A Charge-Neutral Self-Assembled L₂Zn₂ Helicate as Bench-Stable Receptor for Anion Recognition at Nanomolar...

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Analytical Chemistry

Background:

• Anion recognition chemistry traditionally uses neutral covalent hosts or charged metal-assembled receptors.
• A gap exists in developing charge-neutral, metal-assembled, and stable anion receptors.
• Existing methods have limitations in combining advantages of covalent and metal-driven approaches.

Purpose of the Study:

• To create a charge-neutral, metal-assembled anion receptor by combining established design strategies.
• To investigate the binding capabilities of a novel hydroxyquinoline-based zinc(II) helicate for dicarboxylate anions.
• To demonstrate a new pathway for designing efficient anion receptors.

Main Methods:

• Synthesis of a double-stranded hydroxyquinoline-based zinc(II) helicate.
• Fluorescence spectroscopy to monitor anion binding.
• Binding studies in dimethyl sulfoxide (DMSO) to determine binding constants.

Main Results:

• A fluorescent, uncharged zinc(II) helicate was successfully synthesized.
• The helicate demonstrated high-fidelity binding of environmentally relevant dicarboxylate anions.
• Binding constants reached up to 145,000,000 M⁻¹ in DMSO at nanomolar concentrations.

Conclusions:

• The developed zinc(II) helicate effectively bridges covalent and metal-driven design principles for anion receptors.
• This work presents a new structural motif for efficient and stable charge-neutral anion recognition.
• The findings open avenues for designing advanced receptors for environmental and analytical applications.