The files provided here are based on the article by:
(1) B. Brupbacher-Gatehouse,
Re-investigation of SF2 Hyperfine Structure using
Transitions in the 26–34 GHz Frequency Range,
J. Mol. Struct. 599 (2001) 51–55.
View the abstract.
The initial hyperfine analysis was presented in:
(2) B. Gatehouse, H. S. P. Müller, M. C. L. Gerry,
19F Spin-Rotation Constants and Shielding Tensor
of Sulphur Difluoride from its Microwave Spectrum,
J. Chem. Phys., 106 (1997) 6916–6922.
View the abstract.
The increased list of transition frequencies with 19F hyperfine splitting obtained in (1) helped the analysis, but the key to a modefied set of nuclear spin-rotation parameters was the rerecording and reanalysis of the J = 1 – 1 transition. It consists of six hyperfine components. Only two features could be idenfied easily in (2) whereas four features were identified in (1) which accounted for all of the six components. The F = 2 – 2 had to be the one lowest in frequency, and the highest frequency feature was caused by the three components 1 – 1, 0 – 1, and 1 – 0. Interestingly, the assignment of the remaining two features to the 1 – 2 and 2 – 1 is not obvious as both assignment choices yield reasonable fits of similar quality. The slightly poorer fit, however, suggests that the feature caused by three HFS components should be rather broad if not barely resolved, in contrast to what has been observed. The alternative assignments changed the spin-rotation parameters somewhat more from the values in (2), but gave a better fit with a calculated spectrum closer to the observed one, and an average shielding parameter better in agreement with that from gas phase NMR measurements.
The first 18 lines are 19F HFS components, the next 5 lines are from (1) and (2), and the remaining lines are from previous work. A set of parameters up to sixth order could not be determined completely. Instead of ΦJK in (1), φJK was used here, which gave a slightly better fit. The nuclear spin-nuclear spin coupling term S was calculated from the structure and was not released in the present fit, even though it is barely determined with significance. But the uncertainty is larger than the deviation from the calculated value would be.