DFT computations and molecular dynamics investigations on conformers of some pyrazinamide derivatives as corrosion inhibitors for aluminum

Electrochemical behavior and theoretical studies of arylazo (1-naphthyl-2-cyanoacetamide) derivatives as new corrosion inhibitors for Inconel 800 in chloride solution

In this study, synthesize and insight the corrosion inhibition properties of two novel derivatives of 1-naphthyl-2-cyanoacetamide (NCDs) [2-cyano-2-((5,6-dimethyl-1H-benzo[d]imidazol-2-yl) diazenyl)-N (naphthalene-1-yl)acetamide] (NCD1) and [2-Cyano-N-(naphthalene-1-yl)-2-[(4,6-dimethyl-1H-pyrazolo [3, 4-b] pyridine-3-yl) hydrazono] acetamide] (NCD2). The characterization of the synthesized NCDs was confirmed through the utilization of Mass fragmentation analysis, 1H-NMR, and IR. The corrosion inhibition performance of NCDs as a novel and environmentally safe corrosion inhibitor has been investigated by electrochemical techniques, a chemical technique, and theoretical studies for its anti-corrosion behavior of Inconel 800 in chloride medium. In addition, the surface morphology and inhibitor adsorption on the Inconel 800 surface were confirmed utilizing SEM, EDX, FTIR, and AFM. The advantages of NCDs include their low toxicity, environmental friendliness, ease of preparation, low odor, contain (N, O, and π-Bonds), and the inhibition efficiency elevated with decreasing solution temperature as well as inhibitor dose increase, yielding increased efficiencies of 91.8% and 95.7% for NCD1 and NCD2, respectively, at the optimum concentration of 21 × 10-6 mol. L-1 and 298 K temperature. An analysis of Tafel plots reveals that NCDs adhere to a mixed and isothermal Langmuir adsorption mechanism. Density Functional Theory (DFT) and Monte Carlo (MC) simulation manifest the two compounds of NCDs can be adsorbed at the Fe (110) surface in a paralleled way, and can have a smaller energy gap (ΔE) value and exhibit higher efficiency. The experimental and theoretical findings confirm that the synthesized compounds obtained are capable of protecting the Inconel 800 from corrosion by creating an anti-corrosion coating on the surface.

Photodegradation for different dissociated species of norfloxacin and ofloxacin in water ice under solar irradiation

Ice is an important medium that regulates the transformation of organic contaminants. Nonetheless, photodegradation of emerging fluoroquinolone (FQ) antibiotics in the ice, particularly those with varying dissociated species, remains inadequately explored. In this study, the photodegradation of norfloxacin (NOR) and ofloxacin (OFL) in different dissociated species in water ice were investigated. Results indicated that the quantum yield of the zwitterion for NOR in the ice was 1.7-5.0 times higher than that of the cation, and 1.3 times higher than that of the anion. The quantum yield of the zwitterion for OFL in the ice was 2.5-3.4 times higher than that of the cation, and 1.4 times higher than that of the anion. The degradation pathways of NOR and OFL with different dissociated species depended on their molecular structure. Most products possessed lower developmental toxicity than parent NOR and OFL, respectively. OFL showed a higher inhibitory rate of Escherichia coli activity at the initial time of photodegradation, which was higher than that of NOR. This study offers novel insights into the impact of dissociated species on the photodegradation of FQs in ice and contributes to understanding the environmental behavior of fluorinated pharmaceuticals in the cryosphere.

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

Several new possible biobased corrosion inhibitors derived from fatty hydrazide derivatives were analyzed using quantum chemical calculations via the density functional theory method to investigate the chemical reactivity and inhibition efficiencies against corrosion in metal steel. The study confirmed that the fatty hydrazides showed significant inhibitive performances based on their electronic properties, revealing band gap energies of 5.20 to 7.61 eV between the HOMO and LUMO. These energy differences decreased from 4.40 to 7.20 eV when combined with substituents of varying chemical compositions, structures, and functional groups, associated with higher inhibition efficiency. The most promising fatty hydrazide derivatives are terephthalic acid dihydrazide combined with a long-chain alkyl chain, which resulted in the lowest energy difference of 4.40 eV. Further inspection showed that the fatty hydrazide derivatives' inhibitive performances increased with increasing carbon chain length [from 4 (4-s-4) to 6 (6-s-6)], with a concomitant increase and decrease in hydroxyl and carbonyl groups, respectively. Fatty hydrazide derivatives containing aromatic rings also showed increased inhibition efficiencies following their contribution to improve the compounds' binding ability and adsorption on the metal surface. Overall, all data were consistent with previously reported findings, envisaging the potential of fatty hydrazide derivatives as effective corrosion inhibitors.

Experimental and computational approaches of methoxy naphthylbithiophene derivatives and their use as corrosion protection for carbon steel in acidic medium

The inhibition efficiency and adsorption affinity were investigated for two novel compounds, namely: 6-methoxy-2-naphthyl-[2, 2'-bithiophene]-5-carboxamidine hydrochloride salt (MA-1440) and 5'-(4-chlorophenyl)-2, 2'-bifuran-5-carboxamidine hydrochloride salt (MA-1456). The inhibition study was conducted on carbon steel surface in 1.0 M HCl with different inhibitor doses and different temperature levels, to investigate the optimum dose and preferable temperature. The performed investigation included chemical, electrochemical, instrumental, and quantum computation techniques. A chemical technique was accomplished by using weight-loss measurements. Different factors were studied using weight-loss measurements in order to reach the maximum inhibition efficiency. The adsorption study revealed that the examined inhibitors obey the Langmuir adsorption isotherm and are chemically adsorbed on the steel surface. The electrochemical measurements were accomplished through the electrochemical impedance (EIS) and potentiodynamic polarization (PDP) techniques. Based on the electrochemical measurements, the examined compounds were categorized as mixed inhibitors. The instrumental examination using different techniques namely: scanning electron microscope (SEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) confirmed that the considered inhibitors are excellently adsorbed over the carbon steel surface. The extent of the adsorption affinity of these compounds on the carbon steel surface was studied theoretically using quantum computations and Monte Carlo simulation. The theoretical investigation results of quantum chemistry were validated with those obtained by chemical and electrochemical methodologies. All investigations prove that, the tested compounds were adsorbed chemically on the steel surface and achieved maximum inhibition efficiency of, 94.69% and 90.85% for M-1440 and MA-1456, respectively, at the optimum concentration 30 [Formula: see text] 10^-6 mol L^-1 and temperature 328 K.

DFT Study on Corrosion Inhibition by Tetrazole Derivatives: Investigation of the Substitution Effect

Corrosion is one of the problems that most industries face. Our aim in the current study is to perform density functional theory calculations and Monte Carlo simulation to theoretically investigate the corrosion inhibition of the copper (1 1 1) surface by tetrazole molecules and a group of their derivatives. These compounds have electron-donating groups (CH₃, CH₃O, and OH) and electron-withdrawing groups (F, CN, and NO₂). Two different isomeric forms of tetrazole molecules and their derivatives, including 1H and 2H tautomers, were studied in two configurations, parallel and perpendicular to the Cu (1 1 1) surface. With the help of DMol3 calculations, the most important parameters related to the molecular ability of tetrazole derivatives as corrosion inhibitors include the adsorption energy (ΔE), E _HOMO, E _LUMO, E _gap, and issues related to chemical reactions, including total hardness (η), electronegativity (χ), and electron fraction transitions from the anti-corrosion molecule to the copper atom (ΔN), were calculated and compared in the tetrazole molecules and their derivatives. Also, with the help of adsorption locator calculations, the inhibitory effects of these compounds were theoretically investigated in an acidic environment. Through these calculations, it was determined that tetrazole molecules with electron-donating groups adsorbed perpendicularly to the copper (1 1 1) surface, by forming a stronger bond, are considered suitable corrosion inhibitors. Also, among the examined molecules, the 2H-tetrazole isomer form plays a more influential role than the 1H-tetrazole form.

Corrosion protection of carbon steel by methoxy naphthylbithiophene derivatives in acidic medium: Electrochemical, surface characterization and computational approaches.. [DOI: 10.21203/rs.3.rs-2233861/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The inhibition efficiency and adsorption affinity were investigated for two novel compounds, namely: 6-methoxy-2-naphthyl-[2, 2’-bithiophene]-5-carboxamidine hydrochloride salt (MA-1440) and 5'-(4-chlorophenyl)-2, 2’-bifuran-5-carboxamidine hydrochloride salt (MA-1456). The inhibition study was conducted on carbon steel surface in 1.0 M HCl with different inhibitor doses and different temperature levels, to investigate the optimum dose and preferable temperature. The performed investigation included chemical, electrochemical, instrumental, and quantum computation techniques. A chemical technique was accomplished by using weight-loss measurements. Different factors were studied using weight-loss measurements in order to reach the maximum inhibition efficiency. The adsorption study revealed that the examined inhibitors obey the Langmuir adsorption isotherm and are chemically adsorbed on the steel surface. The electrochemical measurements were accomplished through the electrochemical impedance (EIS) and potentiodynamic polarization (PDP) techniques. Based on the electrochemical measurements, the examined compounds were categorized as mixed inhibitors. The instrumental examination using different techniques namely: scanning electron microscope (SEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) confirmed that the considered inhibitors are excellently adsorbed over the carbon steel surface. The extent of the adsorption affinity of these compounds on the carbon steel surface was studied theoretically using quantum computations and Monte Carlo simulation. The theoretical investigation results of quantum chemistry were validated with those obtained by chemical and electrochemical methodologies. All investigations prove that, the tested compounds were adsorbed chemically on the steel surface and achieved maximum inhibition efficiency of, 94.69% and 90.85% for M-1440 and MA-1456, respectively, at the optimum concentration 3010-6 mol. L-1 and temperature 328 K.

Synthesis and Corrosion Inhibition Performance of Mannich Bases on Mild Steel in Lactic Acid Media

Heterocyclic Mannich bases, N-(3-oxo-3-phenylpro-pyl)thiazol-2-aminium chloride (DTZA) and N-(3-oxo-3-phenylpropyl)-1H-pyrazol-3-aminium chloride (DPZA), were developed for the corrosion inhibition of N80 steel in a 15 wt % lactic acid solution. Weight loss measurements, electrochemical techniques, surface characterization, and theoretical calculations were combined to investigate their anticorrosion performance and mechanism. The results showed that DTZA exhibited a satisfactory inhibitor efficiency of 97.56% with a dosage of 0.15% at 363 K, while DPZA achieved only 58.3% under the same conditions. Adsorptions of both inhibitors on the metal surface followed the Langmuir model with physical and chemical adsorptions. Based on X-ray photoelectronic spectroscopy (XPS) analysis, DFT calculations, and molecular dynamics (MD) simulations, stronger interactions between DTZA and iron than those in the case of DPZA were revealed, leading to the formation of a compact protective film on the metal surface, which is attributed to the presence of a thiazole ring in the DTZA chemical structure.

Pyrazinamide–isoniazid hybrid: synthesis optimisation, characterisation, and antituberculous activity

Over time, the effective resistance mechanisms to various first- and second-line drugs against the disease of tuberculosis make its treatment extremely difficult. This work presents a new approach to synthesizing a hybrid of antituberculosis medications: isoniazid (INH) and pyrazinamide (PZA). The synthesis was performed using ultrasound-assisted synthesis to obtain an overall yield of 70%, minimizing the reaction time from 7 to 1 h. The evaluation of the biological activity of the hybrid (compound 2) was tested using the tetrazolium microplate assay (TEMA), showing inhibition in the growth of Mycobacterium tuberculosis H37Rv at a concentration of 0.025 mM at pH 6.0 and 6.7.

Molecular modelling of compounds used for corrosion inhibition studies: a review

Molecular modelling of organic compounds using computational software has emerged as a powerful approach for theoretical determination of the corrosion inhibition potential of organic compounds. Some of the common techniques involved in the theoretical studies of corrosion inhibition potential and mechanisms include density functional theory (DFT), molecular dynamics (MD) and Monte Carlo (MC) simulations, and artificial neural network (ANN) and quantitative structure-activity relationship (QSAR) modeling. Using computational modelling, the chemical reactivity and corrosion inhibition activities of organic compounds can be explained. The modelling can be regarded as a time-saving and eco-friendly approach for screening organic compounds for corrosion inhibition potential before their wet laboratory synthesis would be carried out. Another advantage of computational modelling is that molecular sites responsible for interactions with metallic surfaces (active sites or adsorption sites) and the orientation of organic compounds can be easily predicted. Using different theoretical descriptors/parameters, the inhibition effectiveness and nature of the metal-inhibitor interactions can also be predicted. The present review article is a collection of major advancements in the field of computational modelling for the design and testing of the corrosion inhibition effectiveness of organic corrosion inhibitors.

Computational study of phosphate adsorption on Mg/Ca modified biochar structure in aqueous solution

Phosphate removal in water using biochar is widely investigated. Density functional theory was used to study the adsorption of phosphate (H₂PO₄^-) on biochar in water after metal modification. Two types of metals, Mg and Ca, were used to modify the biochar structure, and the edge and metal adsorptions of H₂PO₄^- were investigated on the modified biochar structure. Results were analyzed from the aspects of structural stability, adsorption energy, change in dipole moment, density of electronic states, and atoms in molecules analysis. The overall effect of metal-modified biochar materials on phosphate adsorption was stronger than that of unmodified biochar materials in terms of molecular level. The stability of the metal-modified structure by adding metal was low, and adsorption was prone to occur in this situation. The Ca-modified biochar showed better phosphate adsorption than the Mg-modified structure. Metal adsorption performed better than edge adsorption, proving that the modified metal in the biochar structure played a leading role in H₂PO₄^- adsorption. Metal adsorption was mainly caused by electrostatic attraction, and edge adsorption was mainly caused by covalent bonding.

Quantum Chemical and Monte Carlo Simulation Studies on Inhibition Performance of Caffeine and Its Derivatives against Corrosion of Copper

Performance tests on caffeine’s corrosion inhibition properties and their derivatives against copper corrosion have been previously reported experimentally using gravimetric and electrochemical analyses. The test was able to measure the efficiency of their corrosion inhibition accurately. However, the caffeine and its derivatives’ structure patterns and coating mechanisms when interacting with metals during copper corrosion inhibition have not been explained in detail by experimental studies. In the present study, the theoretical density functional study (DFT), ab initio MP2, and Monte Carlo simulation approaches explain the problem. The geometrical and quantum chemical parameters of inhibitors were compared under normal and protonated conditions in the gas and aqueous environments. Theoretical studies can accurately determine the molecule’s geometrical parameters and successfully explain the quantum parameters of inhibitors. Molecular dynamics are applied to study the mechanism of interaction between inhibitors and metal surfaces in an explicit water molecule environment. The energy absorption of caffeine and its derivatives on metal surfaces was linear, with quantum parameters calculated from the density functional theory and an ab initio approach. Furthermore, these theoretical study results align with the previously reported experimental studies published by de Souza et al. The inhibition efficiency ranking of studied molecules preventing copper corrosion was caffeine > theobromine > theophylline. This theoretical approach is expected to bridge the gap in designing effective corrosion inhibitors.

MEDT study of the 1,3-DC reaction of diazomethane with Psilostachyin and investigation about the interactions of some pyrazoline derivatives with protease (Mpro) of nCoV-2

The molecular electronic density theory (MEDT) was invested to elucidate the chemo-, regio- and stereo-selectivity of the 1,3-dipolar cycloaddition between Diazomethane (DZM) and Psilostachyin (PSH). The DFT method at B3LYP/6-31 + G (d,p) level of theory was used. Reactivity indices, transition structures theory, IGM and ELF analysis were employed to reveal the mechanism of the reaction. The addition of DZM to PSH takes place through a one-step mechanism and an asynchronous transition states. Eight possible addition channels of reaction were investigated (addition of C (sp2) to Diazomethane at C4, C5, C6 or C7). The addition of C (sp2) at C5 leading to P1 product is the preferred channel. The addition of ether does not affect the chemo-, regio- and stereo-selectivity of the reaction. Analysis of transfer of charges along the IRC path associated with the P1 product shows a polar character for the studied reaction. We have also used the noncovalent interaction (NCI) which is very helpful to reveal the most favored addition channel of the reaction, by analyzing the weak interactions in different TSs. Finally, we investigate about the potential of inhibition of some pyrazoline compounds against COVID-19-M^pro by performing a molecular docking calculations.

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The 1,3-DC reaction between Diazomethane and Psilostachyin has been investigated by MEDT.

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The asynchronicity of TSs has been revealed by IGM and Wiberg indices.

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The electronic description of mechanism of reaction has been performed by ELF analysis.

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The NCI analysis allow a deep description of weak interactions.

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The pyrazolines products possess a potential effect against COVID-19.

Structural, electronic, and energetic investigations of acrolein adsorption on B36 borophene nanosheet: a dispersion-corrected DFT insight

The adsorption of acrolein (AC) onto the surface of B₃₆ borophene nanosheet was studied using dispersion-corrected density functional theory (DFT). The structural and electronic properties were scrutinized by several quantum chemical parameters such as HOMO-LUMO gap, condensed Fukui function, molecular electrostatic potential (ESP), and the density of states (DOS). The non-covalent interactions (NCI) were explored by combined reduced density gradient (RDG-NCI) and energy decomposition analysis (EDA) techniques. It was found that the adsorption of acrolein on both convex and concave surfaces of borophene is mainly governed by van der Waals interactions. Our calculations showed that the adsorption energy is strengthened and favored when multiple acrolein molecules adsorb on the edge sides of borophene through their terminal carbonyl oxygen atom. Furthermore, the calculated HOMO-LUMO energy gaps were significantly reduced upon adsorption affecting, therefore, the electrical conductance of borophene. These results should be useful in designing acrolein sensors.