T-2 selective scanning vibrational echo spectroscopy

Experiments are presented on a mixture of tungsten hexacarbonyl (W(CO)(6)) and (acetylacetonato)dicarbonylrhodium(I) (Rh(CO)(2)acac) in liquid dibutyl phthalate (DBP) in which the spectrum of the asymmetric CO stretching modes (similar to 2000 cm(-1)) is taken by continuously scanning the frequency o f a ps vibrational echo pulse sequence and observing the vibrational echo i ntensity. While the absorption spectrum shows a large solvent background wi th DBP vibrational peaks, the vibrational echo spectrum is background free and contains only the W(CO)(6) and Rh(CO)(2)acac peaks. When the delay betw een the vibrational echo pulses is changed, the ratio of the W(CO)(6) and R h(CO)(2)acac peaks changes because of differences in their homogeneous deph asing times. (C) 1999 Elsevier Science B.V. All rights reserved.