Experimental and Theoretical Evidence of a Pb⋅⋅⋅Pb Ditetrel Bond Without a σ-Hole

Chemphyschem. 2022 Jul 19;23(14):e202200306. doi: 10.1002/cphc.202200306. Epub 2022 May 30.

Abstract

The crystal structure of a newly synthesized compound, [PbL(Ac)]2 , (where L=2 (amino(pyrazin-2-yl) methylene) hydrazinecarbothioamide, Ac=acetate anion) exhibits a close contact between pairs of Pb atoms, suggesting a ditetrel bond, in addition to two Pb⋅⋅⋅O tetrel bonds, and two C-H⋅⋅⋅O H-bonds. The presence of this ditetrel bond as an attractive component is confirmed by various quantum chemical methods. This novelty of this particular bond is its existence even in the absence of a σ-hole on the Pb atom, which is typically considered a prerequisite for a bond of this type. From a wider perspective, a survey of the Cambridge Structural Database suggests this bond may be more common than was hitherto thought, with 44 examples of Pb⋅⋅⋅Pb contacts amongst a total number of 219 examples of T⋅⋅⋅T interactions in general (T=Si, Ge, Sn, Pb).

Keywords: crystal structure; energy decomposition; noncovalent bonds; tetrel bond; σ-hole.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anions
  • Lead*
  • Models, Molecular

Substances

  • Anions
  • Lead