Theoretical Investigation to Corrosion Inhibition Efficiency of Some Chloroquine Derivatives Using Density Functional Theory

Abstract

In this work, the potential of corrosion inhibition of four chloroquine derivatives; N 4-(7-Chloroquinolin-8-ol-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M2), N 4-(7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M3) and N 4-(5-bromo-7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4-diamine (M4) were investigated. Their chemical descriptors which include molecular volume, softness, chemical hardness, electronegativity, fraction (ΔN) and electrophilicity index (ω) dipole moments, surface of the molecule, and electronic parameters which include the EHOMO (the highest occupied molecular orbital of energy); ELUMO (lowest unoccupied molecular orbitals of energy) and energy gap (ELUMO-EHOMO) were calculated using the DFT/B3LYP/6-311 G approach. The results revealed an established correlation between the electronic structures and the quantum parameters of the studied molecules together with their inhibition efficiency toward corrosion process. Also chloroquine derivatives with-NH3 substituent: M3 and M4 were predicted to have enhanced inhibition efficiency.

Density Functional Theory Studies on New Possible Biobased Gemini Corrosion Inhibitors Derived from Fatty Hydrazide Derivatives

“…On the other hand, TADH has the lowest E LUMO values, associated with the highest tendency to accept electrons from the metal ion. The reduced E LUMO values suggested increased CI adsorption on the metal surface, which improved the inhibition efficiency. , Overall, the study found that the value of E LUMO decreased in the following order: CBH > SDH > GADH > MADH > AADH > ODH > TADH.…”

“…The reduced E LUMO values suggested increased CI adsorption on the metal surface, which improved the inhibition efficiency. 14,17 Overall, the study found that the value of E LUMO decreased in the following order: CBH > SDH > GADH > MADH > AADH > ODH > TADH.…”

“…The calculated Δ N represents the probability of electron transfer from the inhibitors to the metal surface, correlating the inhibition efficiency as the highest Δ N to impart the best inhibition efficiency. , The results indicate that Δ N values of all fatty hydrazides were negative (ranging from −0.74 to −0.47), meaning that electron transfer occurs from the metal surface to the inhibitor molecules (Table ) or known as back-donation or retro-donation. This transfer occurs due to the inhibiting molecules’ interaction with the metal surface since the values are less than zero . TADH (−0.47) displayed the highest proportion of transferred electrons; thus, it is predicted to be an effective CI compared to the other studied molecules (ranging from −0.74 to −0.47).…”

Corrosion Inhibition Potential of Thiosemicarbazide Derivatives on ALuminium: Insight from Molecular Modelling and QSARs Approaches

“…The dipole moment (DM) is the first derivative of the energy with respect to an applied field [36] electronic parameter resulting from the unequal distribution of charges on various atoms in a molecule. It measures the polarity of a polar covalent bond, predicts the direction of the corrosion inhibition process, and gives information about the distribution of electrons in the molecules [36][37][38]. The total dipole moment, on the other hand, simply represents a molecule's global polarity.…”

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“…The ΔN values shown in Table 1 follow the order: B5 > B3 > B4 = B6 > B2 > B1 > A6 > A4 > A2 > A3 > A5 > A1. Negative values of ΔEback−donation displayed by all molecules indicate that charge transfer between the surface of the metals and the molecules is energetically favored, implying that all molecules can make electrons available via back-donation [35].…”