Complex formation of phenol, aniline, and their nitro derivatives with β-cyclodextrin

Abstract

The interactions of phenol, aniline, and their nitro derivatives with β-cyclodextrin (cyclohepta-amylose) have been studied by a spectrophotometric method. The complex formation constants have been determined for both the conjugate acid and base forms. The para isomer of nitrophenol is the only case when a more stable complex is formed with the ionic species than with the undissociated one, supporting the concept that resonance charge delocalization and London dispersion interactions are important factors influencing the stability of the complexes.