Anion receptors based on highly fluorinated aromatic scaffolds

Area of Science:

• Supramolecular Chemistry
• Computational Chemistry
• Materials Science

Background:

• Hexafluorobenzene (HFB) scaffolds are explored for molecular recognition.
• Designing effective receptors for small molecules and anions remains a challenge.

Purpose of the Study:

• To investigate novel HFB-based receptors with varying degrees of pentafluorobenzyl substitution.
• To evaluate the complexation energies and interaction mechanisms with diverse guest molecules.
• To establish a design strategy for enhanced molecular recognition.

Main Methods:

• Density Functional Theory (DFT) calculations using the M06L/6-311++G(d,p) level of theory.
• Modeling of receptor-guest complexes, including hexafluorobenzene (HFB), R(I), R(II), and R(III) receptors.
• Analysis of electron density and molecular electrostatic potential to understand interaction mechanisms.

Main Results:

• Complexation energy (E(int)) increases with the number of fluorinated aromatic moieties in the receptor.
• Lone pair-π interactions are identified as the key binding mechanism.
• Receptor R(III) showed the most significant increase in E(int) (1.8-4.7 fold) compared to HFB.
• Specific example: HFB···F(-) E(int) = -21.1 kcal/mol, while R(III)···F(-) E(int) = -50.5 kcal/mol.

Conclusions:

• Tuning lone pair-π interactions is a powerful strategy for designing receptors.
• Substituted HFB scaffolds offer tunable properties for selective molecular recognition.
• These findings pave the way for developing advanced sensors and separation materials.