Vibrational spectroscopy, ab initio calculations and Frontier Orbital analysis of 4,5,6,8,9-pentachloropyrimido-[1,2-a][1,8]naphthyridin-10-one

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2015-10, Vol.149, p.304-311
• Main Authors: Nogueira, C.E.S., Caselli, P.E.S., Freire, P.T.C., Teixeira, A.M.R., Oliveira, I.M.M., Bento, R.R.F., Faria, J.L.B., Gusmão, G.O.M., Silva, L.E.
• Format: Article
• Language: English
• Subjects: C11H2Cl5N3O crystal; DFT; IR spectroscopy; Raman scattering
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2015.04.056

[Display omitted] •FT-IR and Raman of 4,5,6,8,9-pentachloropyrimido-[1,2-a][1,8]naphthyridin-10-one.•Optimized geometry and vibrational frequencies by DFT.•Experimental and theoretical vibrational spectra comparison.•Potential energy distribution (PED) analysis.•Frontier Orbitals analysis. In this work we present a study of the vibrational spectra of 4,5,6,8,9-pentachloropyrimido-[1,2-a][1,8]naphthyridin-10-one, C11H2Cl5N3O, a substance belonging to the important pharmacological class of 1,8-naphthyridine derivatives. The Fourier transform infrared and the Fourier transform Raman spectra of the crystal were recorded at room temperature in the regions 400–4000 and 50–4000cm−1, respectively. Vibrational wavenumbers were predicted using Density Functional Theory calculations with the B3LYP functional on 6-31G(d,p) and 6-311++G(d,p) basis sets. The descriptions of the normal modes were made after calculating the potential energy distribution. Additionally, potential reaction sites were evaluated through Mulliken population and Frontier Orbital analysis.