Conformation analysis and theoretical investigation of the spectroscopic characteristics of thiophen-based Schiff base molecules with DFT

In this study, theoretical calculations of seven (1, 2, 3, 4, 5, 6, 7) new Schiff base derivatives based on thiophene were made with the help of ChemDraw, Chem3D, GaussView and Gaussian programs. Each molecule to be calculated was first drawn in the ChemDraw program and transferred to the Chem3D program. Conformation analysis based on dihedral angle in Chem3D program was performed in 30˚ steps in the range of -180˚-180˚, and the lowest energy conformation was minimized in Chem3D program and selected for theoretical calculations. The chosen conformation geometry has been optimized. The Density Functional Theory DFT/B3LYP/6-31G(d) calculation method was used to examine the theoretical results of optimized molecular geometry. Dipole moments, total energies of all molecules in gas, water, DMSO, acetonitrile, ethanol, methanol, THF and dichloromethane phases, HOMO-LUMO energies, molecular electrostatic potential (MEP) map, solvent accessibility surface (SAS) shapes and UV-Visible region spectrum results were calculated.