Stark field induced perturbations in the ν1 + 3 ν3 vibrational overtone band of acetylene

Abstract

The rotationally resolved, Stark split spectrum of the ν 1 + 3 ν 3 band of acetylene has been investigated with a high resolution molecular beam laser spectrometer. The results indicate a field induced coupling of the vb1030 00 0〉 upper state with the vb0040 00 0〉 state. The number of observed transitions was sufficient to allow a detailed analysis of the field induced coupling. The J-dependent polarisability and anisotropy of the polarisability of the vb1030 00 0〉 state were measured as well as the anisotropy of the polorisability of the ground state (1.071 Å 3). The coupling strength to the vb0040 00 0〉 state, and the origin of the 4 ν m3 band were determined to be 0.0696 D and 12671.50 cm −1. The latter has been compared with predictors made by local mode theory.