scholarly journals Molecular Structure, Frontier Molecular Orbitals, MESP and UV–Visible Spectroscopy Studies of Ethyl 4-(3,4-dimethoxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate: A Theoretical and Experimental Appraisal

2020 ◽  
Vol 17 (SpecialIssue1) ◽  
pp. 13-26
Author(s):  
Bapu Sonu Jagdale ◽  
Vishnu Ashok Adole ◽  
Thansing Bhavsing Pawar ◽  
Bhatu Shivaji Desale
Keyword(s):  
Density Functional ◽  
Dft Method ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Spectral Techniques ◽  
Reactivity Descriptors ◽  
Mass Spectral ◽  
B3lyp Level ◽  
Uv Visible ◽  
Spectroscopy Studies

n the current investigation, we wish to report a combined study on the theoretical and experimental investigation of structural, molecular, and spectral properties of ethyl 4-(3,4-dimethoxyphenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate (EDMT). The EDMT molecule is synthesized and characterized by UV-Visible, FT-IR, 1H NMR, 13C NMR, DEPT, and mass spectral techniques. The density functional theory (DFT) investigation was performed by using the B3LYP level of theory at 6-311++G (d,p) basis set. Frontier molecular orbital (FMO) analysis is likewise examined. An TD-DFT method was used for the UV-Visible spectral analysis by using the B3LYP level and 6-311++G (d,p) basis set in the DMSO solvent. Experimental and theoretical UV-Visible spectra were compared in the present study. Various reactivity descriptors are discussed. Besides, Mulliken atomic charges, molecular electrostatic surface potential (MESP), and some valuable thermodynamic functions are studied.

scholarly journals Molecular Structures and Spectral Properties of Natural Indigo and Indirubin: Experimental and DFT Studies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3831 ◽  
Author(s):  
Zixin Ju ◽  
Jie Sun ◽  
Yanping Liu
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Dft Method ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible

This paper presents a comparative study on natural indigo and indirubin in terms of molecular structures and spectral properties by using both computational and experimental methods. The spectral properties were analyzed with Fourier transform infrared (FTIR), Raman, UV-Visible, and fluorescence techniques. The density functional theory (DFT) method with B3LYP using 6-311G(d,p) basis set was utilized to obtain their optimized geometric structures and calculate the molecular electrostatic potential, frontier molecular orbitals, FTIR, and Raman spectra. The single-excitation configuration interaction (CIS), time-dependent density functional theory (TD-DFT), and polarization continuum model (PCM) were used to optimize the excited state structure and calculate the UV-Visible absorption and fluorescence spectra of the two molecules at B3LYP/6-311G(d,p) level. The results showed that all computational spectra agreed well with the experimental results. It was found that the same vibrational mode presents a lower frequency in indigo than that in indirubin. The frontier molecular orbital analysis demonstrated that the UV-Visible absorption and fluorescence bands of indigo and indirubin are mainly derived from π → π* transition. The results also implied that the indigo molecule is more conjugated and planar than indirubin, thereby exhibiting a longer maximum absorption wavelength and stronger fluorescence peak.

scholarly journals Structure, electronic properties, NBO, NLO and chemi-cal reactivity of bis (1, 4-dithiafulvalene) derivatives: functional density theory study

2017 ◽  
Vol 6 (1) ◽  
pp. 18
Author(s):  
Tahar Abbaz ◽  
Amel Bendjeddou ◽  
Didier Villemin
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Computational Study ◽  
Molecular Geometry ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Reactivity Descriptors ◽  
Nlo Property ◽  
Functional Density Theory ◽  
Nucleophilic Reactivity

In this work, through computational study based on density functional theory (DFT/B3LYP) using basis set 6-31G (d,p) a number of global and local reactivity descriptors for a series of molecules containing a TTF function which are bis (1,4-dithiafulvalene) derivatives. They were computed to predict the reactivity and the reactive sites on the molecules. The molecular geometry and the electronic properties in the ground state such as frontier molecular orbital (HOMO and LUMO), ionization potential (I) and electron affinity (A) were investigated to get a better insight of the molecular properties. Molecular electrostatic potential (MEP) for all compounds were determined to check their electrophilic or nucleophilic reactivity. Fukui index, polarizability, hyperpolarizability, second order NLO property and natural bond orbital (NBO) analyses have also employed to determine the reactivity of bis (1,4-dithiafulvalene) derivatives.

Experimental and Theoretical Studies on the Molecular Structure, FT-IR, NMR, HOMO, LUMO, MESP, and Reactivity Descriptors of (E)-1-(2,3-Dihydrobenzo[b][1,4]dioxin-6-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one

2020 ◽  
Vol 17 (SpecialIssue1) ◽  
pp. 54-72
Author(s):  
Rahul Ashok Shinde ◽  
Vishnu A shok Adole ◽  
Bapu Sonu Jagdale ◽  
Thansing Bhavsing Pawar
Keyword(s):  
Molecular Structure ◽  
Electrostatic Potential ◽  
Density Functional ◽  
Dft Method ◽  
Basis Set ◽  
Group Symmetry ◽  
Ir Absorption ◽  
Hydrogen Atoms ◽  
Reactivity Descriptors ◽  
Ft Ir

The present research deals with the synthesis, characterization and density functional theory (DFT) study of (E)-1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (DTMPP). For the computational investigation, DFT method at B3LYP/6-311++G(d,p) basis set has been used. Herein, structural properties like molecular structure, bond lengths, and bond angles of the DTMPP have been explored. The all-important examination of the electronic properties; HOMO and LUMO energies were studied by the time-dependent DFT (TD-DFT) method. The experimental and theoretical spectroscopic Investigation on FT-IR, 1HNMR, 13C NMR has been unveiled in the present research. To study the chemical behaviour of the DTMPP, Mulliken atomic charges, molecular electrostatic surface potential, and reactivity descriptors have been explored. The dipole moment of the DTMPP is 1.27 Debye with C1 point group symmetry and -1225.77 a.u. E(B3LYP) energy. The most electropositive carbon and hydrogen atoms in the DTMPP are C14 and H27 respectively. The C1-C6 bond is the longest (1.4089 Å) C=C bond in the DTMPP. The oxygen atom O33 is having short contact interaction with the hydrogen atom H44 with a distance of 3.3258 Å. The molecular electrostatic potential plot predicts the positive electrostatic potential is around hydrogen atoms. The FT-IR assignments were made by comparing the experimental FT-IR absorption peaks with the scaled frequencies obtained using DFT method. Furthermore, some valuable insights on thermochemical data are obtained using the harmonic frequencies at same basis set.

scholarly journals Crystal Structure, Hirshfeld Surface and Frontier Molecular Orbital Analyses of N-[2-(trifluoromethyl)phenyl]succinamic Acid

2020 ◽  
Vol 32 (12) ◽  
pp. 3179-3185
Author(s):  
P.A. Suchetan ◽  
S. Naveen ◽  
N.K. Lokanath ◽  
P. Krishna Murthy ◽  
M.V. Deepa Urs
Keyword(s):  
Hydrogen Bonds ◽  
Molecular Orbital ◽  
Density Functional ◽  
Hirshfeld Surface ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Reactivity Descriptors ◽  
Succinamic Acid ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The ortho-CF3 substituent and the N-H bond are in syn-conformation in N-[2-(trifluoromethyl)phenyl]succinamic acid. In amide and acid functionalities, the carbonyl groups are directed in opposite directions to each other and their related-CH2 groups. syn-Conformation is observed for the acid functionality, where the carbonyl C=O and hydroxyl O-H bonds are directed in the same direction. Three planar fragments comprise of the molecule: aromatic ring (A), core portion -Carm-N(H)-C(=O)-C(H2)-C(H2)(B) and -C(H2)-C(=O)-OH(C). The dihedral angle between a pair of fragments being 48.6(4)º (A and B), 81.6 (4)º (B and C) and 70.5 (5)º (A and C). N-H•••O hydrogen bonds bind the molecules forming C(4) chains in the crystal, and the neighbouring anti-parallel chains are bound by O-H•••O hydrogen bonds resulting in a chair shaped ribbon of one-dimensional nature. The Hirshfeld surface study was carried out, including fingerprint plots. Studies have shown that the interactions with O•••H/H•••O (27.4%), H•••H (27.3%) and H•••F/F•••H (20.2%) substantially added to the surface. Theoretically, the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and various global reactivity descriptors were also computed by the density functional theory (DFT/B3LYP) approach with a 6-311G(d, p) basis set in the ground state on the geometrically optimized structure in the gas phase.

scholarly journals Ultrasound Assisted Synthesis, Molecular Structure,UV-Visible Assignments, MEP and Mulliken Charges Study of (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl) prop-2-en-1-one: Experimental and DFT Correlational

2021 ◽  
Vol 18 (1) ◽  
pp. 86-96
Author(s):  
Rohit S. Shinde
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Vibrational Assignments ◽  
Uv Visible

Present investigation deals with the synthesis and density functional theory study (DFT) of a chalcone derivative; (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (CPMPP). The synthesis of a CPMPP has been carried out by the reaction of 4-methoxyacetophenone and 4-chlorobenzalehyde in ethanol at 30 ℃ under ultrasound irradiation. The structure of a synthesized chalcone is affirmed on the basis of FT-IT, 1H NMR and 13C NMR. The geometry of a CPMPP is optimized by using the density functional theory method at the B3LYP/6-31G(d,p) basis set. The optimized geometrical parameters like bond length and bond angles have been computed. The absorption energies, oscillator strength, and electronic transitions have been derived at the TD-DFT method at the B3LYP/6-31G(d,p) level of theory for B3LYP/6-31G(d p) optimized geometries. The effect of polarity on the absorption energies is discussed by computing UV-visible results in dichloromethane (DCM). Since theoretically obtained wavenumbers are typically higher than experimental wavenumbers, computed wavenumbers were scaled with a scaling factor, and vibrational assignments were made by comparing experimental wavenumbers to scaled theoretical wavenumbers. Quantum chemical parameters have been determined and examined. Molecular electrostatic potential (MEP) surface plot analysis has been carried out at the same level of theory. Mulliken atomic charge study is also discussed in the present study.

Efficient Synthesis, Spectroscopic and Quantum Chemical Study of 2,3-Dihydrobenzofuran Labelled Two Novel Arylidene Indanones: A Comparative Theoretical Exploration

2020 ◽  
Vol 17 (2) ◽  
pp. 146-161
Author(s):  
Rahul Ashok Shinde ◽  
Vishnu Ashok Adole ◽  
Bapu Sonu Jagdale ◽  
Thansing Bhavsing Pawar ◽  
Bhatu Shivaji Desale
Keyword(s):  
Magnetic Resonance ◽  
Density Functional ◽  
Computational Study ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Reactivity Descriptors ◽  
B3lyp Method ◽  
The Density Functional Theory

Indanone and 2,3-dihydrobenzofuran scaffolds are considered as special structures in therapeutic science and explicitly associated with various biologically potent compounds. In the present disclosure, we report the synthesis of two new 2,3-dihydrobenzofuran tethered arylidene indanones via an environmentally adequate and viable protocol. The two compounds revealed in this have been characterized well by analytical methods; proton magnetic resonance (PMR), carbon magnetic resonance (CMR). The Density Functional Theory (DFT) study has been presented for the spectroscopic, structural and quantum correlation between (E)-2-((2,3-dihydrobenzofuran-5-yl)methylene)-2,3-dihydro-1H-inden-1-one (DBDI) and (E)-7-((2,3-dihydrobenzofuran-5-yl)methylene)-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one (DBTI). Optimized geometry, frontier molecular orbital, global reactivity descriptors, and thermodynamic parameters have been computed for DBDI and DBTI. DFT/B3LYP method using basis set 6-311++G (d,p) has been employed for the computational study. Mulliken atomic charges are established by using 6-311G (d,p) basis set. Besides, molecular electrostatic potential for DBDI and DBTI is also explored to locate the electrophilic and nucleophilic centres.

Solvent effect on the Molecular structure and Global, Local and Dual Descriptors: A Density Functional Theory Study

2021 ◽  
pp. 305-315
Author(s):  
Faiza Lehraki ◽  
Nadjib Melkemi
Keyword(s):  
Density Functional Theory ◽  
Dipole Moment ◽  
Density Functional ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Nucleophilic Attack ◽  
Functional Theory ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Polarized Continuum Model

This study aims to explore the effects of solvent polarity on the geometry, energy of solvation, dipole moment, polarizability, charge distribution, frontier molecular orbital analysis, and global, local, and dual descriptors for β Carboline. The effects of eight solvents were treated using a conductor-like polarized continuum model. Density Functional Theory calculations were performed at B3LYP level at 6-311++g (d,p) basis set. The computed results showed that the dipole moment, polarizability, the solvation free energy, and atomic charge of β Carboline increased with the increasing polarity of the solvent. Also, the solvation modified the values of the reactivity descriptors as a result of the interaction between the solvent and β Carboline. The dual descriptor provided a clearer difference between electrophilic and nucleophilic attack at specific atomic site than presented by Fukui functions of β Carboline.

DFT METHOD STUDY ON LUBRICANT PROPERTIES OF DISULFIDE COMPOUNDS AS EXTREME PRESSURE ADDITIVE

2006 ◽  
Vol 05 (01) ◽  
pp. 1-10 ◽  
Author(s):  
XUE-YE WANG ◽  
XIN-FANG LI ◽  
XIAO-HONG WEN ◽  
YUAN-QIANG TAN
Keyword(s):  
Density Functional ◽  
Wear Test ◽  
Dft Method ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Extreme Pressure ◽  
Structure Property ◽  
Wear Properties ◽  
Orbital Theory ◽  
Tribochemical Reaction

The molecular geometries optimization and electronic structures of fourteen disulfide compounds had been investigated by density functional theory (DFT) at 6-31G basis set level. The active atoms and active bonds of tribochemical reaction were obtained according to frontier molecular orbital theory, and the interaction energy of chemical adsorption between disulfides and metal surfaces were calculated. The structure-property relationship had been discussed with satisfactory results. The calculated results indicated that the S–S bond and C–S bond of compounds are trended to be broken when organic disulfide compounds interact with a metal, and the order of anti-wear properties for disulfide compounds: diphenyldisulfide >dibenzyldisulfide >di-n-dodecyldisulfide >di-n-octyldisulfide >di-n-butyldisulfide >diethyldisulfide, the extreme pressure properties of DBDS is superior to that of DPDS. The predicted results based on quantum chemical calculations are in excellent agreement with friction and wear test results.

Spectroscopic investigations and DFT studies of synthesized 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate a novel conjugate of gallic acid

2020 ◽  
Vol 17 ◽  
Author(s):  
Sangeeta Srivastava ◽  
Nadeem Ahmad Ansari ◽  
Sadaf Aleem
Keyword(s):  
Gallic Acid ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Major Constituent ◽  
Orbital Energy ◽  
Reactivity Descriptors ◽  
Homo And Lumo ◽  
Electrophilic Reactivity ◽  
Global And Local

: Gallic acid is abundantly found in amla (Phyllanthus emblica), a deciduous of the family phyllanthaceae. Gallic acid, the major constituent of the plant was methylated to 3,4,5 trimethoxy gallic acid, which then underwent steglich esterification first with paracetamol and then with 4-hydroxy acetophenone to yield 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate “respectively”. 1H NMR, 13C NMR, UV, FT-IR and mass spectroscopy were used to characterize the synthesized compounds. Density functional theory (B3YLP) using 6-31G (d,p) basis set have been used for quantum chemical calculations. AIM (Atom in molecule) approach depicted weak molecular interactions within the molecules whereas the reactive site and reactivity within the molecule were examined by global and local reactivity descriptors. The HOMO and LUMO energies and frontier orbital energy gap were calculated by time dependant DFT approach using IEFPCM model. Small value for HOMO–LUMO energy gap indicated that easier charge transfer occurs within compound 4. The nucleophilic and electrophilic reactivity were determined by MEP (molecular electrostatic potential) experiment. Polarizability, dipole moment, and first hyperpolarizability values were calculated to depict the NLO (nonlinear optical) property of both the synthesized compounds. The antimicrobial activity was also carried out and broad spectrum antibacterial activity against several strains of bacteria and certain unicellular fungi were exhibited by synthesized compound 3.

Theoretical investigation on tautomerism and NLO properties of Salicylideneaniline derivatives

2021 ◽  
Author(s):  
N. Daho ◽  
N. Benhalima ◽  
F. KHELFAOUI ◽  
O. SADOUKI ◽  
M. Elkeurti ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Intramolecular Proton Transfer ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Molecular Orbital Calculations ◽  
Visible Absorption ◽  
Charge Delocalization ◽  
Intramolecular Hydrogen

In this work, a comprehensive investigation of the salicylideneaniline derivatives is carried out using density functional theory to determine their linear and non-linear optical properties. Geometry optimizations, for gas and solvent phases, of the tautomers (enol and keto forms) are calculated using B3LYP levels with 6–31G (d,p) basis set . An intramolecular proton transfer, for 1SA-E and 2SA-E, is performed by a PES scan process at the B3LYP/6-31G (d,p) level. The optical properties are determined and show that they have extremely high nonlinear optical properties. In addition, the RDG analysis, MEP, and gap energy are calculated. The low energy gap value indicates the possibility of intramolecular charge transfer. The frontier molecular orbital calculations clearly show the inverse relationship of HOMO–LUMO gap with the first-order hyperpolarizability (β = 59.6471 × 10-30 esu), confirming that the salicylideneaniline derivatives can be used as attractive future NLO materials. Therefore, the reactive sites are predicted using MEP and the visible absorption maxima are analyzed using a theoretical UV–Vis spectrum. Natural bond orbitals are used to investigate the stability, charge delocalization, and intramolecular hydrogen bond.

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