Are beryllium-containing biphenyl derivatives efficient anion sponges?

Area of Science:

• Theoretical Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Anion recognition and binding are crucial in various chemical and biological processes.
• Developing effective anion receptors, or "anion sponges," is an active area of research.
• Beryllium-containing compounds are known for their Lewis acidity and potential for anion interactions.

Purpose of the Study:

• To theoretically investigate the structures, stabilities, and anion affinities of 2,2 -diBeX-1,1 -biphenyl derivatives.
• To evaluate the potential of these biphenyl derivatives as anion sponges for fluoride (F-), chloride (Cl-), and cyanide (CN-) ions.
• To compare their anion binding capabilities with related naphthalene analogs and known anion capturers.

Main Methods:

• Density functional theory (DFT) calculations using the B3LYP functional.
• A high-level basis set (6-311 +G(3df,2p)) was employed for geometry optimization and energy calculations, with a smaller basis set (6-31 +G(d,p)) for the // part.
• Analysis of structural parameters, relative stabilities, and binding energies with target anions.

Main Results:

• The 2,2 -diBeX-1,1 -biphenyl derivatives (X = H, F, Cl, CN) exhibit significant affinities for F-, Cl-, and CN-.
• Despite greater flexibility, their affinities are lower than analogous naphthalene compounds but still remarkably high.
• Some derivatives demonstrate anion affinities exceeding that of antimony pentafluoride (SbF5).

Conclusions:

• The studied biphenyl derivatives function as effective anion sponges due to the electron-deficient and Lewis acidic BeX groups.
• These compounds represent a promising class of materials for anion capture applications.
• The findings support the design principles for creating novel anion-binding molecules based on chelating electron-deficient moieties.