Inhibition of the Corrosion of Zinc in H2SO4 by 9-deoxy-9a-aza-9a-methyl-9a-homoerythromycin A (Azithromycin)

Density functional theory (DFT) at the B3LYP/6-31G (d,p) and BP86/ CEP-31G* basis set levels and ab initio calculations using the RHF/6-31G (d,p) methods were performed on four sulfonamides (namely sulfaacetamide (SAM), sulfapyridine (SPY), sulfamerazine (SMR), and sulfathiazole (STI)) used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies (%IE). The order of inhibition efficiency obtained was SMR > SPY > STI > SAM which corresponded with the order of most of the calculated quantum chemical parameters namely E HOMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), the energy gap (DE), the Mulliken charges on the C, O, N, S atoms, hardness (g), softness (S), polarizability (a), dipole moment (l), total energy change (DE T ), electrophilicity (x), electron affinity (A), ionization potential (I), the absolute electronegativity (v), and the fraction of electrons transferred (DN). Quantitative structure activity relationship (QSAR) approach has been used and a correlation of the composite index of some of the quantum chemical parameters was performed to characterize the inhibition performance of the sulfonamides studied. The results showed that the %IE of the sulfonamides was closely related to some of the quantum chemical parameters but with varying degrees/order. The calculated %IE of the sulfonamides studied was found to be close to their experimental corrosion inhibition efficiencies. The experimental data obtained fits the Langmuir adsorption isotherm. The negative sign of the E HOMO values and other thermodynamic parameters obtained indicates that the data obtained supports physical adsorption mechanism.

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“…We have also recently reported on some studies using some drugs as corrosion inhibitors in our laboratories [37][38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Theoretical studies of some sulphonamides as corrosion inhibitors for mild steel in acidic medium

Ebenso

Arslan

Kandemi̇rlı

et al. 2010

Int J of Quantum Chemistry

148

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“…Valuable metals, such as mild steel, aluminium, copper and zinc are prone to corrosion when they are exposed to aggressive media (such as acids, bases and salts) [5][6][7]. Therefore, there is a need to protect these metals against corrosion.…”

Section: Introductionmentioning

confidence: 99%

Experimental and theoretical studies on some amino acids and their potential activity as inhibitors for the corrosion of mild steel, part 2

Eddy

2011

Journal of Advanced Research

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Substituent constants and quantum chemical parameters were calculated from PM6, PM3, AM1, RM1 and MNDO. Hamiltonians were used to predict the corrosion inhibition potential of nine amino acids grouped under three skeletons. Skeleton I consisted of cysteine (CYS), serine (SER) and amino butyric acid (ABU). Those in skeleton II included threonine (THR), alanine (ALA) and valine (VAL) while those in skeleton III are aromatic amino acids, which included phenylalanine (PHE), tryptophan (TRP) and tyrosine (TYR). Trends obtained from substituent constants were not entirely useful in predicting the corrosion inhibition potentials of the studied amino acids. However, the results obtained from quantum chemical parameters indicated that the trends for the variation of corrosion inhibition potentials of the studied amino acids in skeletons I, II and III are CYS > SER > ABU, THR > ALA > VAL and TRP > TYR > PHE, respectively. Highest values of inhibition efficiency were obtained for inhibitors in skeleton III and are attributed to the presence of aromatic ring in the molecule while the corrosion inhibition potential of inhibitors in skeletons I and II are attributed to the presence of -SH and -OH functional groups, respectively. Analysis of data obtained from relative nucleophilicity/electrophilicity, condensed Fukui and softness functions indicated that the sites for electrophilic attacks for the amino acids in skeletons I and II are in the amine bonds but for those in skeleton III the sites were in their q Eddy NO. Part 3. Theoretical study on some amino acids and their potential activity as corrosion inhibitors for mild steel in HCl. Mol Simul 2010;36(5):354-63.

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“…The treatment of zinc with acidic solutions cannot be completely avoided, as this is necessary for scale removal and cleaning of zinc surfaces. Consequently, corrosion prevention of zinc has become a subject of practical, industrial and economic significance [1][2][3] . Corrosion prevention can take a number of forms depending on the circumstances of the metal being corroded, and the familiar corrosion prevention techniques include: cathodic protection, coating, plating and corrosion inhibition, to mention but a few.…”

Section: Introductionmentioning

confidence: 99%

Inhibitive Effect of Dirithromycin on the Corrosion of Zinc in Tetraoxosulphate(VI) Acid Medium

2015

Chem Sci Trans

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The inhibitive effect by dirithromycin, an antibacterial drug, on the corrosion of zinc has been investigated using weight loss method. The results obtained indicate that clindamycin inhibits zinc corrosion in tetraoxosulphate(VI) acid (0.01 to 0.04 M) media. The inhibition efficiency increased with increasing inhibitor's concentration. Kinetic, thermodynamic and adsorption parameters were determined and discussed. The uninhibited corrosion of zinc followed first order kinetics; while the presence of dirithromycin increased the enthalpy of activation, H ‡ and therefore made corrosion less probable. The calculated G ‡ values for the corrosion processes were positive, but increased in the presence of dirithromycin, suggesting that the activated complex was rather unstable. The adsorption of dirithromycin on zinc surface was exothermic, spontaneous and was best described by Langmuir adsorption isotherm. The calculated values of activation energies and free energies of adsorption indicate that the adsorption process supports the mechanism of physical absorption.

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Inhibition of the Corrosion of Zinc in H2SO4 by 9-deoxy-9a-aza-9a-methyl-9a-homoerythromycin A (Azithromycin)

Cited by 31 publications

References 11 publications

Theoretical studies of some sulphonamides as corrosion inhibitors for mild steel in acidic medium

Theoretical studies of some sulphonamides as corrosion inhibitors for mild steel in acidic medium

Experimental and theoretical studies on some amino acids and their potential activity as inhibitors for the corrosion of mild steel, part 2

Inhibitive Effect of Dirithromycin on the Corrosion of Zinc in Tetraoxosulphate(VI) Acid Medium

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