Complexes of monatomic zero-valent heavy group 14 elements have only emerged recently as a new class of main-group compounds. While Si(0) and Ge(0) examples have been found in the last decade, monoatomic Sn(0) compounds remain unknown because of their intrinsically high reactivity.

Matthias Driess, Technical University of Berlin, Germany, and colleagues have developed a synthetic approach that allowed them to isolate the first bis(silylene)-stabilized stannylone (pictured), i.e., an Sn(0) complex. To accomplish Sn(0) formation from an Sn(II) complex, the team used K₂Fe(CO)₄ as a reducing agent to obtain the corresponding bis[Fe(CO)₄] tin(0) complex. The tin(0) compound was then isolated successfully after elimination of the Fe(CO)₄ groups with KC₈.

Density functional theory (DFT) calculations confirm the presence of two lone pairs at the Sn(0) atom, as is expected for a genuine tin(0) complex. The synthetic method could also be useful to access other labile zero-valent main-group element complexes.

• A Genuine Stannylone with a Monoatomic Two‐Coordinate Tin(0) Atom Supported by a Bis(silylene) Ligand,
  Matthias Driess, Jian Xu, Chenshu Dai, Shenglai Yao, Jun Zhu,
  Angew. Chem. Int. Ed. 2021.
  https://doi.org/10.1002/anie.202114073