Torsion-rotation far-infrared spectrum of O-18 methanol

Autor: R. R. J. Goulding, J. W. C. Johns, I. Mukhopadhyay, Ronald M. Lees, Saibei Zhao
Rok vydání: 1994
Předmět:
Zdroj: International Journal of Infrared and Millimeter Waves. 15:2021-2030
ISSN: 1572-9559
0195-9271
DOI: 10.1007/bf02096274
Popis: High-resolution Fourier transform spectra have been recorded from 15–470 cm−1 for the far-infrared trosion-rotation band of O-18 methanol in the vibrational ground state. So far, 57 subbands have been assigned in the 15–220 cm−1 region for a wide range of rotational and torsional states, and their J-independent origins have been determined to an estimated accuracy of ±0.01 cm−1. The observed origins were found to deviate in many cases by several tenths of a cm−1 from the values calculated with the previous molecular parameters. Together with 4 known microwave origins, the new data have been fitted to a model torsion-rotation Hamiltonian in order to refine the set ofb-type molecular constants for the ground state. With the new parameter set, the experimental subband origins are reproduced with an rms error of ±0.02 cm−1, representing a substantial improvement over the earlier situation. The spectroscopic results have also been of great assistance with our assignments of optically-pumped FIR laser emission in CH3 18OH, in providing FIR data for checking the identification of the IR-pump/FIR-laser transition systems through combination loop relations.
Databáze: OpenAIRE
Externí odkaz: