Journal of Chemical Physics, Vol.101, No.5, 3549-3557, 1994
Observation of the Pf2 Radical by Resonance-Enhanced Multiphoton Ionization Spectroscopy
We have observed nine new excited electronic states of the PF2 radical in the wave number range 50 000-71 000 cm(-1) via the two photon resonance enhancements they provide in mass resolved multiphoton ionization spectroscopy. We also report ab initio calculations which yield optimized energies, geometries, and vibrational frequencies for the ground states of PF2 and of the PF2+ ion. Energetic considerations, and the observation that the frequencies of the nu(1)’ (symmetric stretch) and nu(2)’ (bending) modes in these excited states closely parallel those of the ground state ion, lead us to conclude that all nine excited states are Rydberg states belonging to series that converge to the ground state ionization limit. Polarization analyses and band contour simulations allow us to identify the electronic symmetries of the first two of these newly identified states (B-2(1) and (2)A(1) respectively) and to provide an estimate of the excited state geometries [r(P-F)approximate to 1.49 Angstrom angle F-P approximate to 109 degrees].