Molecular structure, vibrational spectra, NBO analysis, first hyperpolarizability, and HOMO-LUMO studies of 2-amino-4-hydroxypyrimidine by density functional method

This study is a comparative analysis of FTIR and FF-Raman spectra of 2-amino-4-hydroxypyrimidine. The total energies of different conformations have been obtained from DFF (B3LYP) method with 6-31+G(d,p) and 6-311++G(d,p) basis sets. The barrier of planarity between the most stable and planar form is also predicted. The molecular structure, vibrational wavenumbers, infrared intensities, Raman scattering activities were calculated for the molecule using the B3LYP density functional theory (DFF) method. The computed values of frequencies are scaled using multiple scaling factors to yield good coherence with the observed values. Reliable vibrational assignments were made on the basis of total energy distribution (TED) along with scaled quantum mechanical (SQM) method. The stability of the molecule arising from hyperconjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Non-linear properties such as electric dipole moment (mu), polarizability (alpha), and hyperpolarizability (beta) values of the investigated molecule have been computed using B3LYP quantum chemical calculation. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Besides, molecular electrostatic potential (MEP), Mulliken's charges analysis, and several thermodynamic properties were performed by the DFT method. (C) 2014 Elsevier B.V. All rights reserved.