babatunde ogunyemi - Academia.edu (original) (raw)
Papers by babatunde ogunyemi
AROC in Natural Products Research, 2022
Background: The ongoing coronavirus pandemic poses a significant social, economic, and health thr... more Background: The ongoing coronavirus pandemic poses a significant social, economic, and health threat worldwide. The situation is exacerbated further by vaccine hesitancy and the ongoing development of mutant strains that could lead to drug resistance. It is therefore critical to find new anti-viral chemotherapeutic agents to reduce or end the epidemic. This study aimed to investigate the antiprotease activity of the oxoaporphine alkaloids in Xylopia aethiopica. Methods: Computational techniques such as molecular docking were used to probe the oxoaporphine alkaloids in the plant for their ability to inhibit the main protease of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The docking score calculations which quantifies the predictive binding affinity of both ligand and target was carried out using Auto-Dock Vina software. Results: The results showed that oxoaporphine alkaloids had a better binding affinity than hydroxychloroquine sulfate (standard). Similarly, the va...
Journal of Nigerian Society of Physical Sciences, Jan 14, 2023
The potentials of six thiosemicarbazide derivatives towards corrosion inhibition were investigate... more The potentials of six thiosemicarbazide derivatives towards corrosion inhibition were investigated theoretically using density functional theory (DFT) and quantitative structural-activity relationships (QSARs) methods. Their performance as corrosion inhibitors were evaluated using their calculated quantum chemical parameters such as molecular weight, softness, electronegativity, dipole moments, hardness, bandgap energy (∆E), highest occupied molecular orbital energy (E HOMO), and the lowest unoccupied molecular orbital energy (E LU MO). Regression analysis was carried out using the ordinary least square method to develop a model that establishes the relationship between chemical parameters and inhibition efficiencies that have been measured experimentally. According to the results, quantum chemical parameters confirm the inhibition potential of TSC 5 to be greater than TSC 2 , while the predicted inhibition efficiencies of the studied thiosemicarbazide derivatives correspond to experimentally reported values with a root mean square error (%) of 1.116 and correlation coefficient of 0.998. The high correlation demonstrates and validates the quantum chemical approach's reliability in studying corrosion inhibition on a metal surface. The validation of the developed model internally and externally demonstrates that it is robust and stable, with high predictability.
Journal of Applied Sciences and Environmental Management, Jun 6, 2018
The effect of iodide ions on the inhibitive performance of ortho, meta and para nitro aniline in ... more The effect of iodide ions on the inhibitive performance of ortho, meta and para nitro aniline in 1M HCl for mild steel has been studied using weight loss method (gravimetric) measurements at 303 and 333K. Results obtained show that the presence of the nitro aniline compounds in 1M HCl solution inhibits the corrosion process of mild steel. Its adsorption was found to be physical, exothermic and spontaneous as confirmed by values of activation energy and free energy of adsorption (not up to −20 kJ mol −1 for free energy of adsorption and below 80 kJ mol −1 for activation energy) and also fitted the Langmuir adsorption model. Addition of iodide ions synergistically increased the inhibition efficiency of the nitro aniline compounds. Quantitative Structure Activity Relationship (QSAR) approach was used on a composite index of some quantum chemical parameters. The results showed that the Inhibition Efficiency was closely related to some of the quantum chemical parameters.
Materials Today Chemistry, Jun 1, 2021
Abstract Considerable attention has been paid to modulating these organic π-conjugates to realize... more Abstract Considerable attention has been paid to modulating these organic π-conjugates to realize effective and efficient organic photovoltaic by the means of theoretical methods. In respect to this, six commonly used heterocyclic compounds: thiophine (Th), thienopyrazine (TP), benzothiadiazole (BD), quinoxahine (BP), benzobisthiadiazole (BBD), and thenothiadiazole (TD) were co-oligomerized with bisazaphosphole (BAP) and theoretically examined for use in solar cells using density functional theory and time-dependent density functional theory to evaluate their optical, electronic, and light harvesting efficiency, as well as voltaic properties. The results showed that TP, TD, BD, BP, and BDD were preferable for optimization of the bandgaps and molecular energy levels of these organophosphorus-based compounds over Th. heterocyclic compounds. The calculated electron transfer process to the conduction band of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and the subsequent regeneration in BAP–BBD and PBAP (polybisazaphosphole)–TD were possible in organic voltaic cells, making these modeled compounds more proficient solar cell sensitizers. The method used can be explored in understanding the relationship between electronic properties and molecular structure of other materials for electronic devices.
FUDMA JOURNAL OF SCIENCES, 2020
The effect of two iminoisatin derivatives [1-morpholinomethyl-3(1-N-dithiooxamide) iminoisatin (m... more The effect of two iminoisatin derivatives [1-morpholinomethyl-3(1-N-dithiooxamide) iminoisatin (molecule 1)] and 1-diphenylaminomethyl-3(1-N-dithiooxamide) iminoisatin (molecule 2) on corrosion inhibition were theoretically investigated using quantum mechanical method. Their electronic parameters and quantum chemical descriptors that predict their adsorption and hence their inhibition efficiency were estimated using the DFT//B3LYP/6-31G (d) method. The results established a relationship between the quantum descriptors and corrosion inhibition efficiency, and also confirmed molecule 2 to be a better corrosion inhibitor and provide a guide to the synthesis of more efficient organic corrosion inhibitors.
![Research paper thumbnail of Synthesis, Corrosion Inhibition Efficiency and Adsorption Behavior of Dibenzo [a,c] Quinoxalino(2,3-I)Phenazine on Mild Steel in Acidic Medium](https://attachments.academia-assets.com/105644520/thumbnails/1.jpg)
](American Journal of Agricultural Science, Engineering, and Technology
Designing new inhibitors and understanding the mechanisms responsible for the inhibition are requ... more Designing new inhibitors and understanding the mechanisms responsible for the inhibition are required in developing techniques to prevent corrosion. A new azaacene organic corrosion inhibitor, DQP (dibenzo[a,c]quinoxalino (2,3-i)phenazine), for mild steel in an acidic medium was successfully synthesized, characterized and reported for the first time using electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization measurement techniques (PDP). Surface morphologies and average percentage by weight of elements existing in mild steel were determined by SEM-EDX. The alterations in the impedance characteristics showed that DQP inhibitor adsorbed to the surface of mild steel, resulting in the creation of a protective coating. At the maximal concentration of 2.618 x 10-5 M, the inhibition efficiency reached 98.02% demonstrating DQP effectiveness in reducing corrosion process that may occur in mild steel in HCl. However, this efficiency is weakened by increase in temperatu...
FUDMA JOURNAL OF SCIENCES
Kinetics and thermodynamics of gas-phase thermal decomposition of 1-phenylethyl acetate to vinyl ... more Kinetics and thermodynamics of gas-phase thermal decomposition of 1-phenylethyl acetate to vinyl benzene and acetic acid (ethanoic) were carried out using the density functional theory (DFT) method at B3LYP/6-31++G**. Geometric parameters obtained include atomic charge distribution, dihedral angles, bond lengths, and bond angle for the ground state reactant (GS), transition state (TS), and the product (PRD) while the thermodynamic parameters such as a change in entropy change (∆S), change in enthalpy (∆Hreaction) and free Gibbs energy were calculated at 623K with an interval of 25K. Kinetic parameters determined include activation energy (Ea), Pre-exponential Arrhenius factor (log A) and rate (k). Geometric results revealed that the decomposition reaction is through asynchronous cleavage of α-ether oxygen bonds and β-carbon-hydrogen in the six-membered cyclic transition state: C2-H1 and C5-O7 bond breaking occurred first while the C9-H1 bond formation process is lagging behind in a single step. The ∆S (5.867 J/mol/K); ∆Hreaction (38.45 kcal/mol), ∆G (39.69 kJ/mol), Ea (43.7 kcal/mol), log A (12.70) and k (6.1 x 10-2 S-1) compared well with the experimental available results in literature at 623K. The intrinsic reaction coordinate (IRC) on the TS structures shows that the reactant connects to the respective minima while the Wilberg bond index shows that the TS possesses 'an early' character closer to the reactant than the products. The theoretical calculation method can be used to study the thermodynamics, mechanism and kinetics of the thermal decomposition of acetates thus reducing the cost, laboratory experiments time and exposure to hazardous chemicals.
The study of αand β-elimination pathways through pyrolysis on the kinetics and thermodynamics of ... more The study of αand β-elimination pathways through pyrolysis on the kinetics and thermodynamics of O-alkyl S-methyl Xanthates in which the alkyl groups are ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl were carried out in the gas-phase using density functional theory (DFT) with B3LYP at 6-311++G** using Spartan. The mechanism proceeded through a six-centered cyclic transition state. The result obtained for the C-H, C-O and S-H bond lengthening character in a single step suggested that the reaction is a concerted and asynchronous. The energy of formation for the α–elimination pathways is lower compared to the β-elimination initiated from the hydrogen of the βcarbon. The activation parameters obtained for the β-elimination pathways ranged from ∆H* (161.34-133.87 kJ/mol), ∆S* (-31.18-25.65 J/mol/K), ∆G* (180.65-149.77 kJ/mol) Ea (166.49-136.82 kJ/mol), k =1.14·10-6.0·10S), A (3.06·10-5.89·10). In addition, α-elimination pathway activation Quantum mechanical study on the kinetic...
International Journal of Computational and Theoretical Chemistry, 2015
Computational investigation on the ground state properties of trans-azobenzene and four kinds of ... more Computational investigation on the ground state properties of trans-azobenzene and four kinds of hydroxy-ended azobenzene-type chromophores containing different substituent groups as electron donor and acceptor in different solvent media was carried out. The effects ofsubstituents-I 2 ,-OHand-CH 3 ,-NH 2 , and-Cl 2 on the electronic properties like the E HOMO , E LUMO , band gap, dipole moments, global hardness, electrophilicity indices were studied using the Ab initio restricted DFT self-consistent field method with the Becke Three Lee Yang Parr (B3LYP)/6-31G* method in vacuum, water, diethylether, ethanol and acetone. The results showed that these properties were altered upon substitution with different groups. The azobenzene gave a slight difference in its band gap in different solvent changing from (3.95 eV) in vacuum to the lowest (3.87 eV) in acetone but changes drastically as we introduce different substituents. It was also found that the dipole moment (µ), polarizability (α), absorption wavelength (λ ab) gave slight change in different solvents but rapidly increased as the band gap reduces, invoking their reactivities. They are also red-shifted as different substituents are added. Of all the studied molecules, compound H gave the lowest band gap of 0.46 eV, the highest dipole moment (875.02 D), the highest polarizability (64.97C.m 2 V-1) and it is the most red-shifted (401.13 nm). Molecule H therefore, has the lowest band gap, highest polarizability and dipole moment. It also has the highest molecular size and the highest planarity. This means that the molecule is the most reactive, most polarizable, highest electro-optic response and it is the softest.
Advanced Journal of Chemistry-Section A, 2020
In this work, the potential of corrosion inhibition of four chloroquine derivatives; N 4-(7-Chlor... more In this work, the potential of corrosion inhibition of four chloroquine derivatives; N 4-(7-Chloroquinolin-8-ol-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M2), N 4-(7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M3) and N 4-(5-bromo-7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4-diamine (M4) were investigated. Their chemical descriptors which include molecular volume, softness, chemical hardness, electronegativity, fraction (ΔN) and electrophilicity index (ω) dipole moments, surface of the molecule, and electronic parameters which include the EHOMO (the highest occupied molecular orbital of energy); ELUMO (lowest unoccupied molecular orbitals of energy) and energy gap (ELUMO-EHOMO) were calculated using the DFT/B3LYP/6-311 G approach. The results revealed an established correlation between the electronic structures and the quantum parameters of the studied molecules together with their inhibition efficiency toward corrosion process. Also chloroquine derivatives with-NH3 substituent: M3 and M4 were predicted to have enhanced inhibition efficiency.
Journal of Taibah University for Science, 2018
This work presents an investigation on the structural and solvent dependence on the molecular, el... more This work presents an investigation on the structural and solvent dependence on the molecular, electronic and nonlinear optical properties of some conjugated organic molecules based on phenothiazine units using quantum chemical calculations with pure BLYP and hybrid B3LYP correlation with a high polar basis set, 6-31G* in the gas-phase and in solutions towards understanding their structure-property relationship. The ground state molecular properties like the frontier orbitals (FMOs) energies, dipole moments (μ), polarizabilities (α), molecular first hyperpolarizabilities (β) were obtained. The results showed that the insertion of substituents enhanced molecular properties like the optical limiting abilities. It was also observed that the energy band gap (E g), derived from the FMOs were reduced while μ, α and β increased. The λ max of the substituted derivatives are higher than the unsubstituted 10-octyl thiophene-based phenothiazine and results obtained are in good agreement with available experimental findings. The substituted derivatives proved to possess better optical responses than the unsubstituted derivative on the basis of the properties analysed.
Journal of Applied Sciences and Environmental Management, 2019
The corrosion inhibition potential of four phenyltetrazole derivatives (M 1-4) were investigated ... more The corrosion inhibition potential of four phenyltetrazole derivatives (M 1-4) were investigated by theoretical methods. The efficiency of corrosion inhibitors depends on many quantum chemical descriptors: chemical hardness, softness, electronegativity, dipole moments, molecular volume, surface area, as well as electronic orbital energies: EHOMO (highest occupied molecular orbital energy); ELUMO (lowest unoccupied molecular orbital energy) and energy gap (ΔE) calculated from DFT approach. A statistical ordinary least square method was used to perform regression analysis that determined the correlations between the calculated descriptors and the experimental inhibition efficiency for phenyltetrazole derivatives while the QSAR model developed was used to predict their corrosion inhibition efficiency. The predicted corrosion inhibition efficiencies of the phenyltetrazoles derivatives correspond well to the experimental measurements. The correlation coefficient was 0.9984 and the root mean square error (%), was 1.36. With the embedded QSAR model, the corrosion inhibition efficiencies of two novel phenyltetrazole derivatives (M5-6) were predicted.
Chemistry and Materials Research, 2014
Pi-Conjugated organophosphorus derivatives have recently emerged as valuable building blocks for ... more Pi-Conjugated organophosphorus derivatives have recently emerged as valuable building blocks for the tailoring of functional molecular materials. In order to guide the synthesis of novels materials with low band gaps, theoretical study on the geometries and electronic properties of new conjugated compounds based on low coordinate heterophosphole compounds were carried out. The theoretical ground-state geometries and the electronic structures of the studied molecules were obtained using the density functional theory (DFT) method at B3LYP level with 6-31G(d) basis set. The effects of the phosphorus and different heteroatom elements on the geometries and electronic properties of these materials were discussed. The results from this study show that conjugated molecules containing phosphorus atom gives better electronic properties compared to their organic counterparts that had been used in optoelectronic devices. Hence these compounds could be a good promising building blocks candidate for opto-electronic applications.
IOP Conference Series: Earth and Environmental Science
The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and... more The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and H2SO4 medium was evaluated using quantum chemical methods. The AM1 semi-empirical method and Density Functional Theory (DFT) at the B3LYP/6-31G* level were used. The orbital energies (EHOMO and ELUMO), Separation Energy (ELUMO-EHOMO), Dipole moment (µ), Log P, Polarizability, molecular volume, molecular weight, Hardness (η) and Softness (S) are the computed quantum chemical characteristics linked to inhibitory efficiency. There was a strong link between quantum chemical parameters and experimental inhibition efficiency. The findings revealed that the Inhibition Efficiency was linked to a number of quantum chemical factors. The 2-mercaptobenzimidazole derivative had a higher Inhibition Efficiency (IE) than the other benzimidazole derivatives, according to the results.
AROC in Natural Products Research, 2022
Background: The ongoing coronavirus pandemic poses a significant social, economic, and health thr... more Background: The ongoing coronavirus pandemic poses a significant social, economic, and health threat worldwide. The situation is exacerbated further by vaccine hesitancy and the ongoing development of mutant strains that could lead to drug resistance. It is therefore critical to find new anti-viral chemotherapeutic agents to reduce or end the epidemic. This study aimed to investigate the antiprotease activity of the oxoaporphine alkaloids in Xylopia aethiopica. Methods: Computational techniques such as molecular docking were used to probe the oxoaporphine alkaloids in the plant for their ability to inhibit the main protease of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The docking score calculations which quantifies the predictive binding affinity of both ligand and target was carried out using Auto-Dock Vina software. Results: The results showed that oxoaporphine alkaloids had a better binding affinity than hydroxychloroquine sulfate (standard). Similarly, the va...
Journal of Nigerian Society of Physical Sciences, Jan 14, 2023
The potentials of six thiosemicarbazide derivatives towards corrosion inhibition were investigate... more The potentials of six thiosemicarbazide derivatives towards corrosion inhibition were investigated theoretically using density functional theory (DFT) and quantitative structural-activity relationships (QSARs) methods. Their performance as corrosion inhibitors were evaluated using their calculated quantum chemical parameters such as molecular weight, softness, electronegativity, dipole moments, hardness, bandgap energy (∆E), highest occupied molecular orbital energy (E HOMO), and the lowest unoccupied molecular orbital energy (E LU MO). Regression analysis was carried out using the ordinary least square method to develop a model that establishes the relationship between chemical parameters and inhibition efficiencies that have been measured experimentally. According to the results, quantum chemical parameters confirm the inhibition potential of TSC 5 to be greater than TSC 2 , while the predicted inhibition efficiencies of the studied thiosemicarbazide derivatives correspond to experimentally reported values with a root mean square error (%) of 1.116 and correlation coefficient of 0.998. The high correlation demonstrates and validates the quantum chemical approach's reliability in studying corrosion inhibition on a metal surface. The validation of the developed model internally and externally demonstrates that it is robust and stable, with high predictability.
Journal of Applied Sciences and Environmental Management, Jun 6, 2018
The effect of iodide ions on the inhibitive performance of ortho, meta and para nitro aniline in ... more The effect of iodide ions on the inhibitive performance of ortho, meta and para nitro aniline in 1M HCl for mild steel has been studied using weight loss method (gravimetric) measurements at 303 and 333K. Results obtained show that the presence of the nitro aniline compounds in 1M HCl solution inhibits the corrosion process of mild steel. Its adsorption was found to be physical, exothermic and spontaneous as confirmed by values of activation energy and free energy of adsorption (not up to −20 kJ mol −1 for free energy of adsorption and below 80 kJ mol −1 for activation energy) and also fitted the Langmuir adsorption model. Addition of iodide ions synergistically increased the inhibition efficiency of the nitro aniline compounds. Quantitative Structure Activity Relationship (QSAR) approach was used on a composite index of some quantum chemical parameters. The results showed that the Inhibition Efficiency was closely related to some of the quantum chemical parameters.
Materials Today Chemistry, Jun 1, 2021
Abstract Considerable attention has been paid to modulating these organic π-conjugates to realize... more Abstract Considerable attention has been paid to modulating these organic π-conjugates to realize effective and efficient organic photovoltaic by the means of theoretical methods. In respect to this, six commonly used heterocyclic compounds: thiophine (Th), thienopyrazine (TP), benzothiadiazole (BD), quinoxahine (BP), benzobisthiadiazole (BBD), and thenothiadiazole (TD) were co-oligomerized with bisazaphosphole (BAP) and theoretically examined for use in solar cells using density functional theory and time-dependent density functional theory to evaluate their optical, electronic, and light harvesting efficiency, as well as voltaic properties. The results showed that TP, TD, BD, BP, and BDD were preferable for optimization of the bandgaps and molecular energy levels of these organophosphorus-based compounds over Th. heterocyclic compounds. The calculated electron transfer process to the conduction band of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and the subsequent regeneration in BAP–BBD and PBAP (polybisazaphosphole)–TD were possible in organic voltaic cells, making these modeled compounds more proficient solar cell sensitizers. The method used can be explored in understanding the relationship between electronic properties and molecular structure of other materials for electronic devices.
FUDMA JOURNAL OF SCIENCES, 2020
The effect of two iminoisatin derivatives [1-morpholinomethyl-3(1-N-dithiooxamide) iminoisatin (m... more The effect of two iminoisatin derivatives [1-morpholinomethyl-3(1-N-dithiooxamide) iminoisatin (molecule 1)] and 1-diphenylaminomethyl-3(1-N-dithiooxamide) iminoisatin (molecule 2) on corrosion inhibition were theoretically investigated using quantum mechanical method. Their electronic parameters and quantum chemical descriptors that predict their adsorption and hence their inhibition efficiency were estimated using the DFT//B3LYP/6-31G (d) method. The results established a relationship between the quantum descriptors and corrosion inhibition efficiency, and also confirmed molecule 2 to be a better corrosion inhibitor and provide a guide to the synthesis of more efficient organic corrosion inhibitors.
American Journal of Agricultural Science, Engineering, and Technology
Designing new inhibitors and understanding the mechanisms responsible for the inhibition are requ... more Designing new inhibitors and understanding the mechanisms responsible for the inhibition are required in developing techniques to prevent corrosion. A new azaacene organic corrosion inhibitor, DQP (dibenzo[a,c]quinoxalino (2,3-i)phenazine), for mild steel in an acidic medium was successfully synthesized, characterized and reported for the first time using electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization measurement techniques (PDP). Surface morphologies and average percentage by weight of elements existing in mild steel were determined by SEM-EDX. The alterations in the impedance characteristics showed that DQP inhibitor adsorbed to the surface of mild steel, resulting in the creation of a protective coating. At the maximal concentration of 2.618 x 10-5 M, the inhibition efficiency reached 98.02% demonstrating DQP effectiveness in reducing corrosion process that may occur in mild steel in HCl. However, this efficiency is weakened by increase in temperatu...
FUDMA JOURNAL OF SCIENCES
Kinetics and thermodynamics of gas-phase thermal decomposition of 1-phenylethyl acetate to vinyl ... more Kinetics and thermodynamics of gas-phase thermal decomposition of 1-phenylethyl acetate to vinyl benzene and acetic acid (ethanoic) were carried out using the density functional theory (DFT) method at B3LYP/6-31++G**. Geometric parameters obtained include atomic charge distribution, dihedral angles, bond lengths, and bond angle for the ground state reactant (GS), transition state (TS), and the product (PRD) while the thermodynamic parameters such as a change in entropy change (∆S), change in enthalpy (∆Hreaction) and free Gibbs energy were calculated at 623K with an interval of 25K. Kinetic parameters determined include activation energy (Ea), Pre-exponential Arrhenius factor (log A) and rate (k). Geometric results revealed that the decomposition reaction is through asynchronous cleavage of α-ether oxygen bonds and β-carbon-hydrogen in the six-membered cyclic transition state: C2-H1 and C5-O7 bond breaking occurred first while the C9-H1 bond formation process is lagging behind in a single step. The ∆S (5.867 J/mol/K); ∆Hreaction (38.45 kcal/mol), ∆G (39.69 kJ/mol), Ea (43.7 kcal/mol), log A (12.70) and k (6.1 x 10-2 S-1) compared well with the experimental available results in literature at 623K. The intrinsic reaction coordinate (IRC) on the TS structures shows that the reactant connects to the respective minima while the Wilberg bond index shows that the TS possesses 'an early' character closer to the reactant than the products. The theoretical calculation method can be used to study the thermodynamics, mechanism and kinetics of the thermal decomposition of acetates thus reducing the cost, laboratory experiments time and exposure to hazardous chemicals.
The study of αand β-elimination pathways through pyrolysis on the kinetics and thermodynamics of ... more The study of αand β-elimination pathways through pyrolysis on the kinetics and thermodynamics of O-alkyl S-methyl Xanthates in which the alkyl groups are ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl were carried out in the gas-phase using density functional theory (DFT) with B3LYP at 6-311++G** using Spartan. The mechanism proceeded through a six-centered cyclic transition state. The result obtained for the C-H, C-O and S-H bond lengthening character in a single step suggested that the reaction is a concerted and asynchronous. The energy of formation for the α–elimination pathways is lower compared to the β-elimination initiated from the hydrogen of the βcarbon. The activation parameters obtained for the β-elimination pathways ranged from ∆H* (161.34-133.87 kJ/mol), ∆S* (-31.18-25.65 J/mol/K), ∆G* (180.65-149.77 kJ/mol) Ea (166.49-136.82 kJ/mol), k =1.14·10-6.0·10S), A (3.06·10-5.89·10). In addition, α-elimination pathway activation Quantum mechanical study on the kinetic...
International Journal of Computational and Theoretical Chemistry, 2015
Computational investigation on the ground state properties of trans-azobenzene and four kinds of ... more Computational investigation on the ground state properties of trans-azobenzene and four kinds of hydroxy-ended azobenzene-type chromophores containing different substituent groups as electron donor and acceptor in different solvent media was carried out. The effects ofsubstituents-I 2 ,-OHand-CH 3 ,-NH 2 , and-Cl 2 on the electronic properties like the E HOMO , E LUMO , band gap, dipole moments, global hardness, electrophilicity indices were studied using the Ab initio restricted DFT self-consistent field method with the Becke Three Lee Yang Parr (B3LYP)/6-31G* method in vacuum, water, diethylether, ethanol and acetone. The results showed that these properties were altered upon substitution with different groups. The azobenzene gave a slight difference in its band gap in different solvent changing from (3.95 eV) in vacuum to the lowest (3.87 eV) in acetone but changes drastically as we introduce different substituents. It was also found that the dipole moment (µ), polarizability (α), absorption wavelength (λ ab) gave slight change in different solvents but rapidly increased as the band gap reduces, invoking their reactivities. They are also red-shifted as different substituents are added. Of all the studied molecules, compound H gave the lowest band gap of 0.46 eV, the highest dipole moment (875.02 D), the highest polarizability (64.97C.m 2 V-1) and it is the most red-shifted (401.13 nm). Molecule H therefore, has the lowest band gap, highest polarizability and dipole moment. It also has the highest molecular size and the highest planarity. This means that the molecule is the most reactive, most polarizable, highest electro-optic response and it is the softest.
Advanced Journal of Chemistry-Section A, 2020
In this work, the potential of corrosion inhibition of four chloroquine derivatives; N 4-(7-Chlor... more In this work, the potential of corrosion inhibition of four chloroquine derivatives; N 4-(7-Chloroquinolin-8-ol-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M2), N 4-(7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4 diamine (M3) and N 4-(5-bromo-7-Chloroquinolin-8-amino-4-yl)-N 1 ,N 1-diethylpentane-1,4-diamine (M4) were investigated. Their chemical descriptors which include molecular volume, softness, chemical hardness, electronegativity, fraction (ΔN) and electrophilicity index (ω) dipole moments, surface of the molecule, and electronic parameters which include the EHOMO (the highest occupied molecular orbital of energy); ELUMO (lowest unoccupied molecular orbitals of energy) and energy gap (ELUMO-EHOMO) were calculated using the DFT/B3LYP/6-311 G approach. The results revealed an established correlation between the electronic structures and the quantum parameters of the studied molecules together with their inhibition efficiency toward corrosion process. Also chloroquine derivatives with-NH3 substituent: M3 and M4 were predicted to have enhanced inhibition efficiency.
Journal of Taibah University for Science, 2018
This work presents an investigation on the structural and solvent dependence on the molecular, el... more This work presents an investigation on the structural and solvent dependence on the molecular, electronic and nonlinear optical properties of some conjugated organic molecules based on phenothiazine units using quantum chemical calculations with pure BLYP and hybrid B3LYP correlation with a high polar basis set, 6-31G* in the gas-phase and in solutions towards understanding their structure-property relationship. The ground state molecular properties like the frontier orbitals (FMOs) energies, dipole moments (μ), polarizabilities (α), molecular first hyperpolarizabilities (β) were obtained. The results showed that the insertion of substituents enhanced molecular properties like the optical limiting abilities. It was also observed that the energy band gap (E g), derived from the FMOs were reduced while μ, α and β increased. The λ max of the substituted derivatives are higher than the unsubstituted 10-octyl thiophene-based phenothiazine and results obtained are in good agreement with available experimental findings. The substituted derivatives proved to possess better optical responses than the unsubstituted derivative on the basis of the properties analysed.
Journal of Applied Sciences and Environmental Management, 2019
The corrosion inhibition potential of four phenyltetrazole derivatives (M 1-4) were investigated ... more The corrosion inhibition potential of four phenyltetrazole derivatives (M 1-4) were investigated by theoretical methods. The efficiency of corrosion inhibitors depends on many quantum chemical descriptors: chemical hardness, softness, electronegativity, dipole moments, molecular volume, surface area, as well as electronic orbital energies: EHOMO (highest occupied molecular orbital energy); ELUMO (lowest unoccupied molecular orbital energy) and energy gap (ΔE) calculated from DFT approach. A statistical ordinary least square method was used to perform regression analysis that determined the correlations between the calculated descriptors and the experimental inhibition efficiency for phenyltetrazole derivatives while the QSAR model developed was used to predict their corrosion inhibition efficiency. The predicted corrosion inhibition efficiencies of the phenyltetrazoles derivatives correspond well to the experimental measurements. The correlation coefficient was 0.9984 and the root mean square error (%), was 1.36. With the embedded QSAR model, the corrosion inhibition efficiencies of two novel phenyltetrazole derivatives (M5-6) were predicted.
Chemistry and Materials Research, 2014
Pi-Conjugated organophosphorus derivatives have recently emerged as valuable building blocks for ... more Pi-Conjugated organophosphorus derivatives have recently emerged as valuable building blocks for the tailoring of functional molecular materials. In order to guide the synthesis of novels materials with low band gaps, theoretical study on the geometries and electronic properties of new conjugated compounds based on low coordinate heterophosphole compounds were carried out. The theoretical ground-state geometries and the electronic structures of the studied molecules were obtained using the density functional theory (DFT) method at B3LYP level with 6-31G(d) basis set. The effects of the phosphorus and different heteroatom elements on the geometries and electronic properties of these materials were discussed. The results from this study show that conjugated molecules containing phosphorus atom gives better electronic properties compared to their organic counterparts that had been used in optoelectronic devices. Hence these compounds could be a good promising building blocks candidate for opto-electronic applications.
IOP Conference Series: Earth and Environmental Science
The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and... more The efficiency of various benzimidazole derivatives as mild steel corrosion inhibitors in HCl and H2SO4 medium was evaluated using quantum chemical methods. The AM1 semi-empirical method and Density Functional Theory (DFT) at the B3LYP/6-31G* level were used. The orbital energies (EHOMO and ELUMO), Separation Energy (ELUMO-EHOMO), Dipole moment (µ), Log P, Polarizability, molecular volume, molecular weight, Hardness (η) and Softness (S) are the computed quantum chemical characteristics linked to inhibitory efficiency. There was a strong link between quantum chemical parameters and experimental inhibition efficiency. The findings revealed that the Inhibition Efficiency was linked to a number of quantum chemical factors. The 2-mercaptobenzimidazole derivative had a higher Inhibition Efficiency (IE) than the other benzimidazole derivatives, according to the results.