scholarly journals Quantum chemical investigation of spectroscopic, electronic and NLO properties of (1E, 4E)-1-(3-nitrophenyl)-5-phenylpenta-1,4-dien-3-one

2018 ◽  
Vol 6 (1) ◽  
pp. 121
Author(s):  
N Benhalima ◽  
S Yahiaoui ◽  
N Boubegra ◽  
M Boulakoud ◽  
Y Megrouss ◽  
...  
Keyword(s):  
Title Compound ◽  
Population Analysis ◽  
Energy Levels ◽  
Visible Spectrum ◽  
Molecular Geometry ◽  
Dft Method ◽  
Nbo Analysis ◽  
Basis Set ◽  
Vibrational Assignments ◽  
Reactivity Descriptors

In the present work the optimized molecular geometry and harmonic vibrational frequencies of chalcone derivative were calculated by DFT/B3LYP method with 6–31G (d,p) basis set. The vibrational assignments were performed on the basis of the potential energy dis-tribution (PED) of the vibrational modes. Natural bond orbital (NBO) analysis has been performed on title compound using B3LYP/6–31G (d,p) and HSEh1PBE /6–31G (d,p) levels in order to elucidate intermolecular hydrogen bonding, intermolecular charge transfer (ICT) and delocalization of electron density. Mulliken atomic charges, natural population analysis (NPA) and atomic polar tensors (APT) were performed. The nonlinear optical properties of the title compound are also calculated and discussed. Molecular electrostatic poten-tial and HOMO-LUMO energy levels are also computed. Ultraviolet–visible spectrum of the title compound has been calculated using TD–DFT method. The molecular orbital contributions were studied by density of states (DOSs). Global reactivity descriptors have been calculated using the HOMO and LUMO to predict compound reactivity.   

scholarly journals Molecular Structure, Vibrational Spectra and Docking Studies of Abacavir by Density Functional Theory

2017 ◽  
Vol 72 ◽  
pp. 9-27 ◽  
Author(s):  
R. Solaichamy ◽  
J. Karpagam
Keyword(s):  
Title Compound ◽  
Density Functional ◽  
Molecular Geometry ◽  
Nbo Analysis ◽  
Docking Studies ◽  
Basis Set ◽  
Vibrational Assignments ◽  
Molecular Stability ◽  
Homo And Lumo ◽  
Ft Ir

In this study, optimized geometry, spectroscopic (FT-IR, FT-Raman, UV) analysis, and electronic structure analysis of Abacavir were investigated by utilizing DFT/B3LYP with 6-31G(d,p) as a basis set. Complete vibrational assignments and correlation of the fundamental modes for the title compound were carried out. The calculated molecular geometry has been compared with available X-ray data of Abacavir. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The molecular stability and bond strength have been investigated by applying the Natural Bond Orbital (NBO) analysis. The computational molecular docking studies of title compound have been performed.

INFLUENCE OF CATION-HETEROATOM (Li+, Na+, AND K+) INTERACTION ON THE STRUCTURAL AND THERMOCHEMICAL PROPERTIES OF 2′-DEOXYTHYMIDINE NUCLEOSIDE: QTAIM AND NBO ANALYZES

2013 ◽  
Vol 12 (02) ◽  
pp. 1250113 ◽  
Author(s):  
MEHDI SHAKOURIAN-FARD ◽  
ALIREZA FATTAHI
Keyword(s):  
Metal Ion ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Population Analysis ◽  
Dft Method ◽  
Closed Shell ◽  
Nbo Analysis ◽  
Basis Set ◽  
Functional Theory ◽  
Sugar Ring

Density functional theory (DFT) method and B3LYP/6-311++G(d,p) basis set were used to determine coordination geometries, binding strength, and metal ion affinity (MIA) for interaction of 2′-deoxythymidine (dT) with alkali metal cations including Li+, Na+ , and K+ . Calculations demonstrated that the interaction of dT with these cations is tri-coordinated η (O2, O4′, O5′). Among these cations, Li+ cation exhibited the most tendency for interaction with dT. Cations via their interaction with dT can affect the N-glycosidic bond length, the values of pseudorotation of the sugar ring, the orientation of base unit with respect to sugar ring and the acidity of O5′H, O3′H, and N3H groups in 2′-dT nucleoside. Natural bond orbital (NBO) analysis was performed to calculate the charge transfer and natural population analysis of the complexes. Quantum theory of atoms in molecules (QTAIM) was also applied to determine the nature of interactions. It was shown that in these complexes, (dT- Li+ , dT- Na+ , and dT- K+ ), the bonds are an electrostatic (closed-shell) interaction in the nature.

Quantum Mechanical Investigation of Geometrical Structure and Dynamic Behavior of h-BNNT (9,9-5) and h-AlNNT (9,9-5)Single-Walled Nanotubes: NBO Analysis

2019 ◽  
Vol 16 (9) ◽  
pp. 705-717
Author(s):  
Mehrnoosh Khaleghian ◽  
Fatemeh Azarakhshi
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional ◽  
Structural Parameters ◽  
Energy Levels ◽  
Nbo Analysis ◽  
Electronic Energy ◽  
Boron Nitride Nanotubes ◽  
Basis Set ◽  
B3lyp Method ◽  
Mechanical Investigation

In the present research, B45H36N45 Born Nitride (9,9) nanotube (BNNT) and Al45H36N45 Aluminum nitride (9,9) nanotube (AlNNT) have been studied, both having the same length of 5 angstroms. The main reason for choosing boron nitride nanotubes is their interesting properties compared with carbon nanotubes. For example, resistance to oxidation at high temperatures, chemical and thermal stability higher rather than carbon nanotubes and conductivity in these nanotubes, unlike carbon nanotubes, does not depend on the type of nanotube chirality. The method used in this study is the density functional theory (DFT) at Becke3, Lee-Yang-Parr (B3LYP) method and 6-31G* basis set for all the calculations. At first, the samples were simulated and then the optimized structure was obtained using Gaussian 09 software. The structural parameters of each nanotube were determined in 5 layers. Frequency calculations in order to extract the thermodynamic parameters and natural bond orbital (NBO) calculations have been performed to evaluate the electron density and electrostatic environment of different layers, energy levels and related parameters, such as ionization energy and electronic energy, bond gap energy and the share of hybrid orbitals of different layers.

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 Synthesis and vibrational spectral (FT-IR, FT-Raman) studies, NLO properties & NBO analysis of (E)-N'(thiophen-2yl methylene)isonicotinohydrazide using quantum chemical method

2018 ◽  
Vol 6 (1) ◽  
pp. 53
Author(s):  
Nathiya A ◽  
Saleem H ◽  
Bharanidharan Bharani ◽  
Suresh M
Keyword(s):  
Molecular Orbital ◽  
Title Compound ◽  
Solid Phase ◽  
Nbo Analysis ◽  
Basis Set ◽  
Excitation Energies ◽  
Charge Delocalization ◽  
Nlo Properties ◽  
Ft Ir ◽  
Ft Raman

FT-IR (4000-400 cm-1) and FT-Raman (3500-50 cm-1) spectra of (E)-N'(thiophen-2yl methylene)isonicotinohydrazide (TMINH) molecule was recorded in solid phase. The optimized geometry was calculated by B3LYP method with 6-311++G(d,p) basis set. The harmonic vibrational frequencies, infrared (IR) intensities and Raman scattering activities of the title compound were performed at same level of theory. The complete vibrational assignments were performed on the basis of the Total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The calculated first hyperpolarizability may be attractive for further studies on non-linear optical (NLO) properties of material. Stability of the molecule arising from hyperconjugative interaction and charge delocalization was analyzed using natural bond orbital (NBO) analysis. Highest occupied molecular orbital-Lowest unoccupied molecular orbital (HOMO-LUMO) energy gap explains the eventual charge transfer interactions taking place within the title molecule. A study on the electronic properties, such as excitation energies and wavelengths, were performed by time-dependent (TD-DFT) approach. Molecular electrostatic potential (MEP) provides the information on the electrophilic, nucleophilic and free radical prone reactive sites of the molecule. The thermodynamic properties such as heat capacity, entropy and enthalpy of the title compound were calculated at different temperatures in gas phase. 1H and 13C-NMR chemical shifts of the molecule were calculated using Gauge-independent atomic orbital (GIAO) method.To establish information about the interactions between human cytochrome protein and this novel compound theoretically, docking studies were carried out using Schrödinger software.

scholarly journals Crystal structure, Hirshfeld surface analysis and computational study of 2-chloro-N-[4-(methylsulfanyl)phenyl]acetamide

2020 ◽  
Vol 76 (4) ◽  
pp. 594-598
Author(s):  
Sitthichok Mongkholkeaw ◽  
Apisit Songsasen ◽  
Tanwawan Duangthongyou ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
...  
Keyword(s):  
Surface Analysis ◽  
Title Compound ◽  
Crystal Packing ◽  
Computational Study ◽  
Dft Method ◽  
Hirshfeld Surface ◽  
Basis Set ◽  
Hirshfeld Surface Analysis ◽  
Compound C ◽  
Out Of Plane

In the title compound, C9H10ClNOS, the amide functional group –C(=O)NH– adopts a trans conformation with the four atoms nearly coplanar. This conformation promotes the formation of a C(4) hydrogen-bonded chain propagating along the [010] direction. The central part of the molecule, including the six-membered ring, the S and N atoms, is fairly planar (r.m.s. deviation of 0.014). The terminal methyl group and the C(=O)CH2 group are slightly deviating out-of-plane while the terminal Cl atom is almost in-plane. Hirshfeld surface analysis of the title compound suggests that the most significant contacts in the crystal are H...H, H...Cl/Cl...H, H...C/C...H, H...O/O...H and H...S/S...H. π–π interactions between inversion-related molecules also contribute to the crystal packing. DFT calculations have been performed to optimize the structure of the title compound using the CAM-B3LYP functional and the 6–311 G(d,p) basis set. The theoretical absorption spectrum of the title compound was calculated using the TD–DFT method. The analysis of frontier orbitals revealed that the π–π* electronic transition was the major contributor to the absorption peak in the electronic spectrum.

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.

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.

scholarly journals EXPERIMENTAL CUM THEORETICAL EVALUATION OF MOLECULAR STRUCTURE, VIBRATIONAL SPECTRA, NBO, UV, NMR, OF A BIOACTIVE COMPOUND – PHENOXYACETOHYDRAZIDE

2015 ◽  
Vol 3 (7) ◽  
pp. 103-115
Author(s):  
M. Sangeetha ◽  
R. Mathammal
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Bioactive Compound ◽  
Nbo Analysis ◽  
Basis Set ◽  
Theoretical Evaluation ◽  
Vibrational Assignments ◽  
Key Species

Hydrazide-Hydrazone compounds are key species for a range of bioactivities. The first complete density functional theoretical study of Phenoxyacetohydrazide(PAH) is reported. The normal mode frequencies, intensities and the corresponding vibrational assignments were calculated using the GAUSSIAN 09W set of quantum chemistry codes at the DFT/B3LYP levels of theory using the 6-311++G** basis set. Stability of the molecule arising from hyperconjugative interactions has been probed using NBO analysis. 1H and 13C NMR spectra have been analysed and the chemical shifts were calculated using the gauge independent atomic orbital(GIAO) method. The theoretical UV-Vis spectrum and the electronic properties, such as HOMO(Highest occupied molecular orbital) and LUMO (Lowest unoccupied molecular orbital) were performed by time dependent density functional theory(TD-DFT) approach.

Sign in / Sign up

Export Citation Format

Share Document