Simplistic correlations between molecular electronic properties and inhibition efficiencies

Simplistic correlations between molecular electronic properties and inhibition efficiencies: Do they really exist?

Kokalj, Anton (Jozef Stefan Institute)
Lozinšek, Matic (Jozef Stefan Institute)
Kapun, Barbara (Jozef Stefan Institute)
Taheri, P. (TU Delft Team Peyman Taheri)
Neupane, Shova (University of Hasselt)
Losada-Pérez, Patricia (University of Hasselt)
Xie, Chenyang (Universitat Politecnica de Catalunya)
Stavber, Stojan (Jozef Stefan Institute)
Crespo, Daniel (Universitat Politecnica de Catalunya)
Renner, Frank U. (University of Hasselt)
Mol, J.M.C. (TU Delft Team Arjan Mol)
Milošev, Ingrid (Jozef Stefan Institute)

2021

The often used simplistic correlations between molecular electronic parameters and experimentally determined corrosion inhibition efficiencies are critically evaluated for a set of 24 heterocyclic organic compounds, tested as corrosion inhibitors for copper in 3 wt.% NaCl aqueous solution. Twelve different molecular electronic descriptors—such as ionization potential, electron affinity, HOMO–LUMO gap, dipole moment—are tested and it is shown that none of them displays any noticeable correlation with the inhibition efficiency. Our results, therefore, cast serious doubt on reported correlations between such parameters and inhibition efficiency, obtained for only a few inhibitors, which are abundant in the literature. We also discuss some pros and cons of inhibition efficiency as a metric for evaluating the performance of corrosion inhibitors, and introduce a new metric termed inhibition power that uses the universal logarithmic scale and dimensionless decibel (dB) units.

A. Copper
B. Modeling studies
B. Polarization
C. Interfaces
C. Neutral inhibition

http://resolver.tudelft.nl/uuid:3a5e1a29-1fb6-4999-b2a3-369b8848d86e

https://doi.org/10.1016/j.corsci.2020.108856

0010-938X

Corrosion Science: the journal on environmental degradation of materials and its control, 179

Institutional Repository

journal article

© 2021 Anton Kokalj, Matic Lozinšek, Barbara Kapun, P. Taheri, Shova Neupane, Patricia Losada-Pérez, Chenyang Xie, Stojan Stavber, Daniel Crespo, Frank U. Renner, J.M.C. Mol, Ingrid Milošev