Scientific Reports (Apr 2021)

Crystal, spectroscopic and quantum mechanics studies of Schiff bases derived from 4-nitrocinnamaldehyde

  • Friday E. Ani,
  • Collins U. Ibeji,
  • Nnamdi L. Obasi,
  • Monsuru T. Kelani,
  • Kingsley Ukogu,
  • Gideon F. Tolufashe,
  • Segun A. Ogundare,
  • Oluwatoba E. Oyeneyin,
  • Glenn E. M. Maguire,
  • Hendrik G. Kruger

DOI
https://doi.org/10.1038/s41598-021-87370-0
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 11

Abstract

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Abstract Two Schiff bases, (E)-1-(4-methoxyphenyl)-N-((E)-3-(4-nitrophenyl)allylidene)methanamine (compound 1) and (E)-N-((E)-3-(4-nitrophenyl)allylidene)-2-phenylethanamine (compound 2) have been synthesized and characterized using spectroscopic methods; time of flight MS, 1H and 13C NMR, FT-IR, UV–VIS, photoluminescence and crystallographic methods. The structural and electronic properties of compounds 1 and 2 in the ground state were also examined using the DFT/B3LYP functional and 6-31 + G(d,p) basis set, while the electronic transitions for excited state calculations were carried out using the TD-DFT/6-31 + G(d,p) method. The Schiff base compounds, 1 and 2 crystallized in a monoclinic crystal system and the P21/c space group. The emission spectra of the compounds are attributed to conjugated π-bond interaction while the influence of the intra-ligand charge transfer resulted in a broad shoulder for 1 and a double emission peak for 2. The calculated transitions at 450 and 369 nm for 1 and 2 respectively are in reasonable agreement with the experimental results. The higher values of dipole moment, linear polarizability and first hyperpolarizability of 1, suggest a better optical property and better candidate for the development of nonlinear optical (NLO) materials.