High-Resolution Fourier Transform Spectra of AsH3: The Vibrational Bands 2ν2(A1), ν2 + ν4(E), ν1(A1), and ν3(E)

Abstract High-resolution Fourier transform spectra of arsine, AsH 3 , have been recorded between 1750 and 2300 cm −1 at a resolution of 0.0023 cm −1 . More than 7000 transitions (from a total number of 10 600) including nearly 3000 "forbidden" (or "perturbation allowed") have been assigned to the 2ν 2 ( A 1 ), ν 2 + ν 4 ( E ), ν 1 ( A 1 ), and ν 3 ( E ) vibrational bands. The A 1 - A 2 splittings of the levels with quantum number K = 1, 2, 4, 5, and 7 for perpendicular bands and K = 3, and 6 for parallel bands have been observed. The rotational, centrifugal distortion, and Coriolis interaction parameters were obtained by fitting to experimental energy levels. The parameters obtained reproduce the initial data with residuals close to the accuracy of the experimental measurements.