Laser-induced fluorescence and Fourier transform spectroscopy of NiCl: Identification of a low-lying (2)Sigma(+) state (1768 cm(-1))

From a comparison with the spectrum of NiF, a low-lying (2)Sigma (+) state is expected to lie in the first 2000 cm(-1) above the ground X(2)Pi (3/2) s tate of NiCl. The identification of this (2)Sigma (+) (v = 0) state (at 176 8 cm(-1)) has been carried out through the analysis of two electronic trans itions (2)Pi (3/2) - (2)Sigma (+) (22 720 cm(-1)) and (2)Pi (1/2) - (2)Sigm a (+) (23 210 cm(-1)) recorded by high-resolution Fourier transform spectro scopy. Dispersed fluorescence spectroscopy allowed these transitions to be located on an absolute energy-level diagram that includes the previously st udied electronic states. (C) 2000 Academic Press.