6-Diphenylphosphinoacenaphth-5-yl-mercurials as ligands for d(10) metals. Observation of closed-shell interactions of the type Hg(II)···M; M = Hg(II), Ag(I), Au(I).

The salt metathesis reaction of ArLi with HgCl2 produced Ar2Hg (1, Ar = 6-Ph2P-Ace-5), which underwent complex formation with d(10)-configurated transition metal chlorides and triflates to give the complexes 1·HgCl2, 1·Hg(O3SCF3)2, 1·AgCl, 1·Ag(O3SCF3), [1·Ag(NCMe)2](O3SCF3), 1·AuCl, and [1·Au](O3SCF3) comprising significant metallophilic interactions between Hg(II) and Hg(II), Ag(I), and Au(I), respectively. The transmetalation reaction of ArSnBu3 with HgCl2 afforded ArHgCl (2) that also forms a complex with additional HgCl2, namely, 2·HgCl2, which however lacks metallophilic interactions. Compounds 2 and 1·HgCl2 possess the same elemental composition and can be interconverted in solution by choice of the solvent. In the presence of tetrahydrothiophene (tht), the complexes 1·AuCl and [1·Au](O3SCF3) underwent rearrangement into the Au(III) cation [cis-Ar2Au](+) ([3](+), which was isolated as Cl(-) and (O3SCF3)(-) salts) and elemental Hg. The reaction of 1·Hg(O3SCF3)2 with ArH produced the complex ArHg(ArH)(O3SCF3) (4). The metallophilic interactions are theoretically analyzed by a set of real-space bonding indicators derived from the atoms-in-molecules (AIM) and electron localizability indicator (ELI) space-partitioning schemes.