Spectroscopic constants for the 2.5 and 3.0 μm bands of acetylene

Abstract

Fourier-transform interferometer and difference-frequency laser spectra of acetylene have been recorded in the 2.5- and 3.0-μm regions, yielding improved rotation-vibration constants for the ν 3 fundamental and its Fermi-resonant partner, ν 2 + ν 4 + ν 5, for their associated hot bands originating in the ν 4 and ν 5 bends, and for the CH stretch-bend combination bands. An analysis of the Fermi resonance gives more reliable estimates for the deperturbed constants and the anharmonic coupling.