Investigations on the infrared spectrum of acetylene between 2500 cm^-1and 2800 cm^-1and studies of the resonance effects

Abstract

The Fourier transform infrared spectrum of acetylene between 2500 cm-1 and 2800 cm-1 has been studied at the Doppler limited resolution of 0·0070 cm-1. The combination band v 2 + v 1 5 and the hot bands (v 2 + 2v 5)2,0 ← v 1 5, v 1 ← v 1 5, v 3 ← v 1 4 and (v 2 + v 4 + v 5)2,0 ← v 1 4 have been analysed considering especially the rotational and vibrational l-type resonances. Also the Fermi-type resonance between the υ3 = 1 energy level and the Σ+ u component of the υ2 = υ4 = υ5 = 1 level has been explicitly taken into account. As a result, the vibrational and rotational constants and the resonance parameters for the bands investigated have been obtained.