Thiadiazoles as potent inhibitors against corrosion of metals and alloys: Challenges and future prospects

Heterocyclic organic compounds find extensive applications in the realm of corrosion inhibition. The thiadiazole (TDZ) ring is one such framework, occurring in a wide range of naturally occurring products and pharmaceutically active molecules. Various derivatives containing the thiadiazole ring are reported as excellent corrosion inhibitors in the aqueous medium. The salient features include the presence of two N atoms, S atoms, lone pair electrons, and the pi-electrons that promote the adsorption on the target metal surface and impact corrosion inhibition. Herein, we have briefly outlined the diverse application aspects of thiadiazole derivatives for corrosion inhibition of different metallic materials in various environments. The importance of thiadiazoles in various areas is provided, followed by a comprehensive overview of the thiadiazole derivatives as inhibitors in various aqueous corrosive media. It is noted from the literature that the thiadiazole-derived molecules present an environmentally benign class of inhibitors with efficient performance. In addition to simple heterocycles, thiadiazole-based salts and polymeric molecules are also reported as corrosion inhibitors. The performance of these inhibitors depends upon structural aspects such as additional heteroatoms, pi-bonds, heterocyclic/phenyl rings, the presence of alkyl chains, etc. Furthermore, various mechanical aspects responsible for the adsorption and protection performance of thiadiazoles are outlined and derived from experimental and computational studies. Prospective research and development in this area are also briefly outlined for interested researchers and readers.