Document Type
Article
Journal/Book Title
Phyical Chemistry Chemical Physics
Publication Date
4-30-2019
Publisher
Royal Society of Chemistry
Issue
20
First Page
1
Last Page
24
Abstract
One of several tetrel (T) atoms was covalently attached to three F atoms and a substituted phenyl ring. A NH3 base can form a tetrel bond with TF3C6H2R3(T = Si, Ge, Sn, Pb; R = H, F, CH3) in a position opposite either an F atom or the ring. The σ-hole opposite the highly electron-withdrawing F (T-F) is more intense than that opposite the ring (T-C). However, when the Lewis base deforms from a tetrahedral to a trigonal bipyramidal shape so as to accommodate the base, it is the T-C σ-hole that is more intense. Accordingly, it is the T-C tetrel-bonded complex for which there is a larger interaction energy with NH3, as high as 34 kcal/mol. Countering this trend, it requires more energy for the TF3C6H2R3 to deform into the geometry it adopts within the T-C complex than within its T-F counterpart. There is consequently a balance between the overall binding energies of the two competing sites. The smaller tetrel atoms Si and Ge, with their larger deformation energies, show a preference for T-F tetrel binding, while the T-C site is preferred by Pb which suffers from a smaller degree of deformation energy. There is a near balance for T=Sn and the two sites show comparable binding energies.
Recommended Citation
Wysokiński, R., Michalczyk, M., Zierkiewicz, W., Scheiner, S. I. (2019). Influence of monomer deformation on the competition between two types of σ-holes in tetrel bonds. Phys. Chem. Chem. Phys., 21(20), 10336-10346. http://dx.doi.org/10.1039/C9CP01759C
