A photodissociation study of HgI2

The photodissociation of jet‐cooled HgI2 has been studied in the 244–323 nm region using a tunable ultraviolet (UV) laser. Dispersed emission, action, and multiphoton ionization spectra have been recorded. A vibrational analysis of the action spectra near 305 nm shows that the production of excited Hg atoms from HgI2 UV photodissociation proceeds through a HgI ground‐state intermediate. Near 248 nm the results are less conclusive. Possible reasons for a wavelength‐dependent kinetic mechanism are discussed.