Microwave spectrum of silicon difluoride in the excited vibrational states, equilibrium structure, anharmonic potential function, and ν1- ν3 Coriolis resonance

Abstract

The microwave spectrum of SiF 2 was identified in the excited states of the stretching vibrations. It was found that the Coriolis resonance between the v 1 = 1 and v 3 = 1 vibrational states has perturbed very much the spectra of these states. An extensive analysis of the Coriolis resonance gave a very accurate value of the difference between the ν 1 and ν 3 fundamental frequencies, ν 1 - ν 3 = − 15.395 ± 0.001 cm −1 and, thus, gave a strong basis to the assignment of the stretching modes by Khanna et al. An intervibrational-state transition, v 1 = 1, 8 54 ← v 3 = 1, 8 17 was identified. The observed rotational constants in the v 1 = 1 and v 3 = 1 states were combined with those in the ground and v 2 = 1 states by Rao and Curl to obtain the equilibrium structure, harmonic force constants and complete sets of the cubic and the third-order potential constants.