Synthesis, Characterization, Analytical Application, and Theoretical Studies of a Schiff Base, (E)-2-(2-aminophenylthio)-N-(Thiophen-2-yl-methylene) Benzenamine

In this study, a new Schiff base, (E)-2-(2-aminophenylthio)-N-(thiophen-2-yl-methylene) benzenamine was synthesized for selective detection of Hg²⁺. This Schiff base was characterized by proton nuclear magnetic resonance (¹HNMR), carbon-13 nuclear magnetic resonance (¹³CNMR), and Fourier-transform infrared (FTIR) spectroscopy. Binding interaction between (E)-2-(2-aminophenylthio)-N-(thiophen-2-yl-methylene)benzenamine and various metal ions has been studied by UV-Vis spectroscopic measurements and shows promising coordination towards Hg²⁺ and almost no interference from other metal ions (Ag⁺, Mn²⁺, Fe³⁺, Al³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Fe²⁺ and Cr³⁺).This Schiff base exhibiting detection limit of 3.8 × 10^{- 8} M. The Schiff base newly synthesized in this study was successfully applied to the determination of Hg²⁺ in water samples. In addition to the experimental study, a theoretical study was conducted using Gaussian 09 program to support the experimental findings. FTIR, NMR, bond angle, bond length, torsional angles, and structural approximation were studied using theoretical consideration.