High-resolution investigation of the excited electronic states of CaSH and SrSH by laser excitation spectroscopy

P. M. Sheridan, M. J. Dick, J. -G. Wang, P. F. Bernath

Research output: Contribution to journalArticlepeer-review

Abstract

A laser ablation/pulsed molecular jet system has been used to record high-resolution laser excitation spectra of the ((C) over tilde (2) A'-(X) over tilde (2)A' transition of CaSH and the (A) over tilde (2) A'-(X) over tilde (2) A', (B) over tilde (2) A"-(X) over tilde (2) A', and (C) over tilde (2) A'-(X) over tilde (2)A' transitions of SrSH. The rotationally-resolved data were analysed using an asymmetric top Hamiltonian (A-reduction) to determine rotational and fine structure parameters. A combined fit of all the newly measured and the previously recorded spectroscopic data for both CaSH and SrSH was performed. In the excited states observed in this study, both species were found to have a bent geometry. The spin-rotation parameters were analysed in terms of the pure precession and unique perturber approximations. In the excited electronic states of SrSH, the large spin-rotation interaction was found to cause perturbations between the K-a = 0 and 1 levels within each state. In the (A) over tilde (2) A' and (B) over tilde (2) A" states of both species, the metal-sulfur bond length was found to decrease relative to the ground state, which is consistent with previous observations of other calcium and strontium radicals.

Original languageEnglish
Pages (from-to)3245-3259
Number of pages15
JournalJournal of Physics B: Atomic, Molecular and Optical Physics
Volume104
Issue number20-21
DOIs
Publication statusPublished - 2006

Keywords

  • PURE ROTATIONAL SPECTRUM
  • ALKALINE-EARTH
  • MILLIMETER/SUBMILLIMETER SPECTRUM
  • LABORATORY DETECTION
  • METAL HYDROSULFIDES
  • TRANSITION
  • MOLECULES
  • FREQUENCIES
  • CALCIUM
  • CANH2

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