Boron-lead multiple bonds in the PbB2O- and PbB3O2- clusters

Despite its electron deficiency, boron can form multiple bonds with a variety of elements. However, multiple bonds between boron and main-group metal elements are relatively rare. Here we report the observation of boron-lead multiple bonds in PbB2O- and PbB3O2-, which are produced and characterized in a cluster beam. PbB2O- is found to have an openshell linear structure, in which the bond order of B Pb is 2.5, while the closed-shell [Pb B-B O](2-) contains a B Pb triple bond. PbB3O2- is shown to have a Y-shaped structure with a terminal B = Pb double bond coordinated by two boronyl ligands. Comparison between [Pb B-B O](2-)/[Pb=B(B O)(2)](-) and the isoelectronic [Pb B-C O](-)/[Pb=B(C O)(2)](+) carbonyl counterparts further reveals transition-metal-like behaviors for the central B atoms. Additional theoretical studies show that Ge and Sn can form similar boron species as Pb, suggesting the possibilities to synthesize new compounds containing multiple boron bonds with heavy group-14 elements.

Automated summary

This study reports the observation of boron-lead multiple bonds and characterizes their structural features. The experimental results show transition-metal-like behaviors for the central B atoms. Additionally, theoretical studies suggest the possibility of similar boron species with heavy group-14 elements like Ge and Sn.