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] A2Δ5/2 and (0,0) band of the [13.8] 2Π1/2 – [0.38] X2Π1/2 transitions

Abstract

The near-infrared spectrum of NiCl has been recorded at high resolution in the 13,200–13,500cm−1 and 13,600–13,750cm−1 regions using Intracavity Laser Spectroscopy (ILS). The NiCl molecules were produced in the plasma discharge of a Ni-lined copper hollow cathode with 0.3–0.6torr 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] A2Δ5/2 transition were observed near 13,318cm−1 and 13,709cm−1, respectively. The (0,0) band of the [13.8]2Π1/2 – [0.38]X2Π1/2 transition was observed near 13,480cm−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 16,000cm−1. Comparison of experimentally observed transitions with the theoretical work is presented.