Isolation of Silylene-Ligated Plumbyliumylidene and Diplumbyne

In this study, we present the synthesis and characterization of bis(silylene)-ligated plumbyliumylidene and silylene-ligated diplumbyne. Plumbyliumylidene 2 was obtained through ion–exchange reaction of the bis(silylene)amido lead(II) bromide complex 1 with one equivalent of Na[BAr^F₄] (Ar^F = 3,5-(CF₃)₂-C₆H₃). Density functional theory calculations confirmed the presence of a lone pair on the lead atom in 2. The reduction of compound 2 yielded silylene-ligated diplumbyne 3, which possesses a Pb–Pb single bond and one lone pair on each lead atom. Remarkably, compound 3 underwent single-electron oxidation to regenerate plumbyliumylidene 2, demonstrating a rare redox cycle between the Pb(I) and Pb(II) states. This study enhances the understanding of the electronic structures and redox behavior of low-valent lead compounds.