Scaling factors for the prediction of vibrational spectra. II. The aniline molecule and several derivatives

Palafox, M. Alcolea; Gill, Michael; Núñez, Noemí; Rastogi, V. K.; Mittal, Lalit Singh; Sharma, Rekha

doi:10.1002/qua.20416

Cited by 160 publications

(41 citation statements)

References 59 publications

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“…The largest noticeable differences between the spectra occur in the intensities, although these are also in qualitative agreement with the experimental results. In Hartree-Fock, all the vibrational frequencies are overestimated and in agreement with this method with an average error of 10-20% [41][42][43]. In our results, the O-H and C-H stretching modes are estimated with the *4.1 error in the average for HF/6-31G(d) level and *30.9 and *33.5.0 error in the average for B3LYP levels, respectively.…”

Section: Resultssupporting

confidence: 62%

Ab initio HF and DFT calculations on an organic non-linear optical material

2009

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The molecular geometric optimization, vibrational frequencies, and gauge-including atomic orbital (GIAO) 1 H and 13 C chemical shift values of 3-[(1E)-N-ethylethanimidoyl]-4-hydroxy-6-methyl-2H-pyran-2-one have been investigated by using ab initio Hartree-Fock (HF) and density functional method (B3LYP: Becke-3-Lee-Yang-Parr) with 6-31G(d) and 6-31??G(d,p) basis sets. Also, the first hyperpolarizabilities have been calculated at the HF and B3LYP levels employing the corresponding basis sets. To understand this phenomenon in the context of molecular orbital picture, we examined the molecular HOMOs and molecular LUMOs generated via HF and B3LYP levels. The computed vibrational frequencies are used to determine the types of molecular motions associated with each of the experimental bands observed. Data of 3-[(1E)-N-ethylethanimidoyl]-4-hydroxy-6-methyl-2H-pyran-2-one display significant second-order molecular nonlinearity and provide the basis for design of efficient nonlinear optical materials.

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Section: Resultssupporting

confidence: 62%

Ab initio HF and DFT calculations on an organic non-linear optical material

2009

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“…The carbonyl stretching vibrations are expected in the region between 1715 -1680 cm -1 [18,24,25]. In our case, two C=O stretching bands were observed in both experimental FT-IR and FT-Raman spectra.…”

Section: C=o Vibrations Of Fpmc and Cfpmcsupporting

confidence: 56%

“…The C-H stretching vibrations in aromatic ring characteristically appear above 3000 cm -1 [25] and are typically exhibited as a multiplicity of weak to moderate bands [28]. …”

Section: C-h Vibrations Of Fpmc and Cfpmcmentioning

confidence: 99%

Synthesis, Spectroscopic Investigation and Computational Studies of 2-Formyl-4-(Phenyldiazenyl)Phenyl Methyl Carbonate and 4-((4-Chlorophenyl)Diazenyl)-2-Formylphenyl Methyl Carbonate

Arokiasamy

Manikandan

Thanikachalam

et al. 2016

ILCPA

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ABSTRACT. Two new compounds namely 2-formyl-4-(phenyldiazenyl)phenyl methyl carbonate (FPMC) and 4-((4-chlorophenyl) diazenyl)-2-formylphenyl methyl carbonate (CFPMC) have been synthesized and have characterized using FT-IR, FT-Raman, 1 H and 13 C NMR techniques. Computational optimization studies have been carried out using Hatree-Fock (HF) and Density Functional Theory (DFT-B3LYP) methods with 6-31+G(d, p) basis set of Gaussian 09W software. The stable configuration of the title compounds were achieved theoretically by potential energy surface scan analysis. The complete vibrational assignments were performed on the basis of total energy distribution (TED) and natural bonding orbital (NBO) have been studied. Various parameters such as E HOMO , E LUMO , total energy, dipole moment, polarizability, first order hyperpolarizability, zero-point vibrational energy as well as thermal properties were analyzed and reported for the title compounds.

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“…2. In the Hartree-Fock method, all the vibrational frequencies are overestimated and have an error within 10-20% for the average of the overall frequencies [40,41]. This overestimation depends on the type of vibrational mode and the wavenumber range.…”

Section: Vibration Mode Assignmentsmentioning

confidence: 90%

DFT Calculations on the Molecular Structure, Vibrational and Chemical Shift Assignments of 4-Allyl-2-(morpholin-4-ylmethyl)-5-(pyridin-4-yl)-2,4-Dihydro-3H-1,2,4-Triazole-3-Thione

et al. 2011

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The molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1 H and 13 C chemical shift values and several thermodynamic parameters of 4-allyl-2-(morpholin-4-ylmethyl)-5-(pyridin-4-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione in the ground state were calculated using density functional methods (BLYP and B3LYP) with the 6-31G(d) basis set. The results of the optimized molecular structure are given and compared with experimentally obtained X-ray diffraction. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. Vibrational mode assignments of the title compound were carried out using a total energy distribution calculation. The calculated 1 H and 13 C chemical shift values are compared with the experimental values. The molecular frontier orbital energies of the title compound were calculated using the BLYP and B3LYP/6-31G(d) levels. The obtained data for the title compound provided its molecular structure, while the IR and NMR analyses provide a basis for the future design of efficient materials containing a 1,2,4-triazole core.

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Scaling factors for the prediction of vibrational spectra. II. The aniline molecule and several derivatives

Cited by 160 publications

References 59 publications

Ab initio HF and DFT calculations on an organic non-linear optical material

Ab initio HF and DFT calculations on an organic non-linear optical material

Synthesis, Spectroscopic Investigation and Computational Studies of 2-Formyl-4-(Phenyldiazenyl)Phenyl Methyl Carbonate and 4-((4-Chlorophenyl)Diazenyl)-2-Formylphenyl Methyl Carbonate

DFT Calculations on the Molecular Structure, Vibrational and Chemical Shift Assignments of 4-Allyl-2-(morpholin-4-ylmethyl)-5-(pyridin-4-yl)-2,4-Dihydro-3H-1,2,4-Triazole-3-Thione

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