Iranian Chemical Science and Technologies Association International Journal of New Chemistry 2645-7237 12 4 2025 03 01 Multiple heteroatom additions effect on the empirical rule for organic corrosion inhibitors with nitrogen, oxygen, and sulfur atoms, a DFT approach. 501 518 705391 10.22034/ijnc.2023.1995885.1344 EN Valentine Osi department of chemistry, Ignatius Ajuru University of Education 0000-0001-6255-7603 Kingsley John Orie Chemistry, Ignatius Ajuru University of Education, Nigeria 0000-0002-5110-7161 Keerabana Sorbari Department of Chemistry, Ignatius Ajuru University of Education, Nigeria Journal Article 2023 06 11 The purpose of this study was to investigate using density functional theory (DFT) whether the general trend of inhibition efficiency, which is in the order of O<N<S, and increased inhibition as the number of heteroatoms increases, holds true under all conditions. Sixteen organic compounds which consisted of N, O, and S atoms in different combinatory ratios were used and were studied using B3LYP level of theory and 6-31G(d,p) basic set with iron being the metal of consideration. It was found that the order O<N<S only applies to single heteroatom configurations, increasing the number of heteroatoms does not always result in increased inhibition, and O played a significant role in improving a compound’s inhibition efficiencies. The multiple heteroatom configuration was in the order of O and N < N and S < O and S, resulting in an order trend of inhibition efficiencies of N<O< S. Therefore, a compound with more O or S and less N atoms would thus be a better corrosion inhibitor https://www.ijnc.ir/article_705391_271283f5fa190ce1b19522273fcfd9ae.pdf