The ground-state recovery dynamics of malachite green adsorbed on silica have been studied by picosecond time-resolved surface second harmonic generation. Reaction dynamics were investigated as a function of coverage, laser intensity and wave-length. A fast component was observed to be independent of all three parameters. This suggests that intramolecular motion may be facile in adsorbates, and that energy disposal is efficient for low-frequency modes. In addition an intensity and coverage dependent disruption of the surface layer was detected. This is tentatively assigned to ultrafast multiphoton chemistry of the aggregates formed at high coverage. © 1993.
|Number of pages||8|
|Journal||Chemical Physics Letters|
|Publication status||Published - 1993|