Investigation of the molecular structures of some organic compounds by experimental and theoretical methods

In this study, the crystal and molecular structures of compounds containing Schiff base were evaluated both experimentally and theoretically. C18H20N2O2 and C23H25N3OS compounds have been synthesized in Chemistry Laboratory of Chemistry Department, Fırat University, and the diffraction data was collected on a Bruker/D8 QUEST diffractometer in Scientific and Technological Research Application and Research Center, Sinop University. The crystal structure was solved by SHELXT-2014 software using direct methods and the atomic parameters were refined by SHELXL-2014 software using full matrix least squares and Difference fourier methods. To support the experimental results, the molecular geometries, IR and NMR spectra of the compound have been determined theoretically by Density Functional Theory (DFT) methods using Gaussian 09 and GaussView 5 softwares. The energies, molecular electrostatic potentials and HOMO and LUMO orbitals of the molecules were also obtained by the theoretical calculations. The 6-311G(d,p) was chosen as basis set for the theoretical calculations.