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
URL:
http://dx.doi.org/10.1002/mrc.1260331004
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