High-resolution fourier transform infrared spectroscopy of vinyl alcohol: Rotational analysis of the nu(13) CH2 wagging fundamental at 817 cm(-1)

The first high-resolution infrared spectra of the unstable molecule vinyl a lcohol are reported. The spectra have been obtained using a new precursor, 2-chloroethanol, which when pyrolyzed at 1050 degrees C gives strong infrar ed spectra of vinyl alcohol free of interfering hydrocarbon absorption band s. In this work, we have analyzed the strong v(13) fundamental at 817 cm(-1 ) and substantially improved the ground state rotational constants by a sim ultaneous fitting of previous microwave data and a large number of infrared combination differences. The 13(1) upper state was found to be perturbed b y the 15(2) "dark" state at 775.7 cm(-1), and a complete analysis of the pe rturbed rotational structure has been achieved using an interacting two-sta te model. Further small perturbations at high K-a, and J have been identifi ed as interactions with the v(10) and v(12) fundamentals at 948 and 960 cm( -1), respectively. (C) 1999 Academic Press.