2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16972We present a simple model of electrical transport through a metal-molecule-metal nanojunction that includes charging effects as well as aspects of the electronic structure of the molecule. The interplay of a large charging energy and an asymmetry of the metal-molecule coupling can lead to various effects in non-linear electrical transport. In particular, strong negative differential conductance is observed under certain conditions.7 pages, 5 figures, accepted by Europhys. LettMesoscale and Nanoscale Physicstext