Turning a Transition State into a Minimum—The Nature of the Bonding in Diplumbylene Compounds RPbPbR (R=H, Ar)

Quantum-chemical calculations at the B3LYP level show that the bulky ligands Ar*=2,6-Ph2C6H3 in Ar*PbPbAr* yield the trans-bent equilibrium structure shown as the lowest lying energy minimum form. There is no Pb−Pb π bond in Ar*PbPbAr*. The parent compounds PhPbPbPh and HPbPbH have doubly bridged energy minima structures.