  Low-temperature three-terminal transport measurements through a thiol
end-capped Pi -conjugated molecule have been carried out. Electronic
excitations, including zero and finite-bias Kondo-effects have been observed
and studied as a function of magnetic field. Using a simplified two-orbital
model we have accounted for the spin and the electronic configuration of the
first four charge states of the molecule. The charge-dependent couplings to
gate, source and drain electrodes suggest a scenario in which charges and spins
are localized at the ends of the molecule, close to the electrodes.
