ABSORPTION AND EMISSION SPECTRA OF THE NOBLE GAS MONOHALIDES ISOLATED IN INERT MATRICES

Abstract

The noble gas monohalides have been investigated in inert matrices, using both optical absorption and laser-induced emission. The optical absorption spectrum of XeF, produced through the in situ photolysis of samples of $Ar/Xe/F_{2}$ = 200/2/1, showed two absorption bands, centered at 324 and 258 nm, each exhibiting considerable vibronic structure. UV laser and mercury are excitation of similar samples led to two extremely intense emission bands, centered at 24 200 and 18 $600 cm^{-l}$. Similar studies of KrF, XeCl and XeBr have yielded optical absorption bands in the near ultraviolet region, and the corresponding emission bands in the visible region. The vibronic structure of the XeF and KrF absorption bands supports the ionic, charge transfer nature of the excited state, and further arguments indicate that the ground states of XeF and KrF are relatively strongly bound, certainly in excess of a van der Waals’ molecule.