Integrated intensities of O-H stretching bands: Fundamentals and overtonesin vapor-phase alcohols and acids

Integrated intensities have been measured for O-H stretching vibrational ba nds, including fundamentals and the first three overtones for methanol, eth anol, 1-propanol, 2-propanol, tert-butyl alcohol, 2,2,2-trifluoroethanol, n itric acid, and acetic acid. Fundamental band strengths are seen to increas e with the electronegativity of the adjacent substituent, though directly a nalogous trends for overtones are less apparent. However, substituent elect ronegativity does parallel the proportional decrease in overtone intensity, relative to the corresponding fundamental. In addition, the intensities ha ve been modeled using a two-parameter, linear-exponential dipole moment fun ction. The agreement between observed and calculated intensities is fair, b ut the overall shapes of the fitted dipole moment functions also parallel t he inductive nature of the substituent. Some tentative rationale for the ob served intensity trends is offered, but definitive claims cannot be made wi thout further investigation. The current results are finally compared to a few studies of C-H-containing compounds, and differences in the respective intensity data are discussed.