We combined femtosecond (fs) VIS pump–IR probe spectroscopy with fs VIS
pump–supercontinuum probe spectroscopy to characterize the photoreaction of
the hexacoordinated Al(tpfc-Br8)(py)2 in a comprehensive way. Upon fs
excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a
time constant of (250 ± 80) fs to the S2 and S1 electronic excited states.
This is evident from the rise time of the stimulated emission signal in the
visible spectral range. On the same time scale, narrowing of broad infrared
signals in the C=C stretching region around 1500 cm−1 is observed. Energy
redistribution processes are visible in the vibrational and electronic
dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is
detected with a time constant of (95 ± 3) ps. This is tracked by the complete
loss of stimulated emission. Electronic transition of the emerging triplet
absorption band overlaps considerably with the singlet excited
stateabsorption. In contrast, two well separated vibrational marker bands for
triplet formation were identified at 1477 cm−1 and at 1508 cm−1. These marker
bands allow a precise identification of triplet dynamics in corrole systems
