Detecting Ni(II) in aqueous solution by3-(2-pyridyl)-[1,2,3]triazolo[1,5-a]pyridine anddimethyl- -cyclodextrin

Abstract

A new supramolecular sensitizer for nickel(II) ion in aqueous solution based on a pyridyltriazolopyridine-cyclodextrin inclusion complex is proposed. The inclusion complexation behavior, characterization andbinding ability of pyridyltriazolopyridine (PTP) with dimethyl- -cyclodextrin (DM CD) has been inves-tigated both in solution and solid state by means of absorption, fluorescence,1H NMR, DSC, and molecularmodeling methods. The stoichiometry of the inclusion complex is 1:1, and the thermodynamic studiesindicate that the inclusion of PTP is mainly an entropic driven process. The 2D NMR studies revealed thatthe pyridyl-triazolopyridine is included by both sides of cyclodextrin which are in good agreement withthe docking results. The fluorescence changes upon addition of divalent cations to the inclusion complexindicate a high selectivity and sensitivity for Ni2+by fluorescence quenching in neutral aqueous solution.