DISPERSED FLUORESCENCE SPECTROSCOPIC STUDY OF THE GROUND ELECTRONIC STATE OF SILVER TRIMER

Dispersed fluorescence spectra of Ag3 have been recorded for the first time. The experimental data provide the first clear determination of the fundamental vibrational frequencies of the trimer in its ground electronic state, i.e. nu1 almost-equal-to 180 cm-1 and nu2 almost-equal-to 67 cm-1, and also lead to a reassignment of previous Raman work on the molecule. Evidence of significant Jahn-Teller activity in Ag3 is clearly demonstrated by the observation of a progression in the nominally degenerate bending vibrational mode, nu2, in both the excitation and dispersed fluorescence spectra. Our observations are consistent with ab initio calculations which have predicted that the triangular 2E' ground electronic state should undergo significant Jahn-Teller distortion.