Ultrafast Raman echoes in liquid acetonitrile

Abstract

Raman echoes are observed for the first time in the liquid phase. The symmetric methyl stretch of acetonitrile is shown to be homogeneously broadened, in disagreement with time-resolved coherent Raman scattering experiments and recent theory, but in agreement with line-shape studies and computer simulations. The vibration interacts primarily with rapid, collisional solvent motions, not with long-lived structural features.