σ- and π-Hole Interactions

Abstract

Supramolecular chemistry is a very active research field that was initiated in the last century [...]

Noncovalent Bonds through Sigma and Pi-Hole Located on the Same Molecule. Guiding Principles and Comparisons

“…Indeed, it is also of intense interest to examine the result when both of these bonds are present at the same time. As has already been ex- There have been a number of earlier reviews addressing the issue of σ-hole and πhole bonds [13,49,51,52,81,84,105,120,121]. However, little attention has been devoted to situations where both hole types are present on a single molecule, and the competition between the two for a nucleophile.…”

Pd and Pt metal atoms as electron donors in σ-hole bonded complexes

“…[33][34][35][36][37][38][39] Over the years, the investigations of these interactions have moved beyond halogen atoms, hence the development of analogous chalcogen or pnicogen bonds which engender robust study. 36,[40][41][42][43][44] The bulk of bonds of this type utilize either a lone pair of the nucleophile as the source of charge to be transferred, or a p-electron system, either localized as in ethylene, or aromatic. A new wrinkle in this bonding is the finding that there are occasions where metal atoms can serve as the electron source, despite their low electronegativity.…”

“…33–39 Over the years, the investigations of these interactions have moved beyond halogen atoms, hence the development of analogous chalcogen or pnicogen bonds which engender robust study. 36,40–44…”

Computational Insight into the Nature and Strength of the π-Hole Type Chalcogen∙∙∙Chalcogen Interactions in the XO2∙∙∙CH3YCH3 Complexes (X = S, Se, Te; Y = O, S, Se, Te)

“…The former is generally located along the extension of the covalent σ-bond involving a chalcogen atom, while the latter is generally located perpendicular to the σ-framework of the molecular entity. Both σ-holes and π-holes are capable of interacting attractively with Lewis bases, and the formed NCIs are called the σ-hole interactions and π-hole interactions [6,7,[10][11][12][13], respectively. Previous studies disclose that the attractive nature of such interactions is mainly composed of electrostatic, dispersion, and charge transfer interactions [1,14].…”