Adsorption and Quantum Chemical Studies on the Inhibition Potentials of Some Thiosemicarbazides for the Corrosion of Mild Steel in Acidic Medium
Autor: | Eno E. Ebenso, David A. Isabirye, Nnabuk Okon Eddy |
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Rok vydání: | 2010 |
Předmět: |
Models
Molecular Quantitative structure–activity relationship corrosion inhibitors Inorganic chemistry Quantitative Structure-Activity Relationship Fukui function Article Catalysis Corrosion lcsh:Chemistry Inorganic Chemistry symbols.namesake Adsorption Molecule Reactivity (chemistry) Physical and Theoretical Chemistry lcsh:QH301-705.5 Molecular Biology Spectroscopy thiosemicarbazides quantum chemical calculations QSAR adsorption Molecular Structure Chemistry Organic Chemistry Langmuir adsorption model General Medicine Semicarbazides Computer Science Applications lcsh:Biology (General) lcsh:QD1-999 symbols Quantum Theory Thermodynamics Gravimetric analysis |
Zdroj: | International Journal of Molecular Sciences, Vol 11, Iss 6, Pp 2473-2498 (2010) International Journal of Molecular Sciences; Volume 11; Issue 6; Pages: 2473-2498 International Journal of Molecular Sciences |
ISSN: | 1422-0067 |
DOI: | 10.3390/ijms11062473 |
Popis: | Three thiosemicarbazides, namely 2-(2-aminophenyl)-N phenylhydrazinecarbothioamide (AP4PT), N,2-diphenylhydrazinecarbothioamide (D4PT) and 2-(2-hydroxyphenyl)-N-phenyl hydrazinecarbothioamide (HP4PT), were investigated as corrosion inhibitors for mild steel in H2SO4 solution using gravimetric and gasometric methods. The results revealed that they all inhibit corrosion and their % inhibition efficiencies (%IE) follow the order: AP4PT > HP4PT > D4PT. The %IE obtained from the gravimetric and gasometric experiments were in good agreement. The thermodynamic parameters obtained support a physical adsorption mechanism and the adsorption followed the Langmuir adsorption isotherm. Some quantum chemical parameters were calculated using different methods and correlated with the experimental %IE. Quantitative structure activity relationship (QSAR) approach was used on a composite index of some quantum chemical parameters to characterize the inhibition performance of the studied molecules. The results showed that the %IE were closely related to some of the quantum chemical parameters, but with varying degrees. The calculated/theoretical %IE of the molecules were found to be close to their experimental %IE. The local reactivity has been studied through the Fukui and condensed softness indices in order to predict both the reactive centers and to know the possible sites of nucleophilic and electrophilic attacks. |
Databáze: | OpenAIRE |
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