Abstract
Fluorescence excitation spectra of the ion-molecule complexes C6F+6•Xn(X = He, Ne, Ar or N2) are reported. It is shown that such data can be used to test model potentials for these complexes. Forn= 1 and X = He and Ne, a simple long-range model of the interaction potential is nearly adequate, but for X = Ar it appears that a substantial charge-transfer component to the interaction is required.