Group 14 elements exist as various allotropes that enjoy broad applications in material science and electronics industries. With growing interest in recent decades in low-valent main-group chemistry, zerovalent group 14 element complexes have been investigated extensively. Such species, including Si, Ge, Sn and Pb compounds have attracted significant interest on account of their unique electronic structures and their synthetic potential as soluble molecular allotropes. In early studies, the transient zerovalent group 14 element carbonyl complexes E_n(CO)_m (E=Si, Ge, Sn, Pb) were generated at low temperature and detected only spectroscopically. Taking advantage of base-stabilization, significant progress has been achieved, marked by the isolation of monatomic and diatomic carbon(0), silicon(0), germanium(0) and tin(0), complexes as well as a triatomic silicon(0) cluster. Pb⁰ complexes however have not been structurally characterized to date due to their low thermodynamic stability and tendency to decompose to elemental Pb.

Recently, Zhenbo Mo’ group synthesized a novel carboborane bisgermanium-bin ligand and used this ligand to react with Pb Br to obtain the novel cyclic dibromo-bisgermanium-based lead-bin compound. This work reports the isolation and characterization of the first stable zero-valent lead compound, which provides a new idea for the stabilization of binuclear zero-valent group 14 elements compounds, and the elaboration of the electronic structure and reaction properties of this complex deepens the knowledge of the structure and properties of zero-valent lead species. Relevant achievements were published in Angew. Chem. Int. Ed., 2022, DOI: 10.1002/anie.202215146.