English abstract
A novel series of 5-fluoro-6-(4-substituted-piperazin-1-yl) benzotriazole was synthesized and characterized. The target molecules were tested for corrosion inhibition of copper. The synthetic strategy includes four steps. Nitration of 3-chloro-4-fluoro aniline (in its protected form) followed by piperazinelation, and reduction. The latter intermediates were diazotized by sodium nitrite in acetic acid to form benzotriazole series. The structures of all synthesized final products and intermediates were confirmed using IR, 'H and 13C NMR and HRMS spectral analysis. The Tafel polarization technique showed good corrosion inhibition efficiency of all of the Target Molecules. The inhibition efficiency of one of the new benzotriazoles synthesized in
this work exceeds that of the benzotriazole for the same corrosive media. The biological results of the target compounds and corresponding precursor will be published in separate study. The relationship between molecular structure of the new benzotriazoles and their inhibition efficiencies has been investigated by ab initio quantum chemical calculations. The electronic properties such as the energy of the highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO) energy levels, energy gap (ELUMO-EHOMO), log P, dipole moment and molecular orbital electronic densities were calculated and correlated to the corrosion activity
