✦ LIBER ✦

Temperature dependence of 13C nuclear magnetic shielding in some aliphatic alcohols

✍ Scribed by K. Jackowski; W. T. Raynes

Publisher: John Wiley and Sons
Year: 1980
Tongue: English
Weight: 447 KB
Volume: 13
Category: Article
ISSN: 0749-1581
DOI: 10.1002/mrc.1270130609

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✦ Synopsis

Abstract

The ^13^C nuclear shielding in methanol, ethanol and isopropanol has been measured over the temperature range 186–325 K. Corrections to the observed shifts have been made to allow for the temperature dependence of the shielding of the external tetramethylsilane reference and for the temperature dependence of the bulk susceptibility effects in the alcohols. The results show that the temperature dependence of ^13^C shielding in the liquid alcohols is smaller than that in tetramethylsilane. By comparison both with temperature coefficients of compounds not involving hydrogen bonding and with N‐protonation studies, it is inferred that the reduction of hydrogen bonding which occurs in the liquid alcohols as the temperature is raised has very little effect on the ^13^C shielding. It is the change in the van der Waals forces which predominates in determining the temperature coefficient.

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