Abstract

A new mefenamic acid derivative, (4-amino-5-(2-(2,3-dimethylphenyl)aminophenyl)-1,2,4-triazole-3-thion (L), has been synthesized and
characterized by spectroscopic and elemental analysis. The ligand (L) has been used as a chelating agent to prepare complexes of Co(ІІ),
Ni(П), Cu(П), Zn(II) and Cd(II) ions. The structure of the complexes, in solid state, has been suggested. The theoretical treatment of the
complexes, in the gas phase, has been studied using the Hyperchem-8 program for the molecular mechanics and semi-empirical
calculations. The heat of formation (ΔHf
○
) and binding energy (ΔEb) for the ligand and their complexes were calculated by PM3 method.
The electrostatic potential of the ligand (L) has been calculated to investigate the reactive sites of the molecule. Photostabilization of PVC
film in air was investigated in the absence and presence of the ligand L and theirs complexes by accelerated weathering tester. It was found
that various indices values increased with irradiation time and this increase depend on the type of additives.

Key words: Triazole; photochemistry; mefenamic acid metal complexes; UV light; photostabilization; semi-empirical calculations.