Rotational and deperturbation analysis of the (0,0) and (1,0) vibrational bands of the [15.30]1-X 31-(0+) transition of WS

The (0,0) and (1,0) bands of the [15.30]1 - X 31-(0+) transition of tungsten sulfide (WS) were recorded at high resolution using intracavity laser spectroscopy integrated with a Fourier-transform spectrometer for detection (ILS-FTS). The target WS molecules were produced in the plasma discharge of a tungsten-lined copper hollow cathode, using a gas mixture of approximately 70 % Ar and 30 % H2, with a trace amount of CS2. The total pressure in the reaction chamber was about 1 torr. Evidence of heterogeneous mass- and J-dependent perturbations was observed in each spectrum for all four abundant isotopologues: 182W32S, 183W32S, 184W32S, and 186W32S. The perturbations were attributed to interactions with the v = 2 and v = 3 vibrational levels of the [14.26]0+ state of WS. A rotational analysis with deperturbation analysis was performed using PGOPHER to determine parameters for both states. A Dunham-like model which constrains parameters to expected mass relationships was used to describe the perturbed states.