Upper Bound to the Ionization Energy of 85Rb2
  We report an upper bound to the ionization energy of 85Rb2 of 31348.0(6) cm-1, which also provides a lower bound to the dissociation energy D0 of 85Rb2+ of 6307.5(6) cm-1. These bounds were measured by the onset of autoionization of excited states of 85Rb2 below the 5s+7p atomic limit. We form 85Rb2 molecules via photoassociation of ultracold 85Rb atoms, and subsequently excite the molecules by single-photon ultraviolet transitions to states above the ionization threshold. 
M. A. Bellos, R. Carollo, J. Banerjee, M. Ascoli, A.-R. Allouche, E.   E. Eyler, P. L. Gould, and W. C. Stwalley
physics.atom-ph physics.chem-ph