scholarly journals Chemical Reactivity, Dipole Moment and First Hyperpolarizability of Aristolochic Acid I

2016 ◽  
Vol 21 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Bhawani Datta Joshi
Keyword(s):  
Dipole Moment ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Aristolochic Acid ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Non Linear ◽  
Linear Optical ◽  
Aristolochic Acid I

Aristolochic acids (AAs) have been used in the treatment of oedema in  Chinese herb medicine  since  long  ago. In this paper, molecular electrostatic potential, chemical reactivity  and non linear optical properties  of  aristolochic  acid  I  (AA  I)  have  been  analyzed  using  density  functional  theory  employing  6-311++G(d,p)  basis set.  The chemical reactivity of the molecule has been explained with the help of chemical reactivity descriptors, molar refractivity and the molecular electrostatic potential surface (ESP).  The calculated dipole moment and first order hyperpolarizability show that the molecule possesses non-linear optical property.Journal of Institute of Science and TechnologyVolume 21, Issue 1, August 2016, page: 1-9

scholarly journals Investigation of Some Antiviral N-Heterocycles as COVID 19 Drug: Molecular Docking and DFT Calculations

2020 ◽  
Vol 21 (11) ◽  
pp. 3922 ◽  
Author(s):  
Mohamed Hagar ◽  
Hoda A. Ahmed ◽  
Ghadah Aljohani ◽  
Omaima A. Alhaddad
Keyword(s):  
Dipole Moment ◽  
Molecular Docking ◽  
Dft Calculations ◽  
Binding Affinity ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Hydrophobic Interactions ◽  
Chemical Reactivity ◽  
Main Protease

The novel coronavirus, COVID-19, caused by SARS-CoV-2, is a global health pandemic that started in December 2019. The effective drug target among coronaviruses is the main protease Mpro, because of its essential role in processing the polyproteins that are translated from the viral RNA. In this study, the bioactivity of some selected heterocyclic drugs named Favipiravir (1), Amodiaquine (2), 2′-Fluoro-2′-deoxycytidine (3), and Ribavirin (4) was evaluated as inhibitors and nucleotide analogues for COVID-19 using computational modeling strategies. The density functional theory (DFT) calculations were performed to estimate the thermal parameters, dipole moment, polarizability, and molecular electrostatic potential of the present drugs; additionally, Mulliken atomic charges of the drugs as well as the chemical reactivity descriptors were investigated. The nominated drugs were docked on SARS-CoV-2 main protease (PDB: 6LU7) to evaluate the binding affinity of these drugs. Besides, the computations data of DFT the docking simulation studies was predicted that the Amodiaquine (2) has the least binding energy (−7.77 Kcal/mol) and might serve as a good inhibitor to SARS-CoV-2 comparable with the approved medicines, hydroxychloroquine, and remdesivir which have binding affinity −6.06 and −4.96 Kcal/mol, respectively. The high binding affinity of 2 was attributed to the presence of three hydrogen bonds along with different hydrophobic interactions between the drug and the critical amino acids residues of the receptor. Finally, the estimated molecular electrostatic potential results by DFT were used to illustrate the molecular docking findings. The DFT calculations showed that drug 2 has the highest of lying HOMO, electrophilicity index, basicity, and dipole moment. All these parameters could share with different extent to significantly affect the binding affinity of these drugs with the active protein sites.

scholarly journals NBO, chemical reactivity, thermodynamic properties and hyperpolarizability analysis of aristolochic acid II

BIBECHANA ◽  
2016 ◽  
Vol 14 ◽  
pp. 86-97 ◽  
Author(s):  
Bhawani Dutt Joshi
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Computational Study ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Medicinal Uses ◽  
Fukui Functions ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Linear Optical

Alkaloids are a group of naturally occurring chemical compounds and show immense potential of medicinal uses in traditional systems. In this work, a computational study on an alkaloid aristolochc acidid II (AA II) is presented using density functional theory, B3LYP functional employing 6-311G (d,p) basis set. Natural bond orbital analysis has been carried out to investigate the various conjugative and hyperconjugative interactions within the molecule and their second-order stabilisation energy (E(2)). The local nucleophilic reactivity descriptors such as Fukui functions (f+k, f-k), local softness (s+k, s-k) and electrophilicity indices (ω+k,ω-k) analyses have been carried out to determine the reactive sites within the molecule. The non-linear optical properties have been calculated using the same basis set. The calculated value of the first order hyperpolarisability (β0), suggests that the investigated molecule is an attractive object in future for non-linear optical properties.

scholarly journals Theoretical Evaluation on The Interaction Between Triglycerides and Methylxanthines Using Density Functional Theory B3LYP/6-31G(d,p) and Molecular Electrostatic Potential

2020 ◽  
Vol 33 (1) ◽  
pp. 171-178
Author(s):  
N.F.M. Azmi ◽  
R. Ali ◽  
A.A. Azmi ◽  
M.Z.H. Rozaini ◽  
K.H.K. Bulat ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Basis Set ◽  
Individual Species ◽  
Interaction Energies ◽  
Binding Interaction ◽  
Functional Theory

The binding, interaction and distortion energies between the main triglycerides, palmitic-oleic-stearic (POS) in cocoa butter versus palmitic-oleic-palmitic (POP) in refined, bleached and deodorized (RBD) palm oil with cocoa′s methylxanthines (caffeine, theobromine, and theophylline) during the production of chocolate were theoretically studied and reported. The quantum mechanical software package of Gaussian09 at the theoretical level of density functional theory B3LYP/6-31G(d,p) was employed for all calculations, optimization, and basis set superposition errors (BSSE). Geometry optimizations were carried out to the minimum potential energy of individual species and binary complexes formed between the triglycerides, methylxanthines and polyphenols. The interaction energies for the optimized complexes were then corrected for the BSSE using the counterpoise method of Boys and Bernardi. The results revealed that the binding energy and interaction energy between methylxanthine components in cocoa powder with triglycerides were almost of the same magnitude (13.6-14.5 and 3.4-3.7 kJ/mol, respectively), except for the binary complex of POS-caffeine (25.1 and 10.7 kJ/mol, respectively). Based on the molecular geometry results, the hydrogen bond length and angle correlated well with the interaction energies. Meanwhile, the POS-caffeine complex with two higher and almost linear bond angles showed higher binding and interaction energies as compared to the other methylxanthines. Therefore, a donor-acceptor analysis showed that the hydrogen bond strength was proven using the molecular electrostatic potential (MEP), which resulted in parallel outcomes. The research results were believed to be one of the factors that contributed to the rheological behaviour and sensory perception of cocoa products, especially chocolate.

scholarly journals Computational Design, Spectral, NBO, DOS, Bioactivity Evaluation, ADMET Analysis, Third-Order non-linear Optical and Quantum Chemical Investigations on Hydrogen Bonded Novel Organic Molecular Complex of 4-[Bis[2-(acetyloxy)ethyl]amino]benzaldehyde (4B2AEAB) Derivatives for Opto-Electronic Applications

2020 ◽  
Vol 32 (11) ◽  
pp. 2793-2820
Author(s):  
Ashutosh Kumar ◽  
Anil Mishra
Keyword(s):  
Gas Phase ◽  
Function Analysis ◽  
Chemical Reactivity ◽  
Computational Design ◽  
Basis Set ◽  
Mulliken Charge ◽  
Water Solvent ◽  
Non Linear ◽  
Linear Optical ◽  
Vibrational Wavenumbers

In this paper, the authors reported a theoretical investigation on molecular structure, geometry optimization, global and local chemical reactivity descriptors calculations, NBO study, DOS, non-linear optical behaviour and vibrational wavenumbers of the novel 4-[bis[2- (acetyloxy)ethyl]amino]benzaldehyde (4B2AEAB) were carried out by DFT (B3LYP and B3PW91) methods with 6-31+G (d, p) basis set in water solvent. The calculated vibrational wavenumbers are found to be in good agreement with experimental FT-IR spectra and PED analysis using GaussView 5.0 and VEDA 4 program. The UV-Vis absorption spectrum of 4B2AEAB was calculated by using TD-DFT/B3LYP/6-31+G(d,p) in gas phase, water, CHCl3, DMSO and CH2Cl2 solvents using CPCM model and λmax in range of 354.16, 341.35, 343.74, 342.18 and 342.64 nm, respectively. The density of state (DOS spectrum) of the compound in term of HOMOs and LUMOs and MESP were calculated and analyzed. The temperature effects on the thermodynamic properties are also discussed. The calculated 1H NMR and 13C NMR chemical shift using GIAO method and solvent effect are investigated by B3LYP/6-31+G(d,p) in gas phase, chloroform, water, DMSO and CH2Cl2 solvents and correlate with experimental chemical shifts. The dipole moment, polarizability and the first static hyperpolarizability values show that the 4B2AEAB molecule is active non-linear optical (NLO) material. The nucleophilic and electrophilic reactive sites in the 4B2AEAB and its derivatives were analyzed by Fukui function analysis using Mulliken charge. The charge transfer, conjugative interactions and delocalization of electron density are analyzed by natural bond orbital (NBO) analysis. The biological properties and ADMET study of 4B2AEAB and its derivatives are also discussed.

Experimental and theoretical investigation of molecular structure, vibrational analysis, chemical reactivity, electrostatic potential of benzyl methacrylate monomer and homopolymer

2016 ◽  
Vol 94 (9) ◽  
pp. 853-864 ◽  
Author(s):  
Feride Akman
Keyword(s):  
Electrostatic Potential ◽  
Density Functional ◽  
Chemical Shifts ◽  
Chemical Reactivity ◽  
Atomic Orbital ◽  
Vibrational Analysis ◽  
Calculated Data ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Molecular Approaches

Until now, a number of new polymers have been discovered with the aid of experimental and computational molecular approaches and indicated to have potential applications. All the computational molecular approaches provide information helpful to further study. So, monomer and homopolymer of benzyl methacrylate (BzMA), which is a popular methacrylate ester monomer, were synthesized and investigated based on density functional theory (DFT) and Hartree–Fock (HF) methods. The monomer and homopolymer were characterized by FTIR, 1H, and 13C NMR techniques. The molecular geometry, geometrical parameters, Mulliken atomic charges, and vibrational frequencies of BzMA monomer and homopolymer (in dimer form) were calculated by using the DFT and HF methods with 6-31G (d, p) as basis set. The molecular electrostatic potential maps and molecular orbitals properties of monomer and homopolymer were calculated using the 6-31G (d, p) basis set of theories. Besides, 1H and 13C chemical shifts were calculated by the gauge–including atomic orbital approach. The results demonstrated that the theoretical values were in good agreement with the experimental values. The calculated data are important to providing insight into molecular analysis and may be used in technological applications.

scholarly journals Spectroscopic and computational study of chromone derivatives with antitumor activity: detailed DFT, QTAIM and docking investigations

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Y. Sheena Mary ◽  
Y. Shyma Mary ◽  
K. S. Resmi ◽  
Ali Shokuhi Rad
Keyword(s):  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Energy Gap ◽  
Computational Study ◽  
Chemical Reactivity ◽  
Biological Activities ◽  
Docking Studies ◽  
Chromone Derivatives ◽  
Theoretical Investigations

AbstractTheoretical investigations of three pharmaceutically active chromone derivatives, (E)-3-((2,3,5,6-tetrafluorophenyl)hydrazono)methyl)-4H-chromen-4-one (TPC), (E)-3-((2-(2,4,6-trifluorophenyl)hydrazono)methyl)-4H-chromen-4-one (FHM) and(E)-3-((2-(perfluorophenyl)hydrazono)methyl)-4H-chromen-4-one (PFH) are reported. Molecular geometries, vibrational spectra, electronic properties and molecular electrostatic potential were investigated using density functional theory. Quantum theory of atoms in molecules (QTAIM) study shows that the maximum of ellipticity parameters in the existing bonds in TPC, FHM and PFH, attributes to the bonds involving in aromatic region points toward the π-bond interactions in the molecules. Based on energy gap (1.870, 1.649 and 1.590 eV) and electrophilicity index (20.233, 22.581 and 23.203 eV) values of TPC, FHM and PFH, we can conclude that all molecules have more biological activity. The molecular electrostatic potential maps were calculated to provide information on the chemical reactivity of the molecule and also to describe the intermolecular interactions. All these studies including docking studies, help a lot in determining the biological activities of chromone derivatives. Activities of chromone derivatives are compared with 5-fluorouracil and azathioprine (antitumor, antiproliferative standards) and were found to be higher than reference ones.

scholarly journals The synthesis and spectroscopic characterization of (+)-demethoxyaspidospermine: Density functional theory calculations of the structural, electronic, and non-linear optic and spectroscopic properties

2019 ◽  
Vol 43 (11-12) ◽  
pp. 531-541 ◽  
Author(s):  
Goncagül Serdaroğlu ◽  
Nesimi Uludağ
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Density Functional Theory Calculations ◽  
Spectroscopic Studies ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Linear Optic ◽  
Non Linear ◽  
Orbital Analysis

(+)-Demethoxyaspidospermine was synthesized via the acylation of aspidospermidine with acetic anhydride, and the structure was determined by elemental analysis and Fourier-transform infrared and nuclear magnetic resonance spectroscopic tools and was supported by the simulated spectroscopic studies. Next, the stable geometries obtained by the conformational analysis performed at the B3LYP/6-31G(d, p) level were used for further investigations carried out in B3LYP and M06-2X functionals, and Hartree–Fock (HF) method, employed by the 6-311++G(d, p) basis set. Also, the natural bond orbital analysis revealed that the most contribution to the lowering of the stabilization energy came from n → π* and π → π* interactions. Moreover, the non-linear optic analysis has shown that the title compound can be a useful agent in the optoelectronic devices because of the optical properties. Also, the chemical reactivity tendency for nucleophilic or electrophilic attack reactions on the compound was evaluated by frontier molecular orbital analysis, and the reactive sites of the compound was shown by highest molecular orbital and lowest unoccupied orbital amplitudes and molecular electrostatic potential diagrams.

scholarly journals Computational Insights on Molecular Structure, Electronic Properties, and Chemical Reactivity of (E)-3-(4-Chlorophenyl)-1-(2-Hydroxyphenyl)Prop-2-en-1-one

2020 ◽  
Vol 17 (SpecialIssue1) ◽  
pp. 41-53
Author(s):  
Vishnu A. Adole ◽  
Prashant B. Koli ◽  
Rahul A. Shinde ◽  
Rohit S. Shinde
Keyword(s):  
Electronic Properties ◽  
Electrostatic Potential ◽  
Molecular Electrostatic Potential ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Group Symmetry ◽  
Ir Absorption ◽  
Hydrogen Atoms ◽  
Ft Ir ◽  
Title Molecule

In the current examination, (E)-3-(4-chlorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one has been studied to investigate geometrical entities, electronic properties, and chemical reactivity viewpoints. To inspect structural, spectroscopic, and chemical reactivity aspects, density functional theory method (DFT) at B3LYP/6-311G(d,p) basis set has been employed. The (E)-3-(4-chlorophenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one has been synthesized and characterized by FT-IR, 1HNMR, and 13C NMR spectral techniques. The detailed investigation of bond lengths and bond angles is discussed to comprehend the geometrical framework. To explore its chemical behaviour, Mulliken atomic charges, molecular electrostatic potential surface, and electronic parameters are introduced. The imperative exploration of the electronic properties, such as HOMO and LUMO energies, was studied by the time-dependent DFT (TD-DFT) method. The dipole moment of the title molecule is 2.57 Debye with C1 point group symmetry. The most electropositive carbon and hydrogen atoms in the title molecule are C14 and H27 respectively. Amongst aromatic C=C, the C16-C18 is the longest, and C17-C19 is the shortest bond. The molecular electrostatic potential plot predicts the positive electrostatic potential is around hydrogen atoms. The vibrational assignments were made by comparing the experimental FT-IR absorption peaks with the scaled frequencies obtained using computational work. Besides, some significant thermochemical information is obtained using the same basis set using frequencies.

scholarly journals Molecular structure, HOMO, LUMO, MEP, natural bond orbital analysis of benzo and anthraquinodimethane derivatives

2018 ◽  
Vol 5 (2) ◽  
pp. 27 ◽  
Author(s):  
Tahar Abbaz ◽  
Amel Bendjeddou ◽  
Didier Villemin
Keyword(s):  
Electrostatic Potential ◽  
Density Functional ◽  
Molecular Electrostatic Potential ◽  
Natural Bond Orbital ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Charge Delocalization ◽  
B3lyp Method ◽  
Optimized Geometries

Objective: Optimized molecular structures have been investigated by DFT/B3LYP method with 6-31G (d,p) basis set. Stability of Benzo and anthraquinodimethane derivatives 1-4, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed and the relocation of the electron density was determined. Molecular electrostatic potential (MEP), local density functional descriptors has been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analyses have been performed from the optimized geometries. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (µ), electronegativity (χ), hardness (η), and softness (S), have been investigated. All the above calculations are made by the method mentioned above.Methods: The most stable optimized geometries obtained from DFT/B3LYP method with 6-31G(d,p) basis set were investigated for the study of molecular structures, nonlinear properties, natural bond orbital (NBO), molecular electrostatic potential (MEP) and frontier molecular orbital of Benzo and anthraquinodimethane derivatives.Results: Reactive sites of electrophilic and nucleophilic attacks for the investigated molecule were predicted using MEP at the B3LYP/6-31G(d,p). Compound 4 possesses higher electronegativity value than all compounds so; it is the best electron acceptor; the more reactive sites for electrophilic attacks are shown in compounds 1 and 4, for nucleophilic attacks are indicated in compounds 2 and 3 and the more reactive sites in radical attacks are detected in compounds 2 and 4.Conclusions: Compound 1 is softest, best electron donor and more reactive than all compounds. The calculated first order hyperpolarizability was found much lesser than reported in literature for urea.

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