Photo and thermally stable branched corrosion inhibitors containing two benzotriazole groups for copper in 3.5 wt% sodium chloride solution

•Synthesis of new branched organic molecules bearing double benzotriazole segments.•Corrosion of copper was inhibited by the branched molecules in NaCl solution.•Chemisorption adsorption of the new inhibitors on copper was demonstrated.•Photo and thermal stabilities of the studied new inhibitors were presented. New branched conjugated derivatives with two benzotriazole groups as well as a linear analog containing one benzotriazole segment used as corrosion inhibitors for copper in 3.5 wt% sodium chloride solution containing 90 vol% water and 10 vol% ethanol solvents at 298 K were synthesized. It is shown that the corrosion of copper is inhibited more efficiently by the branched inhibitors. The adsorption mechanism on copper surface was analyzed by Langmuir isotherm and various spectral characterizations, and the results suggest a primary chemisorption adsorption on copper surface. Molecular modeling was performed. Photo and thermal stabilities of the studied inhibitors were investigated.