Enhancing efficiency and thermal stability of amino benzotriazole fluorescent dye via ligand-to-metal charge transfer reactions for solar cell applications: A comprehensive compositional and spectroscopic study

Herein in this study, we have synthesized three new iron(III), chromium(III), and vanadium(III) transition metal complexes of the 2-(2'-hydroxy-5'-phenyl)-5-aminobenzotriazole (hpabt) fluorescent dye. Infrared, and ultraviolet-visible spectral examinations, as well as elemental analysis, magnetic susceptibility, and molar conductivity analyses, all supported the structural interpretations. The complexes have a stoichiometry of 1:1 (M3+: hpabt) based on the analytical, spectroscopic, and thermal data. The molar conductance measurements showed that the chloride ions inside the coordination sphere and all the metal chelates are non-electrolytes. These three complexes decomposition processes are examined and their thermal stabilities were examined using thermogravimetric (TGA) analysis. Activation entropy (ΔS*), activation enthalpy (ΔH*), free energy of activation (ΔG*), pre-exponential factor (A), and energy of activation (E*) are examples of kinetic parameters that have been recorded. The surface morphology of iron(III), chromium(III), and vanadium(III) complexes were studied by scanning electron microscopy (SEM). The 2-(2'-hydroxy-5'-phenyl)-5-aminobenzotriazole photostability as a fluorescent dye and its synthesized metal complexes doped in polymethyl methacrylate (PMMA) were subjected to UV-Vis. light, and the absorption spectra changed at various points during the exposure period. KEY WORDS: Benzotriazole, Fluorescent dye, Transition metals, Thermal stabilities, Spectroscopic analyses Bull. Chem. Soc. Ethiop. 2025, 39(6), 1057-1070. DOI: https://dx.doi.org/10.4314/bcse.v39i6.3