OBSERVATION OF THE 4-(3)SIGMA(+)(G), 3-(3)PI(G), 2-(3)DELTA(G), AND B-(3)PI(U) STATES OF K-39(2) BY PERTURBATION FACILITATED OPTICAL-OPTICAL DOUBLE-RESONANCE SPECTROSCOPY

The 4 3Σg+, 3 3Π g, and 2 3Δg states of K2 have been studied by perturbation facilitated optical-optical double resonance spectroscopy for the first time. Molecular constants of those states are derived and compared with theoretical calculations. Varying the trial vibrational quantum numbers of these upper states, absolute vibrational quantum number assignments are obtained by comparison between the observed resolved fluorescence intensities and the calculated Franck-Condon factors. The Rydberg-Klein-Rees potential curves are constructed and compared with theoretical calculations. Finally, the observation of the lowest "dark" vibrational levels of the b 3Πu state by resolved fluorescence from the 2 3Δg state confirmed the absolute vibrational numbering of this state and allowed refinement of the b 3Πu molecular constants. © 1995 American Institute of Physics.