ISSN:
0749-1581
Keywords:
1H NMR
;
13C NMR
;
n-Alkanes
;
ASIS
;
Conformation
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The 1H and 13C NMR spectra of a series of n-alkanes (C5-C32) were measured in CCl4, CDCl3, C6D6, C6H5Cl and C6D5CD3 and the aromatic solvent-induced shifts (ASIS) are discussed. The chemical shifts of the inner methylene protons show a steady downfield shift as the carbon number of the n-alkane increases, while the shifts of the methyl protons are smaller than those of the inner methylene protons in aromatic solvents. The ASIS of the outer carbons are larger than those of the inner carbons up to the sixth carbon from the end. The ASIS of the sixth and further inner carbons of the short chains are larger than those of the long chains. These results suggest that n-alkanes have a folded structure in aromatic solvents and that the degree of folding increases with increasing chain length.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260280502
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