Investigation of crystal and molecular structures of Schiif base compounds including thiophene by experimental and theoretical methods

In this study, C12H6BrF3N2O3S (I) and C11H8N2O3S (II) Schiff base compounds have been synthesized, their crystal structures have been characterized by X-ray diffraction and IR methods. These compounds were synthesized in the chemistry laboratory of the chemistry department of Ondokuz Mayıs University and the diffraction data from crystals have been obtained from STOE IPDS-II in the crystallography laboratory of physics department at Ondokuz Mayıs University. IR spectra of the molecules were obtained using a Bruker Vertex 80V FT-IR spectrophotometer in the chemistry department of Ondokuz Mayıs University. In theoretical studies Gaussian 09W and Gaussview 5.0 software packages were used. The molecular geometry and IR spectra of the crystals is performed using the HF and DFT theoretical methods. The energies of molecules, dipole moments, molecular electrostatic potentials and the frontier orbitals (HOMO and LUMO) was also obtained by calculations. The 6-311++G(d,p) was chosen as basis set for the theoretical calculations.