Contribution of Directional Dihydrogen Interactions in the Supramolecular Assembly of Single Crystals: Quantum Chemical and Structural Investigation of C₁₇H₁₇N₃O₂ Azine

Abstract

Crystalline systems can be organized from several types of intermolecular interactions, among which classical and weak H-bonds are the most common, playing a very important role in the supramolecular assembly. However, in recent years a number of works have considered the influence of the homonuclear dihydrogen interaction, which had been neglected for a long time, to describe the supramolecular assembly of single crystals. In the C17H17N3O2 azine of the present study, a nonclassical dihydrogen interactions (C–H···H–C contact) have appeared in the crystal structure with a fundamental contribution toward the stability of crystalline packing. Nonetheless, an X-ray structural analysis is not conclusive to assess the real importance of the C–H···H–C contact. In order to characterize the nature and implications of C–H···H–C contacts concomitant with the classical interactions, the crystallized compound was evaluated by Hirshfeld surface, Quantum Theory of Atoms in Molecules, natural bond orbital, and Car–Parrinello molecular dynamics. The results establish that these interactions really exist, and their extension is responsible for the cooperative effect on the stability of crystalline packing. We expect that a more thorough understanding and description of homonuclear dihydrogen interactions in the supramolecular assembly of C17H17N3O2 can assist in the crystal engineering of small molecules, offering progress on physical–chemistry parameters of biological and material processes.

Using the Supermolecule Approach To Predict the Nonlinear Optics Potential of a Novel Asymmetric Azine

“…Moreover, parts a and b of Figure show the evidence of nonconventional hydrophobic intermolecular interaction of the type C5–H5···H14–C14 viewed in detailed regions (3) and (8) with symmetry code x , y , 1 + z , distance d (H···H) of 2.27 Å (8), and angle (∠ D–H···A ) of 133.84° (16). The nonconventional interactions of type C–H···H–C predominantly with distance d (H···H) between 2.18 and 2.896 Å agree with past studies. , Geometric and energetic parameters of this type of interaction in azines were analyzed in the literature …”

Chameleon-like Nature of Anagostic Interactions and Its Impact on Metalloaromaticity in Square-Planar Nickel Complexes

“…Furthermore, the recent computational data based on accurate CCSD­(T)-based computations indicate that in addition to the mentioned DCD-related charge transfers and Coulombic contributions, London dispersion stabilization is of crucial importance . It fits well to the current novel findings which highlight a vital role of dispersion stabilization in various C–H containing species. − It is necessary to point out, however, that the nature of the so-called anagostic interactions, where the C–H···M distances are longer, that is ∼2.3–3.0 Å, is significantly less explored and understood with respect to stronger agostic bonding. − ,− The anagostic name has been coined to distinguish repulsive anagostic interactions from typical attractive agostic bonds. − ,− …”

Crystal structure and homopolar dihydrogen interactions in propano‐bridged indigo

“…This kind of C-HÁ Á ÁH-C DHIs (with comparable d i + d e distance) with dominant contribution to the total HS were also reported earlier. [7,22] Other interactions like CÁ Á ÁH and CÁ Á ÁC contribute 15% and 12%, respectively, to the total HS. Thus, the high percentage (49%) of dihydrogen intermolecular contacts in PBI molecule implies its importance in controlling and stabilizing the crystal structure.…”

“…[1][2][3] Among the different types of hydrogen bonds, [4] the exploration of a subclass of hydrogen bonds, [5] specifically HÁ Á ÁH interactions, is relatively limited. The HÁ Á ÁH interactions that include the heteropolar dihydrogen bonds and the homopolar dihydrogen interactions (DHIs), exist in different forms [6] from van der Waals contacts, [2,7] through strong interactions, [8,9] and to even covalent bonds. [10] The heteropolar dihydrogen bond is described as X-HÁ Á ÁH-E bond, one H atom bound to an electronegative atom (X), and the other one bound to another element which behaves as an acceptor.…”

“…[16][17][18] Matta et al, based on QTAIM analyses concluded the existence of HÁ Á ÁH stabilizing interactions in planar biphenyl system, [16] although Bickelhaupt et al, [18] disagreed. However, recent reports have been able to highlight its existence and stability experimentally as well as theoretically in various molecular systems ranging from the metal hydrides, [19,20] alkali-metal amido boranes, [21] lipids, [3] azines, [7] thioureas, [22] to alkanes [2,23,24] and organic crystals. [25] Table S1 summarizes the representative HÁ Á ÁH interactions occurring in various compounds.…”