Ionic Recognition Controlled by Conformational Change: A DFT Investigation.
Renato P Orenha1, Ana L O Andrade1, Renato G Rocha1
1Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, Av. Dr. Armando Salles Oliveira 201, Franca, São Paulo 14404-600, Brazil.
ACS Omega
|May 5, 2025
Summary
This study shows how molecule shapes influence ion recognition. Electron-donating groups favor cation binding, while electron-withdrawing groups favor anion binding, guiding molecular design for specific ion capture.
Area of Science:
- Supramolecular Chemistry
- Computational Chemistry
- Materials Science
Background:
- Ions are critical in material production and impact health and environment.
- Noncovalent interactions are key for controlling ion availability.
- Understanding ion recognition mechanisms is vital for designing functional molecules.
Purpose of the Study:
- Investigate cation and anion recognition by two conformations of a 2,6-bis(1,2,3-triazol-4-yl)pyridine molecule.
- Analyze the influence of molecular conformation and substituent groups on ion binding preferences.
- Elucidate the underlying electronic and electrostatic interactions governing ion recognition.
Main Methods:
- Utilized two distinct molecular conformations of 2,6-bis(1,2,3-triazol-4-yl)pyridine for analysis.
- Employed Energy Decomposition Analysis-Natural Orbitals for Chemical Valence (EDA-NOCV) analysis.
- Investigated interactions with various cations (Li+, Na+, K+) and anions (F-, Cl-, Br-).
Main Results:
- Conformers showed preferential recognition based on ion size: K+ > Na+ > Li+ and Br- > Cl- > F-.
- Smaller ions were preferentially recognized due to stronger electrostatic and orbital interactions (N···cation, C-H···anion bonds).
- Electron-donating groups (-NH2) enhanced cation recognition, while electron-withdrawing groups (-NO2) improved anion recognition.
Conclusions:
- Molecular conformation and substituent effects significantly tune cation and anion recognition.
- Cation recognition by the electron-donating conformer was more favorable than anion recognition by the electron-withdrawing conformer.
- Findings offer insights for designing molecules with tailored ion-binding functionalities.
More Related Videos
10:59Visualizing the Conformational Dynamics of Membrane Receptors Using Single-Molecule FRET
Published on: August 17, 2022
3.1K
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
9.1K
Related Concept Videos
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
777
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
777
01:15¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
1.0K
The axial and equatorial protons in cyclohexane can be distinguished by performing a variable-temperature NMR experiment. In this process, except for one proton, the remaining eleven protons are replaced by deuterium. The deuterium substitution avoids the possible peak splitting caused by the spin-spin coupling between the adjacent protons. The remaining proton flips between the axial and equatorial positions.
1.0K
01:04IR Absorption Frequency: Delocalization
674
Electron delocalization refers to the distribution of electrons across multiple atoms within a molecule rather than being confined to a single atom or bond. This phenomenon is common in systems with conjugated bonds—structures where alternating single and double bonds allow π-electrons to move freely across the network. The movement of electrons stabilizes the molecule and can affect various chemical properties, including vibrational frequencies observed in IR spectroscopy.
In IR...
In IR...
674
01:03IR Frequency Region: Fingerprint Region
645
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...
645
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
23.1K
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given...
23.1K
02:02Chair Conformation of Cyclohexane
14.1K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
14.1K