Coordination compounds as corrosion inhibitors of metals: A review

Corrosion is a significant threat that devalues the environment and compromises the lifespan of metallic assets, infrastructures, and industrial installations. Consequently, using chemical inhibitors, particularly coordination compounds as a means of mitigating corrosion holds the potential to extend the lifespan of infrastructures and result in substantial cost savings in terms of equipment, materials and structures. This aspect of studies remains a vital area of research. Coordination compounds used as inhibitors of corrosion and described in this review article include compounds with a metal atom bonded to a carbon atom (organometallic), and molecules having metal-N, metal-S, metal-O and metal-P bonds, respectively. Experimental analyses and theoretical assessments of coordination compounds as corrosion control agents have been reviewed in this article. Established and current approaches in corrosion inhibition using coordination compounds have also been discussed. Data reviewed and presented in this article show that the corrosion inhibition efficacies and adsorption of coordination compounds depend on the ligands and metal centres, the methods used for corrosion studies, the corrodents, metal substrates and other experimental conditions. Additionally, notable knowledge gaps are identified, and future research perspectives are highlighted.