Hydride-Triel Bonds.

Abstract

In this article, we present the results of our comprehensive studies of 72 dimers of the R3XXH⋯YR3Y type (X = Si, Ge; Y = B, Al, Ga; RX = H, Cl, Me; RY = H, F, Cl, Me) and featuring hydride-triel bonds (i.e., charge-inverted hydrogen bonds). Influence of X and Y atoms as well as RX and RY substituents on various properties of these dimers is investigated in detail. In particular the strength of the H⋯Y hydride-triel bonds is paid a close attention and it is shown that hydride-triel bonds can be strong enough to considerably determine structure and properties of molecular systems. In addition, properties of the investigated dimers are largely governed by the charge transfer from the Lewis base to the Lewis acid, which is particularly important if more bulky and polarizable RY and Y atoms are present in the YR3Y molecule. Several excellent linear (R2 close to 1) and exponential correlations between pairs of diverse parameters are presented. Few instances are discussed where somewhat unexpected bond paths exist between two atoms featuring partial negative charges (e.g., between hydride hydrogen and halogen and between lateral sides of two halogens) showing that in some cases a bond path prefers to link two closely spaced electron-rich atoms instead of two atoms that are expected to form a bond. © 2018 Wiley Periodicals, Inc.