A cationic calixarene derivative binds both aliphatic and aromatic anions in aqueous solution thanks to concerted electrostatic and hydrophobic interactions. 1H NMR and potentiometric data show that the host flexibility changes as a function of pH. 1H NMR and isothermal titration calorimetry (ITC) studies, also supported by ESI-MS data, show that inclusion yields supramolecular complexes of the guest⊂host type only. Binding becomes weaker as the pH increases due to rigidification of the host in neutral aqueous solutions, and is enthalpically favoured for all the supramolecular complexes, regardless of pH.
ASJC Scopus subject areas
- Materials Chemistry