Synthesis, molecular conformation, vibrational and electronic transition, isometric chemical shift, polarizability and hyperpolarizability analysis of 3-(4-Methoxy-phenyl)-2-(4-nitro-phenyl)-acrylonitrile: A combined experimental and theoretical analysis (original) (raw)
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Russian Journal of Physical Chemistry A, 2014
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Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012
In this work, the FT-IR and FT-Raman spectrum of 1-(chloromethyl)-2-methyl naphthalene (abbreviated as 1-ClM-2MN, C 12 H 11 Cl) have been recorded in the region 3600-10 cm −1 . The optimum molecular geometry, normal mode wavenumbers, infrared and Raman intensities, Raman scattering activities, corresponding vibrational assignments, Mullikan atomic charges and thermo-dynamical parameters were investigated with the help of HF and B3LYP (DFT) method using 6-311G(d,p), 6-311++G(d,p) basis sets. Also, the dipole moment, linear polarizabilities, anisotropy, first and second hyperpolarizabilities values were also computed using the same basis set. Reliable vibrational assignments were made on the basis of total energy distribution (TED) calculated with scaled quantum mechanical (SQM) method. The correlation equations between heat capacities, entropies, enthalpy changes and temperatures were fitted by quadratic formulas. Lower value in the HOMO and LUMO energy gap explains the eventual charge transfer interactions taking place within the molecule. UV-vis spectral analysis of 1-ClM-2MN has been researched by theoretical calculations. In order to understand the electronic transitions of the compound, TD-DFT calculations on electronic absorption spectra in gas phase and solvent (DMSO and chloroform) were performed. The calculated frontier orbital energies, absorption wavelengths ( ), oscillator strengths (f) and excitation energies (E) for gas phase and solvent are also illustrated.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2014
Spectroscopic properties were examined by FT-IR and FT-Raman techniques. The vibrations were assigned with PED. NLO and NBO analysis of the title molecule were studied. HOMO and LUMO energies and MEP distribution of the molecule were calculated. Thermodynamic properties were investigated. g r a p h i c a l a b s t r a c t a b s t r a c t In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 4000-100 cm À1 and 4000-400 cm À1 , respectively, for 4-chloro-N-(2-methyl-2,3-dihydroindol-1-yl)-3-sulfamoyl-benzamide (C 16 H 16 O 3 N 3 SCl) molecule. Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) and 6-311G(d,p) basis sets. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The frontier orbital energy gap and dipole moment illustrates the high reactivity of the title molecule. The first order hyperpolarizability (b 0 ) and related properties (l, a, and Da) of the molecule were also calculated. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The UV-vis spectrum of the compound was recorded in the region 200-400 nm in ethanol and electronic properties such as excitation energies, oscillator strength and wavelength were calculated by TD-DFT/ B3LYP method. Molecular electrostatic potential (MEP) and HOMO-LUMO energy levels are also constructed. The thermodynamic properties of the title compound were calculated at different temperatures.
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 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.
The FT-IR and Laser-Raman spectra of the title compound were recorded in solid phase. The optimized geometry and vibrational frequencies were calculated for the first time. The HOMO–LUMO energies and related molecular properties were evaluated. g r a p h i c a l a b s t r a c t a b s t r a c t The experimental FT-IR (4000–400 cm À1) and Laser-Raman spectra (4000–100 cm À1) of ethyl (2E)-2-cyano-3-(4-methoxyphenyl)-acrylate in solid phase have been recorded. Its theoretical vibrational frequencies , IR intensities, Raman activities and optimized geometric parameters (bond lengths and bond angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee– Yang–Parr and DFT/M06-2X: the highly parameterized empirical exchange correlation function) with 6-311++G(d, p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis using VEDA4 software. The optimized geometric parameters and vibrational frequencies have been seen to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated by using the same theoretical calculations.
Journal of Molecular Structure, 1999
The IR (4000-400 cm Ϫ1) and Raman (4000-50 cm Ϫ1) spectra of 3-methoxymethylene-2,4-pentanedione (H 3 CO -CHyC (COCH 3) 2) in the liquid and solute forms in various solvents of different polarity were recorded at ambient temperature. Additional IR and Raman spectra were obtained for amorphous and crystalline solid at low temperature. The vibrational spectra revealed that compound exists atleast in two dominant conformers with different polarity and that conformer present in the solid phase is less polar. NMR spectra in various solvents at different temperatures were also obtained.The compound can exist in several conformers as a result of rotation around O-Cy and both yC-C bonds with planar or nonplanar arrangement of the heavy atoms. Semiempirical (AM1, PM3, MNDO, MINDO3) and ab initio using TZP and 6-31G** basis sets calculations were carried out. According to ab initio calculations at least five conformational structures with the methoxy group oriented as anti or syn and carbonyl groups oriented as Z or E towards the CyC double bond were obtained at energy surface. The calculated ab initio and AM1 energies of all conformers suggest as the most stable anti-ZE conformer where Z and E regard of the trans and cis acetyl group, respectively. As the second most stable conformer with energy at least 10 kJ mol Ϫ1 higher was calculated anti-EZ conformer. Assignments of the vibrational spectra for the studied compound were made with the aid of normal coordinate calculations employing scaled ab initio force field constants. The scaled ab initio frequencies as well as calculated energies indicate that the conformer present in the solid phase is anti-ZE.
The FT-IR and FT-Raman spectra of 3-pyridinemethanol (3PYRM) have been recorded in the regions 4000 e400 and 4000e100 cm À1 respectively. The vibrational analysis of 3PYRM was carried out using wavenumbers computed by HF and DFT (B3LYP) methods with 6-311þþG (d, p) basis set, along with experimental values. The conformational analyses were performed and the energies of the different possible conformers were determined. The total electron density and MESP surfaces of the molecules were constructed using B3LYP/6-311þþG (d, p) method to display nucleophilic and electrophilic region globally. The HOMO and LUMO energies were measured and different reactivity descriptors are discussed the active sites of the molecule. Natural Bond Orbital Analysis is discussed and possible transition are correlated with the electronic transitions. Milliken's net charges and the atomic natural charges are also predicted. The 13 C and 1 H NMR chemical shifts were computed at the B3LYP/6-311þþG (2d, p) level by applying GIAO theory and compared with the experimental spectra recorded using the high resolution of 100 MHz and 400 MHz NMR spectrometer with electromagnetic field strength 9.1T, respectively. The temperature dependence of the thermodynamic properties; heat capacity, entropy and enthalpy for the title compounds were also determined by B3LYP/6-311þþG (d, p) method.
Indian Journal of Chemistry -Section A
In this paper, the structural, electronic, non-linear optical (NLO) properties and vibrational frequencies of 4-(methoxycarbonyl)-phenylboronic acid have been examined theoretically using ab initio Hartree-Fock (HF) and Density Functional Theory (DFT/B3LYP) methods applying the standard 6-311++G(d,p) basis set. 1 Hand 13 C NMR chemical shifts are calculated by employing the direct implementation of the gauge including-atomic-orbital (GIAO) method at the B3LYP/6-311++G(d,p) and HF/6-31G(d) levels of the theory. There are two conformers, cis-trans(ct) and trans-cis (tc) for title molecule. The energy difference between ct and tc conformers of studied molecule are of 0.126 kcal/mol with B3LYP/6-311++G(d,p) and 0.138 kcal/mol with HF/6-311++G(d,p), respectively. The conformer ct is more stable than the conformer tc. Also, the energy gap differences between the highest occupied and the lowest unoccupied molecular orbitals, dipole moment, polarizability and first static hyperpolarizability are calculated as a function of both dihedral angle (C3-C4-C7-O3), between methoxycarbonyl group (CH 3-O-CO-) and benzene ring, and dihedral angle (C2-C1-B-O1), between boronic acid group (-B(OH) 2) and benzene ring. In the change of the energy gap and polarizability depending on dihedral angles, it is shown that the polarizabilities follow inverse relationship the energy gaps.