QTAIM View of Pd…Pd Binding in Complex [Pd<sub>2</sub>(m-Cl) (m-P) (m-N) (m-O)]

The bonding in the Palladium tetra-bridge complex [Pd2(m-Cl) (m-P) (m-N) (m-O)] was investigated using "Atoms in Molecules theory (AIM)". The calculated topological parameters for M-M and M-L interactions, including ρ(b), ∇2ρ(b), G(b), H(b), V(b), and ε(b), as well as the delocalization indices δ(A, B), agree with previous results for organometallic compounds. The Pd1-O1, Pd-P, Pd-Cl, Pd-N and Pd2-O1 core component has a multicenter 3C-8e interaction. The bond critical point and bond bath vanish when four atoms are coordinated to the Pd atom. However, a non-zero delocalization index was computed for this bonding interaction. The estimated topological features for the Pd1-N, Pd1-Cl and Pd1-P bonds confirm that these interactions have a pure bond character. Delocalization indices for the Pd1-N, Pd1-Cl and Pd1-P bonds range in magnitude from 0.127 to 0.301, showing that each pair of linked atoms shares 0.3 to 0.1 electron pairs.