Exploring the Capability of Mechanically Interlocked Molecules in Anion Recognition: A Computational Insight.

Area of Science:

• Supramolecular Chemistry
• Computational Chemistry
• Organic Chemistry

Background:

• Anion recognition is crucial in chemical sensing and drug delivery.
• Catenanes offer unique architectures for molecular recognition.
• Understanding non-covalent interactions like hydrogen and halogen bonds is key to designing effective receptors.

Purpose of the Study:

• To elucidate the role of hydrogen and halogen bonds in anion recognition by a [2]catenane.
• To investigate the impact of varying σ-hole donors on anion binding.
• To quantify the contributions of different bonding types to the recognition process.

Main Methods:

• Synthesis of modified [2]catenanes with different σ-hole donors (Br, Cl, F, Te-CH3).
• Utilized the Gaussian and Kessler-Grieshammer (GKS) Energy Decomposition Analysis (EDA) scheme.
• Employed homodesmotic reactions for energy partitioning.

Main Results:

• The [2]catenane (1) effectively recognizes both spherical and nonspherical anions.
• Chloride (Cl-) and tosylate (TS-) anions showed the most stabilizing interactions.
• Modifying σ-hole donors significantly impacted anion interaction strength, highlighting the role of halogen bonds.

Conclusions:

• Halogen bonds play a pivotal role in the anion recognition capabilities of the studied [2]catenane.
• The strength of the σ-hole donor directly influences the effectiveness of halogen bonding in anion recognition.
• This work provides insights into designing advanced supramolecular systems for selective anion binding.