Terahertz Spectroscopy and Global Analysis of the Bending Vibrations of Acetylene 12C2D2
Abstract
Two hundred and fifty-one 12C2D2 transitions have been measured in the 0.2-1.6 THz region of its ν5-ν4 difference band and 202 of them were observed for the first time. The accuracy of these measurements is estimated to be ranging from 50 kHz to 100 kHz. The 12C2D2 molecules were generated under room temperature by passing 120-150 mTorr D2O vapor through calcium carbide (CaC2) powder. A multistate analysis was carried out for the bending vibrational modes ν4 and ν5 of 12C2D2, which includes the lines observed in this work and prior microwave, far-infrared and infrared data on the pure bending levels. Significantly improved molecular parameters were obtained for 12C2D2 by adding the new measurements to the old data set, which had only 10 lines with microwave measurement precision. New frequency and intensity predictions have been made based on the obtained molecular parameters. The more precise measurements and new predictions reported here will support the analyses of astronomical observations by the future high-resolution spectroscopy telescopes such as Herschel, SOFIA, and ALMA, which will work in the terahertz spectral region.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2009
- DOI:
- 10.1088/0004-637X/698/2/2114
- Bibcode:
- 2009ApJ...698.2114Y
- Keywords:
-
- catalogs;
- ISM: molecules;
- methods: laboratory;
- molecular data;
- techniques: spectroscopic