Fig. 2. Transient absorption spectra measured with Ia, IIIa and IVa in acetonitrile. The contour plots in the top row illustrate the sub-ps decay of the excited-state absorption (ESA) and stimulated emission (SE) of the S1 state together with the rise of the charge-separated state (CSS) band. The spectral changes upon charge separation and charge recombination are illustrated in the bottom panel. The band “X” is visible with Ia and IIIa at around 100 ps.
