Interacting Quantum Atoms and Multipolar Electrostatic Study of XH···π Interactions

ACS Omega, Journal Year: 2023, Volume and Issue: 8(38), P. 34844 - 34851

Published: Sept. 14, 2023

The interaction energies of nine XH···π (X = C, N, and O) benzene-containing van der Waals complexes were analyzed, at the atomic fragment levels, using QTAIM multipolar electrostatics energy partitioning method interacting quantum atoms/fragment (IQA/IQF). These descriptors paired with relative gradient method, which solidifies connection between mechanical properties chemical interpretation. This combination provides a precise understanding, both qualitative quantitative, nature these interactions, are ubiquitous in biochemical systems. formation OH···π NH···π systems is electrostatically driven, Qzz component quadrupole moment benzene carbons charges X H XH. There unexpectedly intramonomeric role X-H O, N) where its electrostatic helps complex covalent thwarts it. However, CH···π governed by exchange-correlation energies, thereby establishing character, as opposed to literature's designation noncovalent interaction. Moreover, dispersion relevant, statically absolute terms, but less relevant compared other components terms complex. Multipolar similar across all

Language: Английский

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Probing Non-Covalent Interactions through Molecular Balances: A REG-IQA Study

Molecules, Journal Year: 2024, Volume and Issue: 29(5), P. 1043 - 1043

Published: Feb. 28, 2024

The interaction energies of two series molecular balances (1-X with X = H, Me, OMe, NMe2 and 2-Y Y CN, NO2, NMe2) designed to probe carbonyl…carbonyl interactions were analysed at the B3LYP/6-311++G(d,p)-D3 level theory using energy partitioning method Interacting Quantum Atoms/Fragments (IQA/IQF). partitioned are by Relative Energy Gradient (REG) method, which calculates correlation between these total a system, thereby explaining role atoms have in energetic behaviour system. traditional “back-of-the-envelope” open closed conformations do not correspond those lowest energy. Hence, more care needs be taken when considering geometries use for comparison experiment. REG-IQA shows that 1-H 1-OMe behave differently 1-Me 1-NMe2 because latter show prominent electrostatics carbonyl groups undergoes larger dihedral rotation due bulkiness functional groups. For balance, same across as balances. From an atomistic point view, formation conformer is favoured polarisation charge-transfer effects on amide bond all counterbalanced de-pyramidalisation nitrogen. Moreover, focusing oxygen α-carbon remaining group, major conformer, goes against well-known n-π* orbital overlap concept. However, REG-IQF exchange–correlation overtake working fragments around groups, while they act par 1-NMe2. also balance correlated inductive electron-donating -withdrawing trends aromatic We demonstrate methods such REG-IQA/IQF can help fine-tuning prior experiment govern probed highly dependent involved.

Language: Английский

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Section Introduction: The Analysis of Chemical Bonding and the Interpretation of Wave Functions‘Are we there yet?’

Elsevier eBooks, Journal Year: 2023, Volume and Issue: unknown, P. 1 - 12

Published: Sept. 12, 2023

Language: Английский

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