Quinoline and its derivatives as corrosion inhibitors: A review

Quinoline is a nitrogenous bicyclic heterocyclic compound with molecular formula of C9H7N in which pyridine moiety is fused with benzene ring. Quinoline and its derivatives are widely used as anticorrosive materials. Quinoline derivatives show reasonable good effectiveness against metallic corrosion because of their association with high electron density (10-pi& 2-non-bonding electron). Quinoline derivatives containing polar substituents such as hydroxyl (-OH), methoxy (-OMe), amino (-NH2) and nitro (-NO2) etc. effectively adsorb and form highly stable chelating complexes with surface metallic atoms through coordination bonding. Present review article describes the collection some recent reports published on quinoline-based compounds as anticorrosive materials. Numerous aspects of corrosion and its adverse impact, corrosion inhibition, inhibitors with particular emphasis on green corrosion inhibitors, past and present scenarios of corrosion inhibition are also described in this report. To the best of our knowledge-, this is the first comprehensive and detailed report on the use of quinoline derivatives as corrosion inhibitors.