Abstract
Three Mn(II), Co(II), and Cu(II) new transition metal complexes of the fluorescence dye: 2-(2'-hydroxy-5'-phenyl)-5-aminobenzotriazole/PBT derived from o-aminophenol and m-phenylenediamine have been synthesized. The structural interpretations were confirmed from elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV-Vis spectral studies. From the analytical, spectroscopic, and thermal data, the stoichiometry of the mentioned complexes was found to be 1:2 (metal:ligand). The molar conductance data revealed that all the metal chelates are non-electrolytes and the chloride ions exist inside the coordination sphere. The thermal stabilities of these complexes were studied by thermogravimetric (TG/DTG) and the decomposition steps of these three complexes are investigated. The kinetic parameters such as the energy of activation (E*), pre-exponential factor (A), activation entropy (Delta S*), activation enthalpy (Delta H*), and free energy of activation (Delta G*) have been reported. Photostability of phenyl benzotriazole as fluorescence dye and their metal complexes doped in polymethyl methacrylate/PMMA were exposed to UV-Vis radiation and the change in the absorption spectra was achieved at different times during irradiation period.