FTIR STUDY OF THE PHOTOCHEMISTRY OF HG AND H-2 IN A NITROGEN MATRIX -FORMATION AND DISSOCIATION OF HGH2 AND HHGHGH

The insertion of Hg into H-2 in a nitrogen matrix at low temperature h as been induced using KrF laser irradiation, and the HgH2 produced is identified by FTIR absorption spectroscopy. This reaction is in compet ition with the E-V transfer from Hg(P-3(1)) to nitrogen, which has als o been observed through the IR emission of vibrationally excited nitro gen. The spectra of isolated and complexed HgH2 have been observed. In the nitrogen matrix, annealing induces a much larger than usual frequ ency shift, which is related to the appearance of a vacancy close to t he HgH2 at its formation. The photochemistry of the HgH2 .. Hg complex es at 249 nm gives a new molecule HHgHgH, which may be dissociated. Th e isolated HgH2 is shown to be very stable under 249 nm irradiation an d is found to dissociate under 193 nm irradiation. All the absorption studies have also been done with deuterated compounds, and the force c onstants of the HgH bonds of the new molecules have been determined.