The synthesis and crystal structure of two heteronuclear compounds stabilized by four dipyridylamide (dpa) ligands is reported. Cu2Pd(dpa)(4)Cl-2 (1) and Cu2Pt(dpa)(4)Cl-2 (2) exhibit an approximate D-4 symmetry and a linear metal framework. They are structurally similar to the homotrinuclear complexes M-3(dpa)(4)L-2 already characterized with various transition metals (M = Cr, Co, Ni, Cu, Rh, Flu). With 26 metal valence electrons, they are also isoelectronic to the oxidized form of the tricopper complex [Cu-3(dpa)(4)Cl-2](+) (3), previously characterized and investigated by Berry et al.(10) The magnetic properties and the EPR spectra of 1 and 2 are reported. The results for 1 are interpreted in terms of a weak antiferromagnetic interaction (2J = -7.45 cm(-1) within the framework of the Heisenberg Hamiltonian (H) over cap = -2J(AB) (S) over cap (A) (S) over cap (B)) between the Cu(II) magnetic centers. For 2, the antiferromagnetic interaction sharply decreases to <1 cm(-1). These properties are at variance with those of (3), for which a relatively strong antiferromagnetic interaction (2J = -34 cm(-1)) had been reported. DFT/UB3LYP calculations reproduce the decrease of the magnetic interaction from 3 to 1 and assign it to the role of the nonmagnetic metal in the transference of the superexchange coupling. However, the vanishing of the magnetic interaction in 2 could not be reproduced at this level of theory and is tentatively assigned to spin-orbit coupling.