Revealing the Correlation between Molecular Structure and Corrosion Inhibition Characteristics of N-Heterocycles in Terms of Substituent Groups

Abstract

Controlling metal corrosion can directly address the waste of metal and the environmental pollution and resource depletion caused by metal recycling, very significant factors for green and sustainable development. The addition of corrosion inhibitors is a relatively cost-effective means of corrosion prevention. Among these, N-heterocycles have been widely used because heteroatoms contain lone pairs of electrons that can be strongly adsorbed onto metals, protecting them in highly corrosive environments at relatively low concentrations. However, due to the large variety of N-heterocycles, their corrosion inhibition characteristics have seldom been compared; therefore, the selection of appropriate N-heterocycles in the development of anti-corrosion products for specific applications was very difficult. This review systematically analyzed the influence of different substituents on the corrosion inhibition performance of N-heterocycles, including different alkyl chain substituents, electron-donating and electron-withdrawing substituents, and halogen atoms, respectively. The correlation between the molecular structure and corrosion inhibition characteristics of N-heterocycles was comprehensively revealed, and their action mechanism was analyzed deeply. In addition, the toxicity and biodegradability of N-heterocycles was briefly discussed. This study has provided a significant guideline for the development of green, promising corrosion inhibitors for advanced manufacturing and clean energy equipment protection.

Experimental and theoretical investigations of the effect of bis-phenylurea-based aliphatic amine derivative as an efficient green corrosion inhibitor for carbon steel in HCl solution

“…Consequently, the anodic and cathodic current densities notably declined after adding the BPUA inhibitor. This suggests that the structure of BPUA facilitates the attachment of molecules to the C-steel surface through free electron pairs around the aromatic moieties or heteroatoms [ 40 ]. The coordination bonds formed with BPUA and the steel surface obstruct the available active sites, thereby decelerating both reactions of the anodic metallic dissolution and hydrogen evolution [ 41 ].…”

Isolation, Characterisation and Corrosion Inhibition Evaluation of 1, 3, 5-Trimethoxymethyl benzene from Seeds Extract of Cola nitida on Mild Steel Surface in Hyhrochloric Acid Solution

“…In view of the positive values of ∆N, it implies that electrons will be donated to the metal surface by TMMB. It is important to note that in as much as the value of ∆N is less than 3.6, the inhibition efficiency increases with the ability of the molecules to donate electrons to the metal surface [50]. The electronegativity, χ, of TMMB is 3.446 eV is lower than the work function of Fe(110) surface given as 4.82 eV and this points to the fact that electrons migrate from the inhibitor to the Fe surface.…”

Condensed Fukui function and experimental evaluation of the corrosion inhibition properties of some antipyrinyl‐imidazotriazole and their derivatives for copper in an acidic environment

“…5 inhibitors. To determine the synergism parameter (S), the formula that follows should be utilized as in Equation (10). The injection of 0.0001 M KI to the corrosive environment that contains 0.020 and 0.040 gL À1 of Comp.…”

“…With progressively strict environmental guidelines, N‐heterocyclic compounds assist as ideal alternates, especially for natural sources and nontoxic categories of compounds. [9, 10]. The strong adsorption between metals and N‐heterocyclics compounds is generally due to nitrogen atom, unshared electron pair, as well as the presence of multiple bonds including double and triple bonds of nonpolar (>CS, >CCCO, >CN, CN) functional groups of either aromatic rings or of side chain.…”

“…The amidine moiety ( N CH NH 2 ) of these materials is a suitable center for coordination and, accordingly, is used for studying the anticorrosion behavior of metallic constructions in corrosive environments [18,19]. Also, N-heterocyclic compounds have a significant effect on the corrosion inhibition of different metals in different electrolytes [9,10,[20][21][22][23][24][25][26][27][28]. Another important factor in maximizing organic cations inhibitors' efficiency is synergism via chemisorption interconnecting pathways with a negatively charged metallic surface.…”