Resonance Raman spectroscopy of matrix-isolated mass-selected Fe_3 and Ag_3

摘要

Raman spectroscopy of matrix-isolated, mass-selected Fe_3 and Ag_3 reveal that both are Jahn-Teller distorted triangular molecules. The observed spectrum of Ag_3 can be accounted for adequately using an approximate Jahn-Teller potential truncated at the quadratic term [Wedum et al., J. Chem. Phys. 100,6312 (1994)] with parameters #omega#_a = 119 cm~(-1), #omega#_e = 99 cm~(-1) , k = 1.92, and g = 0.29. For Fe_3, the spectrum is more complex, most likely due to the fact that spin-orbit coupling plays an important role in this high-spin cluster in addition to the quadratic Jahn-Teller terms. The overall pattern of the spectrum suggests that in Fe_3 the Jahn-Teller distortion is likely small, and a peak at 249 cm~(-1) is tentatively assigned to its symmetric stretch.