Fate of Excited Molecule in Solution

The fate of an excited molecule depends on the rates (time scales) of competing processes. As already mentioned above, the time scale for photon absorption (A) is very 

---

In the case of optical pulse excitation of molecules we use the incoming solutions E, n ) because the nature of the system in the remote past is already known to us and we are interested in determining the fate of the system in the distant future. 

Abstract It is well known that solvents can modify the frequency and intensity of the solute spectral bands, the thermodynamics and kinetics of chemical reactions, the strength of molecular interactions or the fate of solute excited states. The theoretical study of solvent effects is quite complicated since the presence of the solvent introduces additional difficulties with respect to the smdy of analogous problems in gas phase. The mean field approximation (MFA) is used for many of the most employed solvent effect theories as it permits to reduce the computational cost associated to the smdy of processes in solution. In this chapter we revise the performance of ASEP/MD, a quanmm mechanics/molecular mechanics method developed in our laboratory that makes use of this approximation. It permits to combine state of the art calculations of the solute electron distribution with a detailed, microscopic, description of the solvent. As examples of application of the method we smdy solvent effects on the absorption spectra of some molecules involved in photoisomerization processes of biological systems. 

---