Intracavity Laser Spectroscopy of NiCl System G: Identification of a [13.0] 2Π3/2 State

Abstract

The (0,0) vibronic band of NiCl system G with a bandhead near 12 961 cm−1 was recorded at high resolution in absorption using intracavity laser spectroscopy (ILS). For the ILS absorption spectra, the NiCl molecules were produced in a nickel hollow cathode, operated with a small amount of CCl4, and line positions were referenced to iodine spectra. Fourier transform (FT) emission spectroscopy was used to record an extensive region of the spectrum used in a vibronic analysis of system G. For the FT spectra, excited NiCl molecules were produced in a high-temperature King-type carbon tube furnace. We show that this transition is the (0,0) vibronic band associated with a newly identified 2Π3/2 excited state and the X2Π3/2 ground state. The molecular constants for the new 2Π3/2 electronic state are derived from the rotational analysis. Improved vibronic constants for the band are obtained from analysis of the FT spectra.