Analysis of the 4-μm ν1 + ν3 combination band of SO 2

Abstract

The recently measured Doppler-limited spectrum of the 4-μm ν 1 + ν 3 combination band of SO 2 has been analyzed theoretically within the framework of Watson's asymmetric rotor Hamiltonian. The principal lines have been identified with the cold band of 32S 16O 2 and fit to better than 10 −3 cm −1. The residual lines observed in the spectrum have been assigned to the ν 2 hot band of 32S 16O 2 and the cold band of the isotope 34S 16O 2 and fit with similar precision. In addition, a Fermi resonance has been observed in the K A = 13 subband of ν 1 + ν 3 which has permitted a determination of the band center of the interacting 2 ν 2 + ν 3 vibration. The integrated ν 1 + ν 3 band strength for the principal isotope has been measured to be 52.0 ± 2.5 × 10 −20 cm −1/(mol/cm 2).