Light absorption in strongly irradiated long range polar electron transfer systems

Light absorption of long range electron transfer (ET) complexes immersed in polar solvents is analyzed. At sufficiently high laser intensities absorption or emission of multiple photon quanta occurs. In addition, the equilibrium population of the two donor and acceptor electronic states is strongly perturbed from its field-off value. The combination of these two effects results in dramatic variations in the frequency dependence of the absorption cross section as a function of laser intensity. Certain bands in the absorption spectrum can be eliminated simply by changing the laser intensity. For commonly utilized mixed-valence transition metal ET complexes and polar solvents an applied electric field strength of approximate to 10(7) V/cm should be sufficient to induce noticeable changes in the weak-field spectrum.