No abstract

The mercury dimer is among the most weakly bound metal dimers and has been extensively studied.1 The ground state O+g dissociation energy has been considered to lie between 0.55 eV (440 cm−1) and 0.091 eV (730 cm−1). We report here a spectroscopic study of Hg2 in a supersonic jet. The first optical transition, 1u←O+g, was characterized by its fluorescence excitation spectrum and the binding energy of the ground state has been measured precisely through the threshold of collision induced dissociation of Hg2 1u to Hg(1S0)+Hg(3P0).

Fluorescence excitation spectra of silver–argon van der Waals complexes are presented. An alternative experimental technique to laser evaporation has been used to produce the cold complexes. The van der Waals states observed correlate with the (4d10 5s1) 2S Ag ground state and (4d10 5p1)2P0 Ag first excited state. The excited state of the Ag–Ar complex is found to be 1235 cm−1 deep, which is unusually large for such metal–rare gas complexes. A perturbation due to a state correlating with the (4d9 5s2)2D metastable Ag state is also observed and analyzed.