A new aspect of reactivity of the cluster [Pd-3(dppm)(3)(mu(3)-CO)](n+), ([Pd-3](n+), n = 2, 1, 0) with the low-valent metal-metal-bonded Pd-2(dppm)(2)Cl-2 dimer (Pd2Cl2) was observed using electrochemical techniques. The direct reaction between [Pd-3](2+) and Pd2Cl2 in THF at room temperature leads to the known [Pd-3(dppm)(3)(mu(3)-CO)(Cl)](+) ([Pd-3(Cl)](+)) adduct and the monocationic species Pd-2(dppm)(2)Cl+ (very likely as Pd-2(dppm)(2)(Cl)(THF)(+), [Pd2Cl](+)) as unambiguously demonstrated by UV-vis and P-31 NMR spectroscopy. In this case, [Pd-3](2+) acts as a strong Lewis acid toward the labile Cl- ion, which weakly dissociates from Pd2Cl2 (i.e., dissociative mechanism). Host-guest interactions between [Pd-3](2+) and Pd2Cl2 seem unlikely on the basis of computer modeling because of the strong screening of the Pd-Cl fragment by the Ph-dppm groups in Pd2Cl2. The electrogenerated clusters [Pd-3](+) and [Pd-3](0) also react with Pd2Cl2 to unexpectedly form the same oxidized adduct, [Pd-3(Cl)](+), despite the known very low affinity of [Pd-3](+) and [Pd-3](0) toward Cl- ions. The reduced biproduct in this case is the highly reactive zerovalent species "Pd-2(dppm)(2)" or "Pd(dppm)" as demonstrated by quenching with CDCl3 (forming the well-known complex Pd(dppm)Cl-2) or in presence of dppm (forming the known Pd-2(dppm)(3) d(10)-d(10) dimer). To bring these halide-electron exchange reactions to completion for [Pd-3](+) and [Pd-3](0), 0.5 and 1.0 equiv of Pd2Cl2 are necessary, respectively, accounting perfectly for the number of exchanged electrons. The presence of a partial dissociation of Pd2Cl2 into the Cl- ion and the monocation [Pd2Cl](+), which is easier to reduce than Pd2Cl2, is suggested to explain the overall electrochemical results. It is possible to regulate the nature of the species formed from Pd2Cl2 by changing the state of charge of the title cluster.