2,2′-(Hydrazine-1,2-diylidenedimethylylidene)bis(6-isopropyl-3-methylphenol) based selective dual-channel chemosensor for Cu2+ in semi-aqueous media

Abstract

A novel receptor based on a substituted salicylaldehyde derivative, 2,2′-(hydrazine-1,2-diylidenedimethylylidene)bis(6-isopropyl-3-methylphenol) (1), was synthesized and characterized using various spectroscopic techniques. The UV-visible spectroscopic studies of the receptor showed selectivity for Cu²⁺ in the presence of other metal ions by a change in colour from colourless to yellow. A red shift was observed with the appearance of a new absorption band at 450 nm in CH₃OH–H₂O (60 : 40 v/v). Fluorescence studies of the receptor showed “turn-off” recognition properties for the Cu²⁺ ion with a 1 : 1 binding stoichiometry and the detection limit was 50 nM.