CHED 453 |
| We have recently examined the infrared spectra of selected disubstituted phenols as an extension of our study of how ortho, meta, and para substitution in phenols affects the frequency of free and hydrogen-bonded OH stretching bands. In monosubstituted phenols there is evidence that the electron-releasing or withdrawing nature of the substituent group affects the free OH stretching frequency. In 2,6-disubstituted phenols our results suggest that the free OH stretching frequency is influenced by both electronic and steric effects. For the OH stretching bands in 0.02M 2,6-dimethylphenol and 2,6-di-tert-butylphenol in cyclohexane solution, the size of the frequency shift relative to phenol depends of the size of the alkyl group indicating a significant steric effect. Where nonequivalent conformations are possible as in 2,6-diisopropyl phenol, multiple OH stretching bands are observed at frequencies consistent with differing amounts of steric crowding. |
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Undergraduate Research Poster Session: Organic Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |