Abstract
The pure rotational spectrum of the KS radical (X2Πi) has been recorded using millimeter/submillimeter direct absorption techniques in the range 248-409 GHz. This work is the first laboratory detection of KS by any method. The species was created by the reaction of potassium vapor and CS2 under DC discharge conditions. Twenty-three rotational transitions were measured in both spin-orbit components, Ω=1/2 and Ω=3/2; lambda-doubling splittings were resolved in each substate. These data were analyzed with a 2Π case (a) Hamiltonian, and the rotational, spin-orbit, and lambda-doubling parameters have been determined. The lambda-doubling p-constant was found to be anomalously large, indicating the presence of a 2Σ state that is close by. The detection of KCl in the circumstellar shell of IRC +10216 indicates that potassium is present in the gas phase and may be in the form of other species such as KS.
Export citation and abstract BibTeX RIS