scholarly journals Synthesis, characterization and DFT computational studies of new heterocyclic azo compounds

2018 ◽  
Vol 9 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Faeza Almashal ◽  
Abeer Mohamed Jabar ◽  
Adil Muala Dhumad
Keyword(s):  
Electronic Structures ◽  
Basis Set ◽  
Azo Compounds ◽  
Mulliken Charge ◽  
Diazonium Salts ◽  
B3lyp Method ◽  
Nmr Techniques ◽  
Ft Ir ◽  
Theory Calculation ◽  
Homo Lumo

New heterocyclic azo compounds were prepared by coupling the diazonium salts with N-(4-methylphenyl)maleimide with various different sulfa compounds. The structure of heterocyclic azo compounds was determined by MS, FT-IR and 1H NMR techniques. The density function theory calculation at the B3LYP method with 6-311G(d,p) basis set is used to investigate the electronic structures of the prepared heterocyclic azo compounds. Mulliken charge distributions and HOMO-LUMO energies of the mentioned compounds have been also computed by same method and basis set.

scholarly journals FT-IR, FT-Raman, Homo-Lumo and UV-Visible Spectral Analysis of E-(N′-(1H-INDOL-3YL) Methylene Isonicotinohydrazide)

2017 ◽  
Vol 1 (3) ◽  
pp. 1-37
Author(s):  
D. Sumathi ◽  
H. Saleem ◽  
A. Nathiya ◽  
N. RameshBabu ◽  
D. Usha
Keyword(s):  
Energy Gap ◽  
Solid Phase ◽  
Basis Set ◽  
Excitation Energies ◽  
B3lyp Method ◽  
Td Dft ◽  
Ft Ir ◽  
Experimental Values ◽  
Homo Lumo ◽  
Ft Raman

A combined experimental and theoretical study on molecular and vibrational structure of E-N¢ (ICINH) had been carried out. The FTIR, FT-Raman and UV-Vis spectra of ICINH were recorded in the solid phase. The optimized geometry was calculated by B3LYP method with 6-311++G(d,p) level of basis set. The harmonic vibrational frequencies, IR intensities and Raman scattering activities of the title compound were calculated at same level of theory. The scaled theoretical wavenumber showed very good agreement with the experimental values. The mulliken charges and thermodynamic functions of the ICINH were also performed at same level of theory. NLO and a study on the electronic properties such as excitation energies and wavelength, were performed by TD-DFT approach. HOMO–LUMO energy gap was also calculated and interpreted.

Density functional theory, Comparative vibrational spectroscopic studies, HOMO-LUMO, and NBO analysis of Trichloro isocyanuric acid and Trithio cyanuric acid

2015 ◽  
Vol 8 (3) ◽  
pp. 2197-2221
Author(s):  
Theraviyum Chithambarathanu ◽  
M. Darathi ◽  
J. DaisyMagdaline ◽  
S. Gunasekaran
Keyword(s):  
Density Functional ◽  
Cyanuric Acid ◽  
Nbo Analysis ◽  
Basis Set ◽  
Potential Energy Distribution ◽  
Point Energy ◽  
Isocyanuric Acid ◽  
Ft Ir ◽  
Homo Lumo ◽  
Ft Raman

The molecular vibrations of Trichloro isocyanuric acid (C3Cl3N3O3) and Trithio cyanuric acid (C3H3N3S3) have been investigated in polycrystalline sample at room temperature by Fourier Transform Infrared (FT-IR) and FT-Raman spectroscopies in the region 4000-450 cm-1 and 4000-50 cm-1 respectively, which provide a wealth of structural information about the molecules. The spectra are interpreted with the aid of normal co-ordinate analysis following full structure optimization and force field calculations based on density functional theory   (DFT) using standard B3LYP / 6-311++ G (d, p) basis set for investigating the structural and spectroscopic properties. The vibrational frequencies are calculated and the scaled values are compared with experimental FT-IR and FT-Raman spectra. The scaled theoretical wave numbers shows very good agreement with experimental ones. The complete vibrational assignments are performed on the basis of potential energy distribution (PED) of vibrational modes, calculated with scaled quantum (SQM) method. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that change in electron density (ED) in σ* and π* anti-bonding orbitals and second order delocalization   energy (E2) confirm the occurrence of Intra molecular Charge Transfer (ICT) within the molecule. The thermodynamic properties like heat capacity, entropy, enthalpy and zero point energy have been calculated for the molecule. The frontier molecular orbitals have been visualized and the HOMO-LUMO energy gap has been calculated. The Molecular Electrostatic Potential (MEP) analysis reveals the sites for electrophilic attack and nucleophilic reactions in the molecule.

Synthesis and DFT Studies of Pyrimidin-1(2H)-ylaminofumarate Derivatives

2020 ◽  
Vol 42 (5) ◽  
pp. 746-746
Author(s):  
Murat Saracoglu Murat Saracoglu ◽  
Zulbiye Kokbudak Zulbiye Kokbudak ◽  
M Izzettin Yilmazer and Fatma Kandemirli M Izzettin Yilmazer and Fatma Kandemirli
Keyword(s):  
Quantum Chemical ◽  
Energy Gap ◽  
Basis Set ◽  
Chemical Hardness ◽  
Pyrimidine Derivatives ◽  
1H And 13C Nmr ◽  
Solvent Phase ◽  
B3lyp Method ◽  
Ft Ir ◽  
New Compounds

Pyrimidine derivatives have biological and pharmacological properties. Therefore, in this study we focused on the synthesis various Pyrimidine derivatives to make noteworthy contributions this class of heterocyclic compounds. In the present study, the new compounds (4-6) were obtained by the reactions of 1-amino-5-benzoyl-4-phenylpyrimidin-2(1H)-one (1), 1-amino-5-(4-methylbenzoyl)-4-(4-methylphenyl)pyrimidin-2(1H)-one (2) and 1-amino-5-(4-methoxybenzoyl)-4-(4-methoxyphenyl)pyrimidin-2(1H)-one (3) with dimethyl acetylenedicarboxylate. The structures of these compounds were proved by elemental analysis, FT-IR, 1H and 13C-NMR spectra. In addition to, quantum chemical calculations were made to find molecular properties of the pyrimidin-1(2H)-ylaminofumarate derivatives (4-6) by using DFT/B3LYP method with 6-311++G(2d,2p) basis set. Quantum chemical features such as EHOMO, ELUMO, energy gap, ionization potential, chemical hardness, chemical softness, electronegativity etc. values for gas and solvent phase of neutral molecules were calculated and discussed.

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.

Vibrational spectroscopic and conformational studies of 1-(4-pyridyl)piperazine

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Özgür Alver ◽  
Mustafa Şenyel
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Stable Form ◽  
Functional Theory ◽  
B3lyp Method ◽  
Ft Ir ◽  
Hybrid Density Functional ◽  
Ir And Raman

AbstractPossible stable conformers of the 1-(4-pyridyl)piperazine (1-4pypp) molecule were experimentally and theoretically studied by FT-IR and Raman spectroscopy. FT-IR and Raman spectra were recorded in the region of 4000–200 cm−1. Optimized geometric structures related to the minimum on the potential energy surface were investigated by the B3LYP hybrid density functional theory method using the 6-31G(d) basis set. Comparison of the experimental and theoretical results indicates that the density functional B3LYP method provides satisfactory results for the prediction of vibrational wavenumbers and structural parameters and equatorial-equatorial (e-e) isomer is supposed to be the most stable form of the 1–4pypp molecule.

scholarly journals Density functional theory study on the molecular structure of loganin

2011 ◽  
Vol 25 (6) ◽  
pp. 287-302 ◽  
Author(s):  
Anoop Kumar Pandey ◽  
Shamoon Ahmad Siddiqui ◽  
Apoorva Dwivedi ◽  
Kanwal Raj ◽  
Neeraj Misra
Keyword(s):  
Molecular Structure ◽  
Density Functional ◽  
Solid Phase ◽  
Density Functional Method ◽  
Functional Method ◽  
Basis Set ◽  
Equilibrium Geometry ◽  
B3lyp Method ◽  
Ft Ir ◽  
Detailed Interpretation

The computational Quantum Chemistry (QC) has been used for different types of problems, for example: structural biology, surface phenomena and liquid phase. In this paper we have employed the density functional method for the study of molecular structure of loganin. The equilibrium geometry, harmonic vibrational frequencies and infrared intensities were calculated by B3LYP/6-311G (d, p) method and basis set combinations. It was found that the optimized parameters obtained by the DFT/B3LYP method are very near to the experimental ones. A detailed conformational analysis was carried out. A detailed interpretation of the infrared spectra of loganin is also reported in the present work. The FT-IR spectra of loganin were recorded in solid phase. The thermodynamic calculations related to the title compound were also performed at B3LYP/6-311G (d, p) level of theory.

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.

scholarly journals FT-IR, Molecular Structure and Nonlinear Optical Properties of 2-(pyranoquinolin-4-yl)malononitrile (PQMN): A DFT Approach

2021 ◽  
Vol 11 (5) ◽  
pp. 13729-13739
Keyword(s):  
Dipole Moment ◽  
Chemical Potential ◽  
Basis Set ◽  
Electrophilicity Index ◽  
Spintronic Devices ◽  
Repulsive Energy ◽  
Ft Ir ◽  
Homo Lumo ◽  
Electronic Affinity ◽  
Made In

A combined experimental and theoretical study for Fourier transform infrared spectra for 2-(pyranoquinolin-4-yl)malononitrile (PQMN) compound has been made. In advance, we investigate many physical characteristics based on DFT/B3LYP using 6-311G(d,p) basis set such as optimum structure, vibrational frequencies, thermo-chemistry, overall dipole moment, HOMO/LUMO Bandgap, nuclear repulsive energy and ionization energies, electronic affinity and chemical potential, global electrophilicity index, global hardness and finally softness (ζ). Also, we studied the non-linear optical (NLO) properties of PQMN. Results emphasize both degeneracy and diamagnetic properties of PQMN. PQMN Frontiers’ molecular orbitals (FMOs) split into two distinguished alpha (spin ↑) and beta (spin ↓) states with the same energy 3.7 eV, although its singlet spins state. Moreover, the calculated dipole moment (DM) value (13.3 Debye) for PQMN explains the mystery behind its reactive tendency with the nearby media. PQMN is a unique model for a degenerate diamagnetic semiconductor that can be easily used for optoelectronic manufactured devices such as solar cells and spintronic devices.

scholarly journals Density Functional Calculations on the Molecular, Electronic Structures of Metal-Free, N,N'-Dideuterio and Magnesium Tetra-3,4-Pyridino-Porphyrazines

2019 ◽  
pp. 40-44
Author(s):  
Zhongqiang Liu ◽  
Xianxi Zhang
Keyword(s):  
Electronic Structures ◽  
Density Functional ◽  
Atomic Charge ◽  
Substitution Effect ◽  
Membered Ring ◽  
Basis Set ◽  
Metal Free ◽  
B3lyp Level ◽  
Homo Lumo ◽  
Optimized Geometries

A theoretical calculation of the fully optimized geometries and electronic structures of the metal-free Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2*), N,N-Dideuterio (TPdPzD2*), and Magnesium (TPdPzMg*) tetra-3,4-pyridino-porphyrazine has been conducted with the density functional B3LYP level using the 6-31G(d) basis set. A comparison among the different Phthalocyanine (Pc) derivatives, including Tetra-2,3-Pyridino-Porphyrazine (TPdPzH2) compounds, for the geometry, molecular orbital, and atomic charge was made. The substitution effect of the N atoms and the isotopic effect of D atoms on the properties of these compounds were discussed. The farther the heterocyclic N atoms in the benzo rings from 16-membered ring are, the smaller it influence the size of the central hole, the bond lengths and bond angles of 16-membered ring, the HOMO-LUMO gaps, and the atomic charges on the core Pz fragment. In other words, the properties of TPdPz* compounds are closer to Pc than TPdPz. With the order of H2Pc<TPdPzH2<TPdPzH2*, the acidity of the inner N-H bonds in the three molecules increased in turn.

scholarly journals Molecular Structure and Vibrational Analysis of 1-Bromo-2-Chlorobenzene Using ab initio HF and Density Functional Theory (B3LYP) Calculations

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
G. Shakila ◽  
S. Periandy ◽  
S. Ramalingam
Keyword(s):  
Density Functional ◽  
Vibrational Analysis ◽  
Vibrational Frequencies ◽  
Basis Set ◽  
Geometrical Parameters ◽  
B3lyp Method ◽  
B3lyp Calculations ◽  
Ft Ir ◽  
Experimental Values ◽  
Ft Raman

The FT-Raman and FT-IR spectra for 1-bromo-2-chlorobenzene (1B2CB) have been recorded in the region 4000–100 cm−1 and compared with the harmonic vibrational frequencies calculated using HF/DFT (B3LYP) method by employing 6-31+G (d, p) and 6-311++G (d, p) basis set with appropriate scale factors. IR intensities and Raman activities are also calculated by HF and DFT (B3LYP) methods. Optimized geometries of the molecule have been interpreted and compared with the reported experimental values of some substituted benzene. The experimental geometrical parameters show satisfactory agreement with the theoretical prediction from HF and DFT. The scaled vibrational frequencies at B3LYP/6-311++G (d, p) seem to coincide with the experimentally observed values with acceptable deviations. The theoretical spectrograms (IR and Raman) have been constructed and compared with the experimental FT-IR and FT-Raman spectra. Some of the vibrational frequencies of the benzene are affected upon profusely with the halogen substitutions in comparison to benzene, and these differences are interpreted.

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