Comment on: High resolution laser spectroscopy of the C̃ 2Δ–X̃ 2Σ+ transition of CaOH and CaOD: Vibronic coupling and the Renner–Teller effect

Spectroscopy of diatomic ZrF and ZrCl: 760-555 nm

The optical spectrum of diatomic ZrF has been investigated, with transitions recorded in the range from 14,700 to 18,000 cm(-1). Many bands have been observed, several of which can be grouped into three band systems. Rotationally resolved investigations are hampered by perturbations that are rampant among the excited states, but three unperturbed bands have revealed that the ground state of ZrF has Ω" = 3/2, with a bond length of r(e)'' = 1.854(1) Å. Hot bands originating from v" = 1 provide the ground state vibrational interval, ΔG(1/2)'' = 691.45(2) cm(-1) for (90)Zr(19)F. Based on comparisons to ZrCl and ligand-field considerations, the ZrF ground state is assigned as a (2)Δ(3/2) level deriving from the 3σ(2) 1δ(1) configuration, in agreement with a previous study. In addition to the measurements on ZrF, vibronically resolved spectra of ZrCl have been recorded over the 13,000 to 18,000 cm(-1) range, and four band systems have been identified.