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Influence of γ-hydrogens (hydrogens three bonds away) in calculating 13C chemical shifts of acyclic alkanes and alcohols

✍ Scribed by Arupjyoti Saikia; Iragavarapu Suryanarayana

Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
115 KB
Volume
37
Category
Article
ISSN
0749-1581

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✦ Synopsis

The 13C NMR chemical shifts of acyclic alkanes and alcohols are reproduced by an equation having two parameters, the charge on the carbon atom as calculated by iterative partial equalization of orbital electronegativity and the e †ective number of hydrogen atoms three bonds away from the carbon atom under consideration. The data sets consist of 183 carbons of all alkane isomers up to and 184 carbons of aliphatic alcohol C 8 isomers up to

The alkane carbons are correlated with a correlation coefficient of 0.994 and a standard devi-C 8 . ation of 1.06 ppm and the alcohol carbons with a correlation coefficient of 0.997 and a standard deviation of 1.37 ppm. The inÑuence of e †ective number of hydrogen atoms three bonds away is discussed in terms of 1,4 steric interactions in the molecules.

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