  In order to study the tunneling of electrons through an interacting, 1D,
dimerized molecule connected to leads, we consider the persistent current in a
ring embedding this molecule. We find numerically that, for spinless fermions,
a molecule with a gap mostly due to interactions, i.e. a Mott-Hubbard gap,
gives rise to a larger persistent current than a molecule with the same gap,
but due only to the dimerization. In both cases, the tunneling current
decreases exponentially with the size of the molecule, but more slowly in the
interacting case. Implications for molecular electronic are briefly discussed.
