Experimental study of the cold mercury dimer

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).