Effect of ultrafast electron transfer on photon echo signal: Decoherence process in electron-donating solvents

The effect of ultrafast electron transfer (ET) on the coherent state was investigated by means of three pulse photon echo for an azaporphyrin (AzP) derivative, 2,7,12,17-Tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphine, in electron-donating solvents. The peak shift and fwhm of the echo signal substantially decreased in the reactive solvents, indicating that the ultrafast ET affected the coherent state of the chromophore significantly. By integrating the present results in reactive and inert solvents with those previously performed for other systems, the role of the rapid reaction in the decoherence process was discussed from the viewpoints of the strength of the solute–solvent coupling.