  Ultrafast reaction processes take place when resonant features of nonlinear
model systems are taken into account. In the targeted energy or electron
transfer dimer model this is accomplished through the implementation of
nonlinear oscillators with opposing types of nonlinearities, one attractive
while the second repulsive. In the present work we show that this resonant
behavior survives if we take into account the vibrational degrees of freedom as
well. After giving a summary on the basic formalism of chemical reactions we
show that resonant electron transfer can be assisted by vibrations. We find the
condition for this efficient transfer and show that in the case of additional
interaction with noise a distinct non-Arrhenius behavior develops that is
markedly different from the usual Kramers-like activated transfer.
