The Extramolecular Electrostatic Potential. An Indicator of the Chemical Reactivity

1991 ◽  
pp. 229-268 ◽  
Author(s):  
Jacopo Tomasi ◽  
Rosanna Bonaccorsi ◽  
Roberto Cammi
Keyword(s):  
Electrostatic Potential ◽  
Chemical Reactivity

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.

Chemical Reactivity Descriptors for Ambiphilic Reagents: Dual Descriptor, Local Hypersoftness, and Electrostatic Potential

2009 ◽  
Vol 113 (30) ◽  
pp. 8660-8667 ◽  
Author(s):  
Carlos Cárdenas ◽  
Nataly Rabi ◽  
Paul W. Ayers ◽  
Christophe Morell ◽  
Paula Jaramillo ◽  
...  
Keyword(s):  
Electrostatic Potential ◽  
Chemical Reactivity ◽  
Dual Descriptor ◽  
Reactivity Descriptors ◽  
Chemical Reactivity Descriptors

A theoretical investigation of the isomers of diazomethane (CH2N2). I. Geometry, bonding, and chemical reactivity

1973 ◽  
Vol 26 (3) ◽  
pp. 461 ◽  
Author(s):  
BT Hart
Keyword(s):  
Electronic Structure ◽  
Theoretical Investigation ◽  
Electrostatic Potential ◽  
Chemical Reactivity ◽  
Structural Isomers

A searching theoretical investigation has been carried out on the five structural isomers of diazomethane, CH2N2; the isomers are diazomethane, cyanamide, isocyanamide, nitrilimine, and carbodiimide. The non- empirically calculated structures for the latter three compounds are the first to be reported. ��� Use has been made of localized exclusive orbitals to help explain the bonding and electronic structure in this series of molecules. ��� In addition, interesting use has been made of electrostatic potential maps in assessing positions of high nucleophilicity in each isomer. This information has allowed mechanistic pathways to be postulated for the protonation of diazomethane and cyanamide and for the production of isocyanamide from diazomethane.

X-ray Diffraction and the Electrostatic Potential

1997 ◽  
Author(s):  
Philip Coppens
Keyword(s):  
Electric Field ◽  
Electrostatic Potential ◽  
Chemical Reactivity ◽  
Lattice Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Positive Unit ◽  
Molecular Potential ◽  
Structure Factors ◽  
Drug Receptor

The distribution of positive and negative charge in a crystal fully defines physical properties like the electrostatic potential and its derivatives, the electric field, and the gradient of the electric field. The electrostatic potential at a point in space, defined as the energy required to bring a positive unit of charge from infinite distance to that point, is an important function in the study of chemical reactivity. As electrostatic forces are relatively long-range forces, they determine the path along which an approaching reactant will travel towards a molecule. A nucleophilic reagent will first be attracted to the regions where the potential is positive, while an electrophilic reagent will approach the negative regions of the molecule. As the electrostatic potential is of importance in the study of intermolecular interactions, it has received considerable attention during the past two decades (see, e.g., articles on the molecular potential of biomolecules in Politzer and Truhlar 1981). It plays a key role in the process of molecular recognition, including drug-receptor interactions, and is an important function in the evaluation of the lattice energy, not only of ionic crystals. This chapter deals with the evaluation of the electrostatic potential and its derivatives by X-ray diffraction. This may be achieved either directly from the structure factors, or indirectly from the experimental electron density as described by the multipole formalism. The former method evaluates the properties in the crystal as a whole, while the latter gives the values for a molecule or fragment “lifted” out of the crystal. Like other properties derived from the charge distribution, the experimental electrostatic potential will be affected by the finite resolution of the experimental data set. But as the contribution of a structure factor F(H) to the potential is proportional to H−2, as shown below, convergence is readily achieved. A summary of the dependence of electrostatic properties of the magnitude of the scattering vector H is given in Table 8.1, which shows that the electrostatic potential is among the most accessible of the properties listed.

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 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 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.

Comparison of Electrostatic Potential Obtained From Different Atomic Point Charges Calculation Methods for a Large Set of Molecules

2020 ◽  
pp. 2150001
Author(s):  
Mustafa Emirik ◽  
Sevil Savaşkan Yılmaz
Keyword(s):  
Electrostatic Potential ◽  
Chemical Reactivity ◽  
Atomic Charge ◽  
Quantum Mechanical Calculation ◽  
Quantum Mechanical ◽  
Large Set ◽  
Partial Charge ◽  
Ab Initio Method ◽  
Calculation Methods ◽  
Mechanical Calculation

The Electrostatic Potential is of great importance in chemical reactivity since it is closely related to many of molecular properties. Despite the fact that there are significant improvements in the quantum mechanical calculation methods, the atom centered partial charge approximation keeps hold of its importance in the field of estimating electrostatic potential as an inexpensive alternative to the ab initio method. However, even today, there is no universally accepted the best method for computing a partial atomic charge. Here, we compared the electrostatic potential obtained from different atomic point charges calculation methods for a large set of molecules. To this end, the large Grimme set of molecules was used. Some of the molecules in the set naturally failed in estimating the electrostatic potential. This failure, therefore, was investigated in depth. The Iterative Hirshfeld method can be preferable for electrostatic potential field generation.

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.

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