A New Co(III) Complex of Schiff Base Derivative for Electrochemical Recognition of Nitrite Anion

Abstract

Abstract: The synthesis and characterization of a new Co(III) complex of a salphen-type Schiff base ligand, (E)-2-{[(2-aminopyridin-3-yl)imino]methyl}-4,6-di-tert-butylphenol (HL), are reported. The characterization has been carried out using X-ray single crystallographic, thermogravimetric, and spectroscopic techniques. The complex has been combined with polyvinyl chloride (PVC) membrane of various compositions and tested as an electrochemical electrode towards recognition of several anions. The electrode exhibits exceptional electrochemical recognition for the nitrite (NO2-) anion in aqueous media. The electrode exhibited a linear response to NO2- with a detection limit of 5.76μM and displayed a linear Nernstian slope over the nitrite concentration range of 1.0 × 10 - 5–1.0×10-1M in the pH range of 3–7 and a fast response time of less than 10 seconds. Theoretical calculations showed that the sensing could be via anion exchange in the Co(III) complex. Graphical Abstract: SYNOPSIS An octahedral Co(III) complex of the salphen-type Schiff base, (E)-2-{[(2-aminopyridin-3-yl)imino]methyl}-4,6-di-tert-butylphenol, was synthesized, characterized and analyzed for its electrochemical anion recognition property through reversible anion exchange mechanism. [Figure not available: see fulltext.]. © 2017, Indian Academy of Sciences.