Study of the Nu3 and 2Nu3 < Nu3 Bands of (12)CH3F by Infrared Laser Sideband and Submillimeter-Wave Spectroscopy

摘要

An infrared laser sideband spectrometer operating in the CO2 laser region with 8-0 to 18-GHz sidebands has been used to record 266 transitions in the nu band and 84 transitions in the 2 nu - nu band of 12CH3F. The accuracy of the measured frequencies is estimated to be 1-3 MHz. A millimeter/submillimeter-wave spectrometer has been used to record the spectra of 48 pure rotational transitions in the ground vibrational state and 55 transitions in the nu = 1 vibrational state with an accuracy of 20-90 kHz. The new measurements have been combined with previous radio frequency and infrared laser results to derive sets of constants for the ground, nu = 1, and nu = 2 states for this molecule. Tables of the vibrational dependence of the parameters and of the near coincidences of the nu and 2 nu - nu band transitions with CO2 laser frequencies are given.