Weak metal−metal bonds between 3d transition metals in organometallic species have received only little attention. The few theoretical analyses that have addressed them so far have often understated the role of intramolecular London dispersion (van der Waals) forces, concentrating on covalency as a prerequisite for stable metal−metal bonds. The electronic structure and structural features of a series of 34-electrons syn-facial Cr−Mn benzylic complexes were investigated in light of a statistical study of the geometrical properties of 14 structures obtained by X-ray diffraction analysis. The statistical study shows that the Cr-to-Mn distance dm is rather independent of the nature and steric size of the substituents present at the benzylic carbon as well at remote position such as the donor ligand. The distance dm, which amounts to an average value of ca. 3.04 A is related to a weak but real attractive bonding interaction whereby London dispersion prevails over covalency and donor−acceptor interactions, as s...