Flash Communication: Metathesis of Heavy Alkyne Analogues in Solution via Dissociation of ‑Terphenyl Substituted Distannynes and Diplumbynes.

The terphenyl substituted distannynes and diplumbynes ArEEAr (E = Sn, Pb; Ar = Ar, CH-2,6-(CH-2,6-Pr); Ar = Ar, CH-2,6-(CH-2,4,6-Pr)) undergo metathesis and ligand redistribution reactions in solution at ambient temperature to yield mixtures of asymmetrically substituted and heterometallic heavy alkyne analogues. The ambient temperature solution EPR spectrum of ArSnSnAr shows a weak signal corresponding to the (SnAr) radical, and the thermolysis of ArPbPbAr (Ar = CH-3,5-Pr-2,6-(CH-2,4,6-Pr)) in toluene yields the plumbylene Pb-(CHCH)-Ar, also suggesting that a transient Pb-(Ar) radical is liberated on heating. These results provide further evidence to the solution equilibria of the heavy group 14 analogues with the respective one-coordinate metal radicals.