Biarylbinding

Biarylbinding is a term used to describe noncovalent association between biaryl fragments, such as two aryl rings connected by a central biaryl bond. It covers both intramolecular interactions within a single molecule and intermolecular interactions between separate species. Biaryl moieties frequently engage in aryl-aryl contacts that contribute to binding, self-assembly, and molecular recognition in diverse chemical contexts.

The binding mode can be face-to-face, edge-to-face, or offset, and is influenced by factors such as substituents, ortho substitution that twists the biaryl linkage, solvent polarity, and temperature. Electron-rich or electron-poor rings can modulate interaction strength, and restricted rotation around the biaryl bond can stabilize particular geometries, enabling selectivity in recognition events.

Quantification typically uses binding constants (Ka or Kd) and thermodynamic data from techniques like isothermal titration calorimetry or NMR spectroscopy. Structural information often comes from X-ray crystallography or advanced NMR methods. Model systems involve biaryl-containing ligands and hosts designed to exploit aryl-aryl contacts for guest binding; examples include substituted biphenyl receptors and related biaryl frameworks, with crystal structures illustrating stacking geometries.

Applications of biarylbinding appear in supramolecular chemistry and materials science, including self-assembling polymers, foldamers, and molecular recognition motifs. Limitations include sensitivity to solvent, competition from other π-π interactions in polar media, and the sometimes weak binding relative to covalent or coordination alternatives. The concept sits alongside broader discussions of aryl-aryl interactions and π-π stacking in chemical design and analysis.