The existence of a special type of bound state supported by chemical forces of a different nature from those involved in traditional chemical bonds has been predicted by theory and confirmed by experiment. It is, however, only in the last decade or so that Van der Waals complexes have acquired great relevance as model systems for the study of energy flow and energy deposition during intramolecular inelastic processes. In the present analysis it is shown how even the simple event where energy is exchanged only between internal rotation and the vibrational motion along the Van der Waals (VdW) bond can lend itself to a very detailed and systematic study of the origin of the dominant dynamical couplings which drive the inelastic rearrangements. A computational example is given at the end for the case of argon and molecular nitrogen, as partners moving under the effect of a realistic interaction potential determined from several experimental data.