Observation of an excimer emission band of the ArOD van der Waals molecule

Abstract

An excimer emission band attributed to a transition from the first excited state to the ground state of the van der Waals Ar(OD) molecule has been observed in experiments where D2O was dissociated in presence of rare gases by two photons of a quadrupled YAG laser (266 nm). KrOD has also been observed in the same experiments. The ArOD excimer band comprises three main peaks at 313.9, 315.1, and 316.0 nm as well as several minor ones nearer to the main OH (A2 Σ+ ,v=0–X2 Π,v=0) emission band. The emission profile is realistically simulated by a one dimension model using recently published potentials for the excited state and modeling the ground state by that of the ArF X 2 Σ+ state. This result tends to demonstrate that the ground state geometry of Ar(OD) involved in the transition is probably L shaped although the high intensity of the observed excimer band is not satisfactorily explained.