Vibrational spectra, molecular structure, NBO, NMR, UV, first order hyperpolarizability, analysis of (S)-(−)-N-(5-Nitro-2-pyridyl) alaninol by Density functional theory

Abstract

In this study, geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance studies of (S)-(−)-N-(5-Nitro-2-pyridyl) alaninol (abbreviated as SN5N2PLA) were investigated by utilizing HF and DFT/B3LYP with 6-31G(d,p) as basis set. The Fourier transform infrared (FT-IR) and FT-Raman spectra of SN5N2PLA were recorded in the region 4000–400cm−1 and 3500–50cm−1, respectively. Complete vibrational assignments, analysis and correlation of the fundamental modes for the title compound were carried out. UV–Visible spectrum of the compound that dissolved in methanol were recorded in the region 200–800nm and the electronic properties HOMO and LUMO energies were measured by TD-DFT approach. 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 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of SN5N2PLA were calculated using the GIAO method in methanol solution and compared with the measured experimental data. The dipole moment, polarizability and first order hyperpolarizability values were also computed. The polarizability and first hyperpolarizability of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The Chemical reactivity and Thermodynamic properties of SN5N2PLA at different temperature are calculated. In addition, molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs) analysis were investigated using theoretical calculations.