and 690 nm at pH 5.5 and 7.4, while the higher energy band is blue shifted to ca. 510 nm at pH 9.8. This transient species continues to slightly blueshift and its intensity to increase for up to 600 ps in pH 5.5 and 7. practically constant thereafter for up to 3 ns. Lifetimes and evolution-associated difference spectra (EADS) extracted from the global and target analyses are reported in Table and Figure , respectively.