scholarly journals Interaction of Two Water Soluble Heterocyclic Hydrazones on Copper in Nitric Acid: Electrochemical, Surface Morphological, and Quantum Chemical Investigations

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Vinod P. Raphael ◽  
Joby Thomas Kakkassery ◽  
Shaju K. Shanmughan ◽  
Sini Varghese
Keyword(s):  
Corrosion Inhibition ◽  
Potentiodynamic Polarization ◽  
Quantum Chemical ◽  
Electrochemical Corrosion ◽  
Water Soluble ◽  
Chemical Hardness ◽  
Corrosion Monitoring ◽  
Spectroscopic Techniques ◽  
Free Energy Of Adsorption ◽  
Monitoring Techniques

Two novel heterocyclic compounds (E)-2-(1-(pyridin-3-yl)ethylidene)hydrazinecarbothioamide (3APTSC) and (E)-3-(1-(2-phenylhydrazono)ethyl)pyridine (3APPH) derived from 1-(pyridin-3-yl)ethanone were synthesized and characterized by various spectroscopic techniques. The corrosion inhibition efficacies of these compounds on copper in 0.1 M HNO3 were screened by electrochemical corrosion monitoring techniques such as potentiodynamic polarization studies and impedance spectroscopy. Investigations clearly established that 3APPH displayed higher corrosion inhibition efficiency on Cu than 3APTSC at all concentrations. The mechanism of inhibition was verified with the help of adsorption isotherms. 3APTSC and 3APPH obeyed Langmuir adsorption isotherm on Cu surface. Thermodynamic parameters such as adsorption equilibrium constant (Kads) and free energy of adsorption (ΔGads) were also evaluated. Potentiodynamic polarization investigations confirmed that the 3APTSC and 3APPH act as mixed type inhibitors. Surface analysis of the metal specimens was performed by scanning electron microscopy. Energy of HOMO and LUMO, their difference, number of electrons transferred, electronegativity, chemical hardness, and so forth were evaluated by quantum chemical studies. Agreeable correlation was observed between the results of quantum chemical calculations and other corrosion monitoring techniques.

scholarly journals Monitoring the Interaction of Two Heterocyclic Compounds on Carbon Steel by Electrochemical Polarization, Noise, and Quantum Chemical Studies

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Vinod P. Raphael ◽  
Shaju K. Shanmughan ◽  
Joby Thomas Kakkassery
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Quantum Chemical ◽  
Reduced Form ◽  
Chemical Hardness ◽  
Corrosion Monitoring ◽  
Chemical Studies ◽  
Quantum Chemical Studies ◽  
Homo And Lumo ◽  
Methyl Pyridine

A heterocyclic phenylhydrazone 2-[(E)-(2-phenylhydrazinylidene)methyl]pyridine (P2APH) and its reduced form 2-[(2-phenylhydrazinyl)methyl]pyridine (RP2APH) were synthesized, characterized, and subjected to corrosion inhibition investigation on carbon steel (CS) in 1 M HCl using gravimetric, polarization, electrochemical noise, quantum chemical, and surface studies. P2APH showed more inhibition capacity than RP2PPH. But RP2PPH was very stable in acid medium and showed pronounced corrosion inhibition efficacy for days. Energy of HOMO and LUMO, their difference, number of electrons transferred, electronegativity, chemical hardness, and so forth were evaluated by quantum chemical studies. Agreeable correlation was observed between the results of quantum chemical calculations and other corrosion monitoring techniques.

scholarly journals New Aromatic Azo-Schiff as Carbon Steel Corrosion Inhibitor in 1 M H2SO4

2018 ◽  
Vol 34 (5) ◽  
pp. 2471-2476 ◽  
Author(s):  
Hamida Edan Salman ◽  
Asim A. Balakit ◽  
Ali Ahmed Abdulridha
Keyword(s):  
Weight Loss ◽  
Carbon Steel ◽  
Corrosion Inhibitor ◽  
Corrosion Inhibition ◽  
Potentiodynamic Polarization ◽  
Inhibition Efficiency ◽  
Steel Corrosion ◽  
Spectroscopic Techniques ◽  
Different Temperatures ◽  
Corrosion Inhibition Efficiency

A new aromatic Schiff base with azo linkage (AS) has been synthesized and characterized by FT-IR, 1H NMR and 13C NMR spectroscopic techniques. The new compound (AS) has been evaluated as carbon steel corrosion inhibitor at different concentrations (0.005, 0.01, 0.02, 0.04 and 0.08 mM) and different temperatures (303 – 333 K). The corrosion inhibition efficiency was studied by potentiodynamic polarization and weight loss measurements. The effects of concentration and temperature on the inhibition efficiency were studied by potentiodynamic polarization studies, the results showed that increasing concentration of AS increases the inhibition efficiency while increasing the temperature decreases it, the highest corrosion inhibition efficiency, 93.9% was recorded with 0.08 mM of AS at 313 K in 1 M H2SO4. Weight loss measurements showed that the inhibition efficiency reached 97.1% in the presence of AS (0.08 mM) at 313 K. The adsorption process was found to obey Langmuir isotherm, and the adsorption thermodynamic parameters were studied. Scanning electron microscope (SEM) was used to confirm the results.

A Quantum-chemical Study of the Corrosion Inhibition of Iron by Means of Aniline Derivatives in Hydrochloric Acid

CORROSION ◽  
1976 ◽  
Vol 32 (5) ◽  
pp. 183-187 ◽  
Author(s):  
JAN VOSTA ◽  
JAROSLAV ELIASEK ◽  
PETR KNIZEK
Keyword(s):  
Hydrochloric Acid ◽  
Quantum Chemistry ◽  
Organic Compounds ◽  
Corrosion Inhibition ◽  
Quantum Chemical ◽  
Quantum Chemical Study ◽  
Electrochemical Corrosion ◽  
Chemical Study ◽  
Substituted Anilines ◽  
Inhibition Process

Abstract When various properties of organic compounds are to be expressed, it is necessary to explore the connection between their experiment and theory. To determine the mechanism of the inhibition process by organic materials, the electron structure of a set of organic compounds is studied and correlated with their electrochemical corrosion measurements. This paper discusses the inhibition of corrosion in 5% hydrochloric acid by means of p-substituted anilines with respect to quantum chemistry.

Synthesis and DFT Quantum Chemical Calculations of 2-Oxopyrimidin-1(2H)-yl-Urea and Thiorea Derivatives

2019 ◽  
Vol 41 (5) ◽  
pp. 841-841
Author(s):  
Murat Saracoglu Murat Saracoglu ◽  
Zulbiye Kokbudak Zulbiye Kokbudak ◽  
Esra Yalcin and Fatma Kandemirli Esra Yalcin and Fatma Kandemirli
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Chemical Potential ◽  
Energy Gap ◽  
Basis Set ◽  
Chemical Hardness ◽  
Spectroscopic Techniques ◽  
Solvent Phase ◽  
B3lyp Method ◽  
Homo Lumo

A series of the new 2-oxopyrimidin-1(2H)-yl-urea (3a-c) and thiourea (4a-d) derivatives were synthesized by the reaction of arylisocyanates (2a-c) or arylisothiocyanates (2d-g) and the 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (1). The structures of the compounds 3a-c and 4a-d were characterized by elemental analysis, FT-IR, 1H and 13C-NMR spectroscopic techniques. In addition to experimental study in order to find molecular properties, quantum-chemical calculations of the synthesized compounds were carried out by using DFT/B3LYP method with basis set of the 6-311G(d,p). Quantum chemical features such as HOMO, LUMO, HOMO-LUMO energy gap, Ionization potential, chemical hardness, chemical softness, electronegativity, chemical potential, dipole moment etc. values for gas and solvent phase of neutral molecules were calculated and discussed.

Synthesis and DFT Quantum Chemical Calculations of Novel Pyrazolo[1,5-c]pyrimidin-7(1H)-one Derivatives

2019 ◽  
Vol 41 (3) ◽  
pp. 479-479
Author(s):  
Murat Saracoglu Murat Saracoglu ◽  
Zulbiye Kokbudak Zulbiye Kokbudak ◽  
Zeynep imen and Fatma Kandemirli Zeynep imen and Fatma Kandemirli
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Chemical Potential ◽  
Energy Gap ◽  
Chemical Hardness ◽  
Spectroscopic Techniques ◽  
Solvent Phase ◽  
B3lyp Method ◽  
Ft Ir ◽  
Homo Lumo

In this study, a convenient procedure for the preparation of pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives is described. The new pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives (2a, b) were synthesized from the cyclocondensation reaction of the compounds 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (1a) and 1-amino-5-(4-methylbenzoyl)-4-(4-methylphenyl)pyrimidin-2(1H)-one (1b) with α-chloroacetone. The structures of the compounds (2a, b) were characterized by elemental analysis, FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. In addition to experimental study in order to find molecular properties, quantum-chemical calculations of the new pyrazolo[1,5-c]pyrimidin-7(1H)-one derivatives (2a, b) were carried out by using DFT/B3LYP method with the 6-311G(d,p) and 6-311++G(2d,2p) basic sets. Quantum chemical features such as HOMO, LUMO, HOMO-LUMO energy gap, chemical hardness, chemical softness, electronegativity, chemical potential, dipole moment etc. values for gas and solvent phase of neutral molecules were calculated and discussed.

scholarly journals Experimental and Theoretical Investigations on the Corrosion Inhibition action of Thiadiazole Derivatives on Carbon Steel in 1M HCl medium

2020 ◽  
Vol 36 (6) ◽  
pp. 1179-1188
Author(s):  
REEJA JOHNSON ◽  
JOBY THOMAS KAKKASSERY ◽  
Vinod Raphael Palayoor ◽  
Ragi Kooliyat ◽  
Vidhya Thomas Kannanaikkal
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Quantum Chemical ◽  
Electrochemical Impedance ◽  
Corrosion Monitoring ◽  
Mechanism Of Inhibition ◽  
Theoretical Investigations ◽  
Thiadiazole Derivatives ◽  
Derivatives Of ◽  
Hcl Medium

Novel thiadiazole derivatives of Schiff bases namely (E)-N-(anthracen-9-ylmethylene)-5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine (A9CNPTDA) and N-(anthracen-9(10H)-ylidene)-5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine (ANNPTDA) were synthesized, characterized and corrosion inhibition behaviour, as well as the mechanism of inhibition were investigated by different monitoring techniques like gravimetric measurements, electrochemical impedance spectroscopy, potentiodynamic polarization, quantum chemical and SEM studies. Both of the thiadiazole derivatives showed excellent corrosion inhibitor action on carbon Steel in acid medium. A9CNPTDA exhibited highest inhibition efficiency of 98.04% at 1mM concentration while ANNPTDA showed a maximum of 95.32%. In HCl medium, both derivatives obeyed Langmuir adsorption isotherm and thermodynamic parameters (Kads, ΔG0ads) were calculated. An acceptable relationship was observed between the results of quantum chemical calculations and other corrosion monitoring analysis.

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