Resonance Raman spectroscopy of matrix-isolated mass-selected Fe3 and Ag3

Abstract

Raman spectroscopy of matrix-isolated, mass-selected Fe3 and Ag3 reveal that both are Jahn–Teller distorted triangular molecules. The observed spectrum of Ag3 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 ωa=119 cm−1, ωe=99 cm−1, k=1.92, and g=0.29. For Fe3, 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 Fe3 the Jahn–Teller distortion is likely small, and a peak at 249 cm−1 is tentatively assigned to its symmetric stretch.