  Molecular systems containing donor-bridge-acceptor sites or molecular
antennas constitute promising candidates for organic photovoltaic device
implementation. Photo-induced electron transfer in multi-chromophore molecular
systems is defined by a subtle interaction between the donor and the molecular
bridge, and by the system-solvent coupling. Here, we address the computation of
quantum properties such as population inversion and electron transfer in
molecular photo-systems composed of fulleroisoxazoline, fulleropyrrolidine,
BODIPY and Zn-porphyrin, as well as their system-solvent ultrafast dynamics.
The molecular complexes are modelled as two- and three-site systems, and we use
the density functional theory (DFT) for obtaining the site energies required in
the construction of the open system diabatic Hamiltonians relevant to the
computation of the electron transfer. The site energies and electronic
couplings are calculated by using a continuous polarizable model that allow for
the analysis of different solvent environments, and the site-to-site couplings
are computed by means of the generalized Mulliken Hush method at the DFT level.
We find that the stabilization energy of the charge transfer states exhibit a
significant variation for a compound embedded in different polar environments,
and thus the effect due to the solvent has been analyzed for the specific cases
of Methanol, THF and Toluene. We show that the incorporation of a molecular
bridge generates the creation of an intermediate state that plays a crucial
role in the charge transfer process by defining $\Lambda$ or cascaded-type
energy schemes; this affects the asymptotic value of the transfer rate and
favors the cascaded-type configuration.
