Theoretical investigations on the molecular structure, vibrational spectra, HOMO-LUMO analyses and NBO study of 1-[(Cyclopropylmethoxy)methyl]-5-ethyl-6-(4-methylbenzyl)-1,2,3,4-tetrahydropyrimidine-2,4-dione

Spectrochim Acta A Mol Biomol Spectrosc. 2014 Dec 10:133:639-50. doi: 10.1016/j.saa.2014.06.042. Epub 2014 Jun 14.

Abstract

The FT-IR and FT-Raman spectra of 1-[(Cyclopropylmethoxy)methyl]-5-ethyl-6-(4-methylbenzyl)-1,2,3,4-tetrahydropyrimidine-2,4-dione were recorded. In this work, experimental and theoretical study on the molecular structure and vibrational wavenumbers of the title compound are presented. The vibrational wavenumbers were obtained theoretically at the DFT level and were compared with the experimental results. The study is extended to calculate the HOMO-LUMO energy gap, NBO, mapped molecular electrostatic potential and first hyperpolarizability. The calculated first hyperpolarizability of the title compound is 9.15 times that of urea and hence the title compound and the series of compounds it represents are attractive candidates for further studies in non linear optical applications. In the title compound, the HOMO of π nature is delocalized over the phenyl ring while the LUMO is located over the pyrimidine ring. The inter-molecular hydrogen bonding at O7 and N1H25 positions in each monomer give rise to a C2-symmetry dimer which is predicted to be about 10kcalmol(-1) more stable than the monomeric form.

Keywords: Cyclopropyl; FT-Raman; FTIR; Methoxy; Pyrimidine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cyclopropanes / chemistry*
  • Models, Molecular
  • Pyrimidines / chemistry*
  • Quantum Theory
  • Spectroscopy, Fourier Transform Infrared
  • Spectrum Analysis, Raman

Substances

  • Cyclopropanes
  • Pyrimidines