The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR). Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO) are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital
The widths involved for different metals, especially iron with its various grades, are widely used in many industrial fields, such as petrochemical industries, petroleum oil production, transportation, and others. That has led to conducting more research into the metal surface protection in various aggressive media, especially acid medium. The most essential aim of corrosion research papers is to determine the best protection compounds for metal and metal alloys in different aggressive corroded media. However, these research papers do not only cost a lot of money, but they also take so much time to detect the most effective inhibitors [
Among numerous corrosion inhibitors, organic compounds are considered as powerful inhibitors, especially hetero organic compounds [
Recently, in the presence of sophisticated hardware and with the development of theoretical chemistry programs, quantum chemical calculation methods are looked upon as some of the most effective tools not only for the molecular structure but also for elucidating the active center of the studied molecules [
The applications of 1,3-benzodioxole derivatives as corrosion inhibitors are not dealt widely with. The efficiency of 5-(1,3-benzodioxol-5-yl)-1-(piperidin-1-yl)penta-2,4-dien-1-one and 5-(1,3-benzodioxol-5-yl)-1-(piperidin-1-yl)pent-2-en-1-one as corrosion inhibitors was experimentally/theoretically studied. Good agreement is obtained between experimental results and quantum parameters [
The aim of this paper is to study the dependence of inhibition efficiencies for different substitutes of 1,3-benzodioxole on their molecular and electronic structures using some semiempirical methods (AM1, PM3, MNDO, MNDO/3, and INDO). The inhibition efficiencies are obtained by different quantum chemical parameters as the energy of the frontier orbital, charge densities, Dipole moment
The molecular structure of the studied 1,3-benzodioxole derivatives.
All the Quantum chemical calculations are carried out at Restricted Hartree-Fock (RHF), by spin pairing case using AM1, PM3, MNDO, MINDO/3, and INDO semiempirical methods and SCF (iteration limit = 50) using Hyperchem 8.0.10 windows program implemented on the Intel core i7 laptop.
The energy of highest occupied molecular orbital,
The quantum chemistry computing method is often used to study the simple systems taking into account that (i) the effect depends only on the inhibitor molecule properties and (ii) everything else in its vicinity is uninvolved either with respect to competition for the surface or with respect to itself. Several researches confirmed that there is little effect of the media on these parameters [
Different 1,3-benzodioxole derivatives are selected to study the effect of molecular electronic properties based on the nature of a substitute. The optimized geometry of the investigated molecules possesses minimum total energy (the net result of the electronic kinetic energy and the interactions between atomic cores and all e’s) is shown in Figure
The optimized structure of the investigated 1,3-benzodioxole derivative.
In adsorption process, frontier orbital (HOMO and LUMO) should be taken into account in order to predict the adsorption site of the studied molecules. The higher
The calculated chemical parameters of the studied 1,3-benzodioxole derivatives.
Cop |
|
|
|
|
||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
AM1 | PM3 | INDO | MNDO | MINDO/3 | AM1 | PM3 | INDO | MNDO | MINDO/3 | AM1 | PM3 | INDO | MNDO | MINDO/3 | AM1 | PM3 | INDO | MNDO | MINDO/3 | |
I | −8.96 | −9.04 | −10.76 | −8.90 | −8.23 | 0.24 | 0.16 | 4.25 | 0.11 | 1.08 | 9.20 | 9.20 | 15.01 | 9.01 | 9.31 | 0.52 | 0.29 | 1.142 | 0.58 | 0.54 |
II | −8.69 | −8.79 | −10.40 | −8.64 | −8.02 | −0.21 | −0.28 | 3.18 | −0.37 | 0.64 | 8.51 | 8.51 | 13.58 | 8.27 | 8.66 | 0.55 | 0.30 | 1.01 | 0.59 | 0.37 |
III | −9.07 | −9.13 | −11.43 | −9.14 | −8.39 | −0.18 | −0.23 | 0.52 | −0.56 | 0.08 | 8.89 | 8.90 | 11.95 | 8.58 | 8.47 | 1.57 | 1.42 | 5.45 | 2.14 | 2.23 |
IV | −8.86 | −8.96 | −10.35 | −8.86 | −8.17 | 0.28 | 0.13 | 3.81 | 0.07 | 0.95 | 9.14 | 9.09 | 14.16 | 8.93 | 9.12 | 0.67 | 0.41 | 1.25 | 0.62 | 0.45 |
V | −8.41 | −8.97 | −.8.93 | −.8.95 | −8.15 | −0.18 | 0.12 | 2.58 | −0.19 | 0.91 | 8.23 | 9.09 | 11.51 | 8.76 | 9.06 | 0.54 | 0.68 | 1.44 | 1.59 | 0.20 |
VI | −8.75 | −8.99 | −10.03 | −8.83 | −8.03 | 0.10 | 0.03 | 3.48 | −0.05 | 0.70 | 8.85 | 9.02 | 13.53 | 8.78 | 8.73 | 1.55 | 1.52 | 1.54 | 1.58 | 1.14 |
VII | −8.54 | −8.90 | −10.20 | −8.84 | −8.04 | −0.12 | −0.04 | 3.35 | −0.21 | 0.68 | 8.33 | 8.86 | 13.55 | 8.63 | 8.72 | 0.91 | 0.85 | 1.73 | 1.22 | 1.03 |
VIII | −9.29 | −9.32 | −10.95 | −9.24 | −8.63 | −0.66 | −0.63 | 2.05 | −0.76 | 0.13 | 8.63 | 9.95 | 13.00 | 8.10 | 8.76 | 2.65 | 2.65 | 2.99 | 2.70 | 3.47 |
IX | −9.54 | −9.59 | −11.11 | −9.47 | −8.72 | −0.83 | −0.81 | 2.17 | 0.93 | 0.16 | 8.71 | 8.87 | 13.28 | 10.40 | 8.88 | 4.57 | 4.62 | 4.55 | 4.42 | 4.88 |
X | −9.31 | −9.35 | −11.03 | −9.26 | −8.61 | −0.60 | 0.60 | 2.20 | −0.74 | 0.26 | 8.71 | 9.95 | 13.23 | 8.52 | 8,87 | 1.97 | 2.06 | 2.18 | 2.16 | 2.16 |
XI | −9.17 | −9.24 | −8.81 | −8.59 | −7.62 | −0.21 | −0.25 | 2.97 | −0.48 | −0.40 | 8.96 | 8.99 | 11.78 | 8.11 | 7.22 | 4.26 | 4.05 | 4.55 | 1.69 | 2.12 |
XII | −8.88 | −8.97 | −10.45 | −8.89 | −8.16 | 0.17 | 0.11 | 4.08 | −0.11 | 0.97 | 9.05 | 9.08 | 14.53 | 8.78 | 9.03 | 1.64 | 1.37 | 2.29 | 1.58 | 1.39 |
The values of
INDO was developed at Carnegie Melon University. This method depends on choosing parameters based on that theory of giving a value near to that obtained by Hartree-Fock.
The calculated values of
AM1 and PM3 provide nearly closed arrangement for the activity of the studied molecules with respect to the calculated values of the energy of the highest occupied molecular orbital. Although AM1 uses the same basic approximation as MNDO, AM1 has a different trend than MNDO. PM3 was developed by Stewart [
1,3-Benzodioxole-5-acetic acid, methyl ester, is predicted by using INDO, MNDO, and MINDO/3 methods as the most effective molecule for metal protection via donating e’s to the vacation d-orbital in metal, while AM1 and PM3 methods have predicted 1,3-benzodioxole-4-methoxy-6(2-propenyl)- and 1,3-benzodioxole 5-ethenyl, respectively. Although 1,3-benzodioxole-5-carboxylic acid has two oxygen atoms compared with XI all applied methods considered it as the lowest tendency to donate e’s for the metal. This may be due to the presence of the methyl group between benzene ring and ester that increases elasticity of the compound (XI) and the delocalization of the electrons.
In most cases, excellent corrosion inhibitors can not only offer e’s to the d-orbital of the metal but also accept e’s from the metal [
Figure
The HOMO and LUMO of the investigated 1,3-benzodioxole derivatives.
Junaedi et al. observed the increases of inhibition efficiency with an increase in EHOMO values along with a decrease in ELUMO values. The corrosion inhibition potential of 1-[3-(2H-1,3-benzodioxol-5-yl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Oxo-1,3-PQPB) was studied for mild steel corrosion in acidic media using electrochemical, spectroscopic techniques and quantum chemical calculations [
The energy gap,
The dipole moment is calculated by the product of distance and the charge on the atoms; it indicates the polarity of the covalent bond of the molecule [
Figure
The total e’s density for the investigated 1,3-benzodioxole derivatives.
Mulliken charges of the atoms in benzodioxole derivatives are listed in Table
Mulliken charges for the investigated 1,3-benzodioxole derivatives.
Compounds | Atoms | Charges | Atoms | Charges | Atoms | Charges | Atoms | Charges | Atoms | Charges | Atoms | Charges |
---|---|---|---|---|---|---|---|---|---|---|---|---|
I | O ( |
−0.342 | O ( |
−0.342 | C (5) | 0.003 | C (7) | 0.139 | C (9) | −0.028 | ||
C ( |
0.149 | C (4) | −0.028 | C (6) | 0.139 | C (8) | 0.003 | |||||
II | C ( |
−0.049 | O ( |
−0.342 | O (5) | −0.342 | C (7) | 0.007 | C (9) | 0.139 | C (11) | −0.024 |
C ( |
−0.031 | C (4) | 0.149 | C (6) | −0.010 | C (8) | 0.139 | C (10) | 0.004 | |||
III | Cl ( |
−0.126 | O ( |
−0.342 | O (5) | −0.342 | C (7) | 0.008 | C (9) | 0.139 | C (11) | −0.024 |
C ( |
0.029 | C (4) | 0.149 | C (6) | 0.001 | C (8) | 0.139 | C (10) | 0.004 | |||
IV | C ( |
−0.050 | C ( |
−0.043 | C (5) | 0.149 | C (7) | −0.025 | C (9) | 0.139 | C (11) | 0.007 |
C ( |
−0.038 | O (4) | −0.342 | O (6) | −0.342 | C (8) | 0.004 | C (10) | 0.139 | C (12) | −0.013 | |
V | C ( |
0.037 | C (4) | −0.038 | C (7) | 0.149 | C (10) | 0.007 | C (13) | 0.139 | ||
O ( |
−0.371 | C (5) | −0.043 | O (8) | −0.342 | C (11) | 0.142 | C (14) | 0.007 | |||
C ( |
−0.050 | O (6) | −0.339 | C (9) | −0.011 | C (12) | 0.170 | |||||
VI | C ( |
0.037 | O ( |
−0.371 | C (7) | −0.040 | O (10) | −0.339 | C (13) | 0.173 | C (16) | 0.010 |
C ( |
0.037 | C (5) | −0.050 | O (8) | −0.339 | C (11) | 0.021 | C (14) | 0.173 | |||
O ( |
−0.371 | C (6) | −0.038 | C (9) | 0.150 | C (12) | 0.142 | C (15) | 0.139 | |||
VII | C ( |
0.037 | O (4) | −0.371 | C (7) | −0.025 | O (10) | −0.339 | C (13) | 0.173 | C (16) | 0.010 |
O ( |
−0.371 | C (5) | −0.062 | O (8) | −0.339 | C (11) | 0.024 | C (14) | 0.173 | |||
C ( |
0.037 | C (6) | −0.037 | C (9) | 0.150 | C (12) | 0.142 | C (15) | 0.139 | |||
VIII | O ( |
−0.229 | O ( |
−0.342 | O (5) | −0.342 | C (7) | 0.010 | C (9) | 0.139 | C (11) | −0.022 |
C ( |
0.130 | C (4) | 0.149 | C (6) | 0.021 | C (8) | 0.139 | C (10) | 0.004 | |||
IX | O ( |
−0.354 | C ( |
0.264 | C (5) | 0.149 | C (7) | 0.054 | C (9) | 0.139 | C (11) | 0.004 |
O ( |
−0.191 | O (4) | −0.342 | O (6) | −0.342 | C (8) | 0.013 | C (10) | 0.139 | C (12) | −0.019 | |
X | O ( |
−0.191 | C (4) | 0.266 | O (7) | −0.342 | C (10) | 0.139 | C (13) | −0.019 | ||
C ( |
0.040 | O (5) | −0.342 | C (8) | 0.054 | C (11) | 0.139 | |||||
O ( |
−0.346 | C (6) | 0.149 | C (9) | 0.013 | C (12) | 0.004 | |||||
XI | C ( |
0.040 | C (4) | 0.259 | C (7) | 0.149 | C (10) | 0.007 | C (13) | 0.004 | ||
O ( |
−0.191 | C (5) | 0.017 | O (8) | −0.342 | C (11) | 0.139 | C (14) | −0.025 | |||
O ( |
−0.346 | O (6) | −0.342 | C (9) | −0.008 | C (12) | 0.139 | |||||
XII | N ( |
−0.327 | C ( |
−0.034 | C (5) | 0.149 | C (7) | −0.012 | C (9) | 0.139 | C (11) | 0.004 |
C ( |
−0.007 | O (4) | −0.342 | O (6) | −0.342 | C (8) | 0.007 | C (10) | 0.139 | C (12) | −0.025 |
The hardness
The quantum chemical parameters and QSAR parameters for the investigated 1,3-benzodioxole derivatives using MNDO.
Compounds |
|
|
|
|
|
Log P | S.A, Ǻ2 |
|
|
TE, eV |
---|---|---|---|---|---|---|---|---|---|---|
I | 8.90 | −0.11 | 4.40 | 4.51 | −1.13 | −0.20 | 217.74 | 12.77 | −6.16 | −37.32 |
II | 8.64 | 0.37 | 4.51 | 4.14 | −1.04 | 2.38 | 267.23 | 16.25 | − 6.52 | −43.85 |
III | 9.14 | 0.56 | 4.85 | 4.29 | −1.07 | 2.34 | 282.74 | 16.53 | −5.12 | −49.22 |
IV | 8.86 | −0.07 | 4.40 | 4.47 | −1.12 | 2.78 | 300.11 | 18.08 | −6.01 | −47.44 |
V | 8.95 | 0.19 | 4.57 | 4.38 | −1.10 | 2.52 | 214.18 | 20.55 | −6.34 | −58.41 |
VI | 8.83 | 0.05 | 4.44 | 4.39 | −1.10 | 2.27 | 370.54 | 23.03 | −6.46 | −69.31 |
VII | 8.84 | 0.21 | 4.53 | 4.32 | −1.08 | 2.23 | 381.31 | 23.03 | −5.40 | −69.38 |
VIII | 9.24 | 0.76 | 5.00 | 4.24 | −1.06 | 1.41 | 260.47 | 14.69 | −6.81 | −47.66 |
IX | 9.47 | −0.93 | 4.27 | 5.02 | −1.26 | 1.43 | 263.81 | 15.33 | −12.38 | −55.06 |
X | 9.26 | 0.74 | 5.00 | 4.26 | −1.07 | 1.46 | 311.69 | 17.16 | −5.86 | −58.46 |
XI | 8.59 | 0.48 | 4.54 | 4.10 | −1.03 | 1.39 | 240.03 | 19.00 | −6.71 | −62.23 |
XII | 8.89 | 0.11 | 4.39 | 4.50 | −1.13 | 1.10 | 289.84 | 17.79 | −10.08 | −49.60 |
Ebenso et al. [
The QSAR calculation is applied and several parameters are obtained. Polarizability measures the change in e’s distribution of the molecule with respect to the applied electric field. As the polarization increases, the intrinsic molecular value increasing the adsorption of the molecule to the metal surface becomes easier [
Hydrophobicity coefficient Log P is another parameter to measure the corrosion efficiencies of the molecule. As the hydrophobicity increases, the water solubility of the molecule decreases. Also, as a result, the transportation to the metal surface becomes slower and the probable adsorption gets low. As shown in Table
The hydration energy of the molecules measures the dissolution extent. The negative values of the hydration energy of the studied molecule indicated an exothermic dissolution. The increase of the hydration energy leads to the increase of the efficiency of the molecule. Concerning the data listed in Table
The larger the surface area of the inhibitor molecules is, the greater the contact adsorbed area and the efficiency of the inhibitor become. The large size of 1,3-benzodioxole-5-acetic acid, methyl ester (Table
It can be concluded from this study that quantum chemical calculations and QSAR for 1,3-benzodioxole derivatives are based on different semiempirical methods; according to INDO, MNDO, and MINDO/3 methods 1,3-benzodioxole-5-acetic acid, methyl ester, is considered as the most effective molecule; the negative value of The surface area and Log P have an excellent correlation with INDO, MNDO, and MINDO/3 calculations while polarization has poor correlations; 1,3-Benzodioxole-5-carboxylic acid is predicted as poor inhibitor by all applied methods.
The author declares that she has no conflicts of interest.