Stronger-together: the cooperativity of aurophilic interactions.

Crystallographic distances and the electron density of bi- and tri-nuclear gold(I) compounds reveal that the existence of multiple Au⋯Au interactions increases their individual strength in the order of 0.9-2.9 kcal mol -1 . We observed this behaviour both experimentally and theoretically in multinuclear systems, confirming a novel important cooperative character in aurophilic contacts.