ABSTRACT
Heterocyclic compounds are most widely used in aqueous corrosion protection because of their strong ability to coordinate and bind with the metallic surface and manifest excellent corrosion inhibition potential. This chapter discusses fundamentals of heterocyclic compounds and their corrosion inhibition performance. It broadly describes the properties, applications, and classification of different series of heterocyclic compounds. The impact of several distinguishing characteristics of heterocyclic compounds and heteroatoms on their capacity to suppress corrosion is also covered in this chapter. Their ability to inhibit corrosion is influenced by the factors of heteroatoms, including basicity, electronegativity, position, relative orientation, and number. Their corrosion inhibition potential increases by increasing the close number of heteroatoms, their basicity, and electron-donating substituents or functional groups. The rise in electronegativity, decrease in the basicity of heteroatom, and the presence of electron-withdrawing substituents or functional groups exert the adverse effect on the inhibition performance of heterocyclic compounds.
