Identification of two new excited electronic states of NiCl: Analyses of the (1,0) & (0,0) bands of the [13.5] 2Φ7/2 - [0.16] A 2Δ5/2 and (0,0) band of the [13.8] 2Π1/2 - [0.38] X 2Π1/2 transitions

•ILS spectra and rotational analysis of 2 new electronic transitions of NiCl in the near infrared.•Rotational parameters reported for v = 0.1 of newly observed [13.5] 2Φ7/2 state of NiCl.•Rotational parameters reported for v = 0 of newly observed [13.8] 2Π1/2 state of NiCl.•Comparison of experimentally observed transitions with theoretical calculations.

The near-infrared spectrum of NiCl has been recorded at high resolution in the 13,200-13,500 cm−1 and 13,600-13,750 cm−1 regions using Intracavity Laser Spectroscopy (ILS). The NiCl molecules were produced in the plasma discharge of a Ni-lined copper hollow cathode with 0.3-0.6 torr of argon as the sputter gas, and a trace amount of CCl4. Several electronic transitions were observed, including three transitions involving two previously unreported excited electronic states. The (0,0) and (1,0) bands of the [13.5] 2Φ7/2 - [0.16] A 2Δ5/2 transition were observed near 13,318 cm−1 and 13,709 cm−1, respectively. The (0,0) band of the [13.8] 2Π1/2 - [0.38] X 2Π1/2 transition was observed near 13,480 cm−1. With analysis of these transitions, molecular constants have been obtained for eleven of the twelve predicted NiCl doublets states with term energies less than 16,000 cm−1. Comparison of experimentally observed transitions with the theoretical work is presented.

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