[2]Rotaxanes Bearing a Tetralactam Macrocycle: The Role of a Trifurcated Hydrogen Bond in the Crystalline State

Abstract

This study investigated the proper classification and quantification of intercomponent trifurcated hydrogen bonds, in the crystalline state, of rotaxanes bearing a tetralactam Leigh‐type macrocycle. Quantum mechanical calculations were carried out to obtain the interaction paths and their stabilization energies. In general, the use and necessity of fragmentation in types of interaction have been reported in the literature, although they are commonly performed only using a geometric approach. This results in N–H···O interactions that are indicated as the main interactions between components, neglecting other possible interactions. The use of energetic fragmentation was demonstrated here under an appropriate demarcation considering all interactions and showing the existence and role of the C–H···O interaction. The C–H···O interactions showed similar energy to N–H···O interactions with average values around –4.75 kcal mol–1 and –4.60 kcal mol–1, respectively. This revealed that the three hydrogen bonds are part of a cooperative set of interactions with a similar contribution. The trifurcated hydrogen bonds presented high contribution in the total intercomponent stabilization energy of the rotaxanes, with an average value of 51 % in the studied series.

Uncovering the origins of supramolecular similarity in a series of benzimidazole structures

“…The quantum theory of atoms in molecules (QTAIM) was used to obtain all the interactions present in each dimer, 43,51 and the fragmentation of the dimer energy in each interaction was performed by G AI analyses to obtain the stabilization energy of each interaction path (Table S9 †). 19,44 Fig. 7a shows the most energetic dimers of compound 1, in which dimer M1⋯M13, the most energetic (−20.18 kcal mol −1 ), has eight interaction paths, mostly π⋯π interactions (Table S9 †).…”

“…The presence of intermolecular interaction is given by a bond critical point (BCP) within the bond path, which connects two interacting atoms. 43 Stabilization energy in each atom⋯atom interaction was obtained utilizing G AI analysis determined by G AI(X⋯Y) = ((ρ BCP /Σρ BCP ) × G M1⋯MN ), 19,44 correlating QTAIM data (ρ BCP ) and the stabilization energy of the considered dimer. The MEP maps were built on the electron density 0.001 a.u.…”

π-Stacking Stopper-Macrocycle Stabilized Dynamically Interlocked [2]Rotaxanes

“…To verify the intercomponent stabilization [ 52 , 53 , 54 , 55 , 56 , 57 ], rotaxanes with stronger π-stacking interaction were synthesized. Dialdehyde 1 was selected due to its conjugated aromatic structure.…”

Persistence of N—H···O═C Interactions in the Crystallization Mechanisms of Trisubstituted Bis-Ureas with Bulky Substituents

“…The QTAIM analysis indicates the presence of intermolecular interactions from a bond critical point (BCP) of attachment along the path that connects two interacting atoms . The stabilization energy in each atom···atom interaction, for the proposed first nuclei of each compound, was obtained utilizing the G AI analysis ,, determined by G AI(X···Y) = (ρ BCP /Σρ BCP ) × G M1···M N , correlating QTAIM data (ρ BCP ) and the stabilization energy of the considered dimer.…”

“…The QTAIM analysis indicates the presence of intermolecular interactions from a bond critical point (BCP) of attachment along the path that connects two interacting atoms. 36 The stabilization energy in each atom•••atom interaction, for the proposed first nuclei of each compound, was obtained utilizing the G AI analysis 15,37,38…”