Intramolecular Metal–Metal Bond Rearrangement in a Pt₂PdHg Heterometallic Cluster Forming a Hg^I–Pd^I Covalent Bond

Reaction of the linear trinuclear complex [Pt2M­(μ-dpmp)2(XylNC)2]­(PF6)2 (M = Pd (1b)) with HgX2 afforded the Pt2PdHg mixed-metal complexes [Pt2PdHgX2(μ-dpmp)2(XylNC)2]­(PF6)2 (X = Cl (2), Br (3), I (4)), which included an unprecedented HgI–PdI covalent bond formed via intramolecular metal–metal bond rearrangement. In contrast, reaction of 1a (M = Pt) with HgCl2 afforded the novel pentagonal-shaped Pt3Hg3 planar cluster [Pt3Hg3Cl4(μ-dpmp)2(XylNC)2]­Cl2(PF6)2 (5).