Dilithioplumbole: A Lead-Bearing Aromatic Cyclopentadienyl Analog

Aromatic Lead The bond stabilization, or aromaticity, observed in cyclic carbon molecules, such as benzene, relies on delocalization of electrons around the ring. Although electron distributions in heavier elements can complicate this arrangement, Saito et al. (p. 339 ) show that even lead, one of the heaviest metals, is able to participate in an otherwise carbon-based aromatic network. In an analog of the well-studied cyclopentadienyl anion, one carbon atom was replaced with lead, and the framework stabilized by appending phenyl groups to the other four carbons. Crystallography revealed a planar structure, which together with spectroscopic data and theoretical calculations confirmed the aromatic character of the product.