Designing Stability into Thermally Reactive Plumbylenes


We complete the picture of thermally stable and volatile N-heterocyclic metallylenes with the synthesis, structural analysis, and thermal characterization of rac-N2,N3-di-tert-butylbutane-2,3-diamido lead(II) (1Pb). Transamination of bis[bis(trimethylsilyl)amido] lead(II) with the free diamino ligand yields 1Pb in high yield, whereas salt-metathesis leads to oxidative cleavage of the butane backbone and production of acetaldehyde-tert-butylimine. 1Pb itself undergoes [2+2+1] cycloreversion at 150 °C to the same imine, but with a vapour pressure of 1 Torr at 94 °C a wide thermal window is available for use as a vapour deposition precursor.

We contrast this with the the extreme instability of its sisters N2,N3-di-tert-butylethane-2,3-diamido lead(II) (2Pb) and N2,N3-di-tert-butylethylene-2,3-diamido lead(II) (3Pb), which both reductively eliminate Pb(0) at or below room temperature. This is also in start contrast to the stability of the lighter Si, Ge and Sn congeners.


Supplementary material