A comparison of metallophilic interactions in group 11[X–M–PH3]n (n = 2–3) complex halides (M = Cu, Ag, Au; X = Cl, Br, I) from density functional theory

Metallophilic interactions in dimeric and trimeric [X–M–PH3]n (n = 2–3) complexes are studied using density functional and second order Møller Plesset perturbation theory together with energy-consistent, small-core scalar-relativistic pseudopotentials and corresponding large sized valence basis sets. A many-body decomposition of the interaction energy shows that the three-body contribution to the metallophilic interaction is repulsive at all levels of theory and non-negligible. However, the two-body contribution of the two end units dominates over the three-body effect, giving a net stabilizing effect in the metal–metal interaction from the dimer to the trimer, and resulting in a further contraction of the trimer metal–metal bond.