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High-resolution terahertz spectrum of CH2 — Low J rotational transitions near 2 THz.

Authors :
Brünken, S.
Michael, E. A.
Lewen, F.
Giesen, Th.
Ozeki, H.
Winnewisser, G.
Jensen, P.
Herbst, E.
Source :
Canadian Journal of Chemistry. Jun2004, Vol. 82 Issue 6, p676-683. 8p. 3 Diagrams, 1 Chart, 5 Graphs.
Publication Year :
2004

Abstract

The methylene radical (CH2) was very important to Gerhard Herzberg. We have carried out high-resolution spectroscopic measurements on two energetically low-lying, pure rotational transitions of methylene in its ground vibrational–electronic state at frequencies near 2 THz. One of the transitions — the NKaKc = 211 ← 202 multiplet — belongs to ortho-CH2 and is centered at 1.954 THz. The other rotational transition — the NKaKc = 110 ← 101 multiplet — belongs to para-CH2 and is centered at 1.915 THz. Since the ground electronic state of methylene has 3B1 symmetry, the rotational transitions are split into three fine-structure components, while the ortho transitions are split additionally by hyperfine structure. In total, we have measured 29 new lines, six for the para transition and the remainder for the ortho transition. The newly measured lines can be added to high-resolution spectral data obtained by ourselves and others at lower frequencies. Progress towards a global fit is discussed. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00084042
Volume :
82
Issue :
6
Database :
Academic Search Index
Journal :
Canadian Journal of Chemistry
Publication Type :
Academic Journal
Accession number :
14703319
Full Text :
https://doi.org/10.1139/V04-034