Synthesis, Electrochemical Studies and Theoretical Calculations of Sulfo-Schiff Bases

In this study, two different water-soluble Schiff base ligands as sodium(Z)-3((2,5-dihydroxybenzylidene)amino)benzene sulfonate (SLI) ve sodium (Z)3-((3,4-dihydroxybenzylidene)amino)benzene sulfonate (SLII) were synthesized as a result of the condensation reaction of 3-aminobenzenesulfonicacid containing sulfo group with 2,5-dihydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde, respectively. The chemical structures of the synthesized Schiff base ligands were characterized by melting point determination, elemental analysis, FT-IR and 1H-NMR techniques. Electrochemical behaviors of synthesized SLI and SLII ligands were examined by cyclic voltammetry technique against Ag/AgCl/KCl(sat) at the glassy carbon electrode in Britton Robinson buffer solution, pH 5.0. Electrode surfaces modified with SLI and SLII ligands were characterized by cyclic voltammetry technique in the presence of ferrocene and potassium hexacyanoferrate (III) redox probes, water contact angle measurement, scanning electron microscope and atomic force microscope and compared with the data of the bare glassy carbon electrode surface. Theoretical calculations of SLI and SLII ligand were performed with Density Functional Theory (DFT) and compared with experimental results. Two water-soluble Schiff base ligands are synthesized, featuring variations in the positioning of -OH groups. The impact of these positional changes on their electrochemical behavior is being investigated. These ligands are then employed to modify electrode surfaces, and the resulting modifications are analyzed. Density Functional Theory calculations are used to support the understanding of the molecules ' electrochemical properties. image