield shift with an increase in the size of the substituent, this being ascribable to the increasing steric interaction between the 2-substituent and the sulphonyl oxygen and consequent changes in the conformation.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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