Raman spectra of ruthenium and tantalum trimers in argon matrices

The resonance Raman spectra of ruthenium trimers (Ru3) in argon matrices have been obtained. Three resonance Raman transitions were observed between 570 and 590 nm. Two of them (303.4 and 603.7 cm−1) are assigned to the totally symmetric vibrational progression, giving ke=1.86 mdyne/Å. The line at 581.5 cm−1 is assigned as the origin of a low-lying electronic state. We also report on the observation of a resonance Raman spectrum of tantalum trimers (Ta3). Observed lines include 251.2 and 501.9 cm−1 which we assign to the fundamental and the first overtone of the symmetric stretch in Ta3. This gives ke=2.25 mdyne/Å.