We have studied the infrared OH stretching bands in dilute solutions of a variety of substituted phenols in cyclohexane.   For a large number of substituted phenols, we observed a single OH stretching band in which substitution of an electron-releasing group shifts the OH stretching band to a higher frequency and an electron-withdrawing group results in a shift to a lower frequency.  However, there are exceptions to this pattern in which the observed shift is in the wrong direction, or two OH stretching bands are observed.  Examples include 2-tert-butylphenol, 4-(trifluoromethoxy)phenol, 2,6-diisopropylphenol, and 2-tert-butyl-6-methylphenol.  In all of these cases it seems likely a change in the orientation of the hydroxyl group is the cause of the atypical appearance of the OH stretching region of the IR spectrum.

Structural features resulting in atypical OH stretching bands in substituted phenols

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.