Study on vibrational spectroscopy, molecular property, UV-VIS, HOMO-LUMO energies and MEP analysis of N-[2-(4-Bromo-benzoyl)-benzofuran-3-yl]-acrylamide monomer by DFT method

2021 ◽  
Vol 51 (1) ◽  
pp. 69-79
Author(s):  
Esra Barim ◽  
Feride Akman
Keyword(s):  
Density Functional ◽  
Chemical Reactivity ◽  
Atomic Orbital ◽  
Molecular Geometry ◽  
Dft Method ◽  
Polymer Science ◽  
Dft Methods ◽  
Content Type ◽  
B3lyp Method ◽  
Acrylamide Monomer

Purpose This study aimed the synthesis and theoretical/experimental characterization of novel benzofuran-based acrylamide monomer. Design/methodology/approach Novel N-substituted acrylamide monomer, i.e. N-[2–(4-Bromo-benzoyl)-benzofuran-3-yl]-acrylamide (BBFA), was synthesized by reacting (3-Amino-benzofuran-2-yl)-(4-bromophenyl) methanone with acryloylchloride at 0–5oC. Nuclear magnetic resonance (1H-NMR), infrared (FT-IR) and UV-Visible spectrophotometer were used to elucidate the chemical structure of BBFA. Computational studies were performed using the DFT (B3LYP) method on the basis of 6-31 + G (d, p) using Gaussian 09 W and Gauss View 5.0 package in addition to the VEDA program, gauge-independent atomic orbital (GIAO) and time-dependent density functional theory (TD-DFT) methods. Findings Molecular geometry and vibration assignments of the BBFA monomer were calculated. The molecular structure of the monomer was examined. Both longest and shortest bonds were determined in the structure. The nucleophilic and electrophilic regions of the monomer were determined. The theoretical spectroscopic data of the monomer were compared with the experimental data; both were consistent with each other. The chemical reactivity of the monomer was also determined. Originality/value The synthesized BBFA monomer can be evaluated in many areas; from medicine to industry (such as textiles) owing to the presence of various active functional groups. Indeed, acrylamide copolymers are remarkable materials for polymer science and industry. The data produced in this study is original and adds to the scientific community.

scholarly journals Molecular Geometry, NLO, MEP, HOMO-LUMO and Mulliken Charges of Substituted Piperidine Phenyl Hydrazines by Using Density Functional Theory

2019 ◽  
Vol 32 (2) ◽  
pp. 401-407
Author(s):  
M. Dinesh Kumar ◽  
P. Rajesh ◽  
R. Priya Dharsini ◽  
M. Ezhil Inban
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Molecular Geometry ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method ◽  
Reactivity Descriptor ◽  
Homo Lumo ◽  
Optimized Geometries

The quantum chemical calculations of organic compounds viz. (E)-1-(2,6-bis(4-chlorophenyl)-3-ethylpiperidine-4-ylidene)-2-phenyl-hydrazine (3ECl), (E)-1-(2,6-bis(4-chlorophenyl)-3-methylpiperidine-4-ylidene)-2-phenylhydrazine (3MCl) and (E)-1-(2,6-bis(4-chloro-phenyl)-3,5-dimethylpiperidine-4-ylidene)-2-phenylhydrazine (3,5-DMCl) have been performed by density functional theory (DFT) using B3LYP method with 6-311G (d,p) basis set. The electronic properties such as Frontier orbital and band gap energies have been calculated using DFT. Global reactivity descriptor has been computed to predict chemical stability and reactivity of the molecule. The chemical reactivity sites of compounds were predicted by mapping molecular electrostatic potential (MEP) surface over optimized geometries and comparing these with MEP map generated over crystal structures. The charge distribution of molecules predict by using Mulliken atomic charges. The non-linear optical property was predicted and interpreted the dipole moment (μ), polarizability (α) and hyperpolarizability (β) by using density functional theory.

DFT computations on vibrational spectra: Scaling procedures to improve the wavenumbers

2018 ◽  
Vol 3 (6) ◽  
Author(s):  
M. Alcolea Palafox
Keyword(s):  
Density Functional ◽  
Dft Method ◽  
Basis Sets ◽  
Linear Scaling ◽  
Dft Methods ◽  
Functional Theory ◽  
Scale Factors ◽  
Scaling Equation ◽  
B3lyp Method ◽  
Vibrational Wavenumbers

Abstract The performance of ab initio and density functional theory (DFT) methods in calculating the vibrational wavenumbers in the isolated state was analyzed. To correct the calculated values, several scaling procedures were described in detail. The two linear scaling equation (TLSE) procedure leads to the lowest error and it is recommended for scaling. A comprehensive compendium of the main scale factors and scaling equations available to date for a good accurate prediction of the wavenumbers was also shown. Examples of each case were presented, with special attention to the benzene and uracil molecules and to some of their derivatives. Several DFT methods and basis sets were used. After scaling, the X3LYP/DFT method leads to the lowest error in these molecules. The B3LYP method appears closely in accuracy, and it is also recommended to be used. The accuracy of the results in the solid state was shown and several additional corrections are presented.

scholarly journals Theoretical Study of the Reaction of Formation of Some Free Phosphines by Stereoselective Hydrophosphination through DFT Method

2018 ◽  
pp. 1-10
Author(s):  
Kouadio Valery Bohoussou ◽  
Anoubilé Bénié ◽  
Mamadou Guy-Richard Koné ◽  
N’guessan Yao Silvère Diki ◽  
Kafoumba Bamba ◽  
...  
Keyword(s):  
Theoretical Study ◽  
Chemical Reactivity ◽  
Dft Method ◽  
Trans Form ◽  
Dft Methods ◽  
Activation Barriers ◽  
Reactivity Descriptors ◽  
Chemical Reactivity Descriptors ◽  
Theoretical Results ◽  
Cis Isomer

In this work the formation of vinylphosphines was studied through the hydrophosphination reaction. The study aims to rationalize the stereoselectivity of these compounds using quantum DFT methods. This theoretical study of chemical reactivity was conducted at B3LYP/6-311 + G (d, p) level. Global chemical reactivity descriptors, stationary point energies and activation barriers were examined to foretell the relative stability of the stereoisomers formed. The various results obtained have revealed that the addition of arylphosphine to dihalogenoacetylene is stereospecific. The Trans form of vinylphosphines is more stable than the Cis form, when the substituent on phosphorus generates less or no π-conjugations. On the other hand, the Cis isomer is predominant when the aryl radical favors more π-conjugations. The theoretical results obtained are in agreement with the experimental results.

scholarly journals Microwave synthesis of some N-phenylhydrazine-1-carbothioamide Schiff bases

2018 ◽  
Vol 9 (2) ◽  
pp. 74-78 ◽  
Author(s):  
Bushra Kamil Al-Salami
Keyword(s):  
1H Nmr ◽  
Density Functional ◽  
Atomic Orbital ◽  
Calculated Data ◽  
Density Functional Theory Method ◽  
13C Nmr Spectroscopy ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method ◽  
Ft Ir

We have synthesized and characterized a series of carbothioamide derivatived molecules, obtained by reaction of aromatic aldehyde (Anisaldehyde, 9-anthraldehyde, cinnamaldehyde, indole-3-carboxaldehyde, 1-naphthaldehyde and o-vanillin) with an equimolar amount of 4-phenylthiosemicarbazide with microwave irradiation. The synthesized compounds have been characterized by FT-IR, 1H NMR and 13C NMR spectroscopy. Quantum calculations of the physical properties, based on density functional theory method at B3LYP/6-31+G(d,p) level of theory, were performed, by means of the Gaussian 09W set of programs. The theoretical 1H NMR chemical shift results of the studied compounds have been calculated at B3LYP method and standard 6-31+G(d,p) basis set using the standard Gauge-Independent Atomic Orbital approach. The calculated values are also compared with the experimental data available for these molecules. A good linear relationship between the experimental and calculated data has been obtained.

Comparison of different theory models and basis sets for the calculation of FbC-M10Iso-Bn geometry and geometries of chlorin-imide and chlorin-isoimide isomeric pairs

2013 ◽  
Vol 17 (05) ◽  
pp. 376-383 ◽  
Author(s):  
Jong-Kil Park ◽  
Sang Joon Choe
Keyword(s):  
Density Functional ◽  
Molecular Geometry ◽  
Basis Sets ◽  
Normal Coordinate ◽  
Dft Methods ◽  
Functional Theory ◽  
X Ray ◽  
Bond Lengths ◽  
X Ray Crystallography ◽  
Isomeric Pairs

Various density functional theory (DFT) methods with different basis sets to predict the molecular geometry of FbC-M10Iso-Bn macrocycle, a chlorin-isoimide, are compared in this study. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-31G*, 6-31+G (d, p), 6-311+G (d, p), 6-311++G (d, p), cc-PVDZ, cc-PVTZ, and cc-PVQZ are also considered. The examined hybrid DFT methods are in agreement with the geometry of X-ray crystallography available for comparison. B3LYP/cc-PVDZ level is particularly consistent with available X-ray crystallography in terms of predicting the geometries of FbC-M10Iso-Bn. Geometries of chlorin-imide and chlorin-isoimide isomeric pairs are described through B3LYP/cc-PVDZ method. The bond lengths of chlorin-isoimide, specifically C13–C14, C14–C15, and C2–C3, increase as bond overlap index decreases because of charge transfer. β-β bond lengths (C2–C3 bond lengths) with a three-substituent benzylcarbamoyl group also increase as bond overlap index decreases compared with other molecules. The bond lengths of chlorin-imide are smaller than those of chlorin-isoimide. Angles with β-β bond lengths, specifically C2–C3–C4 in ring A, also decrease with a three-substituent benzylcarbamoyl group; however, the angles in C1–C2–C3 increase. Potential energy on the surfaces of the chlorin-imide and chlorin-isoimide isomeric pairs is optimized by calculating the total and relative energies at B3LYP/cc-PVDZ level. Results indicate that chlorin-imides are more stable than chlorin-isoimides. Normal-coordinate structural decomposition shows that chlorin-imides exhibit greater deformation than chlorin-isoimides except for FbC-M10Iso-Ph.

The experimental and quantum chemical investigation for two isomeric compounds as aminopyrazine and 2-amino-pyrimidine against mild steel corrosion

2016 ◽  
Vol 63 (5) ◽  
pp. 369-376 ◽  
Author(s):  
Basak Dogru Mert ◽  
Mehmet Erman Mert ◽  
Gülfeza Kardas ◽  
Birgül Yazici
Keyword(s):  
Mild Steel ◽  
Molecular Orbital ◽  
Density Functional ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Molecular Geometry ◽  
Orbital Energy ◽  
Content Type ◽  
Inhibition Effect ◽  
Amino Pyrimidine

Purpose The purpose of this paper is to investigate the adsorption and corrosion inhibition of two isomeric compounds (C4H5N3) as aminopyrazine (AP) and 2-amino-pyrimidine (2AP) on mild steel (MS) in 0.5 M HCl. The study was a trial to combine experimental and modelling studies and research effect of molecular geometry on inhibition effect of inhibitor molecules. Design/methodology/approach The thermodynamic, kinetic and quantum parameters were determined. The electrochemical impedance spectroscopy and anodic polarisation measurements were obtained. The scanning electron microscope was used for monitoring electrode surface. The highest occupied molecular orbital, energy of the lowest unoccupied molecular orbital, Mulliken and natural bonding orbital charges on the backbone atoms, absolute electronegativity, absolute hardness were calculated by density functional theory (DFT)/B3LYP/6-311G (++ d,p). Findings Results showed that AP and 2AP suppressed the corrosion rate of MS. The corrosion current values were 0.530, 0.050 and 0.016 mA cm-2 in HCl, AP and 2AP containing HCl solutions, respectively. It was illustrated with the blocked fraction of the MS surface by adsorption of inhibitors which obeyed the Langmuir isotherm. The inhibition efficiency follows the order: 2AP > AP which is in agreement with experimental and quantum results. Originality/value This paper provides lay a bridge on the molecular geometry and inhibition efficiency by electrochemical tests and modelling study. The inhibition effect of AP and 2AP has not been compared with each other, neither experimentally nor theoretically. This study put forward possible application of 2AP as corrosion inhibitor especially for closed-circuit systems.

scholarly journals Density Functional Theory Study on Conformers of Benzoylcholine Chloride

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Mustafa Karakaya ◽  
Fatih Ucun ◽  
Ahmet Tokatlı
Keyword(s):  
Density Functional Theory ◽  
Ground State ◽  
Density Functional ◽  
Atomic Orbital ◽  
Nbo Analysis ◽  
Vibrational Frequencies ◽  
Molecular Structures ◽  
Basis Set ◽  
Functional Theory ◽  
B3lyp Method

The optimized molecular structures and vibrational frequencies and also gauge including atomic orbital (GIAO)1H and13C NMR shift values of benzoylcholine chloride [(2-benzoyloxyethyl) trimethyl ammonium chloride] have been calculated using density functional theory (B3LYP) method with 6-31++G(d) basis set. The comparison of the experimental and calculated infrared (IR), Raman, and nuclear magnetic resonance (NMR) spectra has indicated that the experimental spectra are formed from the superposition of the spectra of two lowest energy conformers of the compound. So, it was concluded that the compound simultaneously exists in two optimized conformers in the ground state. Also the natural bond orbital (NBO) analysis has supported the simultaneous exiting of two conformers in the ground state. The calculated optimized geometric parameters (bond lengths and bond angles) and vibrational frequencies for both the lowest energy conformers were seen to be in a well agreement with the corresponding experimental data.

A study of experimental and theoretical analysis of N-cyclohexylmethacrylamide monomer based on DFT and HF computations

2016 ◽  
Vol 45 (5) ◽  
pp. 301-307 ◽  
Author(s):  
Feride Akman ◽  
Nevin Çankaya
Keyword(s):  
Density Functional ◽  
Functional Group ◽  
Theoretical Calculations ◽  
Calculated Data ◽  
Basis Set ◽  
Polymer Science ◽  
Content Type ◽  
Hartree Fock ◽  
Good Accord ◽  
Experimental Values

Purpose This paper aims to synthesise and characterise N-cyclohexylmethacrylamide (NCMA) monomer which contains thermosensitive group. The characterisation of monomer was performed both theoretically and experimentally. Design/methodology/approach The monomer was prepared by reacting cyclohexylamine with methacryloyl chloride in the presence of triethylamine at room temperature. The synthesised monomer was characterised by using not only Density Functional Theory (DFT) and Hartree–Fock (HF) with the Gaussian 09 software but also fourier transform infrared (FT–IR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Findings Both the experimental and the theoretical methods demonstrated that the monomer was successfully synthesised. The vibrational frequencies, the molecular structural geometry, such as optimised geometric bond angles, bond lengths and the Mulliken atomic charges of NCMA were investigated by using DFT/B3LYP and HF methods with the 3-21G* basis set. The experimental results were compared with theoretical values. The results revealed that the calculated frequencies were in good accord with the experimental values. Besides, frontier molecular orbitals (FMOs) and molecular electrostatic potential of NCMA were investigated by theoretical calculations at the B3LYP/3–21G* basis set. Research limitations/implications Monomer and polymer containing a thermosensitive functional group have attracted great interest from both industrial and academic fields. Their characterisation can provide great opportunities for polymer science by using DFT and HF methods. Originality/value The monomer containing a thermosensitive functional group and a various polymer may be prepared by using DFT and HF methods described in this paper. The calculated data are greatly important to provide insight into molecular analysis and then used in technological applications.

scholarly journals INVESTIGATION OF MOLECULAR STRUCTURE AND EXPERIMENTAL AND THEORETICAL SPECTROSCOPIC STUDIES OF ANTICANCER DRUGS - A REVIEW

2016 ◽  
Vol 38 (2) ◽  
pp. 1124
Author(s):  
Ashraf Sadat Ghasemi ◽  
Mahsan Deilam ◽  
Fereydoun Ashrafi
Keyword(s):  
Molecular Structure ◽  
Density Functional Theory ◽  
Anticancer Drugs ◽  
Density Functional ◽  
Computational Study ◽  
Molecular Geometry ◽  
Dft Method ◽  
Spectroscopic Studies ◽  
Functional Theory ◽  
Vibrational Assignments

In many literatures, both experimental and computational study on molecular structure and spectroscopic assignments of anticancer drugs has been reported. The molecular geometry was obtained from the X-ray structure determination exprimentally and optimized using computational chemistry methods like Density Functional Theory (DFT) method. In this review, we have investigated calculations based on density functional theory at the B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) levels of theory. From the optimized geometry of the molecules, Molecular structure (bond lengths, bond angles and torsion angles) and vibrational assignments have been obtained.

Theoretical study ofFeB35+nN36-n(n = 0, 1) nanocages: Chemical reactivity descriptors

2015 ◽  
Vol 14 (04) ◽  
pp. 1550026 ◽  
Author(s):  
Davood Farmanzadeh ◽  
Hamid Rezainejad
Keyword(s):  
Density Functional ◽  
Chemical Reactivity ◽  
Chemical Species ◽  
Dft Method ◽  
High Reactivity ◽  
Binding Energies ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
Chemical Reactivity Descriptors

In this study, by the density functional theory (DFT) method-based reactivity descriptors, the electronic properties and chemical reactivity of Fe substituted nanocage, FeB35+nN36-n(n = 0, 1), were investigated in gaseous and aqueous phases. The calculated binding energies of Fe atoms revealed that the substituting Fe atom in some locations of nanocage make the system more stable. The calculated global descriptors showed that the substituted Fe remarkably increases the chemical reactivity of B36N36. Also, local descriptors showed that the high reactivity of substituted nanocages is mainly related to Fe atom and these chemical species are more talented for nucleophilic attacks. The results of this work may be useful to investigate the effects of substituted metals in chemical reactivity of BN nanostructures.

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