The previously reported bis(6-diphenylphosphinoacenaphth-5-yl)mercury (1) was used as ligand for the preparation of the copper(I) complexes, 1 center dot CuCl and [1 center dot Cu(NCMe)]BF4, which were characterized by multinuclear NMR spectroscopy and X-ray crystallography. DFT calculations employing topological analysis of the electron and electron pair densities within the AIM and ELI-D space-partitioning schemes revealed significant metallophilic Hg center dot center dot center dot Cu interactions. Evaluation of noncovalent bonding aspects according to the noncovalent interaction (NCI) index was applied not only for the Cu complexes 1 center dot CuCl and [1 center dot Cu(NCMe)]BF4 but also for the previously reported Ag and Au complexes, namely, [1 center dot MCl] (M = Ag, Au) and [1 center dot M(NCMe)(+) (M = Ag, n = 2; M = Au, n = 0), and facilitated the assignment of attractive dispersive Hg center dot center dot center dot M interactions with the Hg center dot center dot center dot Cu contacts being comparable to the Hg center dot center dot center dot Ag but weaker than the Hg center dot center dot center dot Au interactions. The localization of the attractive noncovalent bonding regions increases in the order Cu < Ag < Au.