Revaluation of copper(II)-Schiff base complex for sensing of d-penicillamine and development of a molecular logic gate: A combined approach

Abstract

d-penicillamine (D-PA) being a tri-functional organic compound (thiol, amine, and carboxylic acid) is used as a chelating drug for many serious diseases like Wilson’s disease. Due to its serious adverse effects, regular monitoring of blood and urine for D-PA is required during the clinical application of the drug. The dye-containing Cu(II)-Schiff base complex is revisited for easy monitoring of D-PA and the development of a new molecular logic gate through extensive studies. Revaluation is carried out in light of extensive experimental evidence and theoretical rationalization which help to achieve the target. The synthesized Cu(II)-salicylaldehyde rhodamine B hydrazone complex is characterized through FTIR, NMR, Mass spectrometry, UV–Vis, and fluorescence titrations. The crystal structure of the complex is optimized through DFT studies and found distorted square planar. Calculations of Frontier Molecular Orbitals (FMOs) assist to understand the electronic and optical properties of the complex. The recognition of D-PA (LOD = 2.60 × 10-8 M) is executed both colorimetrically and fluorometrically through the “Turn-off” mechanism. The NAND-type molecular logic gate has been developed.