Quantum mechanical calculations, using both CASPT2 and DFT methods, for the model systems (MeMMMe, PhMMPh, (MeMMMe)(C6H6)2, Ar§MMAr§, Ar#MMAr#; M = Cr, Fe, Co; Ar§ = C6H4-2(C6H5), Ar# = C6H3-2,6(C6H3-2,6-Me2)2) are described. These studies were undertaken to provide a multireference description of the metal−metal bond in the simple dimers MeMMMe and PhMMPh (M = Cr, Fe, Co) and to determine the extent of secondary metal−arene interaction involving the flanking aryl rings of the terphenyl ligands in quintuply bonded Ar'CrCrAr' (Ar' = C6H3-2,6(C6H3-2,6-Pri2)2). We show that in the Cr−Cr species the Cr−arene interaction is a feeble one that causes only a small weakening of the quintuple bond. In sharp contrast, in the analogous Fe and Co species strong η6-arene interactions that preclude significant metal−metal bonding are predicted.