Molecular Structure and Vibrational Spectra of 2-Ethylhexyl Acrylate by Density Functional Theory Calculations

The Fourier transform infrared spectra (FTIR) of 2-ethylhexyl acrylate have been measured in liquid phase. The molecular geometry, vibrational frequencies, and infrared intensities have been calculated by using density functional theory. We found two local minima representing s-cis and s-trans conformations for 2-ethylhexyl acrylate molecule. The optimized geometries at DFT//B3LYP/6-311+ are in good agreement with electron diffraction data of methyl acrylate for the acrylic group. The two conformers were used for the interpretation of the experimental infrared spectrum of title compound. PED calculations are represented for a more complete and concise assignment. There is one band in the infrared spectrum at 1646 cm−1 that definitely indicates the conformer with s-trans arrangement of acrylic moiety to be present or not in the liquid 2-ethylhexyl acrylate