The ultrafast dynamics of solutions of phenol and two phenol derivativesshydroquinone (1,4-benzenediol) and pyrocatechol (1,2-benzenediol)shave been studied with Optically Heterodyne-Detected Optical Kerr-Effect (OHD-OKE) spectroscopy. The solvents, methanol and acetonitrile, were selected to provide strong and weak solvent-solute hydrogen-bonding interactions, respectively, while pyrocatechol features an intramolecular hydrogen bond. Together these provide a series of model systems for polypeptides such as polytyrosine, which facilitate the direct study of inter- and intramolecular hydrogen bonding. A broad contribution to the Raman spectral density of the methanol solutions at frequencies between 150 and 300 cm-1 has been observed that is absent in acetonitrile. This contribution has been assigned to solvent-solute hydrogen-bond stretching vibrations. The OHD-OKE response of poly-L-tyrosine has been measured and was found to contain a similar contribution. Density functional theory geometry optimizations and normal mode calculations have been performed using the B3LYP hybrid functional and 6-311++G** basis set. These have yielded a complete assignment of the low-frequency Raman and far-infrared spectra of pyrocatechol for the first time, which has provided information on the nature of the intramolecular hydrogen bond of pyrocatechol.
- inter- and intramolecular hydrogen bonding
- phenol derivatives
Hunt, N. T., Turner, A. R., & Wynne, K. (2005). Inter- and intramolecular hydrogen bonding in phenol derivatives: A model system for poly-L-tyrosine. Journal of Physical Chemistry B, 109(40), 19008-19017. https://doi.org/10.1021/jp052964o