Aryl C-H···Cl(-) hydrogen bonding in a fluorescent anion sensor

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Chemical Sensing

Background:

• Anion recognition is crucial in biological and chemical processes.
• Designing receptors with specific hydrogen bond donors is key for selective anion binding.
• Phenyl-acetylene motifs offer unique electronic and structural properties for molecular design.

Purpose of the Study:

• To synthesize and characterize a novel phenyl-acetylene receptor.
• To investigate the activation of anion binding through a carbonaceous hydrogen bond donor.
• To explore the role of stabilizing urea groups in enhancing receptor stability and binding affinity.

Main Methods:

• Synthesis of a new phenyl-acetylene based receptor molecule.
• Anion binding studies using Nuclear Magnetic Resonance (NMR) spectroscopy.
• Solid-state characterization using X-ray crystallography to confirm structural features.

Main Results:

• The new receptor effectively activates anion binding, specifically chloride ions.
• A unique carbon-hydrogen (CH) to chloride (Cl-) hydrogen bond was identified as the primary interaction.
• NMR data revealed significant chemical shifts, confirming the CH···Cl(-) interaction in solution.
• Crystallographic analysis showed a short, linear CH···Cl(-) contact, validating the hydrogen bond in the solid state.

Conclusions:

• The developed phenyl-acetylene receptor demonstrates efficient anion binding activation.
• The study highlights the potential of carbonaceous hydrogen bond donors in supramolecular chemistry.
• This work provides a foundation for designing advanced sensors and recognition systems for anions.