Synthesis, crystal structure and anticorrosion performance of Zn(II) and Ni(II) complexes

• Published in: Journal of molecular structure Vol. 1228; p. 129452
• Main Authors: Wei, Wenchang, Liu, Zheng, Wei, Runzhi, Liang, Chuxin, Feng, Xiao-Zhen, Han, Guo-Cheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.03.2021
• Subjects: Carbon steel; Complex; Corrosion inhibition; Inhibitor; Structure; Carbon steel; Inhibitor; Corrosion inhibition; Structure; Complex
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2020.129452

•Two unreported Zn and Ni complexes were synthesized by solvothermal method.•The two complexes have the excellent heating stability.•The two complexes were cathode type corrosion inhibitors.•The two complexes can effectively protect carbon steel from acid medium corrosion. Two unreported complexes [Zn(6-Me-2,3-pydc)(H2O)2·2H2O]n (namely complex 1, and 6-Me-2,3-pydc = 6-picoline-2,3-dicarboxylic acid) and [Ni(5-Br-2,3-pydc)(1,10-phen)2·9H2O]n (namely complex 2, and 5-Br-2,3-pydc = 5-bromopyridine-2,3-dicarboxylic acid, 1,10-phen = 1,10-phenanthroline) were synthesized by solvothermal method and were characterized and confirmed by elemental analysis, Fourier infrared spectroscopy, X-ray single crystal diffraction, thermogravimetric analysis and scanning electron microscope (SEM). The weight loss measurement (WL) results showed that complex 1 and 2 can maintain the inhibition efficiency above 86% at 85°C. The thermogravimetric analysis showed that two complexes have the excellent heating stability. Electrochemical studies results showed that complex 1 and 2 were cathode type corrosion inhibitors and exhibited maximum inhibition efficiency (ηp%) of 87.56% and 89.59% at the concentration of 1.50 mmol·L−1 in 0.5 N HCl, respectively. The adsorption isotherm analysis confirmed that complex 1 and 2 followed the Langmuir isotherm. SEM results confirmed that two complexes can effectively protect carbon steel from acid medium corrosion, which was consistent with the electrochemical studies results.