Lanthanide detection by novel arylether based receptor with imine functional groups: synthetic, photophysical, electrochemical and computational elucidation

Abstract

The present research discloses a novel chemical sensor (TEI) [1-((E)-(2-(3-(2-((E)-(2-hydroxynaphthalene-1-yl)methyleneamino)phenoxy)phenoxy)phenylimino)methyl)naphthalene-2-ol] for the detection of rare earth element cerium (III) in which spectrophotometric and voltametric sensor techniques were used with a versatile combination of ether and imine group. Various lanthanide ions were checked for the binding in a solution of TEI under identical conditions, including Ce(III), Dy(III), Ho(III), La(III), Sm(III), Eu(III), Gd(III), Tb(III), Er(III), Yb(III), Tm(III), Pr(III) and Nd(III). As observed in absorption studies, the enhancement of spectral intensity at 310 nm caused by Ce(III) was expected over other lanthanide ions. Cyclic and differential pulse voltammograms were also drawn for TEI receptor with and without Ce3+ ions With incremental addition of Ce3+ ions the anodic peak at 0.68 V oxygen gets completely diminished. Another anodic peak at 0.75 V which was due to complete oxidation of ether group and re-oxidation of reduced imine group, got reduced. In case of cathodic peak (due to reduction of imine group) at 0.6 V, there was hardly any decrease in current. This leads to the confirmation that there was no involvement of imine group in binding in the complex. Detection limit obtained by this sensor is 5 × 10–7 M without any interference which makes it a potent sensor for cerium detection.