PHOTOIONIZATION SPECTROSCOPY OF THE IN-N-2 VAN-DER-WAALS COMPLEX

A vibrationally resolved electronic spectrum is observed for the metal atom van der Waals complex In-N2. Two electronic band systems are detected with mass resolved two-color photoionization spectroscopy. A lower energy system is observed slightly to the blue of the In (2D←P) atomic asymptote. It is characterized by a progression in the In-N2 stretching mode with a frequency of ω′e=76.7 cm -1. The higher energy system is slightly to the blue of the In ( 4P←-2P) asymptote. It also exhibits a progression in the In-N2 stretch with a frequency of ω′e=87.7 cm-1. Extrapolation of the vibrational progressions leads to determination of the excited state dissociation energies. Energetic cycles based on the electronic transition energies, excited state dissociation energies, and atomic asymptotes lead to a determination of the ground state dissociation energy of D′0=1519 cm-1 (0.188 eV). A single-photon photoionization experiment determines the ionization potential to be 43 372 cm-1 (5.377 eV). This IP value, together with the atomic IP and the ground state neutral dissociation energy, yields a dissociation energy of D′0=4817 cm-1 (0.597 eV) for the In +-N2 ion-molecule complex. © 1995 American Institute of Physics.