Experimental and quantum chemical computational investigations on molecular and electronic structures of two novel heterocyclic azometin compounds

In this thesis, structural and electronic properties of (E)-3-methoxy-2-[(3-methylpyridin-2-ylimino)methyl]phenol (I) and (E)-3-methoxy-2-[(4-methylpyridin-2-ylimino)methyl] phenol (II) organic molecules of Schiff base were investigated using single crystal X-ray diffraction, IR, NMR and theoretical calculation methods. The crystal structures of the molecules were determined by using SHELXS-13 program with direct methods and the atomic parameters were treated with SHELXL-13 program with the least squares method. Tautomeric forms, geometric structure parameters (bond lengths, bond angles, torsion angles), intramolecular and intermolecular interactions of molecules were obtained. In theoretical calculations, the molecular geometries of crystals, IR and NMR spectra were determined by using Density Functional Theory (DFT) method using Gaussian 03W and GaussView 4.1.2 package programs. Beside these, the total energies, dipole moments, molecular electrostatic potentials (MEP), frontier orbitals (HOMO and LUMO), chemical parameters, non-linear optical (NLO) properties and natural bond orbital (NBO) analyses of the molecules were investigated with the level of B3LYP/6-31G(d,p). The results showed that the experimental and theoretical findings are in a good agreement. Finally, both the experimental results were supported and the new datum about the molecules were attained.