Competition between a Tetrel and Halogen Bond to a Common Lewis Acid

Authors

Steve Scheiner, Utah State UniversityFollow

Document Type

Article

Journal/Book Title

The Journal of Physical Chemistry A

Publication Date

12-22-2020

Publisher

American Chemical Society

Award Number

NSF, Division of Chemistry (CHE) 1954310

Funder

NSF, Division of Chemistry (CHE)

Volume

125

Issue

1

First Page

308

Last Page

316

Abstract

The T and X atoms of TF₃X (T = C, Si, Ge, Sn; X = Cl, Br, I) can engage in a tetrel or halogen bond, respectively, with an approaching NH₃ base. With the exception of T = C, the tetrel bonds are considerably stronger than the halogen bond regardless of the nature of T or X. Because both bonds involve electron acceptance by the central TF₃X Lewis acid, there is a negative cooperativity between these two bonds when both are present. The halogen bond is weakened much more than is the tetrel bond and is in fact completely disrupted in some cases. Replacement of the three F substituents on TF3X by H attenuates the σ-holes on both T and X atoms, weakens and stretches both bonds, and eliminates any halogen bonds involving Cl. Even in those cases where a halogen bond does occur in the dimer, this bond cannot withstand the presence of a simultaneous tetrel bond and so disappears.

Recommended Citation

Steve Scheiner. Competition between a Tetrel and Halogen Bond to a Common Lewis Acid.The Journal of Physical Chemistry A 2021 125 (1), 308-316. https://doi.org/10.1021/acs.jpca.0c10060