Журнал теоретических и вычислительных наук
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Spectroscopic [IR and Raman] Analysis and Gaussian Hybrid Computational Investigation- NMR, UV-Visible, MEP Maps and Kubo Gap on 2,4,6-Nitrophenol

Ramalingam S, John David Ebenezar I, Ramachandra Raja C and Jobe Prabakar PC

In the present methodical study, FT-IR and FT-Raman of the 2,4,6-Nitrophenol (TNP) called as picric acid are recorded and the observed vibrational frequencies are assigned. The hybrid computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31+G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are tabulated. The alternation of structure of nitro phenol due to the subsequent substitutions of NO2 is investigated. The vibrational sequence pattern of the molecule related to the substitutions is analyzed. Moreover, 13C NMR and 1H NMR are calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra are simulated and the chemical shifts related to TMS are compared. A study on the electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The calculated HOMO and LUMO energies and the kubo gap analysis show that the occurring of charge transformation within the molecule. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. NLO properties related to Polarizability and hyperpolarizability are also discussed. The thermodynamic properties (thermal energy, heat capacity and entropy) of the title compound are calculated in gas phase and are interpreted with different types of phenols.