Reinforcement of ‘imine-hydroxyl chelation pocket’ by encapsulating into the β-CD cavity for the sterically protective detection of Al3+

Abstract

The effect of encapsulating a schiff base probe; o-phenolnaphthylimine (pni) into β-cyclodextrin (β-CD) and its impact on the detection of Al3+ was investigated using the spectrofluorometric technique. The impact of imine moiety and the neighbouring hydroxyl groups of pni in the sensing of Al3+ were assessed through the experimental and computational procedure. The role of ‘imine-hydroxyl chelation pocket’ of pni in the detection of Al3+ was estimated, correlated and demonstrated. FTIR, NMR and mass spectral techniques were used for the investigations in solid state. Stoichiometry of the complexes was estimated using UV–visible and fluorescence spectral techniques in liquids state. Molecular modeling and steric maps were obtained using 3D structural data of compounds. Linearity range, LOD and LOQ were estimated from the selectivity and sensitivity studies. The proposed work demonstrates the impact of additional binding centers that has to be considered while designing a chemosensor for metal cations.