Pyrazole, pyrazolone and enaminonitrile pyrazole derivatives: Synthesis, characterization and potential in corrosion inhibition and antimicrobial applications

Six pyrazole and pyrazolone derivatives namely: 3-amino-1-phenyl-5-pyrazolone (1), 3-amino-1-(2,4-dinitrophenyl)-5-pyrazoloneyl) (2), 1H-pyrazole-3,5-diamine-4-(2-phenyldiazenyl) (3), 1-phenyl pyrazole-3, 5-diamine, 4-[2-(4-methylphenyl) diazenyl] (4), 1H-pyrazole-3,5-diamine, 4-[2-(4-methylphenyl) diazenyl] (5), 5-amino-1,3-diphenyl-1H-pyrazolecarbonitrile (6) were synthesized and evaluated as corrosion inhibitors for copper alloy dissolution in basic medium. Corrosion inhibition evaluation was performed using weight loss, polarization and electrochemical impedance measurements. The results showed that the prepared compounds have high efficiency as corrosion inhibitors for dissolution prevention of copper in NH4OH solution at pH of 9. The prepared compounds were evaluated for their antimicrobial activities against gram positive and gram negative bacteria using inhibition zone diameter measurements. The results revealed that the synthesized compounds have higher antibacterial activities than the conventional bactericide agents. The results of the antimicrobial activities and the corrosion inhibition tendencies of these compounds were correlated to their chemical structures. (C) 2018 Elsevier B.V. All rights reserved.