The microwave spectrum of the SF radical

Abstract

The rotational spectrum of the SF radical in the 2 Π 1 2 state was observed by using a source-modulation microwave spectrometer with a 1-m-long discharge cell. The SF radical was generated directly in the cell by a dc discharge in an OCS CF 4 mixture. A previous measurement of the microwave spectrum in the 2 Π 3 2 state was also extended to higher- J transitions. The least-squares analysis of all the observed spectral lines gave the B 0 rotational constant and the D 0 centrifugal distortion constant to be 16 576.9140(46) and 0.02924(10) MHz, respectively, where the values in parentheses denote 2.5 times the standard deviations. The Λ-doubling constant p v was found to be extremely small, 3.409(44) MHz, and it was presumed that contributions of 2Σ + and 2Σ − states to the Λ doubling cancel each other. All the four fluorine hyperfine coupling constants were also determined, from which the spin density on the F atom was calculated to be 0.13.