Ultrafast time-resolved electronic spectra of the primary events induced in the copper tetrasulfonatedphthalocyanine Cu(tsPc)4-) in aqueous solution has been measured by femtosecond pump−probe transientabsorption spectroscopy. The primary events initiated by the absorption of a photon occurring within thefemtosecond time scale are discussed on the basis of the electron transfer mechanism between the adjacentphthalocyanine rings proposed recently in our laboratory. The femtosecond transient absorption results arecompared with the low temperature emission spectra obtained with Raman spectroscopy and the voltammetriccurves.
