Rotational spectra of the thiosulfeno radical, HSS and DSS, between 0.3 and 0.9 THz

The rotational spectra of the HSS and DSS radicals were studied in selected regions between 331 and 883 GHz. The radicals were produced by discharging a gaseous mixture of hydrogen (or deuterium) and hydrogen sulfide in the c ell. The observation of the b-type Q-branch and R-branch lines with K-a = 2 -1 and 3-2 for HSS and DSS, respectively, as well as the a-type R-branch li nes allowed the improvement and the determination of the molecular constant s among them (in MHz) [GRAPHICS] We have reevaluated the harmonic force field of HSS and the ground state av erage and approximate equilibrium structural parameters. For the latter, we obtained r(HS) = 135.23 pm, r(SS) = 196.03 pm, and angle = 101.74 degrees. These results are compared with those from previous and own quantum chemic al calculations as well as with results of related molecules, (C) 2000 Acad emic Press.