Spectroscopy and relaxation of Pb2 in rare gas solids

Abstract

Study of emission and laser excitation spectra of the Pb₂ diatomic species in rare gas solids provides a value of 112 cm⁻¹ for the vibrational frequency in the ground (probably X 0_g⁺) state of the molecule. In light of this conclusion we re‐examined and reassigned the existing gas phase data. We observe that internal conversions into nearby electronic states are fast compared with direct vibrational relaxation within the upper state. The matrix data provide evidence for at least four other low lying electronic states.