Figure 7.

Isotropic absorbance difference spectra in the spectral range of the C₁₉ = O stretching vibration and C₁ = O stretching vibration. Spectra at different delay times as indicated; dots display the individually measured signal. Normalized C₁₉ = O bleaching signal at 0.4 ps. Excitation at 713 nm (a), at 644 nm (b), and at 400 nm (c).