Molecular geometry, NBO analysis, Hyperpolarizability and HOMO-LUMO energies of 2-azido-1-phenylethanone using Quantum chemical calculations (original) (raw)
Related papers
Journal of Innovative Science and Engineering (JISE), 2018
The stable conformer of the synthesized 1-phenylethanone-O-pyropyl oxime ether (PEPOE) has been determined by potential energy profile analysis. All the structural parameters of PEPOE were identified by Density Functional Theory (DFT) with B3LYP method and 6-311++G(d,p) basis set. The spectroscopic properties, FTIR, NMR and UV-Vis results have been theoretically calculated and compared with experimental data. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energies and the electron density distribution were performed by same level. The heat capacity, entropy, and enthalpy of the PEPOE have been calculated at temperature range from 100 to 1000 C. In addition, the molecular docking studies with DNA and Human Serum Albumin (HSA) structures have been performed to find the most preferred binding mode of the ligand inside the DNA and HSA cavity. As a result of these studies, the binding free energies of DNA and HSA have been calculated as-20.92 and-26.78 kJ/mol, respectively. The results show that these calculations are valuable for providing insight into molecular properties of the oxime ether compounds.
Natural Bond Orbital (NBO) Population Analysis of an Energetic Molecule 1-Phenyl-2-Nitroguanidine
international journal of chemical sciences, 2016
The molecular structure of 1-azanapthalene-8-ol was calculated by the B3LYP density functional model with 6-31G(d,p) basis set by Gaussian program. The results from natural bond orbital analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title molecule. The stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital analysis. The electron density based local reactivity descriptors such as the Fukui functions were calculated. The dipole moment (µ) and polarizability (α), anisotropy polarizability (∆α) and rst order hyperpolarizability (βtot) of the molecule have been reported.
Journal of Atomic and Molecular Sciences, 2011
The molecular properties and harmonic wavenumbers of 3-(2-methoxyphenoxy) propane-1,2-diol have been calculated using ab initio and density functional theory. The polarizability and first static hyperpolarizability of the title molecule have been calculated at different basis sets. In general a good agreement between experimental and calculated normal modes has been observed. The frontier orbital and molecular electrostatic potential surface study has also been employed to understand the active sites of 3-(2methoxyphenoxy) propane-1,2-diol. PACS: 31.15.A, 31.15.es, 31.15.ap ½½ Key words: Density functional theory, frontier orbital energy gap, first static hyperpolarizability ½¾ ½¿ 1 Introduction ½ With the standard quantum chemical models (i.e., without the inclusion of parity violation), ½ there is no difference whatsoever in energetics, vibrational frequencies, polarizabilities, NMR ½ spectra, or any other non-chiral property for a given pair, i.e., (R) and (S) forms of enan-½ tiomers [1-4]. Differences in the properties of enantiomers arise either only within chiral en-½ vironments or interactions with other chiral compounds. The present investigation therefore ½ deals with the quantum chemical study of molecular structural, energetic and vibrational data ¾¼ of one of the pair i.e., (R) enantiomer of 3-(2-methoxyphenoxy) propane-1,2-diol [MPPD], in ¾½ gas phase, due to its biological and pharmaceutical importance. The drug MPPD, also known ¾¾ as guaifenesin, is an expectorant, used extensively in anti-tussive and is capable of increasing ¾¿ the excretion of phlegm from the respiratory tract. Bredikhin and others have carried out ¾ * Corresponding author. Email address: ÓÒ ÖÔÖ × ½ Ñ ÐºÓÑ (O. Prasad) http://www.global-sci.org/jams 212 c 2011 Global-Science Press L. Sinha, A. Kumar, V. Narayan, et al. / J. At. Mol. Sci. 2 (2011) 212-224 213 extensive studies on the structure, solid state properties and issues related to the effective ¾ resolution procedure for MPPD [5-7]. ¾ The vibrational spectroscopic analysis is known to provide immensely invaluable molecu-¾ lar structure elucidation in synergy with quantum chemical calculations. In order to obtain a ¾ complete description of molecular dynamics, vibrational wavenumber calculations along with ¾ the normal mode analysis have been carried out at the DFT level employing the basis set ¿¼ 6-311+G(2d,2p). The optimized geometry of molecule under investigation and its molecu-¿½ lar properties such as equilibrium energy, frontier orbital energy gap, molecular electrostatic ¿¾ potential energy map, dipole moment, polarizability, first static hyperpolarizability have also ¿¿ been used to understand the properties and active sites of the drug. ¿ 2 Experimental ¿ 2.1 Structure and Spectra ¿
In this work, FT-IR and FT-Raman spectra of potassium 2-(2-(2,6-dichlorophenylamino)phenyl)acetate (abbreviated as K2DCPAPA) have been reported in the regions 4000–450 cm-1 and 4000–50 cm-1 , respectively.CAM-B3LYP/6-31G(d,p) and HF/6-31G(d,p) calculations were performed to obtain the optimized molecular structures, vibrational frequencies and corresponding vibrational assignment, thermodynamic properties and natural bonding orbital (NBO) analysis. A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated Potential Energy Distribution (PED). The calculations of the electronic spectra were compared with the experimental ones. The time dependent DFT method employed to study its absorption energy and oscillator strength. The calculated HOMO and LUMO energy reveals shows that the charge transfers occurring within the molecule. Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MESP) were also performed. The study is extended to the HOMO-LUMO analysis to calculate the energy gap (∆), Ionization potential (I), Electron Affinity (A), Global Hardness (η), Chemical Potential (µ), Global Electrophilicity (w). Non-linear optical NLO behavior of the examined molecule was investigated by the determination of the electric dipole moment, the polarizability and the hyperpolarizability using the CAM-B3LYP and HF with 6-31G(d,p) basis set. The isotropic calculated chemical shifts computed by 13 C and 1 H NMR analysis also show good agreement with Chemsoft Ultra values. The First order Hyperpolarizability (β) and Molecular Electrostatic Potential (MESP) of the molecule was computed using DFT calculations.
Applied Innovative Research (AIR), 2020
Theoretical calculations of (2E)-1-(2, 4-dihydroxyphenyl)-3-(4-hydroxyphenyl) prop-2-en-1-one have been performed using Gaussian 09 software package. The geometry optimization and vibrational frequency determinations of the molecule have been developed using DFT/B3LYP/6-31G (d, p). Substituents at aliphatic double bond are Trans to each other. The standard thermodynamic functions: heat capacity (CV), entropy (S), and enthalpy (E) were obtained at B3LYP/6-31G (d, p) level. DFT has been used to calculate the total dipole moment (μ), the mean linear polarizability (α), the anisotropic polarizability (∆α), the first-order hyperpolarizability (β) and the second-order hyperpolarizability () in terms of x, y, z components. Simultaneously UV-Vis absorption spectra, electronic transitions, vertical excitation energies and oscillator strengths of the same molecule were computed with the Time Dependent DFT (TD-DFT) method using the same basis sets. FMO, ESP study were also carried out using the same basis set.
In this paper, the spectral analysis of 1-phenyl-2-nitropropene is carried out using the FTIR, FT Raman, FT NMR and UV–Vis spectra of the compound with the help of quantum mechanical computations using abinitio and density functional theories. The FT-IR (4000–400 cm1) and FT-Raman (4000–100 cm1) spectra were recorded in solid phase, the 1H and 13C NMR spectra were recorded in CDCl3 solution phase and the UV–Vis (200–800 nm) spectrum was recorded in ethanol solution phase. The different conformers of the compound and their minimum energies are studied using B3LYP functional with 6-311+G(d,p) basis set and two stable conformers with lowest energy were identified and the same was used for further computations. The computed wavenumbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the modes of vibrations are assigned and the structure the molecule is analyzed in terms of parameters like bond length, bond angle and dihedral angle predicted by both B3LYP and B3PW91 methods with 6-311+G(d,p) and 6-311++G(d,p) basis sets. The values of dipole moment (l), polarizability (a) and hyperpolarizability (b) of the molecule are reported, using which the non-linear property of the molecule is discussed. The HOMO–LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for 1H and 13C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts. NBO analysis is carried out to picture the charge transfer
Natural Bond Orbital (NBO) Population Analysis of 1-Azanapthalene-8-ol
Acta Physica Polonica A, 2014
The molecular structure of 1-azanapthalene-8-ol was calculated by the B3LYP density functional model with 6-31G(d,p) basis set by Gaussian program. The results from natural bond orbital analysis have been analyzed in terms of the hybridization of atoms and the electronic structure of the title molecule. The stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital analysis. The electron density based local reactivity descriptors such as the Fukui functions were calculated. The dipole moment (µ) and polarizability (α), anisotropy polarizability (∆α) and rst order hyperpolarizability (βtot) of the molecule have been reported.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013
This work presents the characterization of (2R,3R,4R,5S)-1-(2-hydroxyethyl)-2-(hydroxymethyl)piperidine-3,4,5-triol (abbreviated as HEHMPT) by quantum chemical calculations and spectral techniques. The spectroscopic properties are investigated by FT-IR, FT-Raman and UV-Vis techniques. The FT-IR and FT-Raman spectra of the title compound have been recorded in the region 4000-400 cm-1 and 4000-100 cm-1 respectively. The UV-Vis absorption spectrum of the HEHMPT that dissolved in water is recorded in the range of 100-400 nm. The structural and spectroscopic data of the molecule are obtained from B3LYP and M06-2X with 6-31G(d,p) basis set calculations. The theoretical wavenumbers are scaled and compared with experimental FT-IR and FT-Raman spectra. The complete assignments are performed on the basis of the normal coordinate analysis (NCA), experimental result and potential energy distribution (PED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method, interpreted in terms of fundamental modes. The stable geometry of the compound has been determined from the potential energy surface scan. The stability of molecule is analyzed by NBO analysis. The molecule orbital contributions are studied by using the total (TDOS), partial (PDOS), and overlap population (OPDOS) density of states. The electronic properties like UV spectral analysis and HOMO-LUMO energies are reported. The calculated HOMO and LUMO energies show that charge transfer interactions taking place within the molecule. Mulliken population analysis on atomic charges is also calculated.
South African Journal of Chemistry
In this study, some molecular properties of (2Z, 5Z)-3-N(4-methoxy phenyl)-2-N'(4-methoxy phenyl imino)-5-((E)-3-(2-nitrophenyl) allylidene) thiazolidin-4-one (MNTZ) are evaluated using a combination of spectroscopic characterization (FT-IR, 1 H and 13 C NMR chemical shifts) and theoretical calculations. Molecular geometry, vibrational wavenumbers, gauge-independent atomic orbital (GIAO), 1 H and 13 C chemical shift values and NBO analysis are investigated using B3LYP and PBE functionals with the 6-31G(d,p) basis set in the ground state. The calculated geometrical parameters and vibrational spectra are compared to available experimental data and each vibrational frequency is assigned on the basis of potential energy distribution (PED). The electronic transitions are calculated using time-dependent density functional theory (TDDFT). The energy band gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies are obtained by computing the frontier molecular orbitals using the B3LYP/6-31G(d,p) and PBE/6-31G(d,p) levels along with the global reactivity descriptors. Mulliken atomic charges and molecular electrostatic potential (MEP) are simulated using both functionals to find more reactive sites for electrophilic and nucleophilic attack. Finally, the thermodynamic functions (heat capacity, entropy, and enthalpy) from spectroscopic data are obtained and discussed in the range of 100-1000 K.