Extreme metastability in Ar–HCl (v=1) and Ar–DF (v=1)

High resolution optothermal spectra have been obtained for the Ar–HCl and Ar–DF complexes which conclusively show that they do not dissociate on H/D–X vibrational excitation. The observed linewidths place a lower limit on the lifetimes of 500 ns, while time-of-flight considerations indicate that the lifetimes are in excess of 0.4 ms. Stark spectra are also reported, which result in the determination of the (v=1) excited state dipole moments of these complexes.