Molecular Investigation and Nonlinear Optical Response of Dihydropyrimidinone: A Comparative Spectroscopic and Quantum Computational Studies

Organic molecule ethyl-4-(4-chloro-3-nitrophenyl)-6-methyl-2-oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate has been synthesized. The molecular structure has been characterized using FT-IR, FT-Raman, 1H and 13C-NMR spectral studies. The structure of the title molecule was theoretically investigated by DFT method using B3LYP/6-31G(d,p) basis set. The firm assignments of vibrational bands are allowed using experimental and computations. The nonlinear optical property of the title molecule has been calculated using first hyperpolarizability components. The intra-molecular charge transfer occurring in the molecule has been analyzed by NBO analysis. The electronic and charge transfer properties have been studied using frontier molecular orbitals. 1H and 13C-NMR spectra were recorded and calculated using the gauge independent atomic orbital (GIAO) method