Two-dimensional time-frequency ultrafast infrared vibrational echo spectroscopy.

K A Merchant, D E Thompson, M D Fayer

Index: Phys. Rev. Lett. 86(17) , 3899-902, (2001)

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Abstract

2D spectrally resolved ultrafast (<200 fs) IR vibrational echo experiments were performed on Rh(CO)(2)acac [(acetylacetonato)dicarbonylrhodium (I)]. The 2D spectra display features that reflect the 0-1 and 1-2 transitions and the combination band transition of the symmetric (S) and antisymmetric (A) CO stretching modes. Three oscillations in the data arise from the frequency difference between the S and A modes (quantum beats) and the S and A anharmonicities. A new explanation is given for these "anharmonic" oscillations. Calculations show that spectral resolution enables the 0-1 and 1-2 dephasing to be measured independently.