The high-resolution infrared spectrum of isoxazole vapor between 800 and 1700 cm−1

The Fourier transform gas-phase IR spectrum of isoxazole, C3H3NO, between 550 and 1700 cm−1 was measured with a resolution of ca. 0.003 cm−1. Ten fundamental bands in the region 800-1700 cm−1 have been analyzed by the Watson Hamiltonian model to yield upper state spectroscopic constants. A number of local resonances have been identified in the bands and explained qualitatively, and the unobserved ν14(A″) fundamental band has been located at 897.5(5) cm−1 from its perturbation effects on the neighboring fundamentals.