A novel naphthol-diazenyl scaffold-based azo ligand was synthesized via the condensation of 2-naphthol with an aromatic amine. The structure of the synthesized ligand was confirmed using IR, NMR, and mass spectroscopic analyses. Significant fluorescence enhancement was observed in the presence of metal ions such as Fe³⁺, Cr³⁺, Co²⁺, and Zn²⁺, which is attributed to the inhibition of non-radiative transitions originating from the n–π* state in the chemosensor. The binding interactions with these metal ions were further confirmed using UV-Visible spectroscopy, photoluminescence studies, and cyclic voltammetry.
The azo ligand demonstrated strong fluorescence emission, while partial fluorescence quenching phenomena were also observed under certain conditions. Computational studies, including analysis of frontier molecular orbitals, molecular electrostatic potential (MEP) surfaces, and Mulliken charge distributions, were performed using the B3LYP/6-31G(d,p) method, providing further insight into the electronic structure and binding characteristics of the ligand.