special efforts were taken to ensure that frequency shifts, which can appear The six lowest rotational transitions of CO have been measured to an from optical misalignment or other sources such as baseline problems, accuracy of {500 Hz. Highly accurate rotational transition frequencies of were insid
Sub-Doppler Measurements of the Rotational Spectrum of 13C16O
✍ Scribed by G. Klapper; F. Lewen; R. Gendriesch; S.P. Belov; G. Winnewisser
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 92 KB
- Volume
- 201
- Category
- Article
- ISSN
- 0022-2852
No coin nor oath required. For personal study only.
✦ Synopsis
The five lowest J rotational transitions of 13 C 16 O have been measured by saturation-dip spectroscopy to an accuracy of about 2 kHz, employing phase-stabilized backward-wave oscillators (BWOs). These highly precise measurements cover the transitions from J ϭ 2 4 1 to J ϭ 6 4 5 with frequencies ranging from 220 to 661 GHz. For each of the five observed rotational transitions, the narrow linewidths of the saturation dips (about 20 kHz) permitted the resolution of the hyperfine splitting for the first time. This splitting is caused by the 13 C-nuclear spin-rotation interaction yielding a value for the nuclear spin-rotation coupling constant of C I ( 13 C 16 O). If combined with the beam measurements (C I ( 13 C 16 O) ϭ 32.63(10) kHz), a slight J-dependence of the spin-rotation coupling constant can be determined (C J ϭ 30 Ϯ 13 Hz). In addition, we have measured in the Doppler-limited mode several higher J rotational line positions of 13 C 16 O up to 991 GHz with an accuracy of 5 kHz. The two line positions ( J ϭ 12 4 11 and J ϭ 14 4 13) were recorded by multiplying BWO frequency with an accuracy of 100 kHz. The rotational transitions J ϭ 17 4 16 and J ϭ 18 4 17 were measured with an accuracy between 15 and 25 kHz by using the Cologne sideband spectrometer for terahertz applications COSSTA.
📜 SIMILAR VOLUMES
High-resolution infrared spectra of the 13 C-methanol OH stretching band, 1 , were obtained by slit-jet absorption spectroscopy at a rotational temperature of 12-15 K. Twenty-eight subbands were assigned within the range of upper state quantum numbers, KЈ ϭ 0 to 2 and JЈ ϭ 0 to 10. The upper state e
In the present work, we study the spectrum of the H 2 Te molecule in the submillimeter-wave and far infrared region. An important aim of this investigation is the further experimental characterization of the anomalous ''four-fold cluster effect'' exhibited by the rotational energy levels in the vibr
The effective operator approach is applied to the calculation of the line positions of two isotopic species, 16 O 12 C 17 O and 16 O 12 C 18 O, of the carbon dioxide molecule. More than 6600 observed line positions of 72 bands of 16 O 12 C 18 O selected from the literature have been used to derive 7
## Abstract The ^13^C NMR spectra of 5‐__O__‐β‐D‐primeverosyl genkwanine and its acetate are studied and assignments are proposed.