Investigation of molecular properties of some Schiff base compounds by quantum mechanical methods

INVESTIGATION OF MOLECULAR PROPERTIES OF SOME SCHIFF BASE COMPOUNDS BY QUANTUM MECHANICAL METHODS ABSTRACT This thesis contains some properties obtained from quantum mechanical methods, of the (Z)-6-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylamino] methylene}-2 - methoxy- 4 -{(E)-[3-(trifluoromethyl)phenyl]diazenyl}cyclohexa 2,4-dienone [C19H20F3N3O5], 4-[(2-hydroxyphenylimino)methyl]phenol [C13H11NO2] and (E)-4-((E)-(2-chlorophenyl) diazenyl)-6-((1,3-dihydroxy-2-(hydroxymethyl)propan-2- ylamino) methylene) - 2 - methoxycyclohexa - 2,4 - dienone [C18H20ClN3O5] organic molecules. In the theoretical calculations, Gaussian 03W and GaussView 4.1.2 software are used. In the calculations, stable states of all molecules in the gas-phase isolated state have been investigated based on Hartree-Fock (HF) theory. Mulliken charges, dipole moments, molecular electrostatic potentials, boundary orbitals, chemical parameters, thermodynamic properties with base set 6-31G(d,p) to find the most stable geometry corresponding to global minima on potential energy surfaces within the Hartree-Fock Theory. Thus, the theoretical results obtained are supported by experimental results and discussed in detail. In addition, the Hirshfeld surface analysis in this thesis study was conducted for investigated molecules. Key Words: Crystal structure, Molecular modeling, Hartree-Fock, 6-31G(d,p), Hirshfeld surface analysis